RET INHIBITORS, PHARMACEUTICAL COMPOSITIONS AND USES THEREOF

Abstract

A RET inhibitor, a pharmaceutical composition thereof and uses thereof. In particular, the present invention provides a compound having Formula (I) or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof. The invention also relates to a pharmaceutical composition including the compound, and uses of the compound and pharmaceutical composition thereof for the preparation of a medicament, in particular for treatment and prevention of RET-related diseases and conditions, including cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priorities and benefits of Chinese Patent Application Serial No 201811496406.8, filed on Dec. 7, 2018; Chinese Patent Application Serial No 201910245269.9, filed on Mar. 28, 2019; and Chinese Patent Application Serial No 201910248485.9, filed on Mar. 29, 2019, all of which are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The invention belongs to the field of medicine, specifically, the present invention relates to novel compounds which exhibit inhibition for re-arranged during transfection (RET) kinase, pharmaceutical compositions comprising the compounds and uses of the compounds or pharmaceutical compositions thereof in the preparation of a medicament. The medicament is particularly useful for the treatment and prevention of RET-related diseases and conditions, including cancer, irritable bowel syndrome and/or pain associated with irritable bowel syndrome.

BACKGROUND ART

Re-arranged during transfection (RET) is one of the receptor-type tyrosine kinases belonging to the cadherin superfamily, which activates multiple downstream pathways involved in cell proliferation and survival.

The results of abnormalities in RET genes (point mutations, chromosomal translocations, chromosomal inversions, gene amplification) have been reported to be involved in canceration. RET fusion proteins are associated with several cancers, including papillary thyroid cancer and non-small cell lung cancer. Identification of RET fusion proteins as a driver of certain cancers has driven the use of multi-kinase inhibitors with RET inhibitory activity to treat patients whose tumors express RET fusion proteins. It has been reported that multi-kinase inhibitors such as Sorafenib, sunitinib, vandetanib and punatinib exhibit cell proliferation inhibition in KIF5B-RET-expressing cell lines (J Clin Oncol 30, 2012, suppl; Abstract no: 7510). In addition, it has been reported that the multi-kinase inhibitor cabozantinib showed partial efficacy in two patients with non-small cell lung cancer positive for RET fusion gene (Cancer Discov, 3(6), June 2013, p.630-5). However, these drugs cannot always be administered at a level sufficient to inhibit RET due to toxicity caused by inhibition of targets other than RET. In addition, one of the biggest challenges in treating cancer is the ability of tumor cells to develop resistance to treatment. Reactivation of kinases via mutations is a common mechanism of resistance. When resistance develops, the patient's treatment options are usually very limited, and in most cases cancer progression is not inhibited. WO 2017011776 discloses a single-targeted RET kinase inhibitor that has a good prophylactic or therapeutic effect on RET-associated and RET mutation-associated cancer. There is still a need to further develop compounds that inhibit RET and its resistant mutants in response to cancers with abnormal RET genes.

SUMMARY OF THE INVENTION

The present invention provides a novel compound exhibiting inhibition of Re-arranged during transfection (RET) kinase, which has a good inhibitory effect on RET wild type and RET gene mutants, and has a good inhibition selectivity on RET wild type and RET gene mutants.

The excellent properties of certain parameters of the compounds of the present invention, such as half-life, clearance, selectivity, bioavailability, chemical stability, metabolic stability, membrane permeability, solubility, etc., can promote the reduction of side effects, the expansion of the treatment index or the improvement of tolerance.

In one aspect, the present invention provides a compound having Formula (I) or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

each of X¹, X², X³, X⁴ and X⁵ is independently CR⁴ or N, wherein 0, 1, or 2 of X¹, X², X³, X⁴ are N;

E is a bond, —NR⁶— or —O—;

A is Cyc or hetCyc, wherein each of Cyc and hetCyc is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶ alkyl, NR⁵R⁶(C═O) alkoxyalkyl, NR⁶R⁷ alkoxy, NR⁶R⁷ alkoxyalkyl, alkyl, haloalkyl, hydroxyalkyl, Cyc, hetCyc, hetCyc-alkyl, alkoxyalkyl, hetCyc-alkoxyalkyl, cycloalkylidene and heterocyclylidene;

Q is —(C═O)—, —O—, —(C═O)NR⁵—, —(C═S)NR⁵—, —S(═O)₂—, —S(═O)₂NR⁵—, —NR⁵(C═O)—, —NR⁵(C═O)O—, —NR⁵(C═O)NR⁵—, —NR⁵—, —(C═O)O— or a bond;

M is —(C═O)—, alkyl, alkenyl, alkynyl, alkylaryl, alkylheteroaryl, alkenylaryl, alkynylaryl, alkenylheteroaryl, alkynylheteroaryl, aryl, heteroaryl, Cyc, hetCyc, arylalkyl, heteroarylalkyl, Cyc-alkyl or hetCyc-alkyl, wherein each of alkyl, alkenyl, alkynyl, alkylaryl, alkylheteroaryl, alkenylaryl, alkynylaryl, alkenylheteroaryl, alkynylheteroaryl, aryl, heteroaryl, Cyc, hetCyc, arylalkyl, heteroarylalkyl, Cyc-alkyl and hetCyc-alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NR⁵R⁶, oxo, alkoxy, cycloalkylidene, heterocyclylidene, hydroxyalkyl, alkyl, cycloalkyl, cycloalkylalkynyl and heterocyclic group;

R¹ is H, D, CN, F, Cl, Br, alkyl, alkenyl or cycloalkyl, wherein each of alkyl, alkenyl and cycloalkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂;

G is H, D, alkyl, hetCyc, Cyc, hetCyc-alkyl, Cyc-alkyl, heteroarylalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, R⁵O(C═O)NR⁶ alkyl, R⁵(C═O)NR⁶ alkyl, NR⁵R⁶(C═O)alkyl, R⁵(C═O)alkyl, NR⁵R⁶(C═O)— or R⁵O-alkyl, wherein each of alkyl, hetCyc, Cyc, hetCyc-alkyl, Cyc-alkyl, heteroarylalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, and an alkyl moiety in R⁵O(C═O)NR⁶ alkyl, R⁵(C═O)NR⁶ alkyl, R⁵(C═O)alkyl, NR⁵R⁶(C═O)alkyl and R⁵O alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, oxo, cycloalkylidene, heterocyclylidene, alkyl, alkoxy, alkoxyalkyl, R⁵(C═O)— and R⁵O(C═O)—;

R³ is H, D, alkyl, Cyc, hetCyc, aryl, heteroaryl, Cyc-alkyl, hetCyc-alkyl, alkoxyalkyl, arylalkyl, heteroarylalkyl or aminoalkyl, wherein each of alkyl, Cyc, hetCyc, aryl, heteroaryl, Cyc-alkyl, hetCyc-alkyl, alkoxyalkyl, arylalkyl, heteroarylalkyl and aminoalkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR⁵R⁶, R⁵O—, R⁵O(C═O)—, R⁵(C═O)—, NR⁵R⁶(C═O)NR⁵—, R⁵S(═O)₂—, NO₂, CN, CF₃, alkyl and cycloalkyl;

R⁴ is H, D, alkyl, F, Cl, Br or alkoxy, wherein each of alkyl and alkoxy is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂;

R⁵ is H, D, alkyl, Cyc, hetCyc, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxyalkyl, aryloxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, Cyc-alkyl or hetCyc-alkyl, wherein each of alkyl, Cyc, hetCyc, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxyalkyl, aryloxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, Cyc-alkyl and hetCyc-alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR⁶R⁷, alkyl, alkylsulfonyl, alkoxy, aryl and heteroaryl;

R⁶ is H or alkyl;

R⁷ is alkyl, arylalkyl or heteroarylalkyl;

each Cyc is independently cycloalkyl, bridged carbocyclyl or spirocarbocyclyl; and

each hetCyc is independently heterocyclyl, bridged heterocyclyl or spiroheterocyclyl.

In some embodiments, G is H, D, C_1-6 alkyl, 3-12 membered hetCyc, 3-12 membered Cyc, (3-12 membered hetCyc)-C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino-C_1-6 alkyl, di(C_1-6 alkyl)amino-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, R⁵O(C═O)NR⁶C_1-6 alkyl, R⁵(C═O)NR⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkyl, R⁵(C═O)C_1-6 alkyl, NR⁵R⁶(C═O)—, R⁵OC_1-6 alkyl, wherein each of C_1-6 alkyl, 3-12 membered hetCyc, 3-12 membered Cyc, (3-12 membered hetCyc)-C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino-C_1-6 alkyl, di(C_1-6 alkyl)amino-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, and a C_1-6 alkyl moiety in R⁵O(C═O)NR⁶C_1-6 alkyl, R⁵(C═O)NR⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkyl, R⁵(C═O)C_1-6 alkyl, R⁵OC_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, C_1-6 alkyl, C_1-6 alkoxy, C_1-6 alkoxy C_1-6 alkyl, R⁵(C═O)—, R⁵O(C═O)—.

In some embodiments, G is H, D, C_1-4 alkyl, 3-10 membered hetCyc, 3-10 membered Cyc, (3-10 membered hetCyc)-C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl, NR⁵R⁶(C═O)—, R⁵OC_1-4 alkyl, wherein each of C_1-4 alkyl, 3-10 membered hetCyc, 3-10 membered Cyc, (3-10 membered hetCyc)-C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, and a C_1-4 alkyl moiety in R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl, R⁵OC_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, C_1-4 alkyl, C_1-4 alkoxy, C_1-4 alkoxy C_1-4 alkyl, R⁵(C═O)—, R⁵O(C═O)—.

In some embodiments, G is H, D, C_1-4 alkyl, 3-6 membered hetCyc, 3-6 membered Cyc, (3-6 membered hetCyc)-C_1-4 alkyl, (3-6 membered Cyc)-C_1-4 alkyl, (5-6 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl, NR⁵R⁶(C═O)— or R⁵OC_1-4 alkyl, wherein each of C_1-4 alkyl, 3-6 membered hetCyc, 3-6 membered Cyc, (3-6 membered hetCyc)-C_1-4 alkyl, (3-6 membered Cyc)-C_1-4 alkyl, (5-6 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, and a C_1-4 alkyl moiety in R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl and R⁵OC_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetanylidene, oxetanylidene, pyrrolidinylidene, pyrazolidinylidene, tetrahydrofuranylidene, methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, isobutyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, methoxymethyl, ethoxymethyl, n-propoxymethyl, isopropoxymethyl, methoxyethyl, ethoxyethyl, n-propoxyethyl, isopropoxyethyl, methoxypropyl, ethoxypropyl, n-propoxypropyl, isopropoxypropyl, CH₃(C═O)—, CH₃O(C═O)—, CH₃CH₂O(C═O)—, and (CH₃)₃CO(C═O)—.

In some embodiments, A is 3-12 membered Cyc or 3-12 membered hetCyc, wherein each of 3-12 membered Cyc and 3-12 membered hetCyc is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-12 membered Cyc, 3-12 membered hetCyc, 3-12 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-12 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, A is one of the following sub-formulae:

wherein each Z¹, Z² and Z⁴ is independently CH or N;

each of Z³ and Z⁵ is independently a bond, CH₂, O, S, NH, C═O, S═O or S(═O)₂; each m is independently 0, 1, or 2;

each n, m1 and n1 is independently 0 or 1;

each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkoxy C_1-4 alkyl, NR⁶R⁷C_1-4 alkoxy, NR⁶R⁷C_1-4 alkoxy C_1-4 alkyl, C_1-4alkyl, C_1-4 haloalkyl, C_1-4 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, 3-10 membered hetCyc-C_1-4 alkoxy C_1-4 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, A is one of the following sub-formulae:

wherein each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-4 alkyl, NR⁶R⁷C_1-4 alkoxy, C_1-4 alkyl, C_1-4 haloalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-4 alkyl, 3-10 membered hetCyc-C_1-4 alkoxy C_1-4 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, OH, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene, pyrrolidinylidene and pyrazolidinylidene.

In some embodiments, M is —(C═O)—, C_1-6 alkyl, C_2-6 alkenyl, C_2-6 alkynyl, C_1-6 alkyl-C_6-10 aryl, C_1-6 alkyl-(5-10 membered heteroaryl), C_2-6 alkenyl-C_6-10 aryl, C_2-6 alkynyl-C_6-10 aryl, C_2-6 alkenyl-(5-10 membered heteroaryl), C_2-6 alkynyl-(5-10 membered heteroaryl), C_6-10 aryl, 5-10 membered heteroaryl, 3-12 membered hetCyc, 3-12 membered Cyc, C_6-10 aryl-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl or (3-12 membered Cyc)-C_1-6 alkyl, wherein each of C_1-6 alkyl, C_2-6 alkenyl, C_2-6 alkynyl, C_1-6 alkyl-C_6-10 aryl, C_1-6 alkyl-(5-10 membered heteroaryl), C_2-6 alkenyl-C_6-10 aryl, C_2-6 alkynyl-C_6-10 aryl, C_2-6 alkenyl-(5-10 membered heteroaryl), C_2-6 alkynyl-(5-10 membered heteroaryl), C_6-10 aryl, 5-10 membered heteroaryl, 3-12 membered hetCyc, 3-12 membered Cyc, C_6-10 aryl-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl and (3-12 membered Cyc)-C_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NR⁵R⁶, oxo, C_1-6 alkoxy, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, hydroxy C_1-6 alkyl, C_1-6 alkyl, C_3-6 cycloalkyl, C_3-6 cycloalkyl C_2-6 alkynyl and 3-7 membered heterocyclic group.

In some embodiments, M is —(C═O)—, C_1-4 alkyl, C_2-4 alkenyl, C_2-4 alkynyl, C_1-4 alkylphenyl, C_1-4 alkyl-(5-10 membered heteroaryl), C_2-4 alkenylphenyl, C_2-4 alkynylphenyl, C_2-4 alkenyl-(5-10 membered heteroaryl), C_2-4 alkynyl-(5-10 membered heteroaryl), phenyl, 5-10 membered heteroaryl, 3-10 membered hetCyc, 3-10 membered Cyc, phenyl-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4 alkyl or (3-10 membered Cyc)-C_1-4 alkyl, wherein each of C_1-4 alkyl, C_2-4 alkenyl, C_2-4 alkynyl, C_1-4 alkylphenyl, C_1-4 alkyl-(5-10 membered heteroaryl), C_2-4 alkenylphenyl, C_2-4 alkynylphenyl, C_2-4 alkenyl-(5-10 membered heteroaryl), C_2-4 alkynyl-(5-10 membered heteroaryl), phenyl, 5-10 membered heteroaryl, 3-10 membered hetCyc, 3-10 membered Cyc, phenyl-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4 alkyl and (3-10 membered Cyc)-C_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NR⁵R⁶, oxo, C_1-4 alkoxy, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, hydroxy C_1-4 alkyl, C_1-4 alkyl, C_3-6 cycloalkyl, C_3-6 cycloalkyl C_2-4 alkynyl and 3-6 membered heterocyclic group.

In some embodiments, M is —(C═O)—, —CH₂—, —(CH₂)₂—, —(CH₂)₃—, —(CH₂)₄—, —CH═CH₂—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —C≡C—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —CH═CH-phenyl, —CH₂CH═CH-phenyl, —CH₂CH═CH—CH₂-phenyl, —C≡C-phenyl, —CH₂C≡C-phenyl, —CH₂C≡C—CH₂-phenyl, —CH═CH-pyridyl, —CH₂CH═CH-pyridyl, —CH₂CH═CH—CH₂-pyridyl, —CH═CH-pyrazolyl, —CH₂CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, —C≡C-pyridyl, —CH₂C≡C-pyridyl, —CH₂C≡C—CH₂-pyridyl, —C≡C-pyrazolyl, —CH₂C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, phenyl, pyridyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, furyl, thienyl, —CH₂-pyridyl, —CH₂CH₂-pyridyl, —CH₂-phenyl, —CH₂CH₂-phenyl, —CH₂-pyrimidinyl, —CH₂-pyrazinyl, —CH₂-imidazolyl, —CH₂-pyrazolyl, phenyl-CH₂—, phenyl-CH₂CH₂—, pyridyl-CH₂—, pyridyl-CH₂CH₂—, pyrimidinyl-CH₂—, pyrazinyl-CH₂—, imidazolyl-CH₂— or pyrazolyl-CH₂—, wherein each of —CH₂—, —(CH₂)₂—, —(CH₂)₃—, —(CH₂)₄—, —CH═CH₂—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —C≡C—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —CH═CH-phenyl, —CH₂CH═CH-phenyl, —CH₂CH═CH—CH₂-phenyl, —C≡C-phenyl, —CH₂C≡C-phenyl, —CH₂C≡C—CH₂-phenyl, —CH═CH-pyridyl, —CH₂CH═CH-pyridyl, —CH₂CH═CH—CH₂-pyridyl, —CH═CH-pyrazolyl, —CH₂CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, —C≡C-pyridyl, —CH₂C≡C-pyridyl, —CH₂C≡C—CH₂-pyridyl, —C≡C-pyrazolyl, —CH₂C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, phenyl, pyridyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, furyl, thienyl, —CH₂-pyridyl, —CH₂CH₂-pyridyl, —CH₂-phenyl, —CH₂CH₂-phenyl, —CH₂-pyrimidinyl, —CH₂-pyrazinyl, —CH₂-imidazolyl, —CH₂-pyrazolyl, phenyl-CH₂—, phenyl-CH₂CH₂—, pyridyl-CH₂—, pyridyl-CH₂CH₂—, pyrimidinyl-CH₂—, pyrazinyl-CH₂—, imidazolyl-CH₂— and pyrazolyl-CH₂— is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NH₂, oxo, methoxy, ethoxy, n-propoxy, isopropoxy, cyclopropylidene, cyclobutylidene, cyclopentylidene, azetidinylidene, hydroxymethyl, hydroxyethyl, 2-hydroxy-2-propyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylethynyl, pyrrolidinyl, morpholinyl.

In some embodiments, R³ is H, D, C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, (3-12 membered Cyc)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl) C_1-6 alkyl or amino C_1-6 alkyl, wherein each of C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, (3-12 membered Cyc)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl) C_1-6 alkyl and amino C_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR⁵R⁶, R⁵O—, R⁵O(C═O)—, R⁵(C═O)—, NR⁵R⁶(C═O)NR⁵—, R⁵S(═O)₂—, NO₂, CN, CF₃, C_1-6 alkyl and C_3-6 cycloalkyl.

In some embodiments, R³ is H, D, C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, (3-10 membered Cyc)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl or amino C_1-4 alkyl, wherein each of C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, (3-10 membered Cyc)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl and amino C_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR⁵R⁶, R⁵O—, R⁵O(C═O)—, R⁵(C═O)—, NR⁵R⁶(C═O)NR⁵—, R⁵S(═O)₂—, NO₂, CN, CF₃, C_1-4 alkyl and C_3-6 cycloalkyl.

In some embodiments, R³ is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopropylmethyl, cyclobutylmethyl, cyclohexylmethyl, spiro[4.4]decylmethyl, bicyclo[3.3.0]octyl, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, azetidinylmethyl, piperidinylmethyl, morpholinylmethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, isopropoxymethyl, isopropoxyethyl, n-butoxymethyl, isobutoxymethyl, tert-butoxymethyl, tert-butoxyethyl, phenyl, pyridyl, imidazolyl, pyrazolyl, pyrimidinyl, 3H-indolyl, indolyl, benzimidazolyl, 3,8a-dihydroindolizinyl, phenylmethyl, 3,8a-dihydroindolizinyl methyl, pyridylmethyl, imidazolylmethyl, pyrazolylmethyl, pyrimidinylmethyl, 3H-indolylmethyl, indolylmethyl, benzimidazolylmethyl, NH₂CH₂—, NH(CH₃)CH₂—, N(CH₃)₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂— or N(CH₃)₂(CH₂)₂—, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopropylmethyl, cyclobutylmethyl, cyclohexylmethyl, spiro[4.4]decylmethyl, bicyclo[3.3.0]octyl, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, azetidinylmethyl, piperidinylmethyl, morpholinylmethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, isopropoxymethyl, isopropoxyethyl, n-butoxymethyl, isobutoxymethyl, tert-butoxy methyl, tert-butoxyethyl, phenyl, pyridyl, imidazolyl, pyrazolyl, pyrimidinyl, 3H-indolyl, indolyl, benzimidazolyl, 3,8a-dihydroindolizinyl, phenylmethyl, 3,8a-dihydroindolizinylmethyl, pyridylmethyl, imidazolylmethyl, pyrazolylmethyl, pyrimidinylmethyl, 3H-indolyl methyl, indolylmethyl, benzimidazolylmethyl, NH₂CH₂—, NH(CH₃)CH₂—, N(CH₃)₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂— and N(CH₃)₂(CH₂)₂— is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NH₂, NO₂, CN, CF₃, C(CH₃)₃O(C═O)—, CH₃(C═O)—, NH₂(C═O)NH—, NHCH₃(C═O)NH—, CH₃S(═O)₂—, methyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenoxy, pyridyloxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl.

In some embodiments, R¹ is H, D, CN, F, Cl, Br, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, vinyl, cyclopentyl or cyclohexyl, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, vinyl, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂; and R⁴ is H, D, F, Cl, Br, CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butylmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butylmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy and tert-butoxy is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂.

In some embodiments, R⁵ is H, D, C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryloxy C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino C_1-6 alkyl, di(C_1-6 alkyl)amino C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl or (3-12 membered hetCyc)-C_1-6 alkyl, wherein each of C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryloxy C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino C_1-6 alkyl, di(C_1-6 alkyl)amino C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl and (3-12 membered hetCyc)-C_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR⁶R⁷, C_1-6 alkyl, C_1-6 alkylsulfonyl, C_1-6 alkoxy, C_6-10 aryl and 5-10 membered heteroaryl;

R⁶ is H, D or C_1-6 alkyl; and

R⁷ is H, D, C_1-6 alkyl, C_6-10 aryl C_1-6 alkyl or (5-10 membered heteroaryl) C_1-6 alkyl.

In some embodiments, R⁵ is H, D, C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenoxy C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino C_1-4 alkyl, di(C_1-4 alkyl)amino C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl or hetCyc-C_1-4 alkyl, wherein each of C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenoxy C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino C_1-4 alkyl, di(C_1-4 alkyl)amino C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl and hetCyc-C_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR⁶R⁷, C_1-6 alkyl, C_1-4 alkylsulfonyl, C_1-4 alkoxy, phenyl and 5-10 membered heteroaryl;

R⁶ is H, D or C_1-4 alkyl; and

R⁷ is H, D, C_1-4 alkyl, phenyl C_1-4 alkyl or (5-10 membered heteroaryl) C_1-4 alkyl.

In some embodiments, R⁵ is H, D, NH₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂—, N(CH₃)₂CH₂—, NH(CH₃)₂(CH₂)₂—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylethyl, cyclobutyl methyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methoxymethyl, methoxyethyl, ethoxyethyl, phenylmethyl, phenylethyl, phenyl-n-propyl, pyridylmethyl, pyridylethyl, pyridyl-n-propyl, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, azetidinyl, oxetanyl or tetrahydropyranyl, wherein each of NH₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂—, N(CH₃)₂CH₂—, NH(CH₃)₂(CH₂)₂—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylethyl, cyclobutylmethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methoxymethyl, methoxyethyl, ethoxyethyl, phenylmethyl, phenylethyl, phenyl-n-propyl, pyridylmethyl, pyridylethyl, pyridyl-n-propyl, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, azetidinyl, oxetanyl and tetrahydropyranyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NH₂, NH(CH₃), CH₃S(═O)₂—, CH₃CH₂S(═O)₂—, CH(CH₃)₂S(═O)₂—, C(CH₃)₃S(═O)₂—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, n-propoxy, phenyl, pyridyl, pyrazolyl, pyrimidinyl;

R⁶ is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; and

R⁷ is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenylmethyl, phenylethyl, phenyl-n-propyl, imidazolylmethyl, pyrazolylmethyl, pyridylmethyl, pyridylethyl, pyrimidinylmethyl or pyrimidinylethyl.

In some embodiments, the present invention provides a compound having Formula (I-1), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

each of Z¹ and Z² is independently CH or N;

each of Z³ and Z⁵ is independently a bond, CH₂, O, S, NH, C═O, S═O or S(═O)₂;

m is 0, 1 or 2;

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene.

In some embodiments,

is one of the following sub-formulae:

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl(C═O)NH—, pyridylmethyl(C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene or pyrazolylidene.

In some embodiments, the present invention provides a compound having Formula (I-2), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

A₁ is one of the following sub-formulae:

each Z¹ and Z² is independently CH or N;

each sub-formula of A₁ is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene.

In some embodiments,

A₁ is one of the following sub-formulae:

wherein each sub-formula of A₁ is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene and pyrazolidinylidene.

In some embodiments, the present invention provides a compound having Formula (I-3) or (I-4), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

wherein each Z¹, Z² and Z⁴ is independently CH or N;

each m is 0, 1, or 2;

each n, m1 and n1 is independently 0 or 1;

each of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene.

In some embodiments,

is one of the following sub-formulae

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene or pyrazolylidene;

is one of the following sub-formulae:

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene and pyrazolylidene.

In another aspect, the invention provides a pharmaceutical composition comprising a compound of the invention, and a pharmaceutically acceptable adjuvant.

In other aspect, provided herein is use of the compound or the pharmaceutical composition disclosed herein in the manufacture of a medicament for preventing or treating a RET-related disease.

In some embodiments, the RET-related diseases include cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

In other aspect, provided herein is the compound or the pharmaceutical composition disclosed herein for use in preventing or treating a RET-related disease.

In some embodiments, the RET-related diseases include cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

In another aspect, the invention provides a method for preventing or treating a RET-related disease in a subject, comprising administering a therapeutically effective amount of the compound or a pharmaceutical composition disclosed herein to the subject.

In some embodiments, the RET-related diseases include cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

In other aspect, the invention relates to an intermediate for the preparation of a compound of Formula (I), (I-1), (I-2), (I-3) or (I-4).

In another aspect, the invention relates to a process for the preparation, isolation and purification of a compound of Formula (I), (I-1), (I-2), (I-3) or (I-4).

In another aspect, the invention provides a pharmaceutical composition comprising a compound of the invention, and a pharmaceutically acceptable adjuvant. In some embodiments, the adjuvants described herein include, but are not limited to, carriers, excipients, diluents, vehicles, or combinations thereof. In some embodiments, the pharmaceutical composition can be in the form of a liquid, solid, semi-solid, gel or spray.

Unless otherwise stated, all stereoisomers, geometric isomers, tautomers, N-oxides, hydrates, solvates, metabolites, salts and pharmaceutically acceptable prodrugs of the compounds disclosed herein are within the scope of the invention.

In particular, the salt is a pharmaceutically acceptable salt. The phrase “pharmaceutically acceptable” refers to that the substance or composition must be compatible chemically and/or toxicologically, with the other ingredients comprising a formulation, and/or the mammal being treated therewith.

Salts of the compounds disclosed herein also include salts of the compounds which are not necessarily pharmaceutically acceptable salts, and which may be useful as intermediates for preparing and/or purifying compounds of Formula (I), (I-1), (I-2), (I-3) or (I-4) and/or for separating enantiomers of compounds of Formula (I), (I-1), (I-2), (I-3) or (I-4).

DETAILED DESCRIPTION OF THE INVENTION

Definitions and General Terminology

Reference will now be made in detail to certain embodiments of the invention, examples of which are illustrated in the accompanying structures and formulas. The invention is intended to cover all alternatives, modifications, and equivalents which may be included within the scope of the present invention as defined by the claims. One skilled in the art will recognize many methods and materials similar or equivalent to those described herein, which could be used in the practice of the present invention. The present invention is in no way limited to the methods and materials described herein. In the event that one or more of the incorporated literature, patents, and similar materials differs from or contradicts this application, including but not limited to defined terms, term usage, described techniques, or the like, this application controls.

It is further appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one skilled in the art to which this invention belongs. All patents and publications referred to herein are incorporated by reference in their entirety.

As used herein, the term “subject” refers to an animal. Typically the animal is a mammal. A subject also refers to for example, primates (e.g., humans, male or female), cows, sheep, goats, horses, dogs, cats, rabbits, rats, mice, fish, birds and the like. In certain embodiments, the subject is a primate. In yet other embodiments, the subject is a human.

As used herein, “patient” refers to a human (including adults and children) or other animal. In some embodiments, “patient” refers to a human.

The term “comprise” is an open expression, it means comprising the contents disclosed herein, but don't exclude other contents.

“Stereoisomers” refers to compounds which have identical chemical constitution, but differ with regard to the arrangement of the atoms or groups in space. Stereoisomers include enantiomer, diastereomers, conformer (rotamer), geometric (cis/trans) isomer, atropisomer, etc.

Stereochemical definitions and conventions used herein generally follow S. P. Parker, Ed., McGraw-Hill Dictionary of Chemical Terms (1984) McGraw-Hill Book Company, New York; and Eliel, E. and Wilen, S., “Stereochemistry of Organic Compounds”, John Wiley & Sons, Inc., New York, 1994.

Any resulting mixtures of stereoisomers can be separated on the basis of the physicochemical differences of the constituents, into the pure or substantially pure geometric isomers, enantiomers, diastereomers, for example, by chromatography and/or fractional crystallization. Cis and trans isomers are diastereomer.

The term “tautomer” or “tautomeric form” refers to structural isomers of different energies which are interconvertible via a low energy barrier. Where tautomerization is possible (e.g. in solution), a chemical equilibrium of tautomers can be reached. For example, protontautomers (also known as prototropic tautomers) include interconversions via migration of a proton, such as keto-enol and imine-enamine isomerizations. Valence tautomers include interconversions by reorganization of some of the bonding electrons. A specific example of keto-enol tautomerization is the interconversion of pentane-2,4-dione and 4-hydroxypent-3-en-2-one tautomers. Another example of tautomerization is phenol-keto tautomerization. The specific example of phenol-keto tautomerisms is the interconversion of pyridin-4-ol and pyridin-4(1H)-one tautomers. Unless otherwise stated, all tautomeric forms of the compounds disclosed herein are within the scope of the invention.

Unless otherwise stated, structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure; for example, the R and S configurations for each asymmetric center, (Z) and (E) double bond isomers, and (Z) and (E) conformational isomers. Therefore, individual stereochemical isomers, enantiomers, diastereomers, or mixtures of geometric isomers (or conformational isomers) are within the scope disclosed herein.

Unless otherwise stated, the structural formula and the compounds described include all isomeric (e.g., enantiomeric, diastereomeric, and geometric or conformational) forms, N-oxides, hydrates, solvates, metabolites, pharmaceutically acceptable salts and prodrugs. Therefore, individual stereochemical isomers, enantiomers, diastereomers, geometric isomers, conformational isomers, N-oxides, hydrates, solvates, metabolites, pharmaceutically acceptable salts and prodrugs are also within the scope disclosed herein. Additionally, unless otherwise stated, the structural formula of the compounds described herein include enriched isotopes of one or more different atoms.

As described herein, compounds disclosed herein may be independently optionally substituted with one or more substituents, such as are illustrated generally above, or as exemplified by particular classes, subclasses, and species of the invention. It should be understood that the phrase “independently optionally substituted” is used interchangeably with the phrase “substituted or unsubstituted”. In general, the term “substituted” refers to the replacement of one or more hydrogen radicals in a given structure with the radical of a specified substituent. Unless otherwise indicated, an optionally substituted group may have a substituent at each substitutable position of the group. When more than one position in a given structure can be substituted with more than one substituent selected from a specified group, the substituent may be either the same or different at each position.

Furthermore, what need to be explained is that the phrase “each . . . is independently” and “each of . . . and . . . is independently”, unless otherwise stated, should be broadly understood. The specific options expressed by the same symbol are independent of each other in different groups; or the specific options expressed by the same symbol are independent of each other in same groups.

At various places in the present specification, substituents of compounds disclosed herein are disclosed in groups or in ranges. It is specifically intended that the invention includes each and every individual subcombination of the members of such groups and ranges. For example, the term “C_1-6 alkyl” is specifically intended to individually disclose methyl, ethyl, C₃ alkyl, C₄ alkyl, C₅ alkyl, and C₆ alkyl.

At various places in the present specification, linking substituents are described. Where the structure clearly requires a linking group, the Markush variables listed for that group are understood to be linking groups. For example, if the structure requires a linking group and the Markush group definition for that variable lists “alkyl” or “aryl”, then it is understood that the “alkyl” or “aryl” represents a linking alkylene group or arylene group, respectively.

The term “alkyl” or “alkyl group” refers to a saturated linear or branched-chain monovalent hydrocarbon group of 1-20 carbon atoms, wherein the alkyl group is optionally substituted by one or more substituents described herein. Unless otherwise stated, the alkyl group contains 1-20 carbon atoms. In some embodiments, the alkyl group contains 1-12 carbon atoms. In other embodiments, the alkyl group contains 1-6 carbon atoms. In still other embodiments, the alkyl group contains 1-4 carbon atoms. In yet other embodiments, the alkyl group contains 1-3 carbon atoms. Some non-limiting examples of the alkyl group include, methyl (Me, —CH₃), ethyl (Et, —CH₂CH₃), n-propyl (n-Pr, —CH₂CH₂CF₃), isopropyl (i-Pr, —CH(CH₃)₂), n-butyl (n-Bu, —CH₂CH₂CH₂CH₃), isobutyl (z-Bu, —CH₂CH(CH₃)₂), sec-butyl (s-Bu, —CH(CH₃)CH₂CH₃), tert-butyl (t-Bu, —C(CH₃)₃), n-pentyl (—CH₂CH₂CH₂CH₂CH₃), 2-pentyl (—CH(CH₃)CH₂CH₂CH₃), 3-pentyl (—CH(CH₂CH₃)₂), 2-methyl-2-butyl (—C(CH₃)₂CH₂CH₃), 3-methyl-2-butyl (—CH(CH₃)CH(CH₃)₂), 3-methyl-1-butyl (—CH₂CH₂CH(CH₃)₂), 2-methyl-1-butyl (—CH₂CH(CH₃)CH₂CH₃), n-hexyl (—CH₂CH₂CH₂CH₂CH₂CH₃), 2-hexyl (—CH(CH₃)CH₂CH₂CH₂CH₃), 3-hexyl (—CH(CH₂CH₃)(CH₂CH₂CH₃)), 2-methyl-2-pentyl (—C(CH₃)₂CH₂CH₂CH₃), 3-methyl-2-pentyl (—CH(CH₃)CH(CH₃)CH₂CH₃), 4-methyl-2-pentyl (—CH(CH₃)CH₂CH(CH₃)₂), 3-methyl-3-pentyl (—C(CH₃)(CH₂CH₃)₂), 2-methyl-3-pentyl (—CH(CH₂CH₃)CH(CH₃)₂), 2,3-dimethyl-2-butyl (—C(CH₃)₂CH(CH₃)₂), 3,3-dimethyl-2-butyl (—CH(CH₃)C(CH₃)₃, n-heptyl and n-octyl, etc.

When an alkyl group is a linking group, and an “alkyl group” is recited for the definition of the Markush group, then “alkyl” means a linked alkylene group. For example, when M is an alkyl group as defined in the present invention, it means that M is a linked alkylene group. The term “alkylene” refers to a saturated divalent hydrocarbon group derived from a straight or branched chain saturated hydrocarbon by the removal of two hydrogen atoms. Some non-limiting examples of the alkyl group represented as the linked alkylene group include —CH₂—, —CH₂CH₂—, —CH(CH₃)CH₂—, and the like.

The term “alkenyl” refers to linear or branched-chain monovalent hydrocarbon radical of 2 to 12 carbon atoms with at least one site of unsaturation, i.e., a carbon-carbon sp² double bond, wherein the alkenyl radical may be optionally substituted by one or more substituents described herein, and includes radicals having “cis” and “trans” orientations, or alternatively, “E” and “Z” orientations. In some embodiments, the alkenyl contains 2-10 carbon atoms. In other embodiments, the alkenyl contains 2-6 carbon atoms. In still other embodiments, the alkenyl contains 2-4 carbon atoms. Some non-limiting examples of the alkenyl group include ethenyl or vinyl (—CH═CH₂), allyl (—CH₂CH═CH₂), propenyl (—C═CHCH₃), isopropenyl (—C(CH₃)═CH₂) and the like.

When an alkenyl group is a linking group, and an “alkenyl group” is recited for the definition of the Markush group, then “alkenyl” means a linked alkenylene group. For example, when M is an alkenyl group as defined in the present invention, it means that M is a linked alkenylene group. Some non-limiting examples of the alkenyl group represented as the linked alkenylene group include —CH═CH₂—, —CH₂CH≡CH—, —CH₂CH═CHCH₂—, and the like.

The term “alkynyl” refers to a linear or branched monovalent hydrocarbon radical of 2 to 12 carbon atoms with at least one site of unsaturation, i.e., a carbon-carbon, sp triple bond, wherein the alkynyl radical may be optionally substituted by one or more substituents described herein. In some embodiments, the alkynyl contains 2-6 carbon atoms. In other embodiments, the alkynyl contains 2-10 carbon atoms. In still other embodiments, the alkynyl contains 2-4 carbon atoms. Examples of such groups include, but are not limited to, ethynyl (—C═CH), propargyl (—CH₂C≡CH), 1-propynyl (—C≡C—CH₃), and the like. When an alkynyl group is a linking group, and an “alkynyl group” is recited for the definition of the Markush group, then “alkynyl” means a linked alkynylene group. Some non-limiting examples of the alkynyl group represented as the linked alkynylene group include —C≡C—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, and the like.

The term “cycloalkylidene” means a divalent saturated monocyclic carbon system formed by the removal of two hydrogen atoms from the same carbon atom in a 3-7 membered saturated monocyclic carbocycle. In some embodiments, the cycloalkylidene group represents a C_3-6 cycloalkylidene group. In other embodiments, the cycloalkylidene group represents a C_3-5 cycloalkylidene group. Examples of the cycloalkylidene group include, but are not limited to, cyclopropylidene, cyclopentylidene, cyclobutylidene, cyclohexylidene, and the like.

The term “heterocyclylidene” means a divalent saturated monocyclic heterocyclic system formed by the removal of two hydrogen atoms from the same carbon atom in a 3-7 membered saturated monocyclic heterocycle, wherein the system contains at least one carbon atom and contains one, two or three heteroatoms selected from O, N and S. In some embodiments, the heterocyclylidene group represents a C_3-6 heterocyclylidene group. In other embodiments, the heterocyclylidene group represents a C_3-5 heterocyclylidene group. Examples of the heterocyclylidene group include, but are not limited to, oxiranylidene, aziridinylidene, oxetanylidene, oxolanylidene, azetidinylidene, and the like.

The term “hydroxyalkyl” refers to an alkyl group substituted with one or more hydroxy groups. In some embodiments, hydroxyalkyl means an alkyl group substituted with 1, 2, 3 or 4 hydroxy groups. In some embodiments, hydroxyalkyl refers to an alkyl group substituted with 1 or 2 hydroxy groups. In some embodiments, hydroxyalkyl means hydroxy C_1-6 alkyl, ie, C_1-6 alkyl in which the alkyl is substituted with one or more hydroxy groups, preferably, hydroxy C_1-6 alkyl refers to C_1-6 alkyl in which the alkyl is substituted with one hydroxy group. In some embodiments, hydroxyalkyl refers to a hydroxy C_1-4 alkyl group. In some embodiments, hydroxyalkyl refers to a hydroxy C_1-3 alkyl group. Some non-limiting examples of hydroxyalkyl include CH₂OH—, CH₂OHCH₂CH₂CH₂—, CH₂OHCH₂—, CH₂OHCH₂CHOHCH₂—, CH(CH₃)OHCH₂CHOHCH₂—, and the like.

The term “alkoxy” refers to an alkyl group, as previously defined, attached to the parent molecular moiety via an oxygen atom. Unless otherwise specified, the alkoxy group contains 1-12 carbon atoms. In one embodiment, the alkoxy group contains 1-6 carbon atoms. In other embodiment, the alkoxy group contains 1-4 carbon atoms. In still other embodiment, the alkoxy group contains 1-3 carbon atoms. The alkoxy group may be optionally substituted with one or more substituents disclosed herein. Some non-limiting examples of the alkoxy group include, but are not limited to, methoxy (MeO, —OCH₃), ethoxy (EtO, —OCH₂CH₃), 1-propoxy (n-PrO, n-propoxy, —OCH₂CH₂CH₃), 2-propoxy (i-PrO, i-propoxy, —OCH(CH₃)₂), 1-butoxy (n-BuO, n-butoxy, —OCH₂CH₂CH₂CH₃), 2-methyl-1-propoxy (i-BuO, i-butoxy, —OCH₂CH(CH₃)₂), 2-butoxy (s-BuO, s-butoxy, —OCH(CH₃)CH₂CH₃), 2-methyl-2-propoxy (i-BuO, t-butoxy, —OC(CH₃)₃), 1-pentoxy (n-pentoxy, —OCH₂CH₂CH₂CH₂CH₃), 2-pentoxy (—OCH(CH₃)CH₂CH₂CH₃), 3-pentoxy (—OCH(CH₂CH₃)₂), 2-methyl-2-butoxy (—OC(CH₃)₂CH₂CH₃), 3-methyl-2-butoxy (—OCH(CH₃)CH(CH₃)₂), 3-methyl-1-butoxy (—OCH₂CH₂CH(CH₃)₂), 2-methyl-1-butoxy (—OCH₂CH(CH₃)CH₂CH₃), and the like.

The term “alkoxyalkyl” refers to an alkyl group substituted with an alkoxy group, wherein the alkoxy group and the alkyl group have the definitions as described herein. In some embodiments, alkoxyalkyl is C_1-6 alkoxy C_1-6 alkyl; in other embodiments, alkoxyalkyl is C_1-4 alkoxy C_1-4 alkyl; in still other embodiments, the alkoxyalkyl is C_1-4 alkoxy C_1-3 alkyl; in yet other embodiments, the alkoxyalkyl is C_1-3 alkoxy C_1-3 alkyl. Such examples include, but are not limited to, methoxymethyl, ethoxymethyl, propoxymethyl, methoxyethyl, methoxypropyl, ethoxyethyl, ethoxypropyl, propoxyethyl, propoxypropyl, and the like.

The term “halogen” means F (fluoro), Cl (chloro), Br (bromine) or I (iodine).

The term “haloalkyl” refers to an alkyl group substituted with one or more halogen atoms, examples of which include, but are not limited to, monofluoromethyl, difluoromethyl, trifluoromethyl, monofluoroethyl, 1,2-difluoroethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, monochloromethyl, dichloromethyl, trichloromethyl, monochloroethyl, 1,2-dichloroethyl, 1,1-dichloroethyl, 2,2-dichloroethyl, 1,1-dibromoethyl, and the like.

The terms “cycloalkyl” or “cycloalkane” are used interchangeably and all denote a monovalent saturated monocyclic carbocyclic ring system of 3-7 carbon atoms. The —CH₂— group in the carbocyclic ring can be optionally replaced by —C(═O)—. In some embodiments, the cycloalkyl group contains 3-6 carbon atoms, i.e., a C_3-6 cycloalkyl group; in other embodiments, the cycloalkyl group contains 3-5 carbon atoms, i.e., a C_3-5 cycloalkyl group. Examples of the cycloalkyl group include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. Some non-limiting examples of that the —CH₂— group in the carbocyclic ring may be replaced by —C(═O)— include cyclopentanone, cyclobutanone, and the like. When a cycloalkyl group is a linking group, and a “cycloalkyl group” is recited for the definition of the Markush group, then “cycloalkyl” means a linked cycloalkylene group. The term “cycloalkylene” means a divalent cycloalkane group formed by removing two hydrogen atoms from a ring carbon atom of a cycloalkyl group. The cycloalkyl group or cycloalkane may be independently and optionally substituted with one or more substituents described herein.

The term “aromatic ring” or “aromatic hydrocarbon” refers to monocyclic, bicyclic and tricyclic carbocyclic ring systems having a total of 6-14 ring members, or 6-12 ring members, or 6-10 ring members, wherein at least one ring in the system is aromatic, wherein each ring in the system contains 3-7 ring atoms. Examples of the aromatic ring may include benzene, naphthalene, and anthracene.

The term “aryl” means a monovalent aromatic ring group formed by removing a hydrogen atom from a ring carbon atom of an aromatic ring. Examples of aryl may include phenyl, naphthyl and anthracene. When an aryl group is a linking group, and an “aryl group” is recited for the definition of the Markush group, then “aryl” means a linked arylene group. For example, when M is an aryl group as defined in the present invention, it means that M is a linked arylene group. The term “arylene” means a divalent aromatic ring group formed by removing two hydrogen atoms from a ring carbon atom of an aromatic ring. Examples of that an aryl group represents an arylene group may include phenylene, naphthylene and anthranylene. The aryl group may be independently and optionally substituted by one or more substituents disclosed herein.

The term “heteroaromatic ring” refers to monocyclic, bicyclic and tricyclic carbocyclic ring systems having a total of five to twelve ring members, or five to ten ring members, or five to six ring members, wherein at least one ring in the system is aromatic, and in which at least one ring member is selected from heteroatom, and wherein each ring in the system contains 5 to 7 ring atoms.

The term “heteroaryl” means a monovalent aromatic ring group formed by removing a hydrogen atom from the ring atom of the heteroaryl ring. The heteroaryl group is optionally substituted by one or more substituents disclosed herein. In one embodiment, a heteroaryl consisting of 5-10 atoms or a 5-10 membered heteroaryl comprises 1, 2, 3 or 4 heteroatoms independently selected from O, S and N. In some embodiments, the term “heteroaryl” means a heteroaryl consisting of 5 ring atoms or a 5-membered heteroaryl, which comprises 1, 2, 3 or 4 heteroatoms independently selected from O, S and N. Some non-limiting examples of heteroaryl include 2-furanyl, 3-furanyl, N-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, N-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, pyridazinyl (e.g., 3-pyridazinyl), 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, tetrazolyl (e.g., 5-tetrazolyl), triazolyl (e.g., 2-triazolyl and 5-triazolyl), 2-thienyl, 3-thienyl, pyrazolyl (e.g., 2-pyrazolyl), isothiazolyl, 1,2,3-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,3-triazolyl, 1,2,3-thiadiazolyl, 1,3,4-thiadiazolyl, 1,2,5-thiadiazolyl, pyrazinyl, 1,3,5-triazinyl, and the following bicycles: benzimidazolyl, benzofuryl, benzothiophenyl, indolyl (e.g., 2-indolyl), purinyl, quinolinyl (e.g., 2-quinolinyl, 3-quinolinyl, 4-quinolinyl), and isoquinolinyl (e.g., 1-isoquinolinyl, 3-isoquinolinyl or 4-isoquinolinyl), imidazo[1,2-a]pyridyl, pyrazolo[1,5-a]pyridyl, pyrazolo[1,5-a]pyrimidyl, imidazo[1,2-6]pyridazinyl, [1,2,4]triazolo[4,3-6]pyridazinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl or [1,2,4]triazolo[1,5-a]pyridyl, etc. When a heteroaryl group is a linking group, and a “heteroaryl group” is recited for the definition of the Markush group, then “heteroaryl” means a linked heteroarylene group. For example, when M is a heteroaryl group as defined in the present invention, it means that M is a linked heteroarylene group. The term “heteroarylene” means a divalent heteroaryl ring group formed by removing two hydrogen atoms from a ring atom of a heteroaryl group. The heteroaryl group may be independently and optionally substituted by one or more substituents disclosed herein.

The term “aryloxy” refers to aryl-O—, i.e., an aryl group, as previously defined, attached to the parent molecular moiety via an oxygen atom. Examples of aryloxy include, but are not limited to, phenoxy, naphthyloxy, and the like.

The term “aryloxyalkyl” refers to an alkyl group substituted with an aryloxy group, wherein the aryloxy group and the alkyl group have the definitions as described herein. In some embodiments, aryloxyalkyl is C_6-10 aryloxy C_1-6 alkyl; in other embodiments, aryloxyalkyl is phenoxy C_1-6 alkyl; in still some embodiments, aryloxyalkyl is phenoxy C_1-4 alkyl. Examples of the aryloxyalkyl group include, but are not limited to, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, phenoxyisopropyl, phenoxy-n-butyl, phenoxy-isobutyl, phenoxy-tert-butyl, and the like.

The term “arylalkyl” refers to an alkyl group substituted with an aryl group, wherein the aryl group and the alkyl group have the definitions as described herein. In some embodiments, arylalkyl is C_6-10 aryl C_1-6 alkyl; in other embodiments, arylalkyl is phenyl C_1-6 alkyl; in still some embodiments, arylalkyl is phenyl C_1-4 alkyl. Examples of arylalkyl include, but are not limited to, phenylmethyl, phenylethyl, phenyl-n-propyl, phenylisopropyl, phenyl-n-butyl, phenylisobutyl, phenyl-tert-butyl, and the like.

The term “heteroarylalkyl” refers to an alkyl group substituted with a heteroaryl group, wherein the heteroaryl group and the alkyl group have the definitions as described herein. In some embodiments, heteroaryl alkyl is (5-10 membered heteroaryl)-C_1-6 alkyl; in other embodiments, heteroaryl alkyl is (5-10 membered heteroaryl)-C_1-4 alkyl; in still some embodiments, heteroaryl alkyl is (5-6 membered heteroaryl)-C_1-4 alkyl. Examples of heteroarylalkyl include, but are not limited to, imidazolylmethyl, imidazolylethyl, pyrazolylmethyl, pyrazolyl ethyl, oxazolylmethyl, oxazolylethyl, imidazolylpropyl, pyridylpropyl, pyridylmethyl, pyridylethyl, pyrimidinylmethyl, furylmethyl, furylethyl, indolylmethyl, pyrazolo[1,5-a]pyrimidinylmethyl, etc.

The terms “bridged carbocycle” and “bridged carbocyclyl” are used interchangeably and both refer to a non-aromatic saturated or partially unsaturated bicyclic or polycyclic ring system that shares two or more carbon atoms, and the ring atom is carbon atom. The —CH₂— group in the bridged carbocycle can be optionally replaced by —C(═O)—. In some embodiments, the bridged carbocycle contains 6-12 ring carbon atoms, i.e., represents a 6-12 membered bridged carbocycle; in other embodiments, the bridged carbocycle contains 6-10 ring carbon atoms, i.e., represents a 6-10 membered bridged carbocycle. Examples of bridged carbocycle include, but are not limited to, bicyclo [3.1.1] heptane, bicyclo [3.2.1] octane, bicyclo [2.2.2] octane, bicyclo [2.2.0] hexane, octahydro-1H-indene, etc. When a bridged carbocycle or a bridged carbocyclyl is a linking group, and a bridged carbocycle or a bridged carbocyclyl is recited for the definition of the Markush group, then the bridged carbocycle or the bridged carbocyclyl means a linked subbridged carbocyclyl. The term “subbridged carbocyclyl” means a divalent bridged carbocyclic group formed by the removal of two hydrogen atoms from the ring atom of a bridged carbocycle. The bridged carbocycle or bridged carbocyclyl may be independently and optionally substituted by one or more substituents disclosed herein.

The terms “spiro carbocycle” and “spiro carbocyclyl” are used interchangeably and both refer to a non-aromatic saturated or partially unsaturated ring system in which two carbon rings share a carbon atom. The —CH₂— group in the spiro carbocyclic ring can be optionally replaced by —C(═O)—. In some embodiments, the spiro carbocycle contains 7-12 ring carbon atoms, i.e., represents a 7-12 membered spiro carbocycle; in other embodiments, the spiro carbocycle contains 7-10 ring carbon atoms, i.e., represents a 7-10 membered spiro carbocycle. Examples of spiro carbocycle include, but are not limited to, spiro[4.4]decane, spiro[3.4]octane, spiro[4.5]decane, and the like. When a spiro carbocycle or a spiro carbocyclyl is a linking group, and a spiro carbocycle or a spiro carbocyclyl is recited for the definition of the Markush group, then the spiro carbocycle or the spiro carbocyclyl means a linked subspiro carbocyclyl. The term “subspiro carbocyclyl” means a divalent spiro carbocyclic group formed by the removal of two hydrogen atoms from the ring atom of a spiro carbocycle. The spiro carbocycle or spiro carbocyclyl may be independently optionally substituted with one or more substituents disclosed herein.

The terms “heterocycle” or “heterocyclyl” are used interchangeably and all denote a monovalent, non-aromatic, saturated or partially unsaturated monocyclic ring system having 3-12 ring atoms, wherein the system contains at least one carbon atom and one, two or three heteroatoms selected from O, N, S. Unless otherwise specified, the heterocyclyl group may be carbon or nitrogen linked, and a —CH₂— group can be optionally replaced by a —C(═O)— group. Ring sulfur atoms may be optionally oxidized to form S-oxides, and ring nitrogen atoms may be optionally oxidized to form N-oxides. In some embodiments, the heterocycle contains 4-7 ring atoms, i.e., represents a 4-7 membered heterocycle; in other embodiments, the heterocycle contains 4-7 ring atoms, i.e., represents a 4-7 membered heterocycle. Examples of the heterocyclyl group include, but are not limited to, oxiranyl, azetidinyl, oxetanyl, thietanyl, pyrrolidinyl, 2-pyrrolinyl, 3-pyrrolinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, dihydrothienyl, 1,3-dioxocyclopentyl, dithiocyclopentyl, tetrahydropyranyl, dihydropyranyl, 2n-pyranyl, 4n-pyranyl, tetrahydrothiopyranyl, piperidinyl, morpholinyl, thiomorpholinyl, piperazinyl, dioxanyl, dithianyl, thioxanyl, homopiperazinyl, homopiperidinyl, 1,1-dioxo-1,3-thiomorpholine, and the like. Some non-limiting examples of heterocyclyl wherein —CH₂— group is replaced by —C(═O)— moiety include 2-oxopyrrolidinyl, oxo-1,3-thiazolidinyl, 2-piperidinonyl and 3,5-dioxopiperidinyl. Some non-limited examples of heterocyclyl wherein the ring nitrogen atom is oxidized is 1,1-dioxo-1,3-thiomorpholine. When a heterocycle or a heterocyclyl is a linking group, and a heterocycle or a heterocyclyl is recited for the definition of the Markush group, then the heterocycle or the heterocyclyl means a linked heterocyclylene group. The term “heterocyclylene” means a divalent heterocyclyl group formed by removing two hydrogen atoms from a ring atom of a heterocyclic ring. The heterocycle or heterocyclyl may be independently and optionally substituted with one or more substituents disclosed herein.

The terms “bridged heterocycle” or “bridged heterocyclyl” are used interchangeably and all denote a non-aromatic saturated or partially unsaturated bicyclic or polycyclic ring system that shares two or more carbon atoms, wherein the system contains at least one carbon atom and 1, 2 or 3 heteroatoms selected from O, N, S. The —CH₂— group in the bridged heterocycle can be optionally replaced by —C(═O)—. Ring sulfur atoms may be optionally oxidized to form S-oxides, and ring nitrogen atoms may be optionally oxidized to form N-oxides. In some embodiments, the bridged heterocycle contains 6-12 ring atoms, i.e., represents a 6-12 membered bridged heterocycle; in other embodiments, the bridged heterocycle contains 6-10 ring atoms, i.e., represents a 6-10 membered bridged heterocycle. Examples of the bridged heterocycle include, but are not limited to, 3,6-diazabicyclo[3.1.1]heptane, 3,8-diazabicyclo[3.2.1]octane, 2-azabicyclo[2.2.1] heptane, octahydroimidazo[1,5-c]pyrimidine, 6-azabicyclo[3.1.1]heptane, 3-azabicyclo[3.1.1]heptane, 8-azabicyclo[3.2.1]octane, 3-azabicyclo[3.2.1]octane, 2-diazabicyclo[2.2.2]octane, and the like. When a bridged heterocycle or a bridged heterocyclyl is a linking group, and a bridged heterocycle or a bridged heterocyclyl is recited for the definition of the Markush group, then the bridged heterocycle or the bridged heterocyclyl means a linked subbridged heterocyclyl group. The term “subbridged heterocyclyl” means a divalent bridged heterocyclyl group formed by removing two hydrogen atoms from a ring atom of a bridged heterocyclic ring. The bridged heterocycle or bridged heterocyclyl may be independently and optionally substituted by one or more substituents disclosed herein.

The terms “spiroheterocycle” or “spiroheterocyclyl” are used interchangeably and all denote a non-aromatic saturated or partially unsaturated ring system in which two rings share a carbon atom, and the system contains one, two or three heteroatoms selected from O, N, S. The —CH₂— group in the spiroheterocycle can be optionally replaced by —C(═O)—. Ring sulfur atoms may be optionally oxidized to form S-oxides, and ring nitrogen atoms may be optionally oxidized to form N-oxides. In some embodiments, the spiroheterocycle contains 7-12 ring atoms, i.e., represents a 7-12 membered spiroheterocycle; in other embodiments, the spiroheterocycle contains 7-10 ring atoms, i.e., represents a 7-10 membered spiroheterocycle. Examples of the spiroheterocycle include, but are not limited to, 4,7-diazaspiro[2.5]octane, 2,8-diazaspiro[4.5]decane, 2,7-diazaspiro[4.5]decane, 2,7-diazaspiro[3.5]decane, 2,6-diazaspiro[3.3]heptane, 2,7-diazaspiro[4.4]nonane, 3-azaspiro[5.5]undecane, 2,7-diazaspiro[4.4]nonane-1-one, and the like. When a spiroheterocycle or a spiroheterocyclyl is a linking group, and a spiroheterocycle or a spiroheterocyclyl is recited for the definition of the Markush group, then the spiroheterocycle or spiroheterocyclyl means a linked spiroheterocyclylene group. The term “spiroheterocyclylene” means a divalent spiroheterocyclyl group formed by removing two hydrogen atoms from a ring atom of a spiroheterocyclic ring. The spiroheterocycle or spiroheterocyclyl may be independently and optionally substituted by one or more substituents disclosed herein.

The term “alkylaryl” refers to an aryl group substituted with an alkyl group, wherein the alkyl group and the aryl group have the definitions as described herein. In some embodiments, “alkylaryl” refers to C_1-6 alkyl-C_6-10 aryl, i.e., C_6-10 aryl substituted with C_1-6 alkyl; in other embodiments, “alkylaryl” refers to C_1-4 alkylphenyl, i.e., phenyl substituted by C_1-4 alkyl. Examples of the alkylaryl group include, but are not limited to, methylphenyl, ethylphenyl, propylphenyl, methylnaphthyl, and the like. When an alkylaryl group is a linking group, and an alkylaryl is recited for the definition of the Markush group, then alkylaryl means a linked alkylarylene group. For example, when M is an alkylaryl group as defined in the present invention, it means that M is a linked alkylarylene group. The term “alkylarylene” means a divalent alkylaryl group formed by removing a hydrogen atom from the alkyl group of the alkylaryl group and removing a hydrogen atom from the ring atom of the aryl group. The alkylaryl group may be independently and optionally substituted by one or more substituents disclosed herein.

The term “alkenylaryl” refers to an aryl group substituted with an alkenyl group, wherein the alkenyl group and the aryl group have the definitions as described herein. In some embodiments, “alkenylaryl” refers to C_2-6 alkenyl-C_6-10 aryl, i.e., C_6-10 aryl substituted with C_2-6 alkenyl; in other embodiments, “alkenylaryl” refers to C_2-4 alkenylphenyl, i.e., phenyl substituted by C_2-4 alkenyl. Examples of the alkenylaryl group include, but are not limited to, CH₂═CH-phenyl, CH₃CH═CH-phenyl, CH₃CH═CH—CH₂-phenyl, and the like. When an alkenylaryl group is a linking group, and an alkenylaryl is recited for the definition of the Markush group, then alkenylaryl means a linked alkenyl aryl ene group. For example, when M is an alkenylaryl group as defined in the present invention, it means that M is a linked alkenyl aryl ene group. Examples of the alkenylaryl ene group include, but are not limited to, —CH═CH-phenyl, —CH₂CH═CH-phenyl, —CH₂CH═CH—CH₂-phenyl, etc. The alkenylarylene group may be independently and optionally substituted by one or more substituents described herein.

The term “alkynylaryl” refers to an aryl group substituted by an alkynyl group, wherein the alkynyl group and the aryl group have the definitions as described herein. In some embodiments, “alkynylaryl” refers to C_2-6 alkynyl-C_6-10 aryl, i.e., C_6-10 aryl substituted by C_2-6 alkynyl; in other embodiments, “alkynylaryl” refers to C_2-4 alkynylphenyl, i.e., phenyl substituted by C_2-4 alkynyl. Examples of the alkynylaryl group include, but are not limited to, CH═C-phenyl, CH₃C≡C-phenyl, CH₃C≡C—CH₂-phenyl, and the like. When an alkynylaryl group is a linking group, and an alkynylaryl is recited for the definition of the Markush group, then alkynylaryl means a linked alkynylarylene group. For example, when M is an alkynylaryl group as defined in the present invention, it means that M is a linked alkynylarylene group. Examples of the alkynylarylene group include, but are not limited to, —C≡C-phenyl, —CH₂C≡C-phenyl, —CH₂C≡C—CH₂-phenyl, and the like. The alkynylaryl group may be independently and optionally substituted by one or more substituents disclosed herein.

The term “alkylheteroaryl” refers to a heteroaryl group substituted by an alkyl group. The alkyl and heteroaryl are as defined herein. In some embodiments, “alkylheteroaryl” means C_1-6 alkyl-(5-10 membered heteroaryl), i.e., 5-10 membered heteroaryl substituted by C_1-6 alkyl; in other embodiments, “alkylheteroaryl” means C_1-4 alkyl-(5-6 membered heteroaryl), i.e., 5-6 membered heteroaryl substituted by C_1-4 alkyl. Examples of the alkylheteroaryl group include, but are not limited to, methylpyridyl, ethylpyridyl, propylpyridyl, methylpyrazolyl, ethylpyrazolyl, propylpyrazolyl, methylpyrimidinyl, methylpyrazinyl, methyl benzimidazolyl, methyl benzopyrazolyl, and the like. When an alkylheteroaryl group is a linking group, and an alkylheteroaryl is recited for the definition of the Markush group, then alkylheteroaryl means a linked alkylheteroarylene group. For example, when M is an alkylheteroaryl group as defined in the present invention, it means that M is a linked alkylheteroarylene group. The term “alkylheteroarylene” means a divalent alkylheteroaryl group formed by removing a hydrogen atom from the alkyl group of the alkylheteroaryl group and removing a hydrogen atom from the ring atom of the heteroaryl group. The alkylheteroaryl group may be independently and optionally substituted by one or more substituents disclosed herein.

The term “alkenylheteroaryl” refers to a heteroaryl group substituted by an alkenyl group. The alkenyl and heteroaryl are as defined herein. In some embodiments, “alkenylheteroaryl” means C_2-6 alkenyl-(5-10 membered heteroaryl), i.e., 5-10 membered heteroaryl substituted with C_2-6 alkenyl; in other embodiments, “alkenylheteroaryl” means C_2-4 alkenyl-(5-6 membered heteroaryl), i.e., 5-6 membered heteroaryl substituted with C_2-4 alkenyl. Examples of the alkenylheteroaryl group include, but are not limited to, CH₂═CH-pyridyl, CH₃CH═CH-pyridyl, CH₃CH═CH—CH₂-pyridyl, CH₂═CH-pyrazolyl, CH₃CH═CH-pyrazolyl, CH₂═CH-pyrimidinyl, CH₂═CH-pyrazinyl, CH₂═CH-benzimidazolyl, CH₂═CH-benzopyrazolyl, and the like. When an alkenylheteroaryl group is a linking group, and an alkenylheteroaryl is recited for the definition of the Markush group, then alkenylheteroaryl means a linked alkenylheteroarylene group. For example, when M is an alkenylheteroaryl group as defined in the present invention, it means that M is a linked alkenylheteroarylene group. Examples of the alkenylheteroarylene group include, but are not limited to, —CH═CH-pyridyl, —CH₂CH═CH-pyridyl, —CH₂CH═CH—CH₂-pyridyl, —CH═CH-pyrazolyl, —CH₂CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, and the like. The alkenylheteroaryl group may be independently and optionally substituted with one or more substituents disclosed herein.

The term “alkynylheteroaryl” refers to a heteroaryl group substituted by an alkynyl group. The alkynyl and heteroaryl are as defined herein. In some embodiments, “alkynylheteroaryl” means C_2-6 alkynyl-(5-10 membered heteroaryl), i.e., 5-10 membered heteroaryl substituted with C_2-6 alkynyl; in other embodiments, “alkynylheteroaryl” means C_2-4 alkynyl-(5-6 membered heteroaryl), i.e., 5-6 membered heteroaryl substituted with C_2-4 alkynyl. Examples of the alkynylheteroaryl group include, but are not limited to, CH≡C-pyridyl, CH₃C≡C-pyridyl, CH₃C≡C—CH₂-pyridyl, CH≡C-pyrazolyl, CH₃C≡C-pyrazolyl, CH≡C-pyrimidinyl, CH≡C-pyrazinyl, CH≡C-benzimidazolyl, CH≡C-benzopyrazolyl, and the like. When an alkynylheteroaryl group is a linking group, and an alkynylheteroaryl is recited for the definition of the Markush group, then alkynylheteroaryl means a linked alkynylheteroarylene group. For example, when M is an alkynylheteroaryl group as defined in the present invention, it means that M is a linked alkynylheteroarylene group. Examples of the alkynylheteroarylene group include, but are not limited to, —C≡C-pyridyl, —CH₂C≡C-pyridyl, —CH₂C≡C—CH₂-pyridyl, —C≡C-pyrazolyl, —CH₂C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, and the like. The alkynylheteroaryl group may be independently optionally substituted with one or more substituents disclosed herein.

The term “aminoalkyl” refers to an alkyl group substituted by one or more amino groups. In some embodiments, the term “aminoalkyl” refers to an alkyl group substituted by one amino group. In other embodiments, the term “aminoalkyl” refers to amino C_1-6 alkyl. In still other embodiments, the term “aminoalkyl” refers to amino C_1-4 alkyl. In yet other embodiments, the term “aminoalkyl” refers to amino C_1-3 alkyl. Examples of the aminoalkyl group include, but are not limited to, aminomethyl, aminoethyl, amino-n-propyl, aminoisopropyl, aminoisobutyl, amino-tert-butyl, 1,2-diaminoethyl, and the like.

The term “alkylamino” refers to an amino group substituted by an alkyl group. In some embodiments, the term “alkylamino” refers to C_1-6 alkylamino. In other embodiments, the term “alkylamino” refers to C_1-4 alkylamino. In some embodiments, the term “alkylamino” refers to C_1-3 alkylamino. Examples of the alkylamino group include, but are not limited to, methylamino, ethylamino, n-propylamino, isopropylamino, isobutylamino, tert-butylamino, and the like.

The term “dialkylamino” refers to an amino group substituted with two alkyl groups. In some embodiments, the term “dialkylamino” refers to a di(C_1-6 alkyl)amino group, i.e., an amino group substituted with two C_1-6 alkyl groups. In other embodiments, the term “dialkylamino” refers to a di(C_1-4 alkyl)amino group, i.e., an amino group substituted with two C_1-4 alkyl groups. In still other embodiments, the term “dialkylamino” refers to a di(C_1-3 alkyl)amino group, i.e., an amino group substituted with two C_1-3 alkyl groups. Examples of the dialkylamino group include, but are not limited to, dimethylamino, diethylamino, di-n-propylamino, diisopropylamino, diisobutylamino, di-tert-butylamino, and the like.

The term “alkylaminoalkyl” refers to an alkyl group substituted with an alkylamino group, wherein the alkyl group and the alkylamino group have the definitions as described herein. In some embodiments, the term “alkylaminoalkyl” refers to C_1-6 alkylamino-C_1-6 alkyl, i.e., C_1-6 alkyl substituted with C_1-6 alkylamino; in other embodiments, the term “alkylaminoalkyl” refers to C_1-4 alkylamino-C_1-4 alkyl, i.e., C_1-4 alkyl substituted with C_1-4 alkylamino. Examples of the alkylaminoalkyl group include, but are not limited to, methylaminomethyl, ethylaminoethyl, methylaminoethyl, ethylaminomethyl, propylaminomethyl, methylaminopropyl, methylamino-/7-butyl, propylaminoethyl, and the like.

The term “dialkylaminoalkyl” refers to an alkyl group substituted with a dialkylamino group, wherein the dialkylamino group and the alkyl group have the definitions as described herein. In some embodiments, the term “dialkylaminoalkyl” is di(C_1-6 alkyl)amino-C_1-6 alkyl; in other embodiments, “dialkylaminoalkyl” is di(C_1-4 alkyl)amino-C_1-4 alkyl.

The term “alkylsulfonyl” refers to alkyl-S(═O)₂—, i.e., alkyl is attached to the parent molecular moiety via —S(═O)₂—. In some embodiments, alkylsulfonyl is C_1-6 alkylsulfonyl; in other embodiments, alkylsulfonyl is phenyl C_1-4 alkylsulfonyl; in still some embodiments, alkylsulfonyl is C_1-4 alkylsulfonyl. Examples of the alkylsulfonyl group include, but are not limited to, methylmethanesulfonyl, ethylmethanesulfonyl, n-propylmethanesulfonyl, isopropylmethanesulfonyl, n-butylmethanesulfonyl, and the like.

The term “Cyc” refers to cycloalkyl, bridged carbocyclyl or spirocarbocyclyl, wherein the cycloalkyl, bridged carbocyclyl and spirocarbocyclyl have the definitions as described herein. In some embodiments, Cyc represents 3-12 membered Cyc; in other embodiments, Cyc represents 3-10 membered Cyc.

The term “hetCyc” refers to heterocyclyl, bridged heterocyclyl or spiroheterocyclyl wherein the heterocyclyl, bridged heterocyclyl and spiroheterocyclyl have the definitions as described herein. In some embodiments, hetCyc represents 3-12 membered hetCyc; in other embodiments, hetCyc represents 3-10 membered hetCyc.

The term “R⁵O(C═O)NR⁶alkyl” means that the hydrogen atom on the alkyl group is substituted by R⁵O(C═O)NR⁶—, wherein the alkyl group and R⁵O(C═O)NR⁶— have the definitions as described herein. The term “R⁵(C═O)NR⁶alkyl” means that the hydrogen atom on the alkyl group is substituted by R⁵(C═O)NR⁶—, wherein the alkyl group and R⁵(C═O)NR⁶— have the definitions as described herein.

The term “NR⁵R⁶(C═O)alkyl” means that the hydrogen atom on the alkyl group is substituted by NR⁵R⁶(C═O)—, wherein the alkyl group and NR⁵R⁶(C═O)— have the definitions as described herein. The term “R⁵(C═O)alkyl” means that the hydrogen atom on the alkyl group is substituted by R⁵(C═O)—, wherein the alkyl group and R⁵(C═O)— have the definitions as described herein. The term “NR⁵R⁶alkyl” means that the hydrogen atom on the alkyl group is substituted by NR⁶R⁷—, wherein the alkyl group and NR⁶R⁷— have the definitions as described herein. The term “NR⁶R⁷alkoxy” means that the hydrogen atom on the alkoxy group is substituted by NR⁶R⁷—, wherein the alkoxy group and NR⁶R⁷— have the definitions as described herein. The term “NR⁶R⁷alkoxyalkyl” refers to an alkyl group substituted by NR⁶R⁷ alkoxy, wherein NR⁶R⁷ alkoxy and alkyl have the definitions as described herein. The term “NR⁵R⁶(C═O)alkoxy” refers to an alkoxy group substituted by NR⁵R⁶(C═O)—, wherein NR⁵R⁶(C═O)— and alkoxy have the definitions as described herein. The term “NR⁵R⁶(C═O)alkoxyalkyl” refers to an alkyl group substituted by NR⁵R⁶(C═O)alkoxy, wherein NR⁵R⁶(C═O)alkoxy and alkyl have the definitions as described herein. The term “R⁵Oalkyl” means that the hydrogen atom on the alkyl group is substituted by R⁵O—, wherein the alkyl group and R⁵O— have the definitions as described herein.

The term “Cyc-alkyl” means that the hydrogen atom on the alkyl group is substituted by Cyc. wherein the alkyl and Cyc are as defined herein. In some embodiments, Cyc-alkyl represents (3-12 membered Cyc)-C_1-6 alkyl; in other embodiments, Cyc-alkyl represents (3-10 membered Cyc)-C_1-4 alkyl; in still other embodiments, Cyc-alkyl represents (3-10 membered Cyc)-C_1-3 alkyl. Examples of the Cyc-alkyl group include, but are not limited to, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclopentylethyl, cyclopentyl-/7-propyl, cyclopropylethyl, cyclopropyl-/7-propyl, cyclobutylethyl, cyclobutylpropyl, cyclohexylethyl, cyclohexylmethyl, and the like.

The term “hetCyc-alkyl” refers to that the hydrogen atom on the alkyl group is substituted by hetCyc, wherein alkyl and hetCyc have the definitions as described herein. In some embodiments, “hetCyc-alkyl” represents (3-12 membered) hetCyc-C_1-6 alkyl; in other embodiments, hetCyc-alkyl represents (3-10 membered hetCyc)-C_1-4 alkyl; in still other embodiments, hetCyc-alkyl represents (3-10 membered hetCyc)-C_1-3 alkyl. Examples of the hetCyc-alkyl group include, but are not limited to, azetidinylmethyl, pyrrolidinylmethyl, morpholinylmethyl, morpholinylethyl, piperazinylmethyl, piperazinylethyl, 2-oxopyrrolidinomethyl, 2-oxopyrrolidinylethyl, oxetanylmethyl, tetrahydrofuranylmethyl, and the like.

The term “alkylhetCyc” refers to a hetCyc substituted with an alkyl group, wherein the alkyl group and the hetCyc group have the definitions as described herein. In some embodiments, “alkylhetCyc” means C_1-6 alkyl-(3-12 membered hetCyc); in other embodiments, “alkylhetCyc” means C_1-4 alkyl-(3-10 membered hetCyc); in still other embodiments, “alkyl hetCyc” means C_1-3 alkyl-(3-10 membered hetCyc). Examples of the alkylhetCyc group include, but are not limited to, isopropylazetidinyl, methylpiperidinyl, methyloxetanyl, methylpyrrolidinyl, methylmorpholinyl, methylimidazolidinyl, etc.

In the formula of the compound of the present invention, the left end of Q is connected to A, and the right end of Q is connected to M. For example, when Q is —S(═O)₂NR⁵—, then

represents

likewise, the left end of A is connected to E, and the right end of A is connected to Q. For example, when A is

then

represents

the left end of M is connected to Q, and the right end of M is connected to ≡R³. For example, when M is —CH₂-phenyl,

represents

As described herein, unless otherwise specified, the ring substituent can attach to the rest of the molecule at any attachable position on the rings. For example, piperidinyl comprises piperidin-1-yl, piperidin-2-yl, piperidin-3-yl and piperidin-4-yl.

The term “protecting group” or “PG” refers to a substituent that is commonly employed to block or protect a particular functionality while reacting with other functional groups on the compound. For example, an “amino-protecting group” is a substituent attached to an amino group that blocks or protects the amino functionality in the compound. Suitable amino-protecting groups include acetyl, trifluoroacetyl, t-butoxy-carbonyl (BOC, Boc), benzyloxycarbonyl (CBZ, Cbz) and 9-fluorenylmethylenoxy-carbonyl (Fmoc). Similarly, a “hydroxy-protecting group” refers to a substituent of a hydroxy group that blocks or protects the hydroxy functionality. Suitable protecting groups include acetyl and silyl. A “carboxy-protecting group” refers to a substituent of the carboxy group that blocks or protects the carboxy functionality. Common carboxy-protecting groups include —CH₂CH₂SO₂Ph, cyanoethyl, 2-(trimethylsilyl)ethyl, 2-(trimethylsilyl) ethoxy-methyl, 2-(p-toluenesulfonyl) ethyl, 2-(p-nitrophenylsulfonyl)-ethyl, 2-(diphenylphosphino)-ethyl, nitroethyl and the like. For a general description of protecting groups and their use, see T. W. Greene, Protective Groups in Organic Synthesis, John Wiley & Sons, New York, 1991; and P. J. Kocienski, Protecting Groups, Thieme, Stuttgart, 2005.

The term “prodrug” refers to a compound that is transformed in vivo into a compound of Formula (I). Such transformation can be affected, for example, by hydrolysis of the prodrug form in blood or enzymatic transformation to the parent form in blood or tissue. Prodrugs of the compounds disclosed herein may be, for example, esters. Some common esters which have been utilized as prodrugs are phenyl esters, aliphatic (C_1-24) esters, acyloxymethyl esters, carbonates, carbamates and amino acid esters. For example, a compound disclosed herein that contains a hydroxy group may be acylated at this position in its prodrug form. Other prodrug forms include phosphates, such as, those phosphate compounds derived from the phosphonation of a hydroxy group on the parent compound. A thorough discussion of prodrugs is provided in T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S. Symposium Series, Edward B. Roche, ed., Bioreversible Carriers in Drug Design, American Pharmaceutical Association and Pergamon Press, 1987, J. Rautio et al., Prodrugs: Design and Clinical Applications, Nature Review Drug Discovery, 2008, 7, 255-270, and S. J. Hecker et al., Prodrugs of Phosphates and Phosphonates, Journal of Medicinal Chemistry, 2008, 51, 2328-2345, all of which are incorporated herein by reference in their entireties.

A “metabolite” is a product produced through metabolism in the body of a specified compound or salt thereof. The metabolites of a compound may be identified using routine techniques known in the art and their activities may be determined using tests as those described herein. Such products may result for example from oxidation, reduction, hydrolysis, amidation, deamidation, esterification, deesterification, enzyme cleavage, etc., of the administered compound. Accordingly, the invention includes metabolites of a compound disclosed herein, including metabolites produced by contacting a compound disclosed herein with a mammal for a sufficient time period.

The “pharmaceutically acceptable salt” as used in the present invention means an organic salt and an inorganic salt of the compound of the present invention. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1-19, which is incorporated herein by reference. Some non-limiting examples of pharmaceutically acceptable and nontoxic salts include salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid and malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, cyclopentylpropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemi sulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, laurylsulfate, malate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, stearate, thiocyanate, p-toluenesulfonate, undecanoate, valerate, and the like. Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N⁺ (C_1-4 alkyl)₄ salts. This invention also envisions the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water soluble or oil soluble or dispersable products may be obtained by such quaternization. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include appropriate and nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions, such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, C_1-8 sulfonate or aryl sulfonate.

The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound, basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting free acid forms of these compounds with a stoichiometric amount of the appropriate base (such as Na, Ca, Mg, or K hydroxide, carbonate, bicarbonate or the like), or by reacting free base forms of these compounds with a stoichiometric amount of the appropriate acid. Such reactions are typically carried out in water or in an organic solvent, or in a mixture of the two. Generally, use of non-aqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile is desirable, where practicable. Lists of additional suitable salts can be found, e.g., in “Remington's Pharmaceutical Sciences”, 20th ed., Mack Publishing Company, Easton, Pa., (1985); and in “Handbook of Pharmaceutical Salts: Properties, Selection, and Use” by Stahl and Wermuth (Wiley-VCH, Weinheim, Germany, 2002).

Furthermore, the compounds disclosed herein, including their salts, can also be obtained in the form of their hydrates, or include other solvents such as ethanol, DMSO, and the like, used for their crystallization. The compounds of the present invention may inherently or by design form solvates with pharmaceutically acceptable solvents (including water); therefore, it is intended that the invention embrace both solvated and unsolvated forms.

The term “solvate” refers to an association or complex of one or more solvent molecules and a compound disclosed herein. Examples of solvents that form solvates include, but are not limited to, water, isopropanol, ethanol, methanol, DMSO, ethyl acetate, acetic acid and ethanolamine. The term “hydrate” refers to the complex where the solvent molecule is water.

An “N-oxide” of the present invention refers to one or more than one nitrogen atoms oxidized to form an N-oxide, where a compound contains several amine functional groups. Particular examples of N-oxides are the N-oxides of a tertiary amine or a nitrogen atom of a nitrogen-containing heterocycle. N-oxides can be formed by treatment of the corresponding amine with an oxidizing agent such as hydrogen peroxide or a per-acid (e.g., a peroxycarboxylic acid) (See, Advanced Organic Chemistry, by Jerry March, 4th Edition, Wiley Interscience, pages). More particularly, N-oxides can be made by the procedure of L. W. Deady (Syn. Comm. 1977, 7, 509-514) in which the amine compound is reacted with m-chloroperoxybenzoic acid (MCPBA), for example, in an inert solvent such as dichloromethane.

As used herein, the term “treat”, “treating” or “treatment” of any disease or disorder refers in one embodiment, to ameliorating the disease or disorder (i.e., slowing or arresting or reducing the development of the disease or at least one of the clinical symptoms thereof). In another embodiment “treat”, “treating” or “treatment” refers to alleviating or ameliorating at least one physical parameter including those which may not be discernible by the patient. In still another embodiment, “treat”, “treating” or “treatment” refers to modulating the disease or disorder, either physically, (e.g., stabilization of a discernible symptom), physiologically, (e.g., stabilization of a physical parameter), or both. In yet another embodiment, “treat”, “treating” or “treatment” refers to preventing or delaying the onset or development or progression of the disease or disorder.

The term “RET-related cancer” as used herein refers to a cancer that is associated with the expression, activity or dysregulation of the RET gene, RET kinase (also referred to herein as RET kinase protein or RET kinase), or any one of them. Non-limiting examples of RET-related cancers are described herein, the expression or activity or level dysregulation of the RET gene, RET kinase, or any one of them is one or more point mutations in the RET gene.

The phrase “expression, activity or, dysregulation of RET gene, RET kinase, or any of them” refers to a mutation in a gene (e.g., a translocation of a RET gene resulting in expression of a fusion protein, a deletion in the RET gene resulting in expression of the RET protein comprising at least one amino acid deletion compared to the wild-type RET protein, or a mutation in the RET gene resulting in the expression of a RET protein with one or more point mutations, or alternatively spliced form of RET mRNA resulting in the deletion of at least one amino acid in the RET protein compared to the wild-type RET protein), or amplification of a RET gene, which results in overexpression of the RET protein or autocrine activity resulting from overexpression of the cellular RET gene and results in increased pathogenicity of the activity of the kinase domain of the RET protein in the cell (e.g., constitutive activation of the kinase domain of the RET protein). As another example, the expression, activity or dysregulation of the RET gene, RET kinase, or any one of them may be a mutation in the RET gene encoding a RET protein, wherein the RET protein has constitutive activity or increased activity compared to a protein encoded by the RET gene not comprising the mutation. For example, the expression, activity or dysregulation of the RET gene, RET kinase, or any one of them can be the result of a gene or chromosomal translocation which results in expression of a fusion protein, wherein the fusion protein comprises a first RET portion comprising a functional kinase domain and a second portion of a chaperone protein (i.e., not RET). In some examples, the RET gene, RET protein, or dysregulation of expression or activity can be the result of gene translation of one RET gene with another RET gene.

The expression, activity or, dysregulation of RET kinase, the RET gene, or any (e.g., one or more) thereof may contribute to tumorigenesis. For example, the expression, activity or dysregulation of the RET gene, RET kinase, or any one of them can be a translocation, overexpression, activation, amplification or mutation of the RET kinase, RET gene or RET kinase domain. A translocation can include a translocation involving an RET kinase domain. A mutation can include a mutation involving a RET ligand binding site, and the amplification can be a RET gene. Other disorders may include RET mRNA splice variants and RET autocrine/paracrine signaling, which may also contribute to tumorigenesis.

In some embodiments, the expression, activity or dysregulation of the RET gene, RET kinase, or any one of them includes one or more deletions (e.g., deletions of the 4 amino acids), insertions, or point mutations in the RET kinase. In some embodiments, the expression or activity or level dysregulation of the RET gene, RET kinase, or any one of them includes deletion of one or more residues of the RET kinase, resulting in constitutive activity of the RET kinase domain.

The term “Irritable Bowel Syndrome” includes diarrhea-predominant, constipation-predominant or alternating defecation patterns, functional bloating, functional constipation, functional diarrhea, non-specific functional bowel disease, functional abdominal pain syndrome, chronic idiopathic constipation, functional esophageal disease, functional gastroduodenal disease, functional anorectal pain, inflammatory bowel disease, etc.

Any formula given herein is also intended to represent isotopically unenriched forms as well as isotopically enriched forms of the compounds. Isotopically enriched compounds have the structure depicted by the general formula given herein, except that one or more atoms are replaced by the atom having a selected atomic mass or mass number. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, and chlorine, such as 2H (deuterium, D), 3H, 11C, 13C, 14C, 15N, 17O, 18O, 18F, 31P, 32P, 35S, 36Cl, 125I, respectively.

In another aspect, the compounds of the invention include isotopically enriched compounds as defined herein, for example those into which radioactive isotopes, such as ³H, ¹⁴C and ¹⁸F, or those into which non-radioactive isotopes, such as ²H and ¹³C are present. Such isotopically enriched compounds are useful in metabolic studies (with ¹⁴C), reaction kinetic studies (with, for example ²H or ³H), detection or imaging techniques, such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT) including drug or substrate tissue distribution assays, or in radioactive treatment of patients. In particular, an ¹⁸F-enriched compound may be particularly desirable for PET or SPECT studies.

Isotopically-enriched compounds of Formula (I) can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described in the accompanying Examples and Preparations using an appropriate isotopically-labeled reagent in place of the non-labeled reagent previously employed.

Further, substitution with heavier isotopes, particularly deuterium (i.e., ²H or D) may afford certain therapeutic advantages resulting from greater metabolic stability. For example, increased in vivo half-life or reduced dosage requirements or an improvement in therapeutic index. It is understood that deuterium in this context is regarded as a substituent of a compound of Formula (I), (I-1), (I-2), (I-3) or (I-4). The concentration of such a heavier isotope, specifically deuterium, may be defined by the isotopic enrichment factor. The term “isotopic enrichment factor” as used herein means the ratio between the isotopic abundance and the natural abundance of a specified isotope. If a substituent in a compound of this invention is denoted deuterium, such compound has an isotopic enrichment factor for each designated deuterium atom of at least 3500 (52.5% deuterium incorporation at each designated deuterium atom), at least 4000 (60% deuterium incorporation), at least 4500 (67.5% deuterium incorporation), at least 5000 (75% deuterium incorporation), at least 5500 (82.5% deuterium incorporation), at least 6000 (90% deuterium incorporation), at least 6333.3 (95% deuterium incorporation), at least 6466.7 (97% deuterium incorporation), at least 6600 (99% deuterium incorporation), or at least 6633.3 (99.5% deuterium incorporation). Pharmaceutically acceptable solvates in accordance with the invention include those wherein the solvent of crystallization may be isotopically substituted, e.g., D₂O, acetone-d₆, DMSO-d₆.

Description of Compounds of the Invention

The present invention provides a novel compound exhibiting inhibition of Re-arranged during transfection (RET) kinase, which has a good inhibitory effect on RET wild type and RET gene mutants, and has a good inhibition selectivity on RET wild type and RET gene mutants.

In one aspect, the present invention provides a compound having Formula (I) or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, A, Q, M and R³ is as defined herein.

In some embodiments, each of X¹, X², X³, X⁴ and X⁵ is independently CR⁴ or N, wherein 0, 1, or 2 of X¹, X², X³, X⁴ are N.

In some embodiments, E is a bond, —NR⁶— or —O—.

In some embodiments, A is Cyc or hetCyc, wherein each of Cyc and hetCyc is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶ alkyl, NR⁵R⁶(C═O) alkoxyalkyl, NR⁶R⁷ alkoxy, NR⁶R⁷ alkoxyalkyl, alkyl, haloalkyl, hydroxyalkyl, Cyc, hetCyc, hetCyc-alkyl, alkoxyalkyl, hetCyc-alkoxyalkyl, cycloalkylidene and heterocyclylidene.

In some embodiments, Q is —(C═O)—, —O—, —(C═O)NR⁵—, —(C═S)NR⁵—, —S(═O)₂—, —S(═O)₂NR⁵—, —NR⁵(C═O)—, —NR⁵(C═O)O—, —NR⁵(C═O)NR⁵—, —NR⁵—, —(C═O)O— or a bond.

In some embodiments, M is —(C═O)—, alkyl, alkenyl, alkynyl, alkylaryl, alkylheteroaryl, alkenylaryl, alkynylaryl, alkenylheteroaryl, alkynylheteroaryl, aryl, heteroaryl, Cyc, hetCyc, arylalkyl, heteroarylalkyl, Cyc-alkyl or hetCyc-alkyl, wherein each of alkyl, alkenyl, alkynyl, alkylaryl, alkylheteroaryl, alkenylaryl, alkynylaryl, alkenylheteroaryl, alkynylheteroaryl, aryl, heteroaryl, Cyc, hetCyc, arylalkyl, heteroarylalkyl, Cyc-alkyl and hetCyc-alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NR⁵R⁶, oxo, alkoxy, cycloalkylidene, heterocyclylidene, hydroxyalkyl, alkyl, cycloalkyl, cycloalkylalkynyl and heterocyclic group.

In some embodiments, R¹ is H, D, CN, F, Cl, Br, alkyl, alkenyl or cycloalkyl, wherein each of alkyl, alkenyl and cycloalkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂.

In some embodiments, G is H, D, alkyl, hetCyc, Cyc, hetCyc-alkyl, Cyc-alkyl, heteroarylalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, R⁵O(C═O)NR⁶ alkyl, R⁵(C═O)NR⁶ alkyl, NR⁵R⁶(C═O)alkyl, R⁵(C═O)alkyl, NR⁵R⁶(C═O)— or R⁵O-alkyl, wherein each of alkyl, hetCyc, Cyc, hetCyc-alkyl, Cyc-alkyl, heteroarylalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, and an alkyl moiety in R⁵O(C═O)NR⁶ alkyl, R⁵(C═O)NR⁶ alkyl, R⁵(C═O)alkyl, NR⁵R⁶(C═O)alkyl and R⁵O alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, oxo, cycloalkylidene, heterocyclylidene, alkyl, alkoxy, alkoxyalkyl, R⁵(C═O)—, R⁵O(C═O)—.

In some embodiments, R³ is H, D, alkyl, Cyc, hetCyc, aryl, heteroaryl, Cyc-alkyl, hetCyc-alkyl, alkoxyalkyl, arylalkyl, heteroarylalkyl or aminoalkyl, wherein each of alkyl, Cyc, hetCyc, aryl, heteroaryl, Cyc-alkyl, hetCyc-alkyl, alkoxyalkyl, arylalkyl, heteroarylalkyl and aminoalkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR⁵R⁶, R⁵O—, R⁵O(C═O)—, R⁵(C═O)—, NR⁵R⁶(C═O)NR⁵—, R⁵S(═O)₂—, NO₂, CN, CF₃, alkyl and cycloalkyl.

In some embodiments, R⁴ is H, D, alkyl, F, Cl, Br or alkoxy, wherein each of alkyl and alkoxy is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂.

In some embodiments, R⁵ is H, D, alkyl, Cyc, hetCyc, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxyalkyl, aryloxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, Cyc-alkyl or hetCyc-alkyl, wherein each of alkyl, Cyc, hetCyc, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxyalkyl, aryloxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, Cyc-alkyl and hetCyc-alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR⁶R⁷, alkyl, alkylsulfonyl, alkoxy, aryl and heteroaryl.

In some embodiments, R⁶ is H or alkyl.

In some embodiments, R⁷ is alkyl, arylalkyl or heteroarylalkyl.

In some embodiments, each Cyc is independently cycloalkyl, bridged carbocyclyl or spirocarbocyclyl.

In some embodiments, each hetCyc is independently heterocyclyl, bridged heterocyclyl or spiroheterocyclyl.

In some embodiments, G is H, D, C_1-6 alkyl, 3-12 membered hetCyc, 3-12 membered Cyc, (3-12 membered hetCyc)-C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino-C_1-6 alkyl, di(C_1-6 alkyl)amino-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, R⁵O(C═O)NR⁶C_1-6 alkyl, R⁵(C═O)NR⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkyl, R⁵(C═O)C_1-6 alkyl, NR⁵R⁶(C═O)—, R⁵OC_1-6 alkyl, wherein each of C_1-6 alkyl, 3-12 membered hetCyc, 3-12 membered Cyc, (3-12 membered hetCyc)-C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino-C_1-6 alkyl, di(C_1-6 alkyl)amino-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, and a C_1-6 alkyl moiety in R⁵O(C═O)NR⁶C_1-6 alkyl, R⁵(C═O)NR⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkyl, R⁵(C═O)C_1-6 alkyl and R⁵OC_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, C_1-6 alkyl, C_1-6 alkoxy, C_1-6 alkoxy C_1-6 alkyl, R⁵(C═O)—, R⁵O(C═O)—.

In some embodiments, G is H, D, C_1-4 alkyl, 3-10 membered hetCyc, 3-10 membered Cyc, (3-10 membered hetCyc)-C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl, NR⁵R⁶(C═O)—, R⁵OC_1-4 alkyl, wherein each of C_1-4 alkyl, 3-10 membered hetCyc, 3-10 membered Cyc, (3-10 membered hetCyc)-C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, and a C_1-4 alkyl moiety in R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl, R⁵OC_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, C_1-4 alkyl, C_1-4 alkoxy, C_1-4 alkoxy C_1-4 alkyl, R⁵(C═O)—, R⁵O(C═O)—.

In some embodiments, G is H, D, C_1-4 alkyl, 3-6 membered hetCyc, 3-6 membered Cyc, (3-6 membered hetCyc)-C_1-4 alkyl, (3-6 membered Cyc)-C_1-4 alkyl, (5-6 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl, NR⁵R⁶(C═O)— or R⁵OC_1-4 alkyl, wherein each of C_1-4 alkyl, 3-6 membered hetCyc, 3-6 membered Cyc, (3-6 membered hetCyc)-C_1-4 alkyl, (3-6 membered Cyc)-C_1-4 alkyl, (5-6 membered heteroaryl)-C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino-C_1-4 alkyl, di(C_1-4 alkyl)amino-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, and a C_1-4 alkyl moiety in R⁵O(C═O)NR⁶C_1-4 alkyl, R⁵(C═O)NR⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkyl, R⁵(C═O)C_1-4 alkyl and R⁵OC_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetanylidene, oxetanylidene, pyrrolidinylidene, pyrazolidinylidene, tetrahydrofuranylidene, methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, isobutyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, methoxymethyl, ethoxymethyl, n-propoxymethyl, isopropoxymethyl, methoxyethyl, ethoxyethyl, n-propoxyethyl, isopropoxyethyl, methoxypropyl, ethoxypropyl, n-propoxypropyl, isopropoxypropyl, CH₃(C═O)—, CH₃O(C═O)—, CH₃CH₂O(C═O)—, and (CH₃)₃CO(C═O)—.

In some embodiments, A is 3-12 membered Cyc or 3-12 membered hetCyc, wherein each of 3-12 membered Cyc and 3-12 membered hetCyc is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-12 membered Cyc, 3-12 membered hetCyc, 3-12 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-12 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, A is one of the following sub-formulae:

wherein each Z¹, Z² and Z⁴ is independently CH or N;

each of Z³ and Z⁵ is independently a bond, CH₂, O, S, NH, C═O, S═O or S(═O)₂;

each m is 0, 1, or 2;

each n, m1 and n1 is independently 0 or 1;

each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-4 alkyl, NR⁵R⁶(C═O)C_1-4 alkoxy C_1-4 alkyl, NR⁶R⁷C_1-4 alkoxy, NR⁶R⁷C_1-4 alkoxy C_1-4 alkyl, C_1-4alkyl, C_1-4 haloalkyl, C_1-4 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, 3-10 membered hetCyc-C_1-4 alkoxy C_1-4 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, A is one of the following sub-formulae:

wherein each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-4 alkyl, NR⁶R⁷C_1-4 alkoxy, C_1-4 alkyl, C_1-4 haloalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-4 alkyl, 3-10 membered hetCyc-C_1-4 alkoxy C_1-4 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments, each sub-formula of A is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, OH, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethyl cy clopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene, pyrrolidinylidene and pyrazolidinylidene.

In some embodiments, M is —(C═O)—, C_1-6 alkyl, C_2-6 alkenyl, C_2-6 alkynyl, C_1-6 alkyl-C_6-10 aryl, C_1-6 alkyl-(5-10 membered heteroaryl), C_2-6 alkenyl-C_6-10 aryl, C_2-6 alkynyl-C_6-10 aryl, C_2-6 alkenyl-(5-10 membered heteroaryl), C_2-6 alkynyl-(5-10 membered heteroaryl), C_6-10 aryl, 5-10 membered heteroaryl, 3-12 membered hetCyc, 3-12 membered Cyc, C_6-10 aryl-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl or (3-12 membered Cyc)-C_1-6 alkyl, wherein each of C_1-6 alkyl, C_2-6 alkenyl, C_2-6 alkynyl, C_1-6 alkyl-C_6-10 aryl, C_1-6 alkyl-(5-10 membered heteroaryl), C_2-6 alkenyl-C_6-10 aryl, C_2-6 alkynyl-C_6-10 aryl, C_2-6 alkenyl-(5-10 membered heteroaryl), C_2-6 alkynyl-(5-10 membered heteroaryl), C_6-10 aryl, 5-10 membered heteroaryl, 3-12 membered hetCyc, 3-12 membered Cyc, C_6-10 aryl-C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl and (3-12 membered Cyc)-C_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NR⁵R⁶, oxo, C_1-6 alkoxy, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, hydroxy C_1-6 alkyl, C_1-6 alkyl, C_3-6 cycloalkyl, C_3-6 cycloalkyl C_2-6 alkynyl and 3-7 membered heterocyclic group.

In some embodiments, M is —(C═O)—, C_1-4 alkyl, C_2-4 alkenyl, C_2-4 alkynyl, C_1-4 alkylphenyl, C_1-4 alkyl-(5-10 membered heteroaryl), C_2-4 alkenylphenyl, C_2-4 alkynylphenyl, C_2-4 alkenyl-(5-10 membered heteroaryl), C_2-4 alkynyl-(5-10 membered heteroaryl), phenyl, 5-10 membered heteroaryl, 3-10 membered hetCyc, 3-10 membered Cyc, phenyl-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4-alkyl or (3-10 membered Cyc)-C_1-4 alkyl, wherein each of C_1-4 alkyl, C_2-4 alkenyl, C_2-4 alkynyl, C_1-4 alkylphenyl, C_1-4 alkyl-(5-10 membered heteroaryl), C_2-4 alkenylphenyl, C_2-4 alkynylphenyl, C_2-4 alkenyl-(5-10 membered heteroaryl), C_2-4 alkynyl-(5-10 membered heteroaryl), phenyl, 5-10 membered heteroaryl, 3-10 membered hetCyc, 3-10 membered Cyc, phenyl-C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4-alkyl and (3-10 membered Cyc)-C_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NR⁵R⁶, oxo, C_1-4 alkoxy, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene, hydroxy C_1-4 alkyl, C_1-4 alkyl, C_3-6 cycloalkyl, C_3-6 cycloalkyl C_2-4 alkynyl and 3-6 membered heterocyclic group.

In some embodiments, M is —(C═O)—, —CH₂—, —(CH₂)₂—, —(CH₂)₃—, —(CH₂)₄—, —CH═CH₂—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —C≡C—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —CH═CH-phenyl, —CH₂CH═CH-phenyl, —CH₂CH═CH—CH₂-phenyl, —C≡C-phenyl, —CH₂C≡C-phenyl, —CH₂C≡C—CH₂-phenyl, —CH═CH-pyridyl, —CH₂CH═CH-pyridyl, —CH₂CH═CH—CH₂-pyridyl, —CH═CH-pyrazolyl, —CH₂CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, —C≡C-pyridyl, —CH₂C≡C-pyridyl, —CH₂C≡C—CH₂-pyridyl, —C≡C-pyrazolyl, —CH₂C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, phenyl, pyridyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, furyl, thienyl, —CH₂-pyridyl, —CH₂CH₂-pyridyl, —CH₂-phenyl, —CH₂CH₂-phenyl, —CH₂-pyrimidinyl, —CH₂-pyrazinyl, —CH₂-imidazolyl, —CH₂-pyrazolyl, phenyl-CH₂—, phenyl-CH₂CH₂—, pyridyl-CH₂—, pyridyl-CH₂CH₂—, pyrimidinyl-CH₂—, pyrazinyl-CH₂—, imidazolyl-CH₂— or pyrazolyl-CH₂—, wherein each of —CH₂—, —(CH₂)₂—, —(CH₂)₃—, —(CH₂)₄—, —CH═CH₂—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —C≡C—, —CH₂CH≡CH—, —CH₂CH≡CHCH₂—, —CH═CH-phenyl, —CH₂CH═CH-phenyl, —CH₂CH═CH—CH₂-phenyl, —C≡C-phenyl, —CH₂C≡C-phenyl, —CH₂C≡C—CH₂-phenyl, —CH═CH-pyridyl, —CH₂CH═CH-pyridyl, —CH₂CH═CH—CH₂-pyridyl, —CH═CH-pyrazolyl, —CH₂CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, —C≡C-pyridyl, —CH₂C≡C-pyridyl, —CH₂C≡C—CH₂-pyridyl, —C≡C-pyrazolyl, —CH₂C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, phenyl, pyridyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, furyl, thienyl, —CH₂-pyridyl, —CH₂CH₂-pyridyl, —CH₂-phenyl, —CH₂CH₂-phenyl, —CH₂-pyrimidinyl, —CH₂-pyrazinyl, —CH₂-imidazolyl, —CH₂-pyrazolyl, phenyl-CH₂—, phenyl-CH₂CH₂—, pyridyl-CH₂—, pyridyl-CH₂CH₂—, pyrimidinyl-CH₂—, pyrazinyl-CH₂—, imidazolyl-CH₂— and pyrazolyl-CH₂— is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF₃, NH₂, oxo, methoxy, ethoxy, n-propoxy, isopropoxy, cyclopropylidene, cyclobutylidene, cyclopentylidene, azetidinylidene, hydroxymethyl, hydroxyethyl, 2-hydroxy-2-propyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylethynyl, pyrrolidinyl and morpholinyl.

In some embodiments, R³ is H, D, C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, (3-12 membered Cyc)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl) C_1-6 alkyl or amino C_1-6 alkyl, wherein each of C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, (3-12 membered Cyc)-C_1-6 alkyl, (3-12 membered hetCyc)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl) C_1-6 alkyl and amino C_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR⁵R⁶, R⁵O—, R⁵O(C═O)—, R⁵(C═O)—, NR⁵R⁶(C═O)NR⁵—, R⁵S(═O)₂—, NO₂, CN, CF₃, C_1-6 alkyl and C_3-6 cycloalkyl.

In some embodiments, R³ is H, D, C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, (3-10 membered Cyc)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl or amino C_1-4 alkyl, wherein each of C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, (3-10 membered Cyc)-C_1-4 alkyl, (3-10 membered hetCyc)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl and amino C_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR⁵R⁶, R⁵O—, R⁵O(C═O)—, R⁵(C═O)—, NR⁵R⁶(C═O)NR⁵—, R⁵S(═O)₂—, NO₂, CN, CF₃, C_1-4 alkyl and C_3-6 cycloalkyl.

In some embodiments, R³ is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopropylmethyl, cyclobutylmethyl, cyclohexylmethyl, spiro[4.4]decylmethyl, bicyclo[3.3.0]octyl, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, azetidinylmethyl, piperidinylmethyl, morpholinylmethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, isopropoxymethyl, isopropoxyethyl, n-butoxymethyl, isobutoxymethyl, tert-butoxymethyl, tert-butoxyethyl, phenyl, pyridyl, imidazolyl, pyrazolyl, pyrimidinyl, 3H-indolyl, indolyl, benzimidazolyl, 3,8a-dihydroindolizinyl, phenylmethyl, 3,8a-dihydroindolizinyl methyl, pyridylmethyl, imidazolylmethyl, pyrazolylmethyl, pyrimidinylmethyl, 3H-indolylmethyl, indolylmethyl, benzimidazolylmethyl, NH₂CH₂—, NH(CH₃)CH₂—, N(CH₃)₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂— or N(CH₃)₂(CH₂)₂—, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopropylmethyl, cyclobutylmethyl, cyclohexylmethyl, spiro[4.4]decylmethyl, bicyclo[3.3.0]octyl, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, azetidinylmethyl, piperidinylmethyl, morpholinylmethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, isopropoxymethyl, isopropoxyethyl, n-butoxymethyl, isobutoxymethyl, tert-butoxy methyl, tert-butoxyethyl, phenyl, pyridyl, imidazolyl, pyrazolyl, pyrimidinyl, 3H-indolyl, indolyl, benzimidazolyl, 3,8a-dihydroindolizinyl, phenylmethyl, 3,8a-dihydroindolizinyl methyl, pyridylmethyl, imidazolylmethyl, pyrazolylmethyl, pyrimidinylmethyl, 3H-indolylmethyl, indolylmethyl, benzimidazolylmethyl, NH₂CH₂—, NH(CH₃)CH₂—, N(CH₃)₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂— and N(CH₃)₂(CH₂)₂— is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NH₂, NO₂, CN, CF₃, C(CH₃)₃O(C═O)—, CH₃(C═O)—, NH₂(C═O)NH—, NHCH₃(C═O)NH—, CH₃S(═O)₂—, methyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenoxy, pyridyloxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl.

In some embodiments, R¹ is H, D, CN, F, Cl, Br, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, vinyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, vinyl, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂.

In some embodiments, R⁴ is H, D, F, Cl, Br, CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butylmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butylmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy and tert-butoxy is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH₂, OH and NO₂.

In some embodiments, R⁵ is H, D, C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryloxy C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino C_1-6 alkyl, di(C_1-6 alkyl)amino C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl or (3-12 membered hetCyc)-C_1-6 alkyl, wherein each of C_1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C_6-10 aryl, 5-10 membered heteroaryl, C_6-10 aryl C_1-6 alkyl, (5-10 membered heteroaryl)-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, C_6-10 aryloxy C_1-6 alkyl, amino C_1-6 alkyl, C_1-6 alkylamino C_1-6 alkyl, di(C_1-6 alkyl)amino C_1-6 alkyl, (3-12 membered Cyc)-C_1-6 alkyl and (3-12 membered hetCyc)-C_1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR⁶R⁷, C_1-6 alkyl, C_1-6 alkylsulfonyl, C_1-6 alkoxy, C_6-10 aryl and 5-10 membered heteroaryl.

In some embodiments, R⁶ is H, D or C_1-6 alkyl.

In some embodiments, R⁷ is H, D, C_1-6 alkyl, C_6-10 aryl C_1-6 alkyl or (5-10 membered heteroaryl) C_1-6 alkyl.

In some embodiments, R⁵ is H, D, C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenoxy C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino C_1-4 alkyl, di(C_1-4 alkyl)amino C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl or hetCyc-C_1-4 alkyl, wherein each of C_1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, phenyl C_1-4 alkyl, (5-10 membered heteroaryl)-C_1-4 alkyl, C_1-4 alkoxy C_1-4 alkyl, phenoxy C_1-4 alkyl, amino C_1-4 alkyl, C_1-4 alkylamino C_1-4 alkyl, di(C_1-4 alkyl)amino C_1-4 alkyl, (3-10 membered Cyc)-C_1-4 alkyl and hetCyc-C_1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR⁶R⁷, C_1-6 alkyl, C_1-4 alkylsulfonyl, C_1-4 alkoxy, phenyl and 5-10 membered heteroaryl.

In some embodiments, R⁶ is H, D or C_1-4 alkyl.

In some embodiments, R⁷ is H, D, C_1-4 alkyl, phenyl C_1-4 aryl or (5-10 membered heteroaryl) C_1-4 alkyl.

In some embodiments, R⁵ is H, D, NH₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂—, N(CH₃)₂CH₂—, NH(CH₃)₂(CH₂)₂—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylethyl, cyclobutyl methyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methoxymethyl, methoxyethyl, ethoxyethyl, phenylmethyl, phenylethyl, phenyl-n-propyl, pyridylmethyl, pyridylethyl, pyridyl-n-propyl, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, azetidinyl, oxetanyl or tetrahydropyranyl, wherein each of NH₂CH₂—, NH₂(CH₂)₂—, NH(CH₃)CH₂—, NH(CH₃)(CH₂)₂—, N(CH₃)₂CH₂—, NH(CH₃)₂(CH₂)₂—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclopropyl ethyl, cyclobutyl ethyl, cyclobutylmethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methoxymethyl, methoxyethyl, ethoxyethyl, phenylmethyl, phenylethyl, phenyl-n-propyl, pyridylmethyl, pyridylethyl, pyridyl-n-propyl, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, azetidinyl, oxetanyl and tetrahydropyranyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NH₂, NH(CH₃), CH₃S(═O)₂—, CH₃CH₂S(═O)₂—, CH(CH₃)₂S(═O)₂—, C(CH₃)₃S(═O)₂—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, n-propoxy, phenyl, pyridyl, pyrazolyl and pyrimidinyl.

In some embodiments, R⁶ is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

In some embodiments, R⁷ is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenylmethyl, phenylethyl, phenyl-n-propyl, imidazolylmethyl, pyrazolylmethyl, pyridylmethyl, pyridylethyl, pyrimidinylmethyl or pyrimidinylethyl.

In some embodiments, the present invention provides a compound having Formula (I-1), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

each Z¹ and Z² is independently CH or N;

each of Z³, Z⁵ is independently a bond, CH₂, O, S, NH, C═O, S═O or S(═O)₂;

m is 0, 1 or 2;

is optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments,

is one of the following sub-formulae:

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl(C═O)NH—, pyridylmethyl(C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene or pyrazolylidene.

In some embodiments, the present invention provides a compound having Formula (I-1a), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

each of Z¹ and Z² is independently CH or N;

is optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments,

is one of the following sub-formulae:

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene and pyrazolidinylidene.

In some embodiments, the present invention provides a compound having Formula (I-2), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

A₁ is one of the following sub-formulae:

each Z¹ and Z² is independently CH or N;

each sub-formula of A₁ is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene, 3-6 membered heterocyclylidene.

In some embodiments,

A₁ is one of the following sub-formulae:

wherein each sub-formula of A₁ is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene and pyrazolidinylidene.

In some embodiments, the present invention provides a compound having Formula (I-3), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of Z¹, Z² and Z⁴ is independently CH or N;

m is 0, 1, or 2;

each n, m1 and n1 is independently 0 or 1;

is optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments,

is one of the following sub-formulae;

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene and pyrazolylidene.

In some embodiments, the present invention provides a compound having Formula (I-4), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

wherein each of R¹, G, X¹, X², X³, X⁴, X⁵, E, Q, M and R³ is as defined herein;

wherein each of Z¹ and Z² is independently CH or N;

m is 0, 1, or 2;

each n, m1 and n1 is independently 0 or 1;

is optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR⁵R⁶, R⁵O—, R⁵(C═O)NR⁶—, NR⁵R⁶C_1-6 alkyl, NR⁵R⁶(C═O)C_1-6 alkoxy C_1-6 alkyl, NR⁶R⁷C_1-6 alkoxy, NR⁶R⁷C_1-6 alkoxy C_1-6 alkyl, C_1-6alkyl, C_1-6 haloalkyl, C_1-6 hydroxyalkyl, 3-10 membered Cyc, 3-10 membered hetCyc, 3-10 membered hetCyc-C_1-6 alkyl, C_1-6 alkoxy C_1-6 alkyl, 3-10 membered hetCyc-C_1-6 alkoxy C_1-6 alkyl, C_3-6 cycloalkylidene and 3-6 membered heterocyclylidene.

In some embodiments,

is one of the following sub-formulae:

wherein each sub-formula of

is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NH₂, NHCH₃, NH(CH₂)₃CH₃, N(CH₃)₂, benzyl OCH₂NH—, benzyl (C═O)NH—, pyridylmethyl (C═O)NH—, CH₃CH₂(C═O)NH—, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, phenoxy-(CH₂)₂O—, NH₂(CH₂)₂O—, N(CH₃)₂(CH₂)₂O—, 1-ethylcyclopropylmethyl, fluoropyridylethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, pyrrolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl, methyl, ethyl, propyl, monofluoromethyl, difluoromethyl, trifluoromethyl, monochloromethyl, dichloromethyl, trichloromethyl, 1,2-dichloroethyl, 1,2-difluoroethyl, hydroxymethyl, hydroxyethyl, pyrrolidinylidene, methoxymethyl, methoxyethyl, ethoxymethyl, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetidinylidene, oxetanylidene and pyrazolylidene.

In some embodiments, the compound described herein has one of the following structures, or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

In another aspect, the invention provides a pharmaceutical composition comprising a compound of the invention, and a pharmaceutically acceptable adjuvant.

In other aspect, provided herein is use of the compound or the pharmaceutical composition disclosed herein in the manufacture of a medicament for preventing or treating a RET-related disease.

In some embodiments, the RET-related diseases include cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

In other aspect, provided herein is use of the compound or the pharmaceutical composition disclosed herein for preventing or treating a RET-related disease.

In some embodiments, the RET-related diseases include cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

In another aspect, the invention provides a method of preventing or treating a RET-related disease, wherein the method comprises administering to a patient a therapeutically effective amount of a compound of the invention or a pharmaceutical composition thereof.

In some embodiments, the RET-related diseases include cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

In other aspect, the invention relates to the intermediate for the preparation of a compound of Formula (I), (I-1), (I-1a), (I-2), (I-3) or (I-4).

In another aspect, provided herein are methods for preparing, separating, and purifying the compound of formula (I), (I-1), (I-1a), (I-2), (I-3) or (I-4).

In another aspect, the invention provides a pharmaceutical composition comprising a compound of the invention, and a pharmaceutically acceptable adjuvant. In some embodiments, adjuvants described herein include, but are not limited to, carriers, excipients, diluents, vehicles, or combinations thereof. In some embodiments, the pharmaceutical composition can be in the form of a liquid, solid, semi-solid, gel or spray.

The invention is also provided a method of inhibiting cell proliferation in vitro or in vivo, the method comprising contacting a cell with an effective amount of a compound of the invention or a pharmaceutical composition thereof.

The invention is also provided a method of treating irritable bowel syndrome (IBS) and/or pain associated with IBS in a patient in need of treatment, the method comprising administering to the patient a therapeutically effective amount of a compound of the invention or a pharmaceutical composition thereof.

Also provided herein is use of the compound or the pharmaceutical composition disclosed herein in the manufacture of a medicament for preventing or treating irritable bowel syndrome (IBS) and/or pain associated with IBS.

Also provided herein is use of the compound or the pharmaceutical composition disclosed herein for preventing or treating irritable bowel syndrome (IBS) and/or pain associated with IBS.

Unless otherwise stated, all stereoisomers, geometric isomers, tautomers, N-oxides, hydrates, solvates, metabolites, salts and pharmaceutically acceptable prodrugs of the compounds disclosed herein are within the scope of the invention.

In particular, the salt is a pharmaceutically acceptable salt. The phrase “pharmaceutically acceptable” refers to that the substance or composition must be compatible chemically and/or toxicologically, with the other ingredients comprising a formulation, and/or the mammal being treated therewith.

Salts of the compounds disclosed herein also include salts of the compounds which are not necessarily pharmaceutically acceptable salts, and which may be useful as intermediates for preparing and/or purifying compounds of Formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4) and/or for separating enantiomers of compounds of Formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4).

In the structures disclosed herein, when the stereochemistry of any particular chiral atom is not indicated, all stereoisomers of the structure are contemplated within the invention, and as disclosed herein are included in the present invention. When stereochemistry is indicated by a solid wedge or dashed line representing a particular configuration, the stereoisomer of the structure is defined.

N-oxides of the compound disclosed herein are also included in the invention. N-oxides of the compound of the invention can be prepared by oxidizing corresponding nitrogen-containing alkaline substances with common oxidants (e.g., hydrogen peroxide) under a rising temperature in the presence of an acid, such as acetic acid, or by reacting with peracid in a suitable solvent, e.g., by reacting with peracetic acid in dichloromethane, ethyl acetate or methyl acetate, or by reacting with 3-chloroperoxybenzoic acid in chloroform or dichloromethane.

If the compound disclosed herein is a base, the desired salt can be prepared by any suitable method available in the art, for example, treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like, or with an organic acid, such as acetic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic acid, oxalic acid, glycolic acid and salicylic acid; a pyranosidyl acid, such as glucuronic acid and galacturonic acid; an alpha-hydroxy acid, such as citric acid and tartaric acid; an amino acid, such as aspartic acid and glutamic acid; an aromatic acid, such as benzoic acid and cinnamic acid; a sulfonic acid, such as p-toluenesulfonic acid, ethanesulfonic acid and the like.

If the compound disclosed herein is an acid, the desired salt may be prepared by any suitable method, for example, treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal hydroxide, ammonium or alkaline earth metal hydroxide, and the like. Some non-limiting examples of suitable salts include organic salts derived from amino acids, such as glycine and arginine; ammonia, such as primary, secondary and tertiary amine and cyclic amines, such as piperidine, morpholine and piperazine, and inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum, lithium, and the like.

Compounds of the Invention and Pharmaceutical Compositions, Preparations, Administration

The present invention provides a compound of the present invention or a pharmaceutical composition thereof which inhibits wild-type RET and RET mutants, for example, RET mutants which are resistant to current standard care treatments (“RET resistance mutant”). In addition, the compounds of the invention or pharmaceutical compositions thereof may be selective for wild-type RET relative to other kinases, resulting in reduced toxicity associated with inhibition of other kinases.

The pharmaceutical composition of the present invention comprises a compound having Formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4), a compound listed in the present invention, or a compound of the examples. The amount of the compound in the composition of the present invention is effective to treat or ameliorate a patient's RET-related disease or condition, including RET-related cancer, irritable bowel syndrome, and/or pain associated with irritable bowel syndrome.

As described above, the pharmaceutically acceptable compositions disclosed herein further comprise a pharmaceutically acceptable adjuvant, which, as used herein, includes any and all solvents, diluents, or other liquid vehicle, dispersion or suspension aids, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, solid binders, lubricants and the like, as suited to the particular dosage form desired. As described in the following: In Remington: The Science and Practice of Pharmacy, 21st edition, 2005, ed. D. B. Troy, Lippincott Williams& Wilkins, Philadelphia, and Encyclopedia of Pharmaceutical Technology, eds. J. Swarbrick and J. C. Boylan, 1988-1999, Marcel Dekker, New York, both of which are herein incorporated by reference in their entireties, discloses various adjuvants used in formulating pharmaceutically acceptable compositions and known techniques for the preparation thereof. Except insofar as any conventional adjuvants incompatible with the compounds disclosed herein, such as by producing any undesirable biological effect or otherwise interacting in a deleterious manner with any other components of the pharmaceutically acceptable composition, its use is contemplated to be within the scope of this invention.

In preparing the compositions provided herein, the active ingredient is usually mixed with excipients, diluted by excipients or enclosed in such carriers, for example, in the form of capsules, sachets, paper or other containers. If the excipient is used as a diluent, it can be a solid, semi-solid or liquid material which acts as a vehicle, carrier or medium for the active ingredient. Suitable carriers include, but are not limited to, magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, low melting point wax, cocoa butter, etc. Therefore, the composition may be in the form of a tablet, a pill, a powder, a troche, a sachet, a flat capsule, an elixir, a suspension, an emulsion, a solution, a syrup, an aerosol (solid form or in a liquid medium), an ointment which for example contains up to 10% by weight of active compound, soft and hard gelatin capsules, a suppository, a sterile injectable solution, and a aseptically packaged powder. In one embodiment, the composition is formulated for oral administration. In one embodiment, the composition is formulated as a tablet or capsule.

When it is possible that, for use in therapy, therapeutically effective amounts of the compounds of the invention, especially the compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4), as well as pharmaceutically acceptable salts thereof, may be administered as the raw chemical, it is possible to present the active ingredient as a pharmaceutical composition. Therefore, the invention further provides pharmaceutical compositions, which comprise therapeutically effective amounts of the compounds of the present invention, especially the compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4) or pharmaceutically acceptable salts thereof, and one or more pharmaceutically acceptable adjuvants, including but not limited to carriers, diluents or excipients, and the like. The term “therapeutically effective amount,” as used herein, refers to the total amount of each active component that is sufficient to show a meaningful patient benefit (such as a decrease in cancer cells). When applied to an individual active ingredient, administered alone, the term refers to that ingredient alone. When applied to a combination, the term refers to combined amounts of the active ingredients that result in the therapeutic effect, whether administered in combination, serially, or simultaneously. The compounds of the invention, especially the compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4), and pharmaceutically acceptable salts thereof are as described above. The carrier(s), diluent(s), or excipient(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. In accordance with another aspect of the present disclosure there is also provided a process for the preparation of a pharmaceutical formulation including admixing the compounds of the invention, in particular the compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4), or pharmaceutically acceptable salts thereof, with one or more pharmaceutically acceptable carriers, diluents, or excipients. The term “pharmaceutically acceptable,” as used herein, refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contacting with the tissues of patients without excessive toxicity, irritation, allergic response, or other problem or complication commensurate with a reasonable benefit/risk ratio, and are effective for their intended use.

The amount of active ingredient combined with one or more adjuvants to produce a single dosage form will necessarily vary depending upon the host treated and the particular route of administration. The amount of the active ingredient of the compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4) mixed with the carrier material to prepare a single dosage form will vary depending upon the disease to be treated, the severity of the disease, the time of administration, the route of administration, the rate of excretion of the compound used, the time of treatment, and the age, sex, weight and condition of the patient. Preferred unit dosage forms are unit dosage forms containing a daily or divided dose of the active ingredient described herein, or a suitable fraction thereof. Treatment can be initiated with a small dose that is clearly below the optimal dose of the compound. Thereafter, the dose is increased in smaller increments until the best results are achieved in this case. In general, the level of concentration at which the compound is most desirably administered generally provides an effective result in anti-tumor without causing any harmful or toxic side effects.

Compositions comprising a compound of the invention may be formulated in unit dosage form, each containing from about 5 to about 1,000 mg (1 g), more typically from about 100 mg to about 500 mg of the active ingredient. The term “unit dosage form” refers to physically discrete units suitable for use as a single dose in a human subject or other patient, each unit containing a predetermined amount of active material (i.e., a compound of formula I as provided herein) and a suitable pharmaceutical excipient, wherein the predetermined amount is calculated to produce the desired therapeutic effect.

In some embodiments, the compositions provided herein contain from about 5 mg to about 50 mg of the active ingredient. Those of ordinary skill in the art will appreciate that this encompasses a compound or composition comprising from about 5 mg to about 10 mg, from about 10 mg to about 15 mg, from about 15 mg to about 20 mg, from about 20 mg to about 25 mg, from about 25 mg to about 30 mg, from about 30 mg to about 35 mg, from about 35 mg to about 40 mg, from about 40 mg to about 45 mg or from about 45 mg to about 50 mg of the active ingredient.

In some embodiments, the compositions provided herein contain from about 50 mg to about 500 mg of the active ingredient. Those of ordinary skill in the art will appreciate that this encompasses a compound or composition comprising from about 50 mg to about 100 mg, from about 100 mg to about 150 mg, from about 150 mg to about 200 mg, from about 200 mg to about 250 mg, from about 250 mg to about 300 mg, from about 350 mg to about 400 mg, from about 400 mg to about 450 mg or from about 450 mg to about 500 mg of the active ingredient.

In some embodiments, the compositions provided herein contain from about 500 mg to about 1000 mg of the active ingredient. Those of ordinary skill in the art will appreciate that this encompasses a compound or composition comprising from about 500 mg to about 550 mg, from about 550 mg to about 600 mg, from about 600 mg to about 650 mg, from about 650 mg to about 700 mg, from about 700 mg to about 750 mg, from about 750 mg to about 800 mg, from about 800 mg to about 850 mg, from about 850 mg to about 900 mg, from about 900 mg to about 950 mg or from about 950 mg to about 1000 mg of the active ingredient.

The pharmaceutical compositions are suitable for administration by any suitable route, for example by oral administration (including buccal or sublingual), rectal, nasal, topical (including buccal, sublingual or transdermal), vaginal or parenteral (including subcutaneous, intradermal, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional, intravenous or subdermal injection or infusion). Such formulations may be prepared by any method known in the art of pharmacy, for example by mixing the active ingredient with carriers or excipients. Oral administration or injection administration is preferred.

The invention also provides a method of treating an individual having a RET-related cancer, the method comprising administering a compound of the invention before, during or after administration of another anti-cancer drug (e.g., not a compound of the invention).

The invention provides a method for treating cancer in a patient in need thereof, the method comprising: (a) determining whether the cancer in the patient is a RET-related cancer (e.g., RET-related cancers including RET-related cancers with one or more RET inhibitor resistance mutations)(for example, using a regulatory agency-approved, e.g., FDA-approved, kit to identify RET genes, RET kinases, or any one of the expression, activity or dysregulation in a patient's biopsy sample, or by performing any non-limiting examples of the invention described herein); (b) if the cancer is determined to be a RET-related cancer, a therapeutically effective amount of a compound of formula (I), (I-1a), (I-1), (I-2), (I-3), or (I-4) or a pharmaceutically acceptable salt or solvate thereof or a pharmaceutical composition thereof is administered to the patient. Some embodiments of these methods further comprise administering to the subject another anti-cancer agent (e.g., another RET inhibitor, e.g., a RET inhibitor that is not a compound of the invention). In some embodiments, the subject has been previously treated with a RET inhibitor that is not a compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4) or a pharmaceutically acceptable salt or solvate thereof, or has been previously treated (e.g., after removal of a tumor or radiation therapy) with other anti cancer agents.

In some embodiments of any of the methods described herein, the compound of formula (I), (I-1a), (I-1), (I-2), (I-3), or (I-4) (or a pharmaceutically acceptable salt or solvate thereof) is administered in combination with a therapeutically effective amount of at least one other therapeutic agent selected from one or more other therapies or therapeutic (e.g., chemotherapeutic) reagents.

Non-limiting examples of other therapeutic agents include: other RET targeted therapeutic agents (i.e., other RET kinase inhibitors: RET inhibitors that are not the compounds of the invention), receptor tyrosine kinase targeted therapeutic agents, signal transduction pathway inhibitors, checkpoint inhibitors, apoptotic pathway regulators (e.g., Obataclax); cytotoxic chemotherapeutic agents, angiogenesis targeted therapeutic agents, immunotargeting agents and radiation therapy.

In some embodiments, other RET targeted therapeutic agents are multi-kinase inhibitors that exhibit RET inhibitory activity.

Non-limiting examples of RET targeted therapeutic agents include alatinib, apatinib, cabozantinib (XL-184), vittinib, levabrinib, morsani, nidanib, punatinib, regrafenib, sitravatinib (MGCD516), sunitinib, sorafenib, vatalani, vandetanib, AUY-922(5-(2,4-dihydroxy-5-isopropyl-phenyl)-N-ethyl-4-[4-(morpholinomethyl)phenyl]isoxazole-3-formamide), BLU6864, BLU-667, DCC-2157, NVP-AST487(1-[4-[(4-ethylpiperazin-1-yl)methyl]-3-(trifluoromethyl) phenyl]-3-[4-[6-(methylamino)pyrimidine-4-yl]oxyphenyl]urea), PZ-1, RPI-1 (1,3-dihydro-5,6-dimethoxy-3-[(4-hydroxyphenyl)methylene]-H-indole-2-one), RXDX-105 (1-(3-(6,7-dimethoxyquinazolin-4-yl)oxy)phenyl)-3-(5-(1,1,1-trifluoro-2-methylpropane)-2-yl)isoxazol-3-yl)urea), SPP86 (1-isopropyl-3-(phenylethynyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine) and TG101209 (N-(1,1-dimethylethyl))-3-[[5-methyl-2-[[4-(4-methyl-1-piperazinyl)phenyl]amino]-4-pyrimidinyl]amino]benzenesulfonamide).

Other therapeutic agents include RET inhibitors such as those described, for example, in U.S. Pat. Nos. 7,504,509; 8,299,057; 8,399,442; 8,067,434; 8,937,071; 9,006,256; and 9,035,063; U.S. Publication No. 2014/0121239; 20160176865; 2011/0053934; 2011/0301157; 2010/0324065; 2009/0227556; 2009/0130229; 2009/0099167; 2005/0209195; International Publication No. WO 2014/184069; WO 2014/072220; WO 2012/053606; WO 2009/017838; WO 2008/031551; WO 2007/136103; WO 2007/087245; WO2007/057399; WO 2005/051366; WO 2005/062795; and WO 2005/044835; and J. Med. Chem. 2012, 55(10), 4872-4876, all of which are incorporated herein by reference in its entirety.

Also provided herein is a method of treating cancer comprising administering to a patient in need thereof a pharmaceutical combination for treating cancer comprising (a) a compound of formula I or a pharmaceutically acceptable salt or solvate thereof, (b) other treatments, and (c) optionally at least one pharmaceutically acceptable carrier for simultaneous, separate or sequential use in the treatment of cancer, wherein the amount of the compound of formula I, or a pharmaceutically acceptable salt or solvate thereof, and the amount of other therapeutic agent are collectively effective in treating cancer.

The compounds and compositions described herein can be administered alone or in combination with other compounds (including other RET modulating compounds) or other therapeutic agents. In some embodiments, the compounds or compositions of the invention can be administered in combination with one or more compounds selected from the group consisting of: cabozantinib (COMETRIQ), vandetanib (CALPRESA), sorafenib (NEXAVAR), sunitinib (SUTENT), regrafenib (STAVARGA), punatinib (ICLUSIG), bevacizumab (Avastin), crizotinib (XALKORI) or gefitinib (IRESSA). The compounds or compositions of the invention may be administered simultaneously or sequentially with other therapeutic agents by the same or different routes of administration. The compounds of the invention may be included in a single formulation or in separate formulations with other therapeutic agents.

In some embodiments, the compounds of the invention are useful for treating irritable bowel syndrome (IBS) in combination with one or more other therapeutic agents or therapies which are effective in the treatment of irritable bowel syndrome by acting on the same or different mechanisms of action. According to standard pharmaceutical practice known to those skilled in the art, at least one additional therapeutic agent may be as part of the same or separate dosage form, administered via the same or different routes, and administered according to the same or different administration schedule with the compound of formula I, or a pharmaceutically acceptable salt or solvate thereof. Non-limiting examples of other therapeutic agents for treating irritable bowel syndrome (IBS) include probiotics, fiber supplements (e.g., psyllium, methylcellulose), antidiarrheals (e.g., loperamide), bile acid binders (e.g., cholestyramine, colestipol, colesevelam), anticholinergics and anticonvulsants (e.g., hyoscyamine, bicyclic amines), antidepressants (e.g., tricyclic antidepressants such as imipramine or nortriptyline, or selective serotonin reuptake inhibitors (SSRI) such as fluoxetine or paroxetine), antibiotics (such as rifaximin), alosetron and lubiprostone.

Use of the Compounds and Pharmaceutical Compositions

The present invention also provides the use of the compound or the pharmaceutical composition disclosed herein in the manufacture of a medicament for preventing or treating a RET-related disease or disorder, wherein the RET-related disease or disorder includes a RET-related cancer, irritable bowel syndrome and/or pain associated with irritable bowel syndrome.

The present invention provides a compound of the present invention or a pharmaceutical composition thereof which inhibits wild-type RET and RET mutants, for example, RET mutants which are resistant to current standard care treatments (“RET resistance mutant”). In addition, the compounds of the invention or pharmaceutical compositions thereof may be selective for wild-type RET relative to other kinases, resulting in reduced toxicity associated with inhibition of other kinases.

The present invention provides the use of a compound of the present invention or a pharmaceutical composition thereof for inhibiting wild-type RET and RET mutants of the present invention in the manufacture of a medicament for preventing or treating a wild-type RET and RET mutant-related disease or disorder.

In some embodiments of any of the methods or uses described herein, the cancer (e.g., RET-related cancer) is a hematological cancer. In some embodiments of any of the methods or uses described herein, the cancer (e.g., RET-related cancer) is a solid tumor. In some embodiments of any of the methods or uses described herein, the cancer (e.g., RET-related cancer) is a lung cancer (e.g., small cell lung cancer or non-small cell lung cancer), papillary thyroid cancer, medullary thyroid carcinoma, differentiated thyroid gland cancer, recurrent thyroid cancer, refractory differentiated thyroid cancer, lung adenocarcinoma, bronchiolar lung cancer, type 2A or 2B multiple endocrine tumors (MEN2A or MEN2B, respectively), pheochromocytoma, parathyroid hyperplasia, mammary gland cancer, colorectal cancer (e.g., metastatic colorectal cancer), papillary renal cell carcinoma, ganglion cell tumor of the gastrointestinal mucosa, inflammatory myofibroblastic tumor or cervical cancer. In some embodiments of any of the methods or uses described herein, the cancer (e.g., RET-related cancer) is selected from the group consisting of: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), juvenile cancer, adrenocortical carcinoma, anal cancer, appendix cancer, astrocytoma, atypical teratoma/rhabdoid tumor, basal cell carcinoma, cholangiocarcinoma, bladder cancer, bone cancer, brainstem glioma, brain tumor, breast cancer, bronchial neoplasm, Burkitt's lymphoma, carcinoid tumor, unknown primary cancer, cardiac tumor, cervical cancer, childhood cancer, chordoma, chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), chronic myeloproliferative neoplasms, colon cancer, colorectal cancer, craniopharyngioma, cutaneous T-cell lymphoma, cholangiocarcinoma, ductal carcinoma in situ, embryonal tumor, endometrial cancer, ependymoma, esophageal cancer, sensory neuroblastoma, ewing sarcoma, extracranial germ cell tumor, extragonadal germ cell tumor, extrahepatic cholangiocarcinoma, eye cancer, fallopian tube cancer, bone fibrous histiocytoma, gallbladder cancer, gastric cancer, gastrointestinal carcinoid tumor, gastrointestinal stromal tumor (GIST), germ-cell tumor, gestational trophoblastic disease, glioma, hairy cell tumor, hairy cell leukemia, head and neck cancer, heart cancer, hepatocellular carcinoma, histiocytosis, Hodgkin's lymphoma, hypopharyngeal carcinoma, intraocular melanoma, islet cell tumor, pancreatic neuroendocrine tumor, Kaposi's sarcoma, kidney cancer, Langerhans cell histiocytosis, laryngeal cancer, leukemia, lip and oral cancer, liver cancer, lung cancer, lymphoma, macroglobulinemia, bone malignant fibrous histiocytoma, bone cancer, melanoma, Merkel cell carcinoma, mesothelioma, metastatic squamous neck carcinoma, midline cancer, oral cancer, multiple endocrine neoplasia syndrome, multiple myeloma, mycosis fungoides granuloma, myelodysplastic syndrome, myelodysplasia/myeloproliferative neoplasms, myeloid leukemia, myeloid leukemia, multiple myeloma, myeloproliferative neoplasms, nasal and sinus cancer, nasopharyngeal carcinoma, neurocytoma, non-Hodgkin's lymphoma, non-small cell lung cancer, oral cancer, mouth cancer, lip cancer, oropharyngeal cancer, osteosarcoma, ovarian cancer, pancreatic cancer, papillomatosis, paraganglioma, paranasal sinus and nasal cancer, parathyroid carcinoma, penile cancer, pharyngeal carcinoma, pheochromocytoma, pituitary cancer, plasmacytoma, pleural lung blastoma, pregnancy and breast cancer, primary central nervous system lymphoma, primary peritoneal cancer, prostate cancer, rectal cancer, renal cell carcinoma, retinoblastoma, rhabdomyosarcoma, salivary gland cancer, sarcoma, Sezari syndrome, skin cancer, small cell lung cancer, small intestine cancer, soft tissue sarcoma, squamous cell carcinoma, squamous neck cancer, gastric cancer, T-cell lymphoma, testicular cancer, throat cancer, thymoma and thymic cancer, thyroid cancer, transitional cell carcinoma of the renal pelvis and ureter, unknown primary cancer, urethral cancer, uterus cancer, uterine sarcoma, vaginal cancer, vulvar cancer and Wilm's tumor.

In some embodiments, the RET-related cancer of the present invention is selected from the group consisting of lung cancer, papillary thyroid cancer, medullary thyroid carcinoma, differentiated thyroid cancer, recurrent thyroid cancer, refractory differentiated thyroid cancer, type 2A or 2B multiple endocrine neoplasia (MEN2A or MEN2B, respectively), pheochromocytoma, parathyroid hyperplasia, breast cancer, colorectal cancer, papillary renal cell carcinoma, gastrointestinal mucosal ganglion cell tumor and cervical cancer. In some embodiments, the RET-related cancer is RET fusion lung cancer or medullary thyroid carcinoma.

In some embodiments, the compound of formula (I), (I-1a), (I-1), (I-2), (I-3), or (I-4), the pharmaceutically acceptable salt and solvate thereof can be used to treat patients with cancers with RET inhibitor resistance mutations (which result in increased resistance to the compound other than formula (I), (I-1a), (I-1), (I-2), (I-3), or (I-4), the pharmaceutically acceptable salt or solvate thereof, for example, a substitution at amino acid position 804, such as V804M, V804L or V804E), wherein the treatment is administered by combination or as a follow-up treatment of existing medical treatments (for example, other RET kinase inhibitor that is not a compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4), a pharmaceutically acceptable salt or solvate thereof). Described herein are exemplary RET kinase inhibitors (e.g., other RET kinase inhibitor that is not a compound of formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4) or a pharmaceutically acceptable salt or solvate thereof). In some embodiments, the RET kinase inhibitor may be selected from the group consisting of cabozantinib, vandetanib, alatinib, sorafenib, levabrinib, punatinib, vittinib, sunitinib, foretinib, BLU667 and BLU6864.

In some embodiments of any of the methods or uses described herein, the irritable bowel syndrome (IBS) comprises diarrhea-predominant, constipation-dominant or alternating, functional bloating, functional constipation, functional diarrhea, non-specific functional bowel disorder, functional abdominal pain syndrome, chronic idiopathic constipation, functional esophageal disease, functional gastroduodenal disease, functional anorectal pain, and inflammatory bowel disease.

The compounds and compositions, according to the method disclosed herein, may be administered using any amount and any route of administration which is effective for treating or lessening the severity of the disorder or disease. The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the infection, the particular agent, its mode of administration, and the like. A compound or composition can also be administered with one or more other therapeutic agents as discussed above.

General Synthetic Procedures of the Compounds of the Invention

Generally, the compounds disclosed herein may be prepared by methods described herein, wherein the substituents are as defined for formula (I), (I-1a), (I-1), (I-2), (I-3) or (I-4) above, except where further noted. The following non-limiting schemes and examples are presented to further exemplify the invention.

Persons skilled in the art will recognize that the chemical reactions described may be readily adapted to prepare a number of other compounds disclosed herein, and alternative methods for preparing the compounds disclosed herein are deemed to be within the scope disclosed herein. For example, the synthesis of non-exemplified compounds according to the invention may be successfully performed by modifications apparent to those skilled in the art, e.g., by appropriately protecting interfering groups, by utilizing other suitable reagents known in the art other than those described, and/or by making routine modifications of reaction conditions. Alternatively, other reactions disclosed herein or known in the art will be recognized as having applicability for preparing other compounds disclosed herein.

In the examples described below, unless otherwise indicated all temperatures are set forth in degrees Celsius. Unless otherwise stated, reagents are commercially available, for example, reagents were purchased from commercial suppliers such as Lingkai Pharmaceuticals, Aldrich Chemical Company, Inc., Arco Chemical Company and Alfa Chemical Company, and were used without further purification unless otherwise indicated. Common solvents were purchased from commercial suppliers such as Shantou XiLong Chemical Factory, Guangdong Guanghua Reagent Chemical Factory Co. Ltd., Guangzhou Reagent Chemical Factory, Tianjin YuYu Fine Chemical Ltd., Qingdao Tenglong Reagent Chemical Ltd., and Qingdao Ocean Chemical Factory.

Anhydrous THF was obtained by refluxing the solvent with sodium. Anhydrous CH₂C₂ and CHCl₃ were obtained by refluxing the solvent with CaH₂. Ethyl acetate, N,N-dimethylacetamide and petroleum ether were treated with anhydrous Na₂SO₄ prior use.

The reactions set forth below were done generally under a positive pressure of nitrogen or argon or with a drying tube (unless otherwise stated) in anhydrous solvents, and the reaction flasks were typically fitted with rubber septa for the introduction of substrates and reagents via syringe. Glassware was oven dried and/or heat dried.

Column chromatography was conducted using a silica gel column. Silica gel (300-400 mesh) was purchased from Qingdao Ocean Chemical Factory. ¹H NMR spectra were obtained by using CDCl₃ or DMSO-d₆ solutions (reported in ppm), with TMS (0 ppm) or chloroform (7.25 ppm) as the reference standard. When peak multiplicities were reported, the following abbreviations were used: s (singlet), d (doublet), t (triplet), m (multiplet), br (broadened), dd (doublet of doublets), and dt (doublet of triplets). Coupling constants, when given, were reported in Hertz (Hz).

Low-resolution mass spectral (MS) data were also determined on an Agilent 6320 series LC-MS spectrometer equipped with G1312A binary pumps and a G1316A TCC (Temperature Control of Column, maintained at 30° C.). A G1329A autosampler and a G1315B DAD detector were used in the analysis. An ESI source was used on the LC-MS spectrometer.

Low-resolution mass spectral (MS) data were also determined on an Agilent 6120 series LC-MS spectrometer equipped with G1311A binary pumps and a G1316A TCC (Temperature Control of Column, maintained at 30° C.). A G1329A autosampler and a G1315D DAD detector were used in the analysis. An ESI source was used on the LC-MS spectrometer.

Both LC-MS spectrometers were equipped with an Agilent Zorbax SB-C18, 2.1×30 mm, 5 m column. Injection volume was decided by the sample concentration. The flow rate was 0.6 mL/min. The HPLC peaks were recorded by UV-Vis wavelength at 210 nm and 254 nm. The mobile phase was 0.1% formic acid in acetonitrile (phase A) and 0.1% formic acid in ultrapure water (phase B).

Purities of compounds were assessed by Agilent 1100 Series high performance liquid chromatography (HPLC) with UV detection at 210 nm and 254 nm (Zorbax SB-C18, 2.1×30 mm, 4 micron). The run time was 10 min, and the flow rate was 0.6 mL/min. The elution was performed with a gradient of 5 to 95% phase A (0.1% formic acid in CH₃CN) in phase B (0.1% formic acid in H₂O). Column was operated at 40° C.

The following abbreviations are used throughout the specification:

• NaSO₄.10H₂O sodium sulfate decahydrate
• AlCl₃ aluminum trichloride
• DCE 1,2-dichloroethane
• PE, pe, Pe petroleum ether
• EA ethyl acetate
• DMA N,N-dimethylaniline
• Pd(PPh₃)₄
• tetrakis(triphenylphosphine)palladium javascript:showMsgDetail(‘ProductSynonyms.aspx?CBNumber=CB 16394&postData3=CN&SYMBOL_Type=D’);
• DIPEA N,N-diisopropylethylamine
• TFA trifluoroacetic acid
• DCM dichloromethane
• DMAP 4-dimethylaminopyridine
• DCC dicyclohexylcarbodiimide
• NH₄Cl ammonium chloride
• DMF N,N-dimethylformamide
• THE tetrahydrofuran
• CuI cuprous iodide
• PdCl₂(PPh₃)₂, Pd(PPh₃)₂Cl₂ bis(triphenylphosphine)palladium dichloride
• DPEPhos bis(2-diphenylphosphinophenyl)ether
• K₂CO₃ potassium carbonate
• MeOH, CH₃OH methanol
• DMSO dimethylsulfoxide
• Na₂S₂O₃ sodium thiosulfate
• NaBH(OAc)₃ sodium triacetoxyborohydride
• EDCI 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
• STAB sodium triacetoxyborohydride
• MsCl methanesulfonyl chloride
• LiOH lithium hydroxide
• LiOH H₂O lithium hydroxide monohydrate
• NaBH₄ sodium borohydride
• NaOH sodium hydroxide
• EtOH ethanol
• NaH sodium hydride
• PPh₃ triphenylphosphine
• t-BuOK potassium tert-butoxide
• SOCl₂ dichlorosulfoxide
• HCl/dioxane a solution of hydrochloric acid in dioxane
• DMAC dimethylacetamide
• AcOH acetic acid
• NaHCO₃ sodium bicarbonate
• THF/H₂O a mixed solution of tetrahydrofuran and water
• TEA, Et₃N triethylamine
• H₂O water
• SOCl₂ thionyl chloride
• mL, ml milliliter
• g gram
• mmol millimole
• mL milliliter
• mol/L mole per liter, mole/liter
• ° C., ° C. Celsius
• h hour, hours
• d day, days
• min minute, minutes
• s second, seconds
• TLC thin layer chromatography
• % percent sign
• N mol/L mole per liter, mole/liter

The following synthetic schemes describe the steps for preparing the compounds disclosed herein. Unless otherwise stated, each of R¹, Q R³, R⁵, R⁶, R¹, X², X³, X⁴, X⁵, X⁵, A, Q and M is as defined herein.

Intermediate I-A Synthesis Scheme

The synthesis of intermediate I-A can be obtained by referring to the synthetic procedure of the intermediate synthesis scheme above. Wherein hal¹ is F, Cl, Br, I, preferably Cl, Br; hal² is F, Cl, Br, I, preferably F, Cl, Br. The compound of formula I-A-1 can be coupled with a compound of formula I-A-2 under suitable coupling conditions (e.g., a palladium coupling agent, preferably Pd(PPh₃)₄) in a suitable solvent (e.g., dioxane) to provide a compound of formula I-A.

Intermediate I-B Synthesis Scheme

The synthesis of intermediate I-B can be obtained by referring to the synthetic procedure of the intermediate synthesis scheme above. Wherein hal¹ is F, Cl, Br, I, preferably F, Cl, Br; Pg is an amino protecting group, including but not limited to Boc, Cbz, Fmoc and the like. The compound of formula I-A can be coupled with a compound of formula I-B-1 under suitable conditions (e.g., DIPEA) in a suitable solvent (e.g., DMSO) to provide a compound of formula I-B-2; the compound of formula I-B-2 can react under acidic conditions (such as HCl) in a suitable solvent (methanol) to provide a compound of formula I-B or a salt of a compound of formula I-B.

When E in the formula (I) of the present invention is a bond, the compound of the formula (I) of the present invention is the compound of the formula (Ia) in the synthesis scheme 1. The synthesis of the compound of the formula (Ia) of the present invention can be obtained by referring to the synthetic procedure of synthesis scheme 1. The compound of formula I-A can be subjected to a coupling reaction with a compound of formula I-B1 or a salt of compound of formula I-B1 (e.g., hydrochloride, trifluoroacetate, hydrobromide) under suitable reagent conditions (e.g., DIPEA) to give the compound of formula (Ia).

When E in the formula (I) of the present invention is —NR⁶—, the compound of the formula (I) of the present invention is the compound of the formula (Ib) in the synthesis scheme 2. The synthesis of the compound of the formula (Ib) of the present invention can be obtained by referring to the synthetic procedure of synthesis scheme 2. The compound of formula I-A can be subjected to a coupling reaction with a salt of compound of formula I-B2 (e.g., hydrochloride, trifluoroacetate, hydrobromide) under suitable reagent conditions (e.g., DIPEA) to give the compound of formula (Ib).

When E in the formula (I) of the present invention is a bond, and the left end of A is bonded to E through an N atom, the compound of the formula (I) of the present invention is the compound of the formula (Ic) in synthesis scheme 3. The synthesis of the compound of the formula (Ic) of the present invention can be obtained by referring to the synthetic procedure of synthesis scheme 3. The compound of formula I-A can be subjected to a coupling reaction with a compound of formula I-B3 or a salt of compound of formula I-B3 (e.g., hydrochloride, trifluoroacetate, hydrobromide) under suitable reagent conditions (e.g., DIPEA) to give the compound of formula (Ic).

When E in the formula (I) of the present invention is a bond, Q is —(C═O)—, the left end of A is bonded to E through an N atom, and the right end of A is bonded to Q through an N atom, the compound of the formula (I) of the present invention is the compound of the formula (Id) in synthesis scheme 4. Wherein Pg is an amino protecting group, including but not limited to Boc, Cbz, Fmoc, etc., and R^a is OH, Cl, Br. The compound of formula I-B4-1 can react with a compound of formula I-B4-2 under suitable basic conditions (e.g., DCC, DIPEA, TEA, DMAP) to give the compound of formula I-B4-3; the compound of formula I-B4-3 can be deaminated under acidic conditions (such as hydrochloric acid, trifluoroacetic acid, hydrobromic acid) to give a salt of the compound of formula I-B4 (such as hydrochloride, trifluoroacetate, hydrobromide); the salt of the compound of formula I-B4 can be coupled with a compound of formula I-A under suitable reagent conditions (e.g., DIPEA) to give a compound of formula (Id).

When E in the formula (I) of the present invention is a bond, Q is —NR⁵(C═O)—, the left end of A is bonded to E through an N atom, and the right end of A is bonded to an N atom in Q, the compound of the formula (I) of the present invention is the compound of the formula (Ie) in synthesis scheme 5. Wherein Pg is an amino protecting group, including but not limited to Boc, Cbz, Fmoc, etc., and R^a is OH, Cl, Br. The compound of formula I-B5-1 can react with a compound of formula I-B4-2 under suitable basic conditions (e.g., DCC, DIPEA, TEA, DMAP) to give the compound of formula I-B5-3; the compound of formula I-B5-3 can be deaminated under acidic conditions (such as hydrochloric acid, trifluoroacetic acid, hydrobromic acid) to give a salt of the compound of formula I-B5 (such as hydrochloride, trifluoroacetate, hydrobromide); the salt of the compound of formula I-B5 can be coupled with a compound of formula I-A under suitable reagent conditions (e.g., DIPEA) to give a compound of formula (Ie).

When E in the formula (I) of the present invention is a bond, Q is —(C═O)—, the left end of A is bonded to E through an N atom, and the right end of A is bonded to Q through an N atom, the compound of the formula (I) of the present invention is the compound of the formula (Id) in synthesis scheme 6. Wherein Pg is an amino protecting group, including but not limited to Boc, Cbz, Fmoc, etc., and R^a is OH, Cl, Br. The compound of formula I-B4-1 can react with a compound of formula I-A under suitable basic conditions (e.g., DCC, DIPEA, TEA, DMAP) to give the compound of formula I-B4-5; the compound of formula I-B4-5 can be deaminated under acidic conditions (such as hydrochloric acid, trifluoroacetic acid, hydrobromic acid) to give a salt of the compound of formula I-B4-6 (such as hydrochloride, trifluoroacetate, hydrobromide); the salt of the compound of formula I-B4-6 can be coupled with a compound of formula I-B4-2 under suitable reagent conditions (e.g., DCC, DIPEA, TEA, DMAP) to give a compound of formula (Id).

When E in the formula (I) of the present invention is —NR⁶—, Q is —(C═O)—, and the right end of A is bonded to Q through an N atom, the compound of the formula (I) of the present invention is the compound of the formula (If) in synthesis scheme 7. Wherein Pg is an amino protecting group, including but not limited to Boc, Cbz, Fmoc, etc., and R^a is OH, Cl, Br. The compound of formula I-B6-1 can react with a compound of formula I-A under suitable basic conditions (e.g., DCC, DIPEA, TEA, DMAP) to give the compound of formula I-B6-2; the compound of formula I-B6-2 can be deaminated under acidic conditions (such as hydrochloric acid, trifluoroacetic acid, hydrobromic acid) to give a salt of the compound of formula I-B6-3 (such as hydrochloride, trifluoroacetate, hydrobromide); the salt of the compound of formula I-B6-3 can be coupled with a compound of formula I-B4-2 under suitable reagent conditions (e.g., DCC, DIPEA, TEA, DMAP) to give a compound of formula (If).

When E in the formula (I) of the present invention is a bond, Q is a bond, the left end of A is bonded to E through an N atom, the right end of A is bonded to Q through an N atom, and M is —CH₂—Cy-, the compound of the formula (I) of the present invention is the compound of the formula (Ig) in synthesis scheme 8. Wherein Pg is an amino protecting group, including but not limited to Boc, Cbz, Fmoc, etc.; Cy is a bond, aryl, heteroaryl, Cyc or hetCyc, wherein aryl, heteroaryl, Cyc, hetCyc have the definitions as described herein. The compound of formula I-B4-1 can react with a compound of formula I-A under suitable basic conditions (e.g., DCC, DIPEA, TEA, K₂CO₃, DMAP) to give the compound of formula I-B4-5; the compound of formula I-B4-5 can be deaminated under acidic conditions (such as hydrochloric acid, trifluoroacetic acid, hydrobromic acid) to give a salt of the compound of formula I-B4-6 (such as hydrochloride, trifluoroacetate, hydrobromide); the salt of the compound of formula I-B4-6 can be coupled with a compound of formula I-B4-7 under suitable reagent conditions (e.g., DCE and NaBH(OAc)₃ conditions) to give a compound of formula (Ig).

The compound of formula (Ih) can be obtained by the preparation method of synthesis scheme 9, wherein hal³ is F, Cl, Br, preferably Cl, Br; Cy1 is a bond, aryl or heteroaryl. The salt of the compound of formula I-B4-6 and the compound of formula Ih-1 can be subjected to a coupling reaction under basic conditions (such as potassium carbonate, triethylamine, etc.) in suitable solvents (such as N, N-dimethylformamide, acetonitrile, etc.) to obtain a compound of formula (Ih).

The compound of formula (Ii) can be obtained by the preparation method of synthesis scheme 10, wherein R^a is OH, Cl, and Br. The salt of the compound of formula I-B and the compound of formula I-B4-2 can react under appropriate reagent conditions (such as EDCI, DIPEA, DMAP, etc.) to obtain a compound of formula (Ii).

The compound of formula (Ij) can be obtained by the preparation method of synthesis scheme 11, wherein R^a is OH, Cl, and Br. The salt of the compound of formula I-C and the compound of formula I-C1 can react under appropriate reagent conditions (such as EDCI, DIPEA, DMAP, etc.) to obtain a compound of formula (Ij).

The compound of formula (Ik) can be obtained by the preparation method of synthesis scheme 11, wherein R^a is OH, Cl, and Br. The salt of the compound of formula I-D and the compound of formula I-C1 can react under appropriate reagent conditions (such as EDCI, DIPEA, DMAP, etc.) to obtain a compound of formula (Ik).

EXAMPLES

Intermediate 1: 3-cyano-6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine

Step 1: 3-cyano-4-bromo-6-methoxypyrazolo[1,5-a]pyridine

(E)-4-Bromo-6-methoxypyrazolo[1,5-a]pyridin-3-formaldoxime (10.0 g, 37.026 mmol) was dissolved in acetic anhydride (250 mL) in a 500 mL single-necked flask. The mixture was refluxed for reaction at 140° C. The solution gradually turned from yellow to brown. The mixture was reacted for 4.5 h, then the completion of reaction was monitored by TLC. The resulting mixture was concentrated in vacuo to remove the solvent. To the residue was added water (100 mL). The resulting mixture was stirred for 5 min, and then filtered by suction. The filter cake was washed with 20 mL of water, then dried in a vacuum oven at 50° C. for 24 h to obtain 6.83 g of a gray solid. The yield was 73.2%. Rf=0.4 (PE/EA=2/1).

Step 2: 3-cyano-4-bromo-6-hydroxypyrazolo[1,5-a]pyridine

3-Cyano-4-bromo-6-methoxypyrazolo[1,5-a]pyridine (6.83 g, 27.1 mmol) was dissolved in DCE (273 mL) in a 1000 mL single-necked flask. AlCl₃ (10.8 g, 81.0 mmol) was added in one portion. The mixture was transferred to an 80° C. oil bath and refluxed for reaction overnight. The completion of reaction was monitored by TLC. The reaction solution was cooled to room temperature, and a solution of 200 mL of NaSO₄.10H₂O in THE was added under stirring. The mixture was stirred for 4 h, then filtered by suction. The filtrate was collected and concentrated in vacuo to give a brown solid 5.8 g. The yield was 90%. Rf=0.2 (PE/EA=2/1).

Step 3: 3-cyano-4-bromo-6-ethoxypyrazolo[1,5-a]pyridine

3-Cyano-4-bromo-6-hydroxypyrazolo[1,5-a]pyridine (5 g, 21.005 mmol) and potassium carbonate (8.7 g, 63 mmol) were dissolved in DMA (125 mL) in a 250 mL single-necked flask. Iodoethane (5 g, 32.057 mmol) was added with stirring. After the addition, the mixture was transferred to 60° C. for reaction. The completion of reaction was monitored by TLC after reaction for 6 h. To the reaction solution was added 40 mL of a mixture of ammonium hydroxide and water (ammonium hydroxide:water(v:v)=1:1). The mixture was stirred for 1 hour, and then filtered by suction. The filter cake was washed with 50 mL of water and concentrated in vacuo to give a gray solid 4.48 g. The yield was 80.2%. Rf=0.95 (PE/EA=1/1).

Step 4: 3-cyano-6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine

3-Cyano-4-bromo-6-ethoxypyrazolo[1,5-a]pyridine (2.5 g, 9.4 mmol) and 2-fluoropyridine-5-boronic acid pinacol ester (2.5 g, 11 mmol) were dissolved in 1,4-dioxane (94 mL) in a pressure tube. After Pd(PPh₃)₄(1.1 g, 0.95 mmol) and sodium carbonate solution (9.4 mL, 19 mmol, 2 mol/L) were added, the tube was sealed and heated in a 100° C. oil bath. The heating was stopped after 9 h, and the completion of reaction was monitored by TLC. The reaction was quenched with 50 mL of saturated ammonium chloride solution, and the reaction solution was transferred to a separatory funnel, and 300 mL of EA and 50 mL of saturated brine were added.

After shaking, the intermediate layer was flocculated with a gray solid. The mixture was filtered by suction, and the gray solid was separated. The organic phase was separated from the filtrate, and the aqueous phase was extracted twice with 250 mL of EA. The organic phases were combined with a gray solid, concentrated in vacuo, and then purified by column chromatography (EA:PE(v/v)=4:1-1:1) to give a pale yellow solid 2.7 g. The yield was 100%. Rf=0.35 (PE/EA=1/1). ¹H-NMR (400 MHz, CDCl₃) δ 8.39 (s, 1H), 8.21 (s, 1H), 8.18 (d, 1H), 8.01 (td, J=8.3, 2.6 Hz, 1H), 7.16 (d, J=1.8 Hz, 1H), 7.12 (dd, J=8.4, 2.9 Hz, 1H), 4.11 (q, J=6.9 Hz, 2H), 1.51 (t, J=6.9 Hz, 3H).

Intermediate 2: 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-bromo-6-hydroxypyrazolo[1,5-a]pyridin-3-carbonitrile

4-Bromo-6-methoxypyrazolo[1,5-a]pyridine-3-carbonitrile (6.83 g, 27.1 mmol) was dissolved in DCE (273 mL) in a 1000 mL single-necked flask. AlCl₃ (10.8 g, 81.0 mmol) was added in one portion. The mixture was transferred to an 80° C. oil bath and refluxed for reaction overnight.

The completion of reaction was monitored by TLC. The reaction solution was cooled to room temperature, and a solution of 200 mL of NaSO₄.10H₂O in THE was added under stirring. The mixture was stirred for 4 hr, then filtered by suction. The filtrate was collected and concentrated in vacuo to give a brown solid 5.8 g. The yield was 90%. Rf=0.2 (PE/EA=2/1).

Step 2: 4-(6-fluoropyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile

To a 50 mL sealed tube were sequentially added 4-bromo-6-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile (1.54 g, 6.47 mmol), 2-fluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (1.88 g, 8.43 mmol), 2 mol/L sodium carbonate (9.7 mL, 19 mmol), 1,4-dioxane (30.8 mL) and tetrakis(triphenylphosphine)palladium (0.75 g, 0.65 mmol). The mixture was degassed and refilled with nitrogen for 10 min. After being sealed, the mixture was stirred at 100° C. for 7 h. The mixture was then cooled to room temperature and stirred overnight. The reaction solution was directly filtered by suction. The filter cake was washed with a large amount of EA (80 ml), and to the filtrate was added 50 mL of water. The aqueous phase was separated and extracted with ethyl acetate (50 ml×2). The organic phase was combined, washed with water (50 ml) and saturated brine (50 ml), dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA(v/v)=4:1-2:1) to give a pale yellow solid 1.14 g. The yield was 69.3%.

Step 3: 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 20 mL pressure tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (0.34 g, 1.3 mmol), potassium carbonate (0.55 g, 4.0 mmol), 2,2-dimethyloxirane (0.96 g, 13 mmol) and DMF (4 mL). After the tube was sealed, the mixture was stirred magnetically at 60° C. for 10 h, and then heated to 80° C. for reaction overnight. After the completion of reaction was monitored by TLC, to the reaction solution was added 50 ml of cold water. The mixture was stirred at room temperature for 1 h, then extracted with EA (80 mL×3). The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=9/1-2/1) to give a white solid 183 mg in a yield of 42%. LC-MS: 327.1[M+1]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.40 (d, 1H), 8.24 (d, J=1.7 Hz, 1H), 8.22 (s, 1H), 8.05-7.98 (m, 1H), 7.23 (d, J=1.8 Hz, 1H), 7.13 (dd, J=8.5, 2.8 Hz, 1H), 3.88 (s, 2H), 1.40 (s, 6H).

Intermediate 3: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride

Step 1: tert-butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate

To a 30 mL microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 1.48 g, 4.54 mmol), tert-butyl 3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (1.1 g, 5.5 mmol), potassium carbonate (1.89 g, 13.7 mmol). The mixture was dissolved with dimethyl sulfoxide (15 ml) and reacted for 4 h at 140° C. under microwave. The mixture was cooled to room temperature, then EA (100 mL) was added. The resulting mixture was washed with water (50 mL×5) and saturated saline (50 mL) in turn. The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and then purified by silica gel column chromatography (PE/EA=50:1-2:1) to give a pale yellow solid 1.61 g as the target product. The yield was 70.3%. Rf=0.50 (PE:EA=1:1). LC-MS: m/z=505.20[M+H]⁺.

Step 2: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride

To a 100 mL single-necked flask were sequentially added tert-butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-3,6-diaza bicyclo[3.1.1]heptane-6-carboxylate (1.61 g, 3.19 mmol) and methanolic hydrochloric acid solution (4 mol/L, 13 ml). The mixture was stirred overnight at room temperature. The reaction solution was directly concentrated in vacuo to form a viscous oily substance, and placed in an oven at 60° C. for vacuum drying to obtain a white solid 1.48 g as the target product. Rf=0.05 (PE:EA=1:1). LC-MS: m/z=405.10[M−2HCl]⁺.

Intermediate 4: 4-(6-(4-amino-4-methylpiperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride

Step 1: tert-butyl 1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-4-methylpiperidin-4-yl)carbamate

To a 10 mL microwave tube were added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-3-carbonitrile (see synthesis of intermediate 2, 400 mg, 1.226 mmol), tert-butyl N-(4-methyl-4-piperidinyl)carbamate (341 mg, 1.5912 mmol) and DIPEA (1.01 mL, 6.11 mmol) sequentially. The mixture was dissolved with dimethyl sulfoxide (4 ml) and reacted for 5 h at 150° C. under microwave. Then EA (50 mL) was added. The resulting mixture was washed with water (20 mL×2) and saturated saline (20 mL) in turn. The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and then purified by silica gel column chromatography (PE/EA=3:1-2:1) to give a yellow solid 0.35 g as the target product. The yield was 54.84%. Rf=0.40 (PE:EA=1:1.5). LC-MS: m/z=521.30[M+H]⁺.

Step 2: 4-(6-(4-amino-4-methylpiperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride

To a 100 mL single-necked flask were added tert-butyl 1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)carbamate (350 mg, 0.6723 mmol) and methanolic hydrochloric acid solution (4 mol/L, 10 ml) in turn. The mixture was stirred at room temperature overnight. The reaction solution was directly concentrated in vacuo to form a viscous oily substance, and placed in an oven at 60° C. for vacuum drying to obtain a white solid 0.3317 g as the target product. The yield was 100%. LC-MS: m/z=421.10[M−2HCl]⁺.

Intermediate 5: 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazole[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-hydroxyazetidin-1-carboxylate

To a single-necked flask were added tert-butyl 3-oxoazetidine-1-carboxylate (5.0 g, 29 mmol) and EtOH (50 mL) at room temperature, then NaBH₄ (1.1 g, 29 mmol) was added portionwise with stirring. After the completion of reaction was monitored by TLC, a saturated ammonium chloride solution was added to the reaction solution until no bubbles were generated, and a large amount of white solid was precipitated. The mixture was filtered with suction. The filter cake was washed with ethanol (10 mL), and the filtrate was concentrated in vacuo to remove most of the ethanol. To the mixture was added 30 mL of water and the resulting mixture was extracted with EA (100 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 5.0 g as the target product. LC-MS: m/z=118.10[M-t-Bu+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 4.53 (s, 1H), 4.13-4.09 (m, 2H), 3.78 (dd, J=9.9, 4.1 Hz, 2H), 3.54-3.45 (m, 1H), 1.41 (s, 9H).

Step 2: tert-butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate

To a two-necked flask were added tert-butyl 3-hydroxyazetidine-1-carboxylate (500 mg, 2.89 mmol), DCM (15 mL) and NaH (0.14 g, 5.8 mmol) under nitrogen. The mixture was transferred to 0° C. and MsCl (0.25 mL, 3.2 mmol) was added dropwise with stirring. After the addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, water (20 mL) and DCM (50 mL) were added to the reaction mixture. The organic phase was separated, and the aqueous phase was extracted with EA (50 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquid was purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 566 mg as the target product. LC-MS: m/z=196.10[M-t-Bu+H]⁺, m/z=152.10[M-Boc+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 5.18 (tt, J=6.7, 4.2 Hz, 1H), 4.26 (ddd, J=10.3, 6.7, 1.0 Hz, 2H), 4.11-4.04 (m, 2H), 3.05 (s, 3H), 1.43 (s, 9H).

Step 3: tert-butyl 3-((6-bromopyridin-3-yl)oxy)azetidin-1-carboxylate

6-Bromopyridin-3-ol (200 mg, 1.15 mmol) was dissolved in DMSO (4 mL) at room temperature, and t-BuOK (168 mg, 1.5 mmol) was added to the solution with stirring. After stirring for 20 min, the temperature was raised to 80° C. tert-Butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate (347 mg, 1.4 mmol) dissolved in DMSO (2 mL) was added dropwise slowly. After the addition, the mixture was kept at this temperature with stirring. After the completion of reaction was monitored by TLC, the reaction mixture was poured into water (20 mL). The resulting mixture was extracted with EA (50 mL×2). The combined organic phases were washed with water (20 mL×2) and saturated saline (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a light yellow solid 320 mg as the target product. LC-MS: m/z=329.05[M+H]⁺.

Step 4: tert-butyl 3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)azetidin-1-carboxylate

To a two-necked flask were added tert-butyl 3-((6-bromopyridin-3-yl)oxy)azetidin-1-carboxylate (320 mg, 0.97 mmol), CuI (37 mg, 0.19 mmol), PdCl₂ (PPh₃) 2 (68 mg, 0.097 mmol), THE (3 mL) and TEA (3 mL) under nitrogen. The mixture was transferred to 50° C. and ethynyl (trimethyl) silane (191 mg, 1.95 mmol) was added dropwise with stirring. After the addition, the mixture was kept at this temperature and reacted. After the completion of reaction was monitored by TLC, the reaction mixture was filtered by suction through a celite pad. The filter cake was washed with a small amount of EA, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a brown solid 240 mg as the desired product. LC-MS: m/z=347.25[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.12 (s, 1H), 7.39 (d, J=8.6 Hz, 1H), 6.97 (dd, J=8.6, 2.9 Hz, 1H), 4.92 (ddd, J=10.4, 6.3, 4.0 Hz, 1H), 4.31 (dd, J=9.6, 6.8 Hz, 2H), 4.00 (dd, J=9.8, 3.4 Hz, 2H), 1.45 (s, 9H), 0.26 (s, 9H).

Step 5: tert-butyl 3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-carboxylate

tert-Butyl 3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)azetidin-1-carboxylate (240 mg, 0.69 mmol) was dissolved in methanol (2 mL) at room temperature, and then potassium carbonate (194 mg, 1.38 mmol) was added with stirring. The reaction solution was reacted at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo. To the residue was added water (10 mL) and the resulting mixture was extracted with EA (30 mL×3). The combined organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a light yellow solid 180 mg as the target product. LC-MS: m/z=275.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.14 (d, J=2.8 Hz, 1H), 7.43 (d, J=8.6 Hz, 1H), 6.99 (dd, J=8.6, 2.9 Hz, 1H), 4.92 (tt, J=6.4, 4.1 Hz, 1H), 4.32 (ddd, J=9.7, 6.3, 0.6 Hz, 2H), 4.01 (dd, J=9.9, 3.9 Hz, 2H), 3.09 (s, 1H), 1.45 (s, 9H).

Step 6: 5-(azetidin-3-yloxy)-2-ethynylpyridine hydrochloride

tert-Butyl 3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-carboxylate (180 mg, 0.66 mmol) was dissolved in HCl/dioxane (3 mL, 12 mmol, 4 mol/L) with stirring at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo to give a light yellow solid 158 mg as the target product.

Step 7: 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (300 mg, 1.18 mmol), 5-(azetidin-3-yloxy)-2-ethynyl-pyridine hydrochloride (373 mg, 1.77 mmol) and DIPEA (0.6 ml, 3.54 mmol), which were dissolved by adding dimethyl sulfoxide (3 ml). The mixture was reacted at 85° C. and 5 bar for 8 h under microwave. After the reaction was completed, to the reaction mixture was added 20 mL of water and the resulting mixture was extracted with EA (100 ml×5). The organic phases were washed with water (100 mL×2) and saturated saline (100 mL) in turn, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo and then purified by silica gel column chromatography (PE/EA=5:1-1:2) to give a brownish yellow solid 301 mg as the target product (yield: 62.45%), Rf=0.15 (PE/EA=1:1). LC-MS: m/z=409.20[M+H]⁺, ¹H NMR (400 MHz, DMSO-d₆) δ 8.48 (s, 1H), 8.31 (d, J=1.9 Hz, 1H), 8.27 (dd, J=5.3, 2.5 Hz, 2H), 7.76 (dd, J=8.6, 2.3 Hz, 1H), 7.55 (d, J=8.6 Hz, 1H), 7.35 (dd, J=8.6, 2.9 Hz, 1H), 7.15 (d, J=1.8 Hz, 1H), 6.58 (d, J=8.6 Hz, 1H), 5.31 (d, J=3.3 Hz, 1H), 4.53-4.47 (m, 2H), 4.16 (s, 1H), 4.00 (dd, J=9.4, 3.4 Hz, 2H), 1.97 (s, 1H).

Intermediate 6: 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate

To a 20 mL microwave tube were added tert-butyl piperazine-1-carboxylate (1 g, 5.3691 mmol), 3-cyano-6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine (500 mg, 1.771 mmol), DMSO (10 mL) and N,N-diisopropylethylamine (0.46 g, 3.6 mmol). The mixture was reacted under microwave at 150° C. for 3 h. Ethyl acetate (50 mL) and water (30 mL) were added. The aqueous phase was extracted with EA (30 mL×2), and the combined organic phases were washed with saturated saline (30 mL). The organic phases were dried over anhydrous sodium sulfate, filtered and purified by silica gel column chromatography (PE/EA=10/1-1/1) to give a pale yellow solid 0.57 g as the target compound. ¹H NMR (400 MHz, DMSO-d₆) δ 8.64 (s, 1H), 8.56 (s, 1H), 8.34 (s, 1H), 7.79 (d, J=8.8 Hz, 1H), 7.27 (s, 1H), 6.95 (d, J=8.8 Hz, 1H), 4.23-4.07 (m, 2H), 3.59 (d, J=5.3 Hz, 4H), 3.45 (s, 4H), 1.42 (d, J=9.8 Hz, 9H), 1.40-1.36 (m, 3H).

Step 2: 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile-ditrifluoroacetate

To a 100 mL single-necked flask was added tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo [1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate (0.57 g, 1.3 mmol) and DCM (11 mL) under ice bath conditions. The mixture was stirred for 5 min, then TFA (3.5 mL) was added. The mixture was naturally warmed to room temperature and monitored by TLC. After the reaction was completed, the mixture was directly concentrated in vacuo to obtain light brown transparent oily liquid as the target product (yield 100%). LC-MS (ES-API): 349.2[M+H−2CF₃COOH]⁺.

Step 3: 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 50 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile-ditrifluoroacetate (1.22 g, 2.42 mmol) and saturated sodium bicarbonate solution (22 mL). The mixture was stirred and reacted at room temperature for 5 h. Then the mixture was filtered, and the filter cake was washed with 10 mL of water and 5 mL of n-hexane, and dried to give a pale yellow solid 420 mg, which was the desired product (yield 50%). ¹H-NMR (400 MHz, CDCl₃) δ 8.32 (d, J=2.2 Hz, 1H), 8.18 (s, 1H), 8.09 (d, J=1.8 Hz, 1H), 7.71 (dd, J=8.8, 2.4 Hz, 1H), 7.08 (d, J=1.8 Hz, 1H), 6.75 (d, J=8.9 Hz, 1H), 4.08 (d, J=7.0 Hz, 2H), 3.63-3.59 (m, 4H), 3.03-2.98 (m, 4H), 1.49 (t, J=6.9 Hz, 3H).

Intermediate 7: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile dihydrochloride

Step 1: tert-butyl 4-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)piperazine-1-carboxylate

To a 30 mL microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 0.75 g, 2.3 mmol), tert-butyl piperazine-1-carboxylate (0.5 g, 3.0 mmol), potassium carbonate (1.0 ml, 7.2 mmol). The mixture was dissolved with dimethyl sulfoxide (8 ml) and reacted for 4 h at 150° C. under microwave. The mixture was diluted with water (70 mL) under low temperature and extracted with EA (100 mL×5). The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and then purified by silica gel column chromatography (PE/EA=2:1-1:1) to give a pale yellow solid 0.65 g as the target product. The yield was 57%. Rf=0.50 (PE:EA=1:1). LC-MS: m/z=493.30[M+H]⁺.

Step 2: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile dihydrochloride

To a 100 mL single-necked flask were added tert-butyl 4-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate (650 mg, 1.32 mmol) and a solution of hydrochloric acid in methanol (4 mol/L, 10 ml) in turn. The mixture was stirred at room temperature overnight. The reaction solution was directly concentrated in vacuo to form a viscous oily substance, and placed in an oven at 60° C. for vacuum drying to obtain a white solid 0.6141 g as the target product. The yield was 100%. Rf=0.05 (PE:EA=1:1). LC-MS: m/z=393.20[M-2HCl]⁺.

Intermediate 8: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-ethoxy[1,5-a]pyridine-3-carbonitrile dihydrochloride

Step 1: tert-butyl 3-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-3,6-diazabicyclo [3.1.1]heptane-6-carboxylate

To a 10 mL microwave tube were sequentially added 6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 1, 50 mg, 0.1771 mmol), tert-butyl 3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (45.65 mg, 0.2303 mmol) and DIPEA (0.146 ml, 0.883 mmol). The mixture was dissolved with dimethyl sulfoxide (0.5 ml) and reacted for 4 h at 150° C. under microwave. The mixture was cooled to room temperature, then added with water (50 mL). The resulting mixture was extracted with EA (50 mL×2). The organic phases were combined, washed with saturated brine (50 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and then purified by silica gel column chromatography (PE/EA=5:1-2:1) to give a white solid 55 mg as the target product. The yield was 67.43%. Rf=0.60 (PE:EA=1:1). LC-MS: m/z=461.20[M+H]⁺.

Step 2: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-ethoxy[1,5-a]pyridine-3-carbonitrile hydrochloride

To a 10 mL single-necked flask were sequentially added tert-butyl 3-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (55 mg, 3.19 mmol) and a solution of hydrochloric acid in methanol (4 mol/L, 13 ml). The mixture was stirred overnight at room temperature. The reaction solution was directly concentrated in vacuo to form a viscous oily substance, and placed in an oven at 60° C. for vacuum drying to obtain a white solid 48.93 mg as the target product. Rf=0 (PE:EA=1:1). LC-MS: m/z=361.10[M-2HCl]⁺.

Intermediate 9: 4-(6-fluoropyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 6-bromo-4-hydroxypyrazolo[1,5-a]pyridin-3-carbonitrile

To a 1 L single-necked flask were added 6-bromo-4-methoxypyrazolo[1,5-a]pyridine-3-carbonitrile (50 g, 198.36 mmol), water (16.5 mL, 916 mmol), sodium hydroxide (16.03 g, 396.8 mmol) and DMAC (500 mL) in turn at room temperature. The mixture was stirred at room temperature for 5 min, then transferred to 0° C. and dodecyl mercaptan (97 mL, 397 mmol) was slowly added. After the addition, the resulting mixture was transferred to 45° C. and reacted overnight. The reaction solution was poured into 3 L of ice water. Saturated aqueous citric acid solution was slowly added into the mixture to adjust to pH=5. The resulting mixture was stirred for half an hour, then stood still, and filtered. The filter cake was washed with water and petroleum ether several times, and dried at 60° C. to give a yellow solid 44.1 g as the target product (the yield was 93.4%). Rf=0.35 (PE:EA=3:1). LC-MS: m/z=239.05[M+H]⁺.

Step 2: 3-bromo-3-cyanopyrazolo[1,5-a]pyridin-4-yl trifluoromethanesulfonate

To a 1 L single-necked flask were added 6-bromo-4-hydroxypyrazolo[1,5-a]pyridin-3-carbonitrile (44.1 g, 185 mmol), pyridine (45 mL, 559 mmol) and DCM (800 mL). The mixture was cooled to below −10° C., then trifluoromethanesulfonic anhydride (50 mL, 297.2 mmol) was slowly added. The mixture was stirred for 1 h, then naturally warmed to room temperature and reacted overnight. The mixture was concentrated in vacuo to remove DCM, then diluted with water (250 mL) and extracted with EA (500 mL×3). The organic phases were collected, washed with saturated brine (250 mL), dried over anhydrous sodium sulfate, filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=50:1-25:1) to give a yellowish solid 61.5 g as the target product. The yield was 89.7%. Rf=0.45 (PE:EA=5:1).

Step 3: 6-bromo-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 1 L three-necked flask were added 3-bromo-3-cyanopyrazolo[1,5-a]pyridin-4-yl trifluoromethanesulfonate (61.5 g, 166 mmol), 2-fluoropyridin-5-borate (44.5 g, 200 mmol), [1,1′-bis(diphenylphosphino)ferrocene]palladium dichloride dichloromethane complex (6.8 g, 8.3 mmol) and 1,4-dioxane (850 mL). The mixture was cooled to −10° C., then potassium acetate solution (115 mL, 345 mmol, 3 mol/L) was slowly added. The mixture was stirred at this temperature for 1 hour, and then naturally warmed to room temperature to continue for reaction overnight. javascript:showMsgDetail(‘ProductSynonyms.aspx?CBNumber=CB4505189&postData3=CN&SYM BOL_Type=D’); javascript:showMsgDetail(‘ProductSynonyms.aspx?CBNumber=CB1347621&postData3=CN&SYMBOL_Type=D’); The mixture was filtered, and the filter cake was washed with EA (500 mL×3). The filtrate was separated, washed with water (500 mL) and saturated brine (250 mL), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/DCM=2:1-0:1) to give a white solid 49 g as the target product. The yield was 93.0%. Rf=0.50 (PE:EA=1:1). LC-MS: m/z=318.10[M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 9.49 (d, J=1.2 Hz, 1H), 8.73 (s, 1H), 8.51 (d, J=1.9 Hz, 1H), 8.27 (td, J=8.2, 2.5 Hz, 1H), 7.86 (d, J=1.2 Hz, 1H), 7.40 (dd, J=8.4, 2.5 Hz, 1H).

Step 4: 4-(6-fluoropyridin-3-yl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a 250 mL single-necked flask were sequentially added 6-bromo-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (8 g, 25.23 mmol), bornazolium diborate (10 g, 39.39 mmol), potassium acetate (10 g, 101.9 mmol) and re-distilled toluene (150 mL) under nitrogen. After bubbling for 10 min under nitrogen, [1,1′-bis(diphenylphosphino)ferrocene]palladium dichloride dichloromethane complex (2.1 g, 2.6 mmol) was added. After bubbling for 10 min under nitrogen, the mixture was heated at 120° C. and reacted overnight. javascript:showMsgDetail(‘ProductSynonyms.aspx?CBNumber=CB4306719&postData3=CN&SYM BOL_Type=D’); javascript:showMsgDetail(‘ProductSynonyms.aspx?CBNumber=CB1347621&postData3=CN&S YMBOL_Type=D’); The mixture was filtered through a celite pad, and the filter cake was washed with EA (50 mL×3). The organic phases were washed with water (250 mL) and saturated brine (250 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/DCM=2:1-0:1) to give an orange solid 8.5 g as the target product (yield: 93.0%). Rf=0.15(DCM). ¹H NMR (400 MHz, CDCl₃) δ 8.99 (s, 1H), 8.43 (d, J=2.1 Hz, 1H), 8.34 (s, 1H), 8.02 (td, J=8.0, 2.5 Hz, 1H), 7.66 (s, 1H), 7.13 (dd, J=8.5, 2.8 Hz, 1H), 1.40 (s, 12H).

Step 5: 4-(6-fluoropyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile

To a 250 mL single-necked flask were sequentially added 4-(6-fluoropyridin-3-yl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (8.5 g, 23 mmol) and tetrahydrofuran (120 mL) under ice bath conditions. Then sodium hydroxide solution (60 mL, 120 mmol, 2 mol/L) and hydrogen peroxide (14 mL, 140 mmol, 30 mass %) were slowly added. The mixture was stirred at low temperature. After the completion of reaction was monitored by TLC, sodium thiosulfate solution (50 mL, 150 mmol, 3 mol/L) was slowly added. The mixture was returned to room temperature, then water (250 mL) was added and the resulting mixture was extracted with EA (250 mL×2). The combined organic phases were washed with 0.1 M NaOH solution (500 mL×2). All the aqueous phases were combined, and then adjusted the pH with diluted hydrochloric acid to 4. The resulting mixture was stirred at room temperature for 15 min and filtered with suction to give a wet cake. The mother liquid was extracted with EA (250 ml×3), and all the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM\MeOH=100: 0-100:1) to give a pale yellow solid. All the solids were combined and dried at 50° C. to give a pale yellow solid 5.1 g, which was the desired product (yield: 86.0%). Rf=0.25 (DCM\MeOH=100:1). LCMS: m/z=255.10[M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 10.44-10.37 (m, 1H), 8.54 (s, 1H), 8.49-8.46 (m, 1H), 8.42-8.40 (m, 1H), 8.26-8.21 (m, 1H), 7.40-7.35 (m, 1H), 7.32-7.30 (m, 1H).

Example 1: 3-cyano-6-ethoxy-4-(6-(4-propioloylpiperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine

Step 1: tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate

To a microwave tube were added tert-butyl piperazine-1-carboxylate (1 g, 5.3691 mmol), 6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (500 mg, 1.771 mmol, see intermediate synthesis), DMSO (10 mL) and DIPEA (0.46 g, 3.6 mmol). The mixture was reacted under microwave at 150° C. After 3 h, the reaction under microwave was stopped. 50 mL of ethyl acetate and 30 mL of water were added to the mixture, and the mixture was separated. The aqueous phase was extracted with ethyl acetate (30 mL×2), and the combined organic phases were washed with saturated brine (30 ml). The organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to remove the organic solvent. The crude product was purified by silica gel column chromatography (PE/EA-10/1-1/1) and concentrated in vacuo to give a pale yellow solid 0.57 g. The yield was 72%. LC-MS: m/z=449.2 [M+1]⁺; m/z=393.1[M-t-Bu+1]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.64 (s, 1H), 8.56 (s, 1H), 8.34 (s, 1H), 7.79 (d, J=8.8 Hz, 1H), 7.27 (s, 1H), 6.95 (d, J=8.8 Hz, 1H), 4.23-4.07 (m, 2H), 3.59 (d, J=5.3 Hz, 4H), 3.41-3.49 (m, 4H), 1.42 (d, J=9.8 Hz, 9H), 1.40-1.36 (m, 3H).

Step 2: 3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate

To a 100 mL single-necked flask was added tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate. DCM (11 mL, 79.1 mmol) was added under ice bath conditions. The mixture was stirred for 5 min, then TFA (3.5 mL) was added. The mixture was naturally warmed to room temperature and monitored by TLC. After 5 h, the reaction of the raw materials was completed. The mixture was directly concentrated in vacuo to obtain light brown transparent oily liquid, and the yield was calculated as 100%. LC-MS: m/z=349.2 [M-CF₃COO]⁺.

Step 3: 3-cyano-6-ethoxy-4-(6-(4-propioloylpiperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine

To a 25 mL single-necked flask were added 3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate (200 mg, 0.4325 mmol) and DCM (5 mL). Propiolic acid (0.04 mL, 0.6 mmol), DCC (0.133 g, 0.645 mmol) and DIPEA (0.11 g, 0.85 mmol) were added under ice bath. The mixture was naturally warmed to room temperature for reaction with stirring and monitored by TLC(PE/EA=1/1, rf=0.55). After 20 h of reaction, propiolic acid (0.04 mL) and DIPEA (0.11 g) were added, and the mixture was further reacted for 24 h. 20 mL of DCM and 15 mL of water were added, and the aqueous phase was separated and extracted with 20 mL of DCM. The organic phases were combined, washed with 15 mL of saturated brine, dried over anhydrous sodium sulfate, concentrated in vacuo to remove the organic solvent. The crude product was purified by silica gel column chromatography (PE/EA=7/1-1/1) and concentrated in vacuo to give a pale yellow solid 7.8 mg. The yield was 4.5%. LC-MS: 401.1[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.35 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.12 (d, J=1.9 Hz, 1H), 7.76 (d, J=6.8 Hz, 1H), 7.10 (d, J=1.9 Hz, 1H), 6.80 (d, J=8.7 Hz, 1H), 4.09 (q, J=7.0 Hz, 2H), 3.95-3.88 (m, 2H), 3.84-3.71 (m, 4H), 3.71-3.64 (m, 2H), 3.18 (s, 1H), 1.50 (t, J=7.0 Hz, 3H).

Example 2: 3-cyano-6-ethoxy-4-(6-(4-(3-phenylpropioloyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine

Step 1: tert-butyl 4-(3-phenylpropioloyl)piperazine-1-carboxylate

tert-Butyl piperazine-1-carboxylate (500 mg, 2.6846 mmol) was dissolved in DCM (10 mL) in a single-necked flask. 3-Phenylprop-2-ynoic acid (0.47 g, 3.2 mmol) and DCC (0.83 g, 4.0 mmol) were added with stirring at room temperature. The mixture was reacted overnight. 20 mL of DCM and 15 mL of water were added, and the aqueous phase was separated and extracted with 20 mL of DCM. The organic phases were combined, washed with 15 mL of saturated brine, dried over anhydrous sodium sulfate, concentrated in vacuo to remove the organic solvent. The crude product was purified by silica gel column chromatography (PE:EA(v/v)=10:1-4:1) to give a pale yellow solid 0.57 g. The yield was 68%.

Step 2: 3-phenyl-1-(piperazin-1-yl)prop-2-yn-1-one 2,2,2-trifluoroacetate

tert-Butyl 4-(3-phenylpropioloyl)piperazin-1-carboxylate (0.57 g, 1.8 mmol) was dissolved in DCM (6 mL) in a 50 mL single-necked flask, then TFA (2.0 mL) was added. The mixture was stirred and reacted at room temperature. The completion of reaction was monitored by TLC after 3 h. The reaction solution was directly concentrated in vacuo to give a colorless, transparent oily liquid product, which was directly used in the next reaction according to the theoretical yield. Rf=0.01 (PE/EA=1/1).

Step 3: 3-cyano-6-ethoxy-4-(6-(4-(3-phenylpropioloyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine

3-Cyano-4-(6-fluoropyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine (100 mg, 0.3542 mmol, see the synthetic part of the intermediate) and 3-phenyl-1-(piperazin-1-yl)prop-2-yn-1-one 2,2,2-trifluoroacetate (350 mg, 1.1 mmol) were added in a microwave tube, then DMSO (2 mL) was added. After the mixture was dissolved, DIPEA (0.25 mL, 1.5 mmol) was added, and the mixture was reacted under microwave at 135° C. for about 7 h. After the reaction was completed, 30 mL of ethyl acetate and 15 mL of water were added to the reaction mixture. The aqueous phase was separated and extracted with EA (20 mL×2). The organic phases were combined and washed with saturated brine (20 mL). The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo to remove the organic solvent. The crude product was purified by column chromatography (PE:EA(v/v)=1:5-1:1) to give a pale yellow solid 46 mg. The yield was 69.7%. Rf=0.5 (PE/EA=3/1). LC-MS: 477.1[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.12 (d, J=1.8 Hz, 1H), 7.75 (dd, J=8.7, 2.4 Hz, 1H), 7.58 (d, J=7.1 Hz, 2H), 7.41 (dt, J=14.6, 7.1 Hz, 3H), 7.10 (d, J=1.8 Hz, 1H), 6.80 (d, J=8.8 Hz, 1H), 4.09 (dd, J=13.8, 6.9 Hz, 2H), 4.01-3.95 (m, 2H), 3.87-3.77 (m, 4H), 3.73-3.68 (m, 2H), 1.50 (t, J=6.9 Hz, 3H).

Example 3: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-3-phenylpropynoic acid amide

Step 1: tert-butyl 4-methyl-4-(3-phenylpropynoic acid amide) piperidine-1-carboxylate

To a 25 mL two-necked flask were added tert-butyl 4-amino-4-methyl-piperidine-1-carboxylate (400 mg, 1.8665 mmol) and DCM (8 mL). Phenylpropynoic acid (0.33 g, 2.3 mmol) and DCC (0.6 g, 3 mmol) were added at room temperature. The mixture was stirred for reaction overnight. After the completion of reaction was monitored by TLC, 20 mL of DCM and 15 mL of water were added, and the aqueous phase was separated and extracted with 20 mL of DCM. The organic phases were combined, washed with 15 mL of saturated brine, dried over anhydrous sodium sulfate, and then purified by silica gel column chromatography (eluent PE:EA(v/v)=10:1-4:1) to give a pale yellow solid 128 mg. The yield was 20%. LC-MS: m/z=365.1[M+Na]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 7.55 (d, J=7.0 Hz, 2H), 7.43 (t, J=7.4 Hz, 1H), 7.37 (t, J=7.3 Hz, 2H), 3.84-3.77 (m, 2H), 3.66 (d, J=5.3 Hz, 2H), 3.55-3.50 (m, 2H), 3.46 (d, J=5.4 Hz, 2H), 1.61 (s, 3H), 1.48 (s, 9H).

Step 2: N-(4-methylpiperidin-4-yl)-3-phenylpropiolamide 2,2,2-trifluoroacetate

tert-Butyl 4-(3-phenylpropynoic acid amide)piperidine-1-carboxylate (0.125 g, 0.365 mmol) was dissolved in DCM (5 mL) in a 50 mL single-necked flask, then TFA (0.5 mL) was added. The mixture was stirred and reacted at room temperature. The completion of reaction was monitored by TLC after 5 h. The reaction solution was directly concentrated in vacuo to give a colorless transparent oily liquid product, which was directly used in the next reaction according to the theoretical yield. Rf=0.01 (PE/EA=1/1).

Step 3: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-3-phenylpropynoic acid amide

3-Cyano-4-(6-fluoropyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine (50 mg, 0.1771 mmol, see the synthetic part of the intermediate) and N-(4-methylpiperidin-4-yl)-3-phenylpropiolamide 2,2,2-trifluoroacetate (130 mg, 0.36 mmol) were added in a microwave tube, then DMSO (2 mL) was added. After the mixture was dissolved, DIPEA (0.15 mL, 0.91 mmol) was added, and the mixture was reacted under microwave at 130° C. for 5 h. 30 mL of ethyl acetate and 15 mL of water were added to the reaction mixture. The aqueous phase was separated and extracted with EA (20 mL×2). The organic phases were combined and washed with saturated brine (20 mL). The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo to remove the organic solvent. The crude product was purified by column chromatography (eluent PE:EA(v/v)=1:5-1:1) to give a pale yellow solid 26 mg. The yield was 27.37%. Rf=0.5 (PE/EA=1/1). LC-MS: 505.2[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.36-8.31 (m, 1H), 8.18 (s, 1H), 8.10 (s, 1H), 7.74-7.67 (m, 1H), 7.53 (s, 2H), 7.35 (s, 3H), 7.09 (s, 1H), 6.85-6.76 (m, 1H), 5.77-5.67 (m, 1H), 4.08 (d, J=7.0 Hz, 2H), 4.02-3.92 (m, 2H), 3.47-3.37 (m, 2H), 2.28-2.21 (m, 2H), 1.83-1.74 (m, 2H), 1.54 (s, 3H), 1.49 (t, J=6.9 Hz, 3H).

Example 4: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-4-ethynylbenzamide

Step 1: 4-ethynylbenzoic acid

Methyl 4-ethynylbenzoate (200 mg, 1.2487 mmol) was dissolved in THF (4 mL) in a 25 mL single-necked flask, and tap water (4 mL) containing sodium hydroxide (125 mg, 3.1252 mmol) was added with stirring. The solution was stirred at room temperature after the addition, and the solution was reddish brown. The completion of reaction was monitored by TLC after reaction for 2 h. The reaction mixture was adjusted by adding 1 N diluted hydrochloric acid with stirring to pH=1, then a large amount of pale yellow solid was precipitated. The mixture was transferred to a separatory funnel and extracted with EA (50 mL×3). The organic phases were combined and washed once with saturated sodium chloride (50 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 180 mg. The yield was 98.64%. Rf=0.01 (PE/EA=8/1). LC-MS: m/z=147.1[M+H]⁺. ¹H-NMR (400 MHz, DMSO-d₆) δ 7.93 (d, J=8.2 Hz, 2H), 7.59 (d, J=8.2 Hz, 2H), 4.44 (s, 1H).

Step 2: tert-butyl 4-(4-ethynylbenzoylamino)-4-methylpiperidin-1-carboxylate

To a 25 mL single-necked flask were added tert-butyl 4-amino-4-methyl-piperidine-1-carboxylate (200 mg, 0.93327 mmol) and 4-ethynylbenzoic acid (178 mg, 1.2180 mmol) at 0° C., which were dissolved by adding DCM (4 mL). Then DCC (289 mg, 1.401 mmol) and DMAP (12 mg, 0.098224 mmol) were added with stirring. After the addition, the reaction mixture was naturally warmed to room temperature and the reaction mixture was orange-yellow. The mixture was reacted for 4.5 h, then the completion of reaction was monitored by TLC. To the reaction solution was added 10 mL of water, and the resulting mixture was transferred to a separatory funnel and extracted with DCM (30 mL×3). The organic phases were combined, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE(v/v)=1:3-1:2) to give colorless oil 210 mg. The yield was 65.72%. Rf=0.5 (PE/EA=1/1). LC-MS: m/z=287.20[M-t-Bu+2H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 7.67 (d, J=8.3 Hz, 2H), 7.54 (d, J=8.1 Hz, 2H), 5.79 (s, 1H), 3.70 (s, 2H), 3.20 (d, J=6.2 Hz, 3H), 2.16 (s, 2H), 1.72-1.64 (m, 2H), 1.52 (s, 3H), 1.46 (s, 9H).

Step 3: 4-ethynyl-N-(4-methylpiperidin-4-yl)benzamide 2,2,2-trifluoroacetate

tert-Butyl 4-(4-ethynylbenzoylamino)-4-methylpiperidin-1-carboxylate (210 mg, 0.6133 mmol) was dissolved in DCM (4.2 mL) in a 10 mL single-necked flask, then TFA (0.91 mL) were added dropwise with stirring. After the addition, the mixture was stirred at room temperature. The completion of reaction was monitored by TLC after reaction for 3 h. The reaction solution was directly concentrated in vacuo to give pale yellow transparent oil (230 mg), which was directly used in the next reaction according to the theoretical yield. Rf=0.01 (PE/EA=1/1).

Step 4: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-4-ethynylbenzamide

3-Cyano-6-ethoxy-4-(6-fluoro-pyridin-3-yl)pyrazolo[1,5-a]pyridine (85 mg, 0.3011 mmol, see the synthetic part of the intermediate) and 4-ethynyl-N-(4-methylpiperidin-4-yl)benzamide 2,2,2-trifluoroacetate (215 mg, 0.6034 mmol) were added in a 10 mL microwave tube, then DMSO (1.7 mL) was added. After the mixture was dissolved, DIPEA (0.25 mL, 1.5 mmol) was added, and the mixture was reacted under microwave (temperature 150° C., pressure 10 bar) for 3 h. The completion of reaction was monitored by TLC. After the temperature was cooled to room temperature, the reaction solution was poured into 20 mL of water. A large amount of black solid was precipitated, and the black solid was filtered out. The aqueous phase was extracted with EA (50 mL×3), and the organic phases were combined and washed once with 50 mL of saturated brine. The organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was combined with the black solid and purified by silica gel column chromatography (eluent EA:PE=1:4-1:1) to give a pale yellow solid 24 mg. The yield was 15.80%. Rf=0.2 (PE:EA=1:1). LC-MS: m/z 505.30 [M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.10 (d, J=1.7 Hz, 1H), 7.71 (d, J=8.2 Hz, 3H), 7.55 (d, J=8.2 Hz, 2H), 7.09 (s, 1H), 6.82 (d, J=8.9 Hz, 1H), 5.90 (s, 1H), 4.08 (dd, J=14.1, 7.0 Hz, 2H), 4.01 (d, J=13.4 Hz, 2H), 3.43 (t, J=11.2 Hz, 2H), 3.19 (s, 1H), 2.33 (d, J=12.8 Hz, 2H), 1.92-1.82 (m, 2H), 1.59 (s, 3H), 1.50 (t, J=6.9 Hz, 3H).

Example 5: 3-cyano-6-ethoxy-4-(6-(4-(4-ethynylbenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine

Step 1: tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate

3-Cyano-6-ethoxy-4-(6-fluoro-3-pyridyl)pyrazolo[1,5-a]pyridine (600 mg, 2.125 mmol, see the synthetic part of the intermediate) and tert-butyl piperazine-1-carboxylate (1.19 g, 6.39 mmol) were added in a microwave tube, then DMSO (12 mL) was added. After the mixture was dissolved, DIPEA (0.7 mL, 4 mmol) was added, and the mixture was reacted under microwave (150° C., pressure 10 bar) for 3 h. The completion of reaction was monitored by TLC. After the reaction system was cooled to room temperature, to the reaction solution was added 40 mL of water and the resulting mixture was extracted with EA (100 mL×3). The organic phases were combined and washed with 50 mL of saturated saline. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:4) to give a light yellow solid 630 mg. The yield was 66.09%.

Rf=0.2 (PE:EA=4:1). LC-MS: m/z=449.20[M+H]⁺.

Step 2: 3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate

To a single-necked flask was added tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate (630 mg, 1.405 mmol), which was dissolved by adding DCM (12.6 mL). Then TFA (2.09 mL, 28.1 mmol) was added dropwise with stirring. After the addition was completed, the mixture was stirred and reacted at room temperature for 3 h. The completion of reaction was monitored by TLC. The reaction solution was directly concentrated in vacuo to give a pale yellow solid 657 mg, which was directly used in the next reaction according to the theoretical yield. Rf=0.01 (PE:EA=1:1).

Step 3: 3-cyano-6-ethoxy-4-(6-(4-(4-ethynylbenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine

3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine trifluoroacetate (50 mg, 0.1110 mmol) and 4-ethynylbenzoic acid (20 mg, 0.13686 mmol) were dissolved in DCM (1 mL) in a single-necked flask. DIPEA (28 mg, 0.21665 mmol) and DCC (34 mg, 0.1648 mmol) were added with stirring at 0° C. After the addition, the mixture was naturally warmed to room temperature and stirred overnight. The completion of reaction was monitored by TLC. To the reaction mixture were added water (2 mL) and DCM (5 mL). The organic phase was separated, and the aqueous phase was extracted with DCM (5 mL). The organic phases were combined, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE(v/v)=1:2-2:1) to give a pale yellow solid 16 mg. The yield was 31.05%. Rf=0.4 (PE:EA=1:1). LC-MS: m/z=477.10[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.74 (dd, J=8.7, 2.2 Hz, 1H), 7.56 (d, J=8.1 Hz, 2H), 7.42 (d, J=8.1 Hz, 2H), 7.09 (d, J=1.8 Hz, 1H), 6.79 (d, J=8.8 Hz, 1H), 4.09 (q, J=13.8, 6.8 Hz, 2H), 3.73 (t, J=66.0 Hz, 8H), 3.16 (s, 1H), 1.49 (t, J=6.9 Hz, 3H).

Example 6: 3-cyano-6-ethoxy-4-(6-(4-(3-ethynylbenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine

Step 1: tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate

3-Cyano-6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine (600 mg, 2.125 mmol, see the synthetic part of the intermediate) and tert-butyl piperazine-1-carboxylate (1.19 g, 6.39 mmol) were added in a microwave tube, then DMSO (12 mL) was added. After the mixture was dissolved, DIPEA (0.7 mL, 4 mmol) was added, and the mixture was reacted under microwave (150° C., pressure 10 bar) for 3 h. The completion of reaction was monitored by TLC. After the reaction system was cooled to room temperature, to the reaction solution was added 40 mL of water and the resulting mixture was extracted with EA (100 mL×3). The organic phases were combined and washed with 50 mL of saturated saline. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:4) to give a light yellow solid 630 mg. The yield was 66.09%.

Rf=0.2 (PE:EA=4:1). LC-MS: m/z=449.20[M+H]⁺.

Step 2: 3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate

To a single-necked flask was added tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate (630 mg, 1.405 mmol), which was dissolved by adding DCM (12.6 mL). Then TFA (2.09 mL, 28.1 mmol) was added dropwise with stirring. After the addition was completed, the mixture was stirred and reacted at room temperature for 3 h. The completion of reaction was monitored by TLC, Rf=0.01 (PE:EA=1:1). The reaction solution was directly concentrated in vacuo to give a yellow solid 657 mg, which was directly used in the next reaction according to the theoretical yield.

Step 3: 3-cyano-6-ethoxy-4-(6-(4-(3-ethynylbenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine

3-Cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate (50 mg, 0.1081 mmol) and 3-ethynylbenzoic acid (20 mg, 0.13686 mmol) were dissolved in DCM (1 mL) in a single-necked flask. DIPEA (28 mg, 0.21665 mmol) and DCC (35 mg, 0.1697 mmol) were added with stirring at 0° C. After the addition, the mixture was naturally warmed to room temperature and stirred overnight. The completion of reaction was monitored by TLC. To the reaction mixture were added 2 mL of water and 5 mL of DCM. The organic phase was separated, and the aqueous phase was extracted with DCM (5 mL). The organic phases were combined, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE(v/v)=1:2-2:1) to give a pale yellow solid 17 mg. The yield was 32.99%. Rf=0.4 (PE:EA=1:1). LC-MS: m/z=477.10[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.9 Hz, 1H), 7.75 (dd, J=8.8, 2.4 Hz, 1H), 7.57 (d, J=4.9 Hz, 2H), 7.42 (d, J=7.7 Hz, 2H), 7.09 (d, J=1.9 Hz, 1H), 6.79 (d, J=8.9 Hz, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.73 (t, J=65.5 Hz, 8H), 3.13 (s, 1H), 1.49 (t, J=6.9 Hz, 3H).

Example 7: 3-cyano-6-ethoxy-4-(6-(4-(5-ethynylpyridineformyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine

Step 1: methyl 5-((trimethylsilyl)ethynyl)picolinate

To a three-necked flask were added methyl 5-bromopyridinecarboxylate (500 mg, 2.3145 mmol), CuI (53 mg, 0.27829 mmol) and PdCl₂(PPh₂)₂(49 mg, 0.06981 mmol) under nitrogen. After the mixture was dissolved by adding anhydrous THF (3 mL), ethynyl (trimethyl) silane (273 mg, 2.779 mmol) was added dropwise. The solution was orange and then TEA (1.5 mL) was added dropwise with stirring at room temperature. The solution turned to black. The mixture was reacted for 4 h, then the completion of reaction was monitored by TLC. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. A large amount of brown solid precipitated. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed once with 30 mL of saturated brine. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:5) to give a yellow solid 450 mg. The yield was 83.32%. Rf=0.5 (PE:EA=5:1). LC-MS: m/z=234.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.76 (s, 1H), 8.07 (d, J=8.1 Hz, 1H), 7.87 (dd, J=8.1, 1.8 Hz, 1H), 4.00 (s, 3H), 0.27 (s, 9H).

Step 2: 5-ethynyl picolinic acid

Methyl 5-((trimethylsilyl)ethynyl)picolinate (450 mg, 1.9285 mmol) was dissolved in anhydrous methanol (9 mL) under nitrogen in a double-necked flask, and then potassium carbonate (533 mg, 3.8565 mmol) was added with stirring in one portion at room temperature. The mixture was stirred overnight. The reaction mixture was added with water (20 mL) and adjusted with 1 N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 280 mg. The yield was 98.68%. Rf=0.01 (PE:EA=5:1). LC-MS: m/z=148.10[M+H]⁺. ¹H-NMR (400 MHz, DMSO-d₆) δ 8.78 (s, 1H), 8.08 (d, J=8.1 Hz, 1H), 8.03 (d, J=8.1 Hz, 1H), 4.67 (s, 1H).

Step 3: 5-ethynylpyridineformyl chloride

5-Ethynylpicolinic acid (20 mg, 0.13593 mmol) was dissolved in DCM (5 mL) in a two-necked flask under nitrogen, and DMF (0.01 mL) was added with stirring. After 5 min, SOCl₂ (20 mg, 0.16811 mmol) was added dropwise. After the addition, the solution precipitated with a large amount of yellow solid. The mixture was continuously stirred at this temperature. The solid gradually dissolved over time and the solution gradually turned orange, clear and transparent. The mixture was reacted for 0.5 h and then directly concentrated in vacuo, which was directly used for the next step without further purification. The yield was calculated as 100%.

Step 4: tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate

3-Cyano-6-ethoxy-4-(-6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine (600 mg, 2.125 mmol) and tert-butyl piperazine-1-carboxylate (1.19 g, 6.39 mmol) were added in a microwave tube, then DMSO (12 mL) was added. After the mixture was dissolved, DIPEA (0.7 mL, 4 mmol) was added, and the mixture was reacted under microwave (150° C., pressure 10 bar) for 3 h. The completion of reaction was monitored by TLC, Rf=0.2 (PE:EA=4:1). After the reaction system was cooled to room temperature, to the reaction solution was added 40 mL of water and the resulting mixture was extracted with EA (100 mL×3). The organic phases were combined and washed with 50 mL of saturated saline. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:4) to give a light yellow solid 630 mg. The yield was 66.09%. LC-MS: m/z=449.20[M+H]⁺.

Step 5: 3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate

To a single-necked flask was added tert-butyl 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazine-1-carboxylate (630 mg, 1.405 mmol), which was dissolved by adding DCM (12.6 mL). Then TFA (2.09 mL, 28.1 mmol) was added dropwise with stirring. After the addition was completed, the mixture was stirred and reacted at room temperature for 3 h. The completion of reaction was monitored by TLC. The reaction solution was directly concentrated in vacuo to give a pale yellow solid 657 mg, which was directly used in the next reaction according to the theoretical yield. Rf=0.01 (PE:EA=1:1).

Step 5: 3-cyano-6-ethoxy-4-(6-(4-(5-ethynylpyridine formyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine

5-Ethynylpyridineformyl chloride (21.5 mg, 0.130 mmol) was dissolved in DCM (5 mL) in a double-necked flask under nitrogen, and then TEA (33 mg, 0.32612 mmol), 3-cyano-6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine 2,2,2-trifluoroacetate (50 mg, 0.1081 mmol) were added with stirring. The solution is orange, clear and transparent. The completion of reaction was monitored by TLC after reaction for 2 h. The reaction was added with 2 mL of water and 5 mL of DCM. The organic phase was separated, and the aqueous phase was extracted with DCM (5 mL). The organic phases were combined, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE(v/v)=1:5-1:2) to give an off-white solid 8 mg. The yield was 15.49%. Rf=0.2 (PE:EA=1:1). LC-MS: m/z=478.15[M+H]⁺. ¹H-NMR (600 MHz, CDCl₃) δ 8.70 (s, 1H), 8.35 (s, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.90 (d, J=8.0 Hz, 1H), 7.74 (d, J=8.7 Hz, 1H), 7.72 (d, J=8.0 Hz, 1H), 7.09 (s, 1H), 6.78 (d, J=8.6 Hz, 1H), 4.09 (q, J=6.8 Hz, 2H), 3.97-3.94 (m, 2H), 3.81-3.78 (m, 4H), 3.74-3.71 (m, 2H), 3.31 (s, 1H), 1.50 (t, J=6.9 Hz, 3H).

Example 8: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-5-ethynylpyridine amide

Step 1: methyl 5-((trimethylsilyl)ethynyl)picolinate

To a three-necked flask were added methyl 5-bromopyridinecarboxylate (500 mg, 2.3145 mmol), CuI (53 mg, 0.27829 mmol) and PdCl₂(PPh₂)₂(49 mg, 0.06981 mmol) under nitrogen. After the mixture was dissolved by adding anhydrous THF (3 mL), ethynyl (trimethyl) silane (273 mg, 2.779 mmol) was added dropwise. The solution was orange and then TEA (1.5 mL) was added dropwise with stirring at room temperature. The solution turned to black. The mixture was reacted for 4 h, then the completion of reaction was monitored by TLC. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. A large amount of brown solid precipitated. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed once with 30 mL of saturated brine. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:5) to give a yellow solid 450 mg. The yield was 83.32%. Rf=0.5 (PE:EA=5:1). LC-MS: m/z=234.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.76 (s, 1H), 8.07 (d, J=8.1 Hz, 1H), 7.87 (dd, J=8.1, 1.8 Hz, 1H), 4.00 (s, 3H), 0.27 (s, 9H).

Step 2: 5-ethynyl picolinic acid

Methyl 5-((trimethylsilyl)ethynyl)picolinate (450 mg, 1.9285 mmol) was dissolved in anhydrous methanol (9 mL) under nitrogen in a double-necked flask, and then potassium carbonate (533 mg, 3.8565 mmol) was added with stirring in one portion at room temperature. The mixture was stirred overnight. To the reaction mixture was added water (20 mL) and the resulting mixture was adjusted with 1 N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 280 mg. The yield was 98.68%. Rf=0.01 (PE:EA=5:1). LC-MS: m/z=148.10[M+H]⁺. ¹H-NMR (400 MHz, DMSO-d₆) δ 8.78 (s, 1H), 8.08 (d, J=8.1 Hz, 1H), 8.03 (d, J=8.1 Hz, 1H), 4.67 (s, 1H).

Step 3: 5-ethynylpyridineformyl chloride

5-Ethynylpicolinic acid (50 mg, 0.33984 mmol) was dissolved in DCM (10 mL) in a two-necked flask under nitrogen, and DMF (0.02 mL) was added with stirring. After 5 min, SOCl₂ (50 mg, 0.42027 mmol) was added dropwise. After the addition, the solution precipitated with a large amount of yellow solid. The mixture was continuously stirred at this temperature. The solid gradually dissolved over time and the solution gradually turned orange, clear and transparent. The mixture was reacted for 0.5 h and then directly concentrated in vacuo, which was directly used for the next step without further purification.

Step 4: tert-butyl 4-(5-ethynylpyridinecarboxamido)-4-methylpiperidine-1-carboxylate

tert-Butyl 4-amino-4-methyl-piperidine-1-carboxylate (60 mg, 0.27998 mmol) and 5-ethynylpyridyl acid chloride (56 mg, 0.33821 mmol) were dissolved in DCM (6 mL) with stirring at room temperature in a two-necked flask under nitrogen, and then TEA (57 mg, 0.56330 mmol) was added. After the addition, the solution was continued to stir at this temperature, and the solution was orange-yellow. The mixture was reacted for 3 h, then the completion of reaction was monitored by TLC. To the reaction solution were added 5 mL of water and 10 mL of DCM. The organic phase was separated, and the aqueous phase was extracted with DCM (10 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE(v/v)=1:5-1:3) to give pale yellow oil 90 mg. The yield was 93.61%. Rf=0.3 (PE:EA=3:1). LC-MS: m/z=283.30[M-t-Bu+2H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.59 (s, 1H), 8.11 (dd, J=7.7, 3.8 Hz, 1H), 7.98-7.86 (m, 2H), 3.83-3.69 (m, 2H), 3.33 (s, 1H), 3.14 (dd, J=16.1, 8.4 Hz, 2H), 2.28-2.18 (m, 2H), 1.67-1.64 (m, 2H), 1.51 (s, 3H), 1.44 (s, 9H).

Step 5: 5-ethynyl-N-(4-methylpiperidin-4-yl)pyridinecarboxamide 2,2,2-trifluoroacetate

tert-Butyl 4-(5-ethynylpyridineamido)-4-methylpiperidin-1-carboxylate (90 mg, 0.2621 mmol) was dissolved in DCM (2 mL) in a single-necked flask, then TFA (0.39 mL, 5.3 mmol) were added dropwise with stirring at room temperature. After the addition, the mixture was reacted continuously at this temperature. The mixture was reacted for 3 h, then the completion of reaction was monitored by TLC, Rf=0.01 (PE:EA=3:1). The reaction mixture was concentrated in vacuo to give light yellow oil 150 mg.

Step 6: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-5-ethynylpyridine amide

3-Cyano-6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine (50 mg, 0.1771 mmol, see the synthetic part of the intermediate) and 5-ethynyl-N-(4-methylpiperidin-4-yl)pyridinecarboxamide 2,2,2-trifluoroacetate (95 mg, 0.2659 mmol) were added in a microwave tube, then DMSO (2 mL) was added. After the mixture was dissolved, DIPEA (0.09 mL, 0.5 mmol) was added, and the mixture was reacted under microwave (150° C., 10 bar) for 2.5 h. To the reaction solution was added 10 mL of water and the resulting mixture was extracted with EA (30 mL×3). The organic phases were combined and washed with 30 mL of saturated saline once. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:5-1:1) to give a light yellow solid 18 mg, Rf=0.5 (PE:EA=2:1). The yield was 20.10%. LC-MS: m/z=506.20[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.60 (s, 1H), 8.31 (d, J=2.3 Hz, 1H), 8.17 (s, 1H), 8.13 (d, J=8.0 Hz, 1H), 8.08 (d, J=1.9 Hz, 1H), 8.05 (s, 1H), 7.91 (dd, J=8.1, 1.9 Hz, 1H), 7.68 (dd, J=8.9, 2.5 Hz, 1H), 7.06 (d, J=2.0 Hz, 1H), 6.78 (d, J=8.9 Hz, 1H), 4.12-4.06 (m, 4H), 3.40-3.33 (m, 2H), 3.32 (s, 1H), 2.41-2.35 (m, 2H), 1.81 (t, J=10.3 Hz, 2H), 1.57 (s, 3H), 1.48 (t, J=6.9 Hz, 3H).

Example 9: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-3-ethynylbenzamide

Step 1: tert-butyl 4-(3-ethynylbenzoylamino)-4-methylpiperidin-1-carboxylate

tert-Butyl 4-amino-4-methyl-piperidin-1-carboxylate (500 mg, 2.33 mmol), 3-ethynylbenzoic acid (409 mg, 2.80 mmol), DCC (729 mg, 3.50 mmol) and DMAP (28 mg, 0.23 mmol) were added in a 50 mL reaction flask. The reaction mixture was degassed and refilled with nitrogen, and then stirred and reacted at room temperature overnight. After the completion of reaction was monitored by TLC, the white insoluble solid of the reaction mixture was filtered by sand core funnel, and the filter cake was washed twice with methylene chloride. The filtrate was concentrated in vacuo and purified by silica gel column chromatography (PE:EA=6:1-4:1) to give a white solid 795 mg as the desired product (yield: 99.5%). LC-MS: m/z=365.20 [M+Na]⁺, 287.20 [M-tBu+2H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 7.79 (s, 1H), 7.72 (d, J=7.8 Hz, 1H), 7.60 (d, J=7.7 Hz, 1H), 7.41 (t, J=7.8 Hz, 1H), 5.79 (s, 1H), 3.70 (br s, 2H), 3.21 (ddd, J=13.6, 10.3, 3.2 Hz, 2H), 3.13 (s, 1H), 2.18 (br s, 2H), 1.72-1.64 (m, 2H), 1.52 (s, 3H), 1.46 (s, 9H).

Step 2: 4-(3-ethynylbenzoylamino)-4-methylpiperidin-1-ium 2,2,2-trifluoroacetate

tert-Butyl 4-(3-ethynylbenzoylamino)-4-methylpiperidine-1-carboxylate (790 mg, 2.31 mmol) was dissolved in DCM (23 mL). Trifluoroacetic acid (1.7 mL, 23 mmol) was added with stirring. The mixture was reacted overnight. The completion of reaction was monitored by TLC. The resulting mixture was concentrated in vacuo to give the crude product, which was used in the next step without further purification. The reaction was carried out in 100% yield. LC-MS: m/z=243.1 [M-CF₃COO]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 8.46 (br s, 1H), 8.23 (br s, 1H), 7.78 (s, 1H), 7.66 (dd, J=18.3, 7.8 Hz, 2H), 7.42 (t, J=7.8 Hz, 1H), 6.18 (s, 1H), 3.33 (br s, 4H), 3.15 (s, 1H), 2.64 (d, J=15.0 Hz, 2H), 2.02-1.90 (m, 2H), 1.58 (s, 3H).

Step 3: N-(1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-3-ethynylbenzamide

4-(3-Ethynylbenzoylamino)-4-methylpiperidine-1-ium 2,2,2-trifluoroacetate (126 mg, 0.36 mmol) and 6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (47.8 mg, 0.17 mmol) were dissolved in DMSO (2 mL), then DIPEA (0.22 mL, 1.3 mmol) was added, and the mixture was stirred for 3 h under microwave (150° C., 10 bar, pre-mixed for 30 s). The reaction mixture was cooled to room temperature, then diluted with EA (100 mL), and the organic phases were washed with water (20 mL) and saturated brine (20 mL) in turn, dried over anhydrous sodium, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=2:1-1.5:1) to give a pale yellow solid 20.3 mg (yield: 53.2%) as the desired product. LC-MS: m/z=505.3 [M+H]⁺; ¹H-NMR (600 MHz, CDCl₃) δ 8.33 (s, 1H), 8.18 (s, 1H), 8.09 (s, 1H), 7.83 (s, 1H), 7.74 (d, J=7.4 Hz, 1H), 7.70 (d, J=8.5 Hz, 1H), 7.60 (d, J=7.2 Hz, 1H), 7.40 (d, J=7.5 Hz, 1H), 7.08 (s, 1H), 6.80 (d, J=8.7 Hz, 1H), 5.94 (s, 1H), 4.12-4.04 (m, 2H), 3.99 (d, J=13.2 Hz, 2H), 3.41 (t, J=10.7 Hz, 2H), 3.12 (s, 1H), 2.32 (d, J=13.1 Hz, 2H), 1.84 (t, J=9.9 Hz, 2H), 1.58 (s, 3H), 1.49 (t, J=5.9 Hz, 3H).

Example 257: 4-(6-(6-((6-ethynyl-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 6-((trimethylsilyl)ethynyl)pyridine

To a mixture of 6-bromopyridine-3-carbaldehyde (1000 mg, 5.3761 mmol), bis(triphenylphosphine)palladium dichloride (151 mg, 0.215128 mmol) and cuprous iodide (52 mg, 0.27304 mmol) were sequentially added triethylamine (8.1 mL, 58 mmol) and trimethylsilylacetylene (1.52 mL, 10.8 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature for 7 h. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=10:1-8:1) to give a yellow white solid 0.66 g (yield: 60%) as the target product.

Step 2: 6-ethynyl nicotinic aldehyde

To a 25 mL single-necked flask were sequentially added 6-((trimethylsilyl)ethynyl)pyridine (660 mg, 3.2463 mmol), potassium carbonate (897 mg, 6.4901 mmol) and methanol (8.12 mL). The mixture was stirred to react at room temperature overnight. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (20 mL×2). The organic phases were combined, and then washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=10:1-4:1) to afford a white solid 240 mg (yield: 56.4%) as the target product. LC-MS(ESI): m/z=132.1 [M+H]⁺.

Step 3: 4-(6-(6-((6-ethynyl-3-yl)methyl))-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxyl-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride (see synthesis of intermediate 3, 25 mg, 0.05237 mmol), 6-ethynylnicotinaldehyde (10 mg, 0.076260 mmol), DCM (2 mL) and sodium triacetylborohydride (45 mg, 0.21232 mmol). The mixture was reacted overnight. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/4) to give a white solid 12 mg (the yield was 44.10%), which was the target product. LC-MS(ESI): m/z=520.2 [M+H]; ¹H NMR (400 MHz, CDCl₃) δ 8.58 (s, 1H), 8.41 (d, J=2.2 Hz, 1H), 8.22 (s, 1H), 8.16 (d, J=2.0 Hz, 1H), 7.78 (dd, J=8.8, 2.5 Hz, 1H), 7.73 (d, J=7.5 Hz, 1H), 7.45 (d, J=8.0 Hz, 1H), 7.17 (d, J=2.0 Hz, 1H), 6.69 (d, J=8.8 Hz, 1H), 3.87 (s, 2H), 3.85-3.77 (m, 4H), 3.68 (s, 2H), 3.66-3.58 (m, 2H), 3.13 (s, 1H), 2.78-2.69 (m, 1H), 2.05-1.98 (m, 1H), 1.40 (s, 6H). HPLC: 97.65%.

Example 258: 4-(6-(6-((5-ethynylpyridine-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 5-((trimethylsilyl)ethynyl)pyridine

To a mixture of 5-bromo-pyridine-3-carbaldehyde (600 mg, 3.2256 mmol), bis(triphenylphosphine)palladium dichloride (90 mg, 0.128222 mmol) and cuprous iodide (30 mg, 0.15752 mmol) were sequentially added triethylamine (4.8 mL, 34 mmol) and trimethylsilylacetylene (0.91 mL, 6.4 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=20:1) to give a pale yellow solid 591 mg (yield: 90%) as the target product.

Step 2: 5-ethynyl nicotinic aldehyde

To a solution of 5-((trimethylsilyl)ethynyl)pyridine (591 mg, 2.9069 mmol) in methanol (7.3 mL) was added potassium carbonate (40 mg, 0.28941 mmol) at room temperature, and the mixture was reacted at room temperature for 1 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=15:1) to afford a white solid 350 mg (yield: 91.8%) as the target product. LC-MS(ESI): m/z=132.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 10.10 (s, 1H), 9.02 (s, 1H), 8.92 (s, 1H), 8.22 (s, 1H), 3.32 (s, 1H).

Step 3: 4-(6-(6-((5-ethynylpyridin-3-yl)methyl))-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-neck flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine 3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 12 mg, 0.02967 mmol), 5-ethynylnicotinaldehyde (10 mg, 0.076260 mmol), sodium triacetoxyborohydride (19 mg, 0.089648 mmol) and DCE (2 mL). The mixture was reacted for 4.5 h. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/4) to give a white solid 4 mg (the yield was 24.0%), which was the target product. LC-MS(ESI): m/z=520.0 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.40 (d, J=2.0 Hz, 1H), 8.21 (s, 1H), 8.16 (d, J=1.1 Hz, 1H), 7.78 (dd, J=9.0, 2.5 Hz, 1H), 7.44-7.39 (m, 1H), 7.15 (s, 1H), 7.09-7.04 (m, 2H), 6.70 (d, J=8.5 Hz, 1H), 4.01-3.95 (m, 2H), 3.92-3.84 (m, 4H), 3.74-3.63 (m, 4H), 3.59-3.48 (m, 4H), 2.79-2.74 (m, 1H), 2.25-2.18 (m, 1H), 1.40 (s, 6H). HPLC: 93.76%.

Example 259: 4-(6-(6-(4-ethynylbenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-((trimethylsilyl)ethynyl)benzaldehyde

To a mixture of 4-bromobenzaldehyde (600 mg, 3.2429 mmol), bis(triphenylphosphine)palladium dichloride (91 mg, 0.129647 mmol) and cuprous iodide (30 mg, 0.15752 mmol) were sequentially added triethylamine (4.9 mL, 35 mmol) and trimethylsilylacetylene (0.92 mL, 6.5 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=20:1) to give a yellow solid 631 mg (yield: 96.2%) as the target product.

Step 2: 4-ethynyl benzaldehyde

To a solution of 4-((trimethylsilyl)ethynyl)benzaldehyde (631 mg, 3.1188 mmol) in methanol (7.8 mL) was added K₂CO₃ (43 mg, 0.31112 mmol) at room temperature. The mixture was reacted at room temperature for 4 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=15:1) to afford a white solid 378 mg (yield: 93.1%) as the target product. LC-MS(ESI): m/z=131.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 9.99 (s, 1H), 7.82 (d, J=8.2 Hz, 2H), 7.61 (d, J=8.1 Hz, 2H), 3.29 (s, 1H).

Step 3: 4-(6-(6-(4-ethynylbenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.03708 mmol), 4-ethynylbenzaldehyde (10 mg, 0.076840 mmol), sodium triacetoxyborohydride (24 mg, 0.11324 mmol) and DCE (2 mL). The mixture was reacted at 35° C. overnight. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/4) to give a white solid 12 mg (the yield was 57.7%), which was the target product. LC-MS(ESI): m/z=519.1 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.41 (d, J=1.9 Hz, 1H), 8.22 (s, 1H), 8.16 (d, J=1.7 Hz, 1H), 7.78 (dd, J=8.8, 2.3 Hz, 1H), 7.45 (d, J=8.0 Hz, 2H), 7.36 (d, J=7.7 Hz, 2H), 7.17 (d, J=1.6 Hz, 1H), 6.69 (d, J=8.9 Hz, 1H), 3.89-3.80 (m, 6H), 3.72-3.57 (m, 5H), 3.05 (s, 1H), 2.82-2.72 (m, 1H), 2.05-1.99 (m, 1H), 1.40 (s, 6H). HPLC: 95.37%.

Example 260: 4-(6-(6-((5-ethynylpyridine-2-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydro-2-methylpropoxy)pyrazole[1,5-a]pyridine-3-carbonitrile

Step 1: 5-((trimethylsilyl)ethynyl)pyridine aldehyde

5-Bromopyridine-2-acetaldehyde (1.00 g, 5.38 mmol), PdCl₂(PPh₃)₂(0.38 g, 0.54 mmol), CuI (102 mg, 0.54 mmol) and PPh₃ (141 mg, 0.54 mmol) were dissolved in THE (15 mL) Under N₂, then trimethylsilylacetylene (0.79 g, 8.0 mmol) and Et₃N (1.09 g, 10.8 mmol) were added. The mixture was reacted with stirring at room temperature for 2 h. The reaction was stopped and quenched with saturated NH₄Cl. The resulting mixture was extracted with EA (10 mL×3), washed with water, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo and then purified by silica gel column chromatography (eluent PE/EA=10/1-3/1) to give a yellow-brown solid 0.69 g as the target product (the yield was 63%). LC-MS: m/z=204.1[M+H]⁺.

Step 2: 4-(6-(6-((5-ethynylpyridine-2-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydro-2-methylpropoxy)pyrazole[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 19 mg, 0.04 mmol) and 5-((trimethylsilyl)ethynyl)pyridine aldehyde (12 mg, 0.06 mmol) were dissolved in DCE (2 mL). Then sodium triacetoxyborohydride (165 mg, 1.19 mmol) was slowly added and the mixture was stirred and reacted at room temperature for 12 h. The reaction solution was directly concentrated in vacuo. The residue was dissolved with CH₃OH (5 mL), then added with K₂CO₃ (0.30 g). The mixture was stirred at room temperature for 0.5 h. The reaction mixture was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/CH₃OH=50/1-20/1) to give a yellow-brown solid 4 mg as the target product. LC-MS: m/z=520.1[M+H]. ¹H NMR (400 MHz, CDCl₃) δ 8.66 (s, 1H), 8.42 (d, J=2.1 Hz, 1H), 8.23 (s, 1H), 8.19 (d, J=1.7 Hz, 1H), 7.85-7.74 (m, 2H), 7.45 (d, J=8.1 Hz, 1H), 7.18 (d, J=1.8 Hz, 1H), 6.73 (d, J=8.9 Hz, 1H), 4.08-3.92 (m, 4H), 3.89 (s, 2H), 3.88 (s, 2H), 3.71 (d, J=11.4 Hz, 2H), 3.21 (s, 1H), 2.90-2.81 (m, 1H), 1.78-1.72 (m, 1H), 1.42 (s, 6H). HPLC: 97.24%.

Example 261: 4-(6-(6-((6-ethynylpyridine-2-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 6-(2-trimethylsilylethynyl)pyridin-2-carbaldehyde

To a mixture of 6-bromopyridine-2-carbaldehyde (600 mg, 3.226 mmol), bis(triphenylphosphine)palladium dichloride (90 mg, 0.128 mmol) and cuprous iodide (30 mg, 0.157 mmol) were sequentially added triethylamine (4.8 mL, 34 mmol) and trimethylsilylacetylene (0.91 mL, 6.4 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=10:1) to give a yellow solid 398 mg (yield: 60.7%) as the target product.

Step 2: 6-ethynylpyridinecarboxaldehyde

To a solution of 6-(2-trimethylsilylethynyl)pyridine-2-carbaldehyde (398 mg, 1.957 mmol) in methanol (4.9 mL) was added K₂CO₃ (27 mg, 0.195 mmol) at room temperature. The mixture was reacted at room temperature for 1 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=10:1) to afford a white solid 214 mg (yield: 83.4%) as the target product. LC-MS(ESI): m/z=132.1 5[M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 10.04 (s, 1H), 7.92 (dd, J=7.7, 0.9 Hz, 1H), 7.86 (t, J=7.7 Hz, 1H), 7.68 (dd, J=7.6, 1.0 Hz, 1H), 3.26 (s, 1H).

Step 3: 4-(6-(6-((6-ethynylpyridin-2-yl)methyl))-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.037 mmol), 6-ethynylpyridinecarboxaldehyde (10 mg, 0.076 mmol), sodium triacetoxyborohydride (24 mg, 0.113 mmol) and DCE (2 mL). The mixture was reacted at 35° C. overnight. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/3) to give a white solid 12 mg (the yield was 57.62%), which was the target product. LC-MS(ESI): m/z=520.1 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.38 (d, J=1.8 Hz, 1H), 8.21 (s, 1H), 8.16 (d, J=1.6 Hz, 1H), 7.76 (dd, J=8.7, 2.1 Hz, 1H), 7.65 (t, J=7.8 Hz, 1H), 7.49 (d, J=7.7 Hz, 1H), 7.36 (d, J=7.4 Hz, 1H), 7.17 (d, J=1.6 Hz, 1H), 6.68 (d, J=8.7 Hz, 1H), 3.93-3.84 (m, 6H), 3.82 (s, 2H), 3.68-3.57 (m, 2H), 3.11 (s, 1H), 2.85-2.70 (m, 1H), 2.06-1.95 (m, 1H), 1.40 (s, 6H). HPLC: 92.41%.

Example 263: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(2-methoxypyridin-4-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.10.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(2-methoxypyridin-4-yl)prop-2-yn-1-ol

To a 50 mL two-necked flask were sequentially added 4-bromo-2-methoxy-pyridine (500 mg, 2.6593 mmol), Pd(PPh₃)₂Cl₂ (9.4 mg, 0.013 mmol) and CuI (20 mg, 0.10502 mmol). The reaction mixture was degassed and refilled with nitrogen, and then was added with propargyl alcohol (0.31 mL, 5.3 mmol), THE (5 mL) and Et₃N (2.5 mL, 18 mmol). The resulting mixture was reacted at 80° C. overnight. The reaction mixture was filtered, then washed with EA (100 mL). The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=50:1-20:1) to give a pale yellow solid 245 mg as the target product. ¹H NMR (400 MHz, CDCl₃) δ 8.13 (d, J=5.2 Hz, 1H), 6.89 (d, J=5.2 Hz, 1H), 6.79 (s, 1H), 4.52 (d, J=4.3 Hz, 2H), 3.95 (s, 3H), 1.86 (s, 1H).

Step 2: 3-(2-methoxypyridin-4-yl)propynal

To a solution of 3-(2-methoxypyridin-4-yl)prop-2-yn-1-ol (240 mg, 1.4709 mmol) in DCE (22 mL) were sequentially added sodium bicarbonate (618 mg, 7.35 mmol) and Dess Martin reagent (945 mg, 2.20577 mmol) at room temperature. The mixture was reacted for 1.5 h at room temperature. The reaction was quenched with saturated Na₂S₂O₃ and the resulting mixture was extracted with DCM (30 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo and purified by silica gel column chromatography (PE:EA=50:1-20:1) to give a white fluffy solid 210 mg as the target product (yield: 88.591%). LC-MS(ESI): m/z=162.0[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 9.45 (s, 1H), 8.24 (d, J=5.2 Hz, 1H), 7.01 (d, J=5.2 Hz, 1H), 6.93 (s, 1H), 3.97 (s, 3H).

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(2-methoxypyridin-4-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.10.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.03708 mmol), 3-(2-methoxy-4-pyridyl)prop-2-ynaldehyde (12 mg, 0.074460 mmol), sodium triacetoxyborohydride (24 mg, 0.10984 mmol) and DCE (2 mL). The mixture was reacted at 35° C. overnight. Then the mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM:MeOH=0-30:1) to give a pale yellow solid 4 mg as the target product (the yield was 19.63%), Rf=0.5 (DCM/MeOH=20/1). LC-MS: m/z=550 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.43 (s, 1H), 8.24 (s, 1H), 8.20 (d, J=1.5 Hz, 1H), 8.12 (d, J=5.3 Hz, 1H), 7.83 (d, J=6.4 Hz, 1H), 7.55 (d, J=8.2 Hz, 1H), 7.37 (s, 1H), 7.18 (d, J=1.9 Hz, 1H), 6.74 (d, J=8.8 Hz, 1H), 5.36 (s, 2H), 5.32 (s, 3H), 3.94 (s, 2H), 3.89 (s, 2H), 3.66 (s, 2H), 2.36 (s, 1H), 2.24 (s, 1H), 1.42 (s, 6H). HPLC: 91.59%.

Example 265: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(6-methoxypyridin-3-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.10.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(6-methoxypyridin-3-yl)prop-2-yn-1-ol

To a mixture of 5-bromo-2-methoxypyridine (500 mg, 2.66 mmol), Pd(PPh₃)₂Cl₂ (93 mg, 0.13 mmol) and CuI (25 mg, 0.13 mmol) were added Et₃N (4.0 mL, 29 mmol) and 2-propyn-1-ol (0.76 mL, 13 mmol) at room temperature under nitrogen. The mixture was reacted at 80° C. overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA(v/v)=3:1) to give a pale yellow solid 80 mg (yield: 18.4%). LC-MS: m/z=164.20 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J=1.7 Hz, 1H), 7.59 (dd, J=8.6, 2.2 Hz, 1H), 6.69 (d, J=8.6 Hz, 1H), 4.49 (s, 2H), 3.94 (s, 3H).

Step 2: 3-(6-methoxypyridin-3-yl)propynal

To a solution of 3-(6-methoxypyridin-3-yl)prop-2-yn-1-ol (80 mg, 0.49 mmol) in DCM (4.9 mL) were added NaHCO₃ (207 mg, 2.45) and Dess-Martin oxidant (420 mg, 0.98 mmol) in turn at room temperature, and the mixture was reacted for 1 h at room temperature. The reaction was quenched with saturated Na₂S₂O₂ (5 mL). After the layering was clear, the mixture was extracted with DCM (20 mL×2). The organic phases were combined and dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=4:1) to give a pale yellow solid 56 mg (yield: 70.9%). LC-MS: m/z=162.10 [M+H]⁺; ¹H NMR (600 MHz, CDCl₃) δ 9.43 (s, 1H), 8.48 (d, J=2.3 Hz, 1H), 7.76 (dd, J=8.6, 2.3 Hz, 1H), 6.80 (d, J=8.6 Hz, 1H), 4.01 (s, 3H).

Step 3: tert-butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate

To a microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (183 mg, 0.56 mmol), tert-butyl 3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (133 mg, 0.67 mmol), potassium carbonate (542 mg, 3.92 mmol) and DMSO (3 mL). The mixture was stirred at room temperature for 10 min, then transferred to 100° C. to react under microwave for 4 h. After the reaction was completed, the reaction solution was added to 15 mL of cold water, extracted with EA (30 mL×3), and the organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and then purified by silica gel column chromatography (PE/EA=9/1-2/1) to obtain a white solid raw material 58 mg and a white solid product 105 mg. The yield was 37.1%. LC-MS: m/z=505.2[M+H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.14 (d, J=1.9 Hz, 1H), 7.73 (dd, J=8.8, 2.4 Hz, 1H), 7.15 (d, J=2.0 Hz, 1H), 6.65 (d, J=8.8 Hz, 1H), 4.31 (d, J=4.5 Hz, 2H), 4.22-4.13 (m, 2H), 3.86 (s, 2H), 3.63-3.45 (m, 2H), 2.72-2.63 (m, 1H), 2.19-2.09 (m, 1H), 1.67 (s, 1H), 1.38 (d, J=4.0 Hz, 15H).

Step 4: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride

tert-Butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (100 mg, 0.198 mmol) and 4 mol/L methanolic hydrochloric acid (5 mL, 20 mmol) were added in a 25 mL single-necked flask in one portion. The mixture was stirred and reacted overnight at room temperature. After the completion of reaction was monitored by TLC, the reaction solution was concentrated in vacuo directly to obtain a pale red solid, which was used in the next step directly without further purification. The yield was calculated as 100%.

Step 5: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(6-methoxypyridin-3-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.10.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride (12 mg, 0.030 mmol), 3-(6-methoxypyridine-3-yl)propynal (10 mg, 0.062 mmol), sodium triacetoxyborohydride (19 mg, 0.090 mmol) and DCM (2 mL) were added sequentially to a 10 mL single-necked flask. The mixture was reacted at 35° C. overnight. After the reaction was completed, the reaction solution was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH(v/v)=100/0-100/4) to give a white solid 11.5 mg (yield: 65.3%). LC-MS: m/z=550.3[M+1]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.39 (d, 1H), 8.24 (d, 1H), 8.21 (s, 1H), 8.16 (d, 1H), 7.78 (dd, 1H), 7.58 (dd, 1H), 7.15 (d, 1H), 6.70 (d, 1H), 6.67 (d, 1H), 3.99-3.94 (m, 2H), 3.93 (s, 3H), 3.89-3.83 (m, 4H), 3.71-3.62 (m, 2H), 3.51 (s, 2H), 2.81-2.73 (m, 1H), 1.70-1.68 (m, 1H), 1.40 (s, 6H).

Example 266: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(prop-2-yn-1-yl)-3,6-diazabicyclo [3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 4-(6-(3,6-diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.031 mmol), potassium carbonate (33 mg, 0.238 mmol) and acetonitrile (1.0 mL). Then bromopropyne (4.5 mg, 0.038 mmol) was added slowly. The resulting mixture was stirred at room temperature overnight. The reaction solution was filtered, and the filtrate was concentrated in vacuo. The residue was purified by silica gel column chromatography (eluent DCM/MeOH=50:1-30:1) to give a yellow solid 11 mg as the target product (the yield was 79.12%). (Rf=0.15, DCM/MeOH=30/1). LC-MS(ES-API): m/z=443.45 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.41 (d, J=2.2 Hz, 1H), 8.26-8.15 (m, 2H), 7.79 (dd, J=8.8, 2.4 Hz, 1H), 7.17 (d, J=2.0 Hz, 1H), 6.70 (d, J=8.8 Hz, 1H), 3.95-3.87 (m, 4H), 3.82 (d, J=12.0 Hz, 2H), 3.63 (d, J=11.6 Hz, 2H), 3.29 (d, J=2.2 Hz, 2H), 2.73 (dd, J=13.7, 6.3 Hz, 1H), 2.23 (t, J=2.4 Hz, 1H), 2.03 (s, 1H), 1.42 (s, 6H). HPLC: 96.94%.

Example 285: 6-ethoxy-4-(6-(4-propargylpiperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-propargylpiperazin-1-carboxylate

To a solution of 1-Boc-piperazine (1.00 g, 5.37 mmol) in acetonitrile (27 mL) were added potassium carbonate (1.11 g, 8.03 mmol) and 3-bromopropyne (0.5 mL, 6 mmol) sequentially. The mixture was stirred at room temperature overnight. The reaction solution was filtered, the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH(v/v)=30:1) to give yellow oil 1.03 g (yield: 85.5%) as the desired product. LC-MS: m/z=225.15[M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 3.46 (t, J=4.9 Hz, 4H), 3.30 (d, J=2.3 Hz, 2H), 2.50 (t, J=4.8 Hz, 4H), 2.25 (t, J=2.3 Hz, 1H), 1.45 (s, 9H).

Step 2: 1-propargylpiperazine

tert-Butyl 4-propargylpiperazin-1-carboxylate (1.03 g, 4.59 mmol) was dissolved in DCM (46 mL) at 0° C., and then trifluoroacetic acid (3.4 mL, 46.0 mmol) was added with stirring. After the addition, the mixture was removed from the cold bath and naturally warmed to room temperature. The mixture was reacted overnight. After the completion of reaction was monitored by TLC, the mixture was adjusted with saturated sodium carbonate solution to pH=11. The aqueous phase was extracted with DCM (30 mL×5), and the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give light yellow oil 350 mg (yield: 61.4%) as a crude product which became a yellow solid after standing overnight. LC-MS: m/z=125.20[M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 3.28 (d, J=2.2 Hz, 2H), 3.02-2.85 (m, 4H), 2.53 (br s, 4H), 2.24 (t, J=2.2 Hz, 1H).

Step 3: 6-ethoxy-4-(6-(4-propargylpiperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

1-propargylpiperazine (39 mg, 0.31 mmol) and 3-cyano-6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine (30 mg, 0.11 mmol) were dissolved in DMSO (1 mL), then DIPEA (0.10 mL, 0.60 mmol) was added, and the mixture was stirred for 3.5 h under microwave (150° C., 10 bar, pre-mixed for 30 s). After the completion of the reaction, the reaction mixture was cooled to room temperature, then diluted with EA (100 mL), and the organic phases were washed with water (20 mL) and saturated brine (20 mL) in turn, dried over anhydrous sodium, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=1:1-1:1.5) to give a pale yellow solid 20.6 mg (yield: 50.2%) as the desired product. LC-MS: m/z=387.15 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J=2.2 Hz, 1H), 8.18 (s, 1H), 8.10 (d, J=1.9 Hz, 1H), 7.72 (dd, J=8.8, 2.5 Hz, 1H), 7.08 (d, J=1.9 Hz, 1H), 6.77 (d, J=8.8 Hz, 1H), 4.08 (q, J=7.0 Hz, 2H), 3.70 (t, J=4.9 Hz, 4H), 3.38 (d, J=2.3 Hz, 2H), 2.70 (t, J=5.0 Hz, 4H), 2.28 (t, J=2.2 Hz, 1H), 1.49 (t, J=6.9 Hz, 3H).

Example 286: 4-(6-(6-(3-ethynylbenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxyl-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-((trimethylsilyl)ethynyl)benzaldehyde

To a mixture of 3-iodobenzaldehyde (800 mg, 3.45 mmol), DPEPhos (75 mg, 0.14 mmol), Pd(PPh₃)₂Cl₂ (96 mg, 0.14 mmol) and CuI (32 mg, 0.17 mmol) were sequentially added Et₃N (5.2 mL, 37 mmol) and trimethylsilylacetylene (0.98 mL, 6.9 mmol) at room temperature under nitrogen. The mixture was reacted overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=10:1) to give light brown oil 687 mg (yield: 98.5%). LC-MS: m/z=203.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 9.98 (s, 1H), 7.96 (s, 1H), 7.82 (d, J=7.7 Hz, 1H), 7.70 (d, J=7.7 Hz, 1H), 7.47 (t, J=7.7 Hz, 1H), 0.26 (s, 9H).

Step 2: 3-ethynyl benzaldehyde

To a solution of 3-((trimethylsilyl)ethynyl)benzaldehyde (680 mg, 3.36 mmol) in MeOH (8.4 mL) was added K₂CO₃ (46 mg, 0.33 mmol) at room temperature, and the mixture was reacted at room temperature for 4.5 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=10:1) to afford a light yellow solid 360 mg (yield: 82.3%). ¹H NMR (400 MHz, CDCl₃) δ 10.00 (s, 1H), 7.99 (s, 1H), 7.87 (d, J=7.7 Hz, 1H), 7.74 (d, J=7.7 Hz, 1H), 7.51 (t, J=7.7 Hz, 1H), 3.16 (s, 1H).

Step 3: tert-butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate

To a microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (183 mg, 0.56 mmol), tert-butyl 3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (133 mg, 0.67 mmol), potassium carbonate (542 mg, 3.92 mmol) and DMSO (3 mL). The mixture was stirred at room temperature for 10 min, then transferred to 100° C. to react under microwave for 4 h. After the reaction was completed, the reaction solution was added to 15 mL of cold water, extracted with EA (30 mL×3), and the organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and then purified by silica gel column chromatography (PE/EA=9/1-2/1) to obtain a white solid raw material 58 mg and a white solid product 105 mg. The yield was 37.1%. LC-MS: m/z=505.2[M+H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.14 (d, J=1.9 Hz, 1H), 7.73 (dd, J=8.8, 2.4 Hz, 1H), 7.15 (d, J=2.0 Hz, 1H), 6.65 (d, J=8.8 Hz, 1H), 4.31 (d, J=4.5 Hz, 2H), 4.22-4.13 (m, 2H), 3.86 (s, 2H), 3.63-3.45 (m, 2H), 2.72-2.63 (m, 1H), 2.19-2.09 (m, 1H), 1.67 (s, 1H), 1.38 (d, J=4.0 Hz, 15H).

Step 4: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride

tert-Butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (100 mg, 0.198 mmol) and 4 mol/L methanolic hydrochloric acid (5 mL, 20 mmol) were sequentially added in a 25 mL single-necked flask. The mixture was stirred and reacted overnight at room temperature. After the reaction was completed, the reaction solution was concentrated in vacuo directly to obtain a pale red solid, which was used in the next step directly without further purification. The yield was calculated as 100%.

Step 5: 4-(6-(6-(3-ethynylbenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride (12 mg, 0.030 mmol), 3-ynylbenzaldehyde (13 mg, 0.10 mmol), sodium triacetoxyborohydride (31 mg, 0.146 mmol) and DCM (2 mL). The mixture was reacted at 35° C. overnight. After the reaction was completed, the reaction solution was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH(v/v)=100/0-100/4) to give a white solid 16.5 mg (yield: 62.8%). LC-MS: m/z=519.1[M+1]⁺; ¹H NMR (400 MHz, DMSO-d₆) δ 8.68 (s, 1H), 8.58 (s, 1H), 8.43 (s, 1H), 7.88 (d, J=7.7 Hz, 1H), 7.83-7.63 (m, 1H), 7.62-7.34 (m, 3H), 7.30 (s, 1H), 6.83 (s, 1H), 4.74 (s, 1H), 4.72-4.59 (m, 1H), 4.51-4.34 (m, 1H), 4.36-4.13 (m, 2H), 4.16-3.98 (m, 2H), 4.01-3.62 (m, 7H), 1.23 (s, 6H).

Example 287: 4-(6-(6-((2-ethynylpyridin-4-yl)methyl))-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 2-((trimethylsilyl)ethynyl)-4-formylpyridine

To a mixture of 2-bromo-4-formylpyridine (600 mg, 3.23 mmol), Pd(PPh₃)₃Cl₂ (90 mg, 0.13 mmol) and CuI (30 mg, 0.16 mmol) were added Et₃N (4.8 mL, 34 mmol) and trimethylsilylacetylene (0.91 mL, 6.4 mmol) in turn at room temperature under nitrogen. The mixture was stirred at room temperature overnight, concentrated in vacuo to remove the solvent. The residue was purified by silica gel column chromatography (PE:EA(v/v)=6:1) to give a pale yellow solid 537 mg (yield: 81.9%).

Step 2: 2-ethynyl-4-formylpyridine

To a solution of 2-((trimethylsilyl)ethynyl)-4-formylpyridine (537 mg, 2.64 mmol) in MeOH (6.6 mL) was added K₂CO₃ (36 mg, 0.26 mmol) at room temperature, and the mixture was reacted at room temperature for 2 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=4:1-2:1) to afford a white solid 297 mg (yield: 85.8%). LC-MS: m/z=132.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 10.05 (s, 1H), 8.84 (d, J=4.8 Hz, 1H), 7.86 (s, 1H), 7.67 (d, J=4.7 Hz, 1H), 3.27 (s, 1H).

Step 3: tert-butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate

To a microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (183 mg, 0.56 mmol), tert-butyl 3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (133 mg, 0.67 mmol), potassium carbonate (542 mg, 3.92 mmol) and DMSO (3 mL). The mixture was stirred at room temperature for 10 min, then transferred to 100° C. to react under microwave for 4 h. After the reaction was completed, the reaction solution was added to 15 mL of cold water, extracted with EA (30 mL×3), and the organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and then purified by silica gel column chromatography (PE/EA=9/1-2/1) to obtain a white solid raw material 58 mg and a white solid product 105 mg. The yield was 37.1%. LC-MS: m/z=505.2[M+H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.14 (d, J=1.9 Hz, 1H), 7.73 (dd, J=8.8, 2.4 Hz, 1H), 7.15 (d, J=2.0 Hz, 1H), 6.65 (d, J=8.8 Hz, 1H), 4.31 (d, J=4.5 Hz, 2H), 4.22-4.13 (m, 2H), 3.86 (s, 2H), 3.63-3.45 (m, 2H), 2.72-2.63 (m, 1H), 2.19-2.09 (m, 1H), 1.67 (s, 1H), 1.38 (d, J=4.0 Hz, 15H).

Step 4: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride

tert-Butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (100 mg, 0.198 mmol) and 4 mol/L methanolic hydrochloric acid (5 mL, 20 mmol) were added in a 25 mL single-necked flask in one portion. The mixture was stirred and reacted overnight at room temperature. After the completion of reaction was monitored by TLC, the reaction solution was concentrated in vacuo directly to obtain a pale red solid, which was used in the next step directly without further purification. The yield was calculated as 100%.

Step 5: 4-(6-(6-((2-ethynylpyridin-4-yl)methyl))-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile-dihydrochloride (20 mg, 0.049 mmol), 2-ethynylpyridine-4-carbaldehyde (25 mg, 0.19 mmol), sodium triacetoxyborohydride (62 mg, 0.29 mmol) and DCE (2 mL). The mixture was reacted at 35° C. overnight. After the reaction was completed, the reaction solution was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH(v/v)=100/0-100/4) to give a white solid 14.6 mg (yield: 56.8%). LC-MS: m/z=520.2[M+1]⁺; ¹H NMR (400 MHz, DMSO-d₆) δ 8.67 (s, 1H), 8.58 (s, 1H), 8.47 (s, 1H), 8.40 (s, 1H), 7.85 (d, 1H), 7.54 (s, 1H), 7.41 (s, 1H), 7.29 (s, 1H), 6.78 (d, J=8.6 Hz, 1H), 4.73 (s, 1H), 4.35-3.48 (m, 13H), 1.23 (s, 6H).

Example 288: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(5-methoxypyridin-3-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.10.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol

To a mixture of 3-bromo-5-methoxypyridine (500 mg, 2.66 mmol), Pd(PPh₃)₂Cl₂ (93 mg, 0.13 mmol) and CuI (25 mg, 0.13 mmol) were added Et₃N (4.0 mL, 29 mmol) and 2-propyn-1-ol (0.76 mL, 13 mmol) at room temperature under nitrogen. A black suspension was obtained, heated to 80° C. and reacted overnight. The reaction mixture was diluted with EA (40 mL), and the organic phase was poured out, then the residual black viscous solid was washed with EA (30 mL×3). The organic phases were combined, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA(v/v)=4:1-2:1) to give a pale yellow solid 280 mg (yield: 68%). LC-MS: m/z=164.15 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (s, 1H), 8.25 (s, 1H), 7.23 (s, 1H), 4.51 (s, 2H), 3.85 (s, 3H).

Step 2: 3-(5-methoxypyridin-3-yl)propynal

To a solution of 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol (280 mg, 1.72 mmol) in DCM (17.2 mL) were added NaHCO₃ (724 mg, 8.58 mmol) and Dess-Martin oxidant (1.10 g, 2.57 mmol) in turn, and the mixture was reacted for 0.75 h at room temperature. The reaction was quenched with saturated Na₂S₂O₂ (20 mL). After the layering was clear, the mixture was extracted with DCM (50 mL×2). The organic phases were combined and dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=3:1) to give a white solid 202 mg (yield: 73.0%). LC-MS: m/z=162.10 [M+1]⁺; and ¹H NMR (400 MHz, CDCl₃) δ 9.42 (s, 1H), 8.42 (s, 1H), 8.38 (d, J=2.5 Hz, 1H), 7.34 (s, 1H), 3.87 (s, 3H).

Step 3: tert-butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate

To a microwave tube were sequentially added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (183 mg, 0.56 mmol), tert-butyl 3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (133 mg, 0.67 mmol), potassium carbonate (542 mg, 3.92 mmol) and DMSO (3 mL). The mixture was stirred at room temperature for 10 min, then transferred to 100° C. to react under microwave for 4 h. After the reaction was completed, the reaction solution was added to 15 mL of cold water, extracted with EA (30 mL×3), and the organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and then purified by silica gel column chromatography (PE/EA=9/1-2/1) to obtain a white solid raw material 58 mg and a white solid product 105 mg. The yield was 37.1%. LC-MS: 505.2[M+H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.14 (d, J=1.9 Hz, 1H), 7.73 (dd, J=8.8, 2.4 Hz, 1H), 7.15 (d, J=2.0 Hz, 1H), 6.65 (d, J=8.8 Hz, 1H), 4.31 (d, J=4.5 Hz, 2H), 4.22-4.13 (m, 2H), 3.86 (s, 2H), 3.63-3.45 (m, 2H), 2.72-2.63 (m, 1H), 2.19-2.09 (m, 1H), 1.67 (s, 1H), 1.38 (d, J=4.0 Hz, 15H).

Step 4: 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride

tert-Butyl 3-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy))pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-3,6-diazabicyclo[3.1.1]heptane-6-carboxylate (100 mg, 0.198 mmol) and 4 mol/L methanolic hydrochloric acid (5 mL, 20 mmol) were added in a 25 mL single-necked flask in one portion. The mixture was stirred and reacted overnight at room temperature. After the completion of reaction was monitored by TLC, the reaction solution was concentrated in vacuo directly to obtain a pale red solid, which was used in the next step directly without further purification. The yield was calculated as 100%.

Step 5: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(5-methoxypyridin-3-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.10.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (12 mg, 0.030 mmol), 3-(5-methoxypyridine-3-yl)propynal (25 mg, 0.19 mmol), sodium triacetoxyborohydride (19 mg, 0.090 mmol) and DCM (2 mL) were added sequentially to a 10 mL single-necked flask. The mixture was reacted at 35° C. overnight. After the completion of reaction was monitored by TLC, the reaction solution was concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH(v/v)=100/0-100/4) to give a white solid 16.5 mg (yield: 71.6%). LC-MS: m/z=550.3[M+H]⁺; ¹H NMR (400 MHz, DMSO-d₆) δ 8.40 (s, 1H), 8.28-8.20 (m, 3H), 8.16 (s, 1H), 7.83-7.72 (m, 1H), 7.21 (s, 1H), 7.15 (s, 1H), 6.70 (d, 1H), 3.95 (d, J=4.9 Hz, 2H), 3.87 (s, 3H), 3.85-3.81 (m, 4H), 3.70-3.59 (m, 2H), 3.52 (s, 2H), 2.80-2.69 (m, 1H), 1.72-1.66 (m, 1H), 1.40 (s, 6H).

Example 289: 6-ethoxy-4-(6-((1-(4-ethynylbenzoyl)piperidin-4-yl)amino)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl (1-(4-ethynylbenzoyl)piperidin-4-yl)carbamate

To a 50 mL reaction flask were added tert-butyl N-(4-piperidinyl)carbamate (500 mg, 2.50 mmol), 4-ethynylbenzoic acid (383 mg, 2.62 mmol), DCC (780 mg, 3.74 mmol) and DMAP (30 mg, 0.24 mmol) were added. The reaction mixture was degassed and refilled with nitrogen, and then DCM (25 mL) was added to dissolve the solids. The mixture was stirred and reacted at room temperature overnight. The completion of reaction was monitored by TLC. The reaction mixture had a large amount of white insoluble solid, which was filtered through a sand core funnel. The filter cake was washed twice with DCM, and the filtrate was concentrated in vacuo and purified by silica gel column chromatography (PE:EA=2:1) to give a white solid 410 mg (the yield was 50.0%), which was the target product. LC-MS: m/z=351.20 [M+Na]⁺, 273.15 [M-t-Bu+2H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 7.52 (d, J=8.2 Hz, 2H), 7.34 (d, J=8.2 Hz, 2H), 4.64-4.40 (m, 2H), 3.76-3.68 (m, 2H), 3.14 (s, 1H), 3.10-2.88 (m, 2H), 2.03-1.88 (m, 2H), 1.44 (s, 9H), 1.40-1.29 (m, 2H).

Step 2: 1-(4-ethynylbenzoyl)piperidin-4-ammonium 2,2,2-trifluoroacetate

tert-Butyl (1-(4-ethynylbenzoyl)piperidin-4-yl)carbamate (400 mg, 1.22 mmol) was dissolved in DCM (6 mL) at room temperature, then trifluoroacetic acid (0.9 mL, 10 mmol) was added with stirring. The mixture was reacted overnight. The completion of reaction was monitored by TLC. The resulting mixture was concentrated in vacuo to give the crude product, which was used in the next step without further purification. The reaction was carried out in 100% yield. LC-MS: m/z=229.2 [M-CF₃COO]⁺.

Step 3: 6-ethoxy-4-(6-((1-(4-ethynylbenzoyl)piperidin-4-yl)amino)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

1-(4-Ethynylbenzoyl)piperidin-4-ammonium 2,2,2-trifluoroacetate (127 mg, 0.37 mmol) and 6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 1, 35 mg, 0.12 mmol) were dissolved in DMSO (2 mL), then DIPEA (0.10 mL, 0.60 mmol) was added, and the mixture was stirred for 4 h under microwave (150° C., 10 bar, pre-mixed for 30 s). After the reaction was completed, the sample was taken and sent to LC-MS. The reaction mixture was cooled to room temperature, then diluted with EA (100 mL), and the organic phases were washed with water (20 mL) and saturated brine (20 mL) in turn, dried over anhydrous sodium, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=1:1-1:1.5 (1% triethylamine)) to give a pale yellow solid 8.3 mg (yield: 14%) as the desired product. LC-MS: m/z=491.30 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.24 (s, 1H), 8.18 (s, 1H), 8.10 (s, 1H), 7.64 (d, J=8.3 Hz, 1H), 7.53 (d, J=7.7 Hz, 2H), 7.38 (d, J=7.8 Hz, 2H), 7.08 (s, 1H), 6.51 (d, J=8.8 Hz, 1H), 4.63 (d, J=7.1 Hz, 2H), 4.08 (q, J=6.7 Hz, 2H), 3.80-3.67 (m, 1H), 3.24-3.05 (m, 3H), 2.24-1.98 (m, 4H), 1.49 (t, J=6.7 Hz, 3H).

Example 290: 6-ethoxy-4-(6-((1-(3-ethynyl)piperidin-4-yl)amino)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl (1-(3-ethynylbenzoyl)piperidin-4-yl)carbamate

To a 50 mL reaction flask were added tert-butyl N-(4-piperidinyl)carbamate (500 mg, 2.50 mmol), 3-ethynylbenzoic acid (383 mg, 2.62 mmol), DCC (780 mg, 3.74 mmol) and DMAP (30 mg, 0.24 mmol) were added. The reaction mixture was degassed and refilled with nitrogen, and then DCM (25 mL) was added to dissolve the solids. The mixture was stirred and reacted at room temperature overnight. The completion of reaction was monitored by TLC. The reaction mixture had a large amount of white insoluble solid, which was filtered through a sand core funnel. The filter cake was washed twice with DCM, and the filtrate was concentrated in vacuo and purified by silica gel column chromatography (PE:EA=2:1) to give a white solid 795 mg (the yield was 92.0%), which was the target product. LC-MS: m/z=351.20 [M+Na]⁺, 273.20 [M-t-Bu+2H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 7.59-7.51 (m, 1H), 7.49 (s, 1H), 7.41-7.32 (m, 2H), 4.69-4.37 (m, 2H), 3.70 (s, 2H), 3.11 (s, 1H), 3.10-2.85 (m, 2H), 2.03-1.86 (m, 2H), 1.44 (s, 9H), 1.41-1.30 (m, 2H).

Step 2: 4-((3-ethynylbenzoyl)amino)-4-methylpiperidin-1-ium 2,2,2-trifluoroacetate

tert-Butyl (1-(3-ethynylbenzoyl)piperidin-4-yl)carbamate (790 mg, 2.31 mmol) was dissolved in DCM (23 mL) at room temperature, then trifluoroacetic acid (1.7 mL, 23 mmol) was added with stirring. The mixture was reacted overnight. The completion of reaction was monitored by TLC. The resulting mixture was concentrated in vacuo to give the crude product, which was used in the next step without further purification. The reaction was carried out in 100% yield. LC-MS: m/z=229.2 [M-CF₃COO]⁺.

Step 3: 6-ethoxy-4-(6-((1-(3-ethynyl)piperidin-4-yl)amino)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-((3-Ethynylbenzoyl)amino)-4-methylpiperidin-1-ium 2,2,2-trifluoroacetate (145 mg, 0.43 mmol) and 6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 1, 40 mg, 0.14 mmol) were dissolved in DMSO (2 mL), then DIPEA (0.12 mL, 0.69 mmol) was added, and the mixture was stirred for 4 h under microwave (150° C., 10 bar, pre-mixed for 30 s). After the completion of the reaction, the reaction mixture was cooled to room temperature, then diluted with EA (100 mL), and the organic phases were washed with water (20 mL) and saturated brine (20 mL) in turn, dried over anhydrous sodium, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=1:1-1:1.5 (1% triethylamine)) to give a pale yellow solid 18 mg (yield: 25.9%) as the desired product. LC-MS: m/z=491.25 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.24 (s, 1H), 8.18 (s, 1H), 8.10 (s, 1H), 7.67-7.59 (m, 1H), 7.58-7.49 (m, 2H), 7.42-7.34 (m, 2H), 7.08 (s, 1H), 6.51 (d, J=8.6 Hz, 1H), 4.77-4.54 (m, 2H), 4.08 (dd, J=14.3, 7.4 Hz, 2H), 3.80-3.66 (m, 1H), 3.29-3.00 (m, 3H), 2.27-2.06 (m, 2H), 1.80-1.63 (m, 2H), 1.49 (t, J=6.9 Hz, 3H).

Example 291: 4-(6-(4-((6-ethynyl-3-yl)amino)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)amino) piperidine-1-carboxylate

To a two-necked flask were added tert-butyl 4-[(6-Bromo-3-pyridyl)amino]piperidine-1-carboxylate (460 mg, 1.3 mmol), CuI (49 mg, 0.26 mmol), PdCl₂(PPh₃)₂(91 mg, 0.13 mmol), THF (3 mL) and TEA (3 mL) under nitrogen. Ethynyl (trimethyl) silane (190 mg, 1.9 mmol) was added dropwise with stirring at 50° C. After the addition, the mixture was kept at this temperature and reacted. After the completion of reaction was monitored by TLC, the reaction mixture was filtered by suction. The filter cake was washed with a small amount of EA, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:3) to give a pale yellow solid 400 mg as the desired product. LC-MS: m/z=374.10[M+H]⁺.

Step 2: tert-butyl 4-(6-ethynylpyridin-3-yl)amino)piperidine-1-carboxylate

tert-Butyl 4-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)amino)piperidine-1-carboxylate (400 mg, 1.071 mmol) was dissolved in methanol (4 mL) at room temperature, and then potassium carbonate (300 mg, 2.1 mmol) was added with stirring. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo, water (10 mL) was added and the resulting mixture was extracted with EA (30 mL×3). The combined organic phases were washed with water (30 mL×3) and saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:8-1:3) to give light yellow oil 130 mg as the target product. LC-MS: m/z=302.10[M+H]⁺.

Step 3: 6-ethynyl-N-(piperidin-4-yl)pyridin-3-amine hydrochloride

tert-Butyl 4-(6-ethynylpyridin-3-yl)amino)piperidine-1-carboxylate (130 mg, 0.43 mmol) was dissolved in 2 mL of HCl/1,4-dioxane. The mixture was stirred at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo to give a light yellow solid 103 mg as the target product.

Step 4: 4-(6-(4-((6-ethynyl-3-yl)amino)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a microwave tube were added 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.092 mmol) and 6-ethynyl-N-(4-piperidyl)pyridin-3-amine trihydrochloride (43 mg, 0.14 mmol), which were dissolved by adding 2 mL DMSO. Then DIPEA (0.08 mL, 0.50 mmol) was added. The mixture was reacted at 120° C. for 4 h under microwave. To the reaction mixture was added water (4 mL) and the resulting mixture was extracted with EA (10 mL×2). The organic phases were washed with water (10 mL) and saturated sodium chloride (10 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=100:1-20:1) to give a brown solid 15 mg as the target product. Rf=0.5(DCM:MeOH=20:1). LC-MS: m/z=508.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 8.00 (d, J=2.4 Hz, 1H), 7.71 (dd, J=8.8, 2.5 Hz, 1H), 7.30 (d, J=8.5 Hz, 1H), 7.14 (d, J=2.0 Hz, 1H), 6.85-6.79 (m, 2H), 4.39-4.34 (m, 2H), 3.90 (s, 1H), 3.86 (s, 2H), 3.62-3.55 (m, 1H), 3.19-3.12 (m, 2H), 3.03 (s, 1H), 2.16 (d, J=10.0 Hz, 2H), 1.56-1.51 (m, 2H), 1.39 (s, 6H). HPLC: 90.32%.

Example 292: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-((4-(3-hydroxy-3-methylbut-1-yn-1-yl) phenyl)amino)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-((4-iodophenyl)amino)piperidine-1-carboxylate

tert-Butyl 1-carboxylate-4-piperidone (1.82 g, 9.13 mmol) and 4-iodoaniline (2.00 g, 9.13 mmol) dissolved in DCC (50 mL) and AcOH (0.83 g, 14 mmol). Then sodium triacetoxyborohydride (3.79 g, 27.4 mmol) was added slowly. The mixture was reacted at room temperature for 14 h. The completion of reaction was monitored by TLC (PE/EA=4/1, Rf=0.35). The mixture was adjusted with 1N NaOH solution to pH=9 and extracted with DCM (10 mL×3). The combined organic phases were washed with water (10 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo and purified by silica gel column chromatography (eluent PE/EA=10/1-5/1) to give a white solid 2.93 g as the target product. LC-MS: m/z=347.1[M-t-Bu+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.43 (d, J=8.7 Hz, 2H), 6.41 (d, J=8.7 Hz, 2H), 4.05 (s, 2H), 3.58 (s, 1H), 3.47-3.30 (m, 1H), 2.94 (t, J=11.9 Hz, 2H), 2.09-1.96 (m, 2H), 1.49 (s, 9H), 1.38-1.29 (m, 2H).

Step 2: tert-butyl 4-((4-(3-hydroxy-3-methylbutan-1-yn-1-yl)phenyl)amino)piperidine-1-carboxylate

tert-Butyl 4-((4-iodophenyl)amino)piperidine-1-carboxylate (1.64 g, 4.08 mmol), CuI (78 mg, 0.41 mmol), PPh₃ (107 mg, 0.41 mmol) and PdCl₂(PPh₃)₂(286 mg, 0.408 mmol) were dissolved in DMF (10 mL), then 2-methylbut-3-yn-2-ol (1.03 g, 12.2 mmol) and Et₃N (1.24 g, 12.3 mmol) were slowly added. The mixture was warmed to 50° C. and reacted with stirring for 16 h. The completion of reaction was monitored by TLC. The mixture was cooled to room temperature and stopped the reaction. The reaction solution was filtered by suction, and extracted with EA (10 mL×3). The combined organic phases were washed with water (10 mL), dried over anhydrous sodium sulfate, filtered. The mother liquor was concentrated in vacuo and purified by silica gel column chromatography (eluent PE/EA=5/1-4/1) to give a brown solid 1.19 g as the target product (yield 82%). LC-MS: m/z=303.3[M-t-Bu+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.19 (d, J=8.6 Hz, 2H), 6.47 (d, J=8.7 Hz, 2H), 4.02 (d, J=7.4 Hz, 2H), 3.47-3.31 (m, 1H), 2.88 (d, J=7.3 Hz, 1H), 2.02-1.98 (m, 2H), 1.98-1.91 (m, 2H), 1.57 (s, 6H), 1.44 (s, 9H), 1.33-1.26 (m, 2H).

Step 3: 4-((4-(3-hydroxy-3-methylbutan-1-yn-1-yl)phenyl)amino)piperidine

tert-Butyl 4-((4-(3-hydroxy-3-methylbutan-1-yn-1-yl)phenyl)amino)piperidine-1-carboxylate (0.11 g, 0.31 mmol) was slowly added in a solution of hydrochloric acid in EA (4 mL, 20 mmol, 5 mol/L) at 0° C. The mixture was naturally warmed to room temperature and reacted with stirring for 3 h. The reaction was stopped. H₂O (15 mL) was added and the mixture was layered. The aqueous phase was adjusted with saturated NaHCO₃ solution to pH=8, and extracted with EA (15 mL×3). The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give a brownish yellow solid 73 mg as the desired product. LC-MS: m/z=259.1[M+H]⁺.

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-((4-(3-hydroxy-3-methylbut-1-yn-1-yl)phenyl) amino)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-((4-(3-Hydroxy-3-methylbutan-1-yn-1-yl)phenyl)amino)piperidine (76 mg, 0.29 mmol) and 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazole[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.09 mmol) were dissolved in DMSO (2 mL), then DIPEA (114 mg, 0.88 mmol) was added. The mixture was reacted with stirring under microwave at 130° C. for 4 h. The resulting mixture was cooled to room temperature and extracted with EA (10 mL×3). The organic phases were washed with water (10 mL), dried over anhydrous sodium sulfate, filtered, the filtrate was concentrated in vacuo and then purified by silica gel column chromatography (eluent DCM/CH₃OH=40/1-20/1) to give a yellow solid 4 mg as the target product (the yield was 2.4%). LC-MS: m/z=565.3[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.23 (s, 1H), 8.18 (d, J=2.0 Hz, 1H), 7.87 (d, J=8.7 Hz, 2H), 7.76-7.71 (m, 1H), 7.17 (d, J=2.0 Hz, 1H), 6.83 (d, J=8.9 Hz, 1H), 6.69 (s, 1H), 6.62 (d, J=8.7 Hz, 2H), 4.39 (d, J=13.5 Hz, 2H), 3.89 (s, 2H), 3.69 (brs, 1H), 3.20 (t, J=11.3 Hz, 2H), 1.42 (s, 6H), 1.35 (brs, 2H), 1.31 (brs, 2H), 1.28 (s, 6H). HPLC: 90.58%.

Example 293: 4-[6-[3-[(6-ethynyl-3-pyridyl)amino]azetidin-1-yl]-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-[(6-bromo-3-pyridyl)amino]azetidin-1-carboxylate

To a 100 mL single-necked flask were sequentially added 6-bromopyridin-3-amine (300 mg, 1.734 mmol) and tert-butyl 3-oxoazetidine-1-carboxylate (342 mg, 1.998 mmol), which were dissolved by adding THE (6 mL). Then trifluoroacetic acid (0.386 mL, 5.20 mmol) was added, and sodium triacetoxyborohydride (568 mg, 2.600 mmol) was slowly added. The mixture was reacted in a 55° C. oil bath for 4 h. TLC showed the reaction was completed. The reaction mixture was quenched with 15 mL of 1 M NaOH solution, extracted with EA (60 mL×2), washed with saturated saline (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was then purified by silica gel column chromatography (eluent n-hexane:EA=8:1-2:1) to give a yellow-white solid 0.335 g (the yield was 59%), which was the target product. LC-MS(ES-API): m/z=328.10[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.65 (d, J=2.9 Hz, 1H), 7.22 (d, J=8.5 Hz, 1H), 6.69 (dd, J=8.6, 3.1 Hz, 1H), 4.63 (d, J=6.1 Hz, 1H), 4.29-4.24 (m, 2H), 3.74-3.70 (m, 3H), 1.41 (s, 9H).

Step 2: tert-butyl 3-[[6-(2-trimethylsilylethynyl)-3-pyridyl]amino]azetidin-1-carboxylate

To a 10 mL two-necked flask were added CuI (14 mg, 0.074 mmol), PdCl₂(PPh₃)₂(25 mg, 0.036 mmol) and tert-butyl 3-[(6-bromo-3-pyridyl)amino]azetidine-1-carboxylate (230 mg, 0.701 mmol). The reaction mixture was degassed and refilled with nitrogen. Anhydrous THE (2.3 mL, 17 mmol) was added to dissolve the solids. The solution was orange-red. Ethynyl (trimethyl)silane (0.2 mL, 1 mmol) was added dropwise, then the solution changed from orange to black, and the mixture was reacted with stirring at 65° C. overnight. TLC showed the reaction was completed. The resulting mixture was filtered by suction. The filter cake was washed with EA (60 mL), and the filtrate was washed with saturated brine (20 mL×2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=10:1-1:5) to give an off-white solid 0.15 g (yield: 62%) as the target product. LC-MS(ES-API): m/z=346.20[M+H]⁺. ¹H NMR (600 MHz, CDCl₃) δ 7.92 (d, J=2.6 Hz, 1H), 7.29 (d, J=8.5 Hz, 1H), 6.69 (dd, J=8.5, 2.8 Hz, 1H), 4.33-4.20 (m, 4H), 3.75 (dd, J=9.1, 4.6 Hz, 2H), 1.44 (s, 9H), 0.24 (s, 9H).

Step 3: N-(azetidin-3-yl)-6-(2-trimethylsilylethynyl)pyridin-3-amine hydrochloride

To a 25 mL single-necked flask were added tert-butyl 3-[[6-(2-trimethylsilylethynyl)-3-pyridyl]amino]azetidin-1-carboxylate (0.15 g, 0.43 mmol) and a solution of hydrogen chloride in ethyl acetate (5 mL, 20 mmol). The mixture was reacted with stirring at room temperature for 2 h. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo to give dark red oil, which was dried in an oven at 60° C. to obtain a theoretical amount of brown red solid 0.12 g. LC-MS(ES-API): m/z=246.50[M+H]⁺.

Step 4: 4-[6-[3-[(6-ethynyl-3-pyridyl)amino]azetidin-1-yl]-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added N-(azetidin-3-yl)-6-(2-trimethylsilylethynyl)pyridin-3-amine hydrochloride (52 mg, 0.185 mmol), 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 40 mg, 0.123 mmol) and potassium carbonate (68 mg, 0.492 mmol), which were dissolved by adding DMSO (1.5 mL). The mixture was reacted at 130° C. in an oil bath overnight. TLC showed the reaction was completed. The resulting mixture was quenched with water (10 mL) and extracted with EA (50 mL×3). The organic phases were washed with saturated saline (50 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=20/0-20/1) to give a pale yellow solid 26.7 mg (yield: 45.4%) as the target product. LC-MS(ES-API): m/z=480.10[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=1.8 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 8.00 (d, J=2.5 Hz, 1H), 7.69 (dd, J=8.6, 2.4 Hz, 1H), 7.34 (d, J=8.5 Hz, 1H), 7.14 (d, J=2.1 Hz, 1H), 6.79 (dd, J=8.5, 2.8 Hz, 1H), 6.45 (d, J=8.9 Hz, 1H), 4.68 (d, J=3.4 Hz, 1H), 4.58-4.49 (m, 3H), 4.44 (s, 1H), 3.94 (dd, J=8.3, 3.9 Hz, 2H), 3.86 (s, 2H), 3.05 (s, 1H), 1.39 (s, 6H). HPLC: 89.66%.

Example 294: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-4-methylpiperidin-4-yl)-4-ethynylpyridine amide

Step 1: methyl 4-bromopyridinecarboxylate

To a 50 mL single-necked flask were sequentially added 4-bromopyridine-2-carboxylic acid (1 g, 4.9505 mmol), DMF (25 mL), cesium carbonate (1.77 g, 5.43 mmol), methyl iodide (0.34 mL, 5.5 mmol). The mixture was reacted with stirring at room temperature overnight. 25 mL of water and 40 mL of ethyl acetate were added. The aqueous phase was extracted with ethyl acetate (40 mL×2), and the combined organic phases were washed with water (25 mL) and saturated sodium chloride (25 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=25/1-8/1) to give a white needle-like crystal solid 805 mg as the desired product (yield: 75.3%). ¹H NMR (400 MHz, CDCl₃) δ 8.56 (d, J=5.2 Hz, 1H), 8.30 (d, J=1.5 Hz, 1H), 7.66 (dd, J=5.2, 1.8 Hz, 1H), 4.02 (s, 3H).

Step 2: methyl 4-((trimethylsilyl)ethynyl)pyridinecarboxylate

To a three-necked flask were added methyl 4-bromopyridinecarboxylate (800 mg, 3.7032 mmol), CuI (84 mg, 0.44106 mmol), PdCl₂(PPh₃)₂(77 mg, 0.1097 mmol), anhydrous THE (5 mL) and ethynyl (trimethyl)silane (436 mg, 4.439 mmol) under nitrogen. TEA (2.4 mL, 100 mass %) was added dropwise with stirring at 0° C. The mixture was reacted overnight at room temperature. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with 30 mL of saturated brine, dried over anhydrous sodium sulfate, filtered by suction, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:7) to give a yellow solid 423 mg as the target product (yield: 48.95%). LC-MS(ESI): m/z=234.2 [M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.68 (d, J=4.9 Hz, 1H), 8.14 (s, 1H), 7.50-7.43 (m, 1H), 4.01 (s, 3H), 0.27 (s, 9H).

Step 3: 4-ethynyl picolinic acid

Methyl 4-((trimethylsilyl)ethynyl)picolinate (420 mg, 1.7999 mmol) was dissolved in anhydrous methanol (8 mL) under nitrogen in a double-necked flask, and then potassium carbonate (500 mg, 3.6177 mmol) was added with stirring in one portion. The mixture was stirred overnight at room temperature. The reaction mixture was added with water (20 mL), adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate, filtered by suction, and concentrated in vacuo to give a yellow solid 95 mg as the target product (yield: 35.9%). ¹H NMR (600 MHz, (CD₃)₂SO) δ 8.73 (d, J=4.9 Hz, 1H), 8.00 (s, 1H), 7.70 (dd, J=4.9, 1.6 Hz, 1H), 4.74 (s, 1H).

Step 4: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-4-ethynylpyridine amide

To a 5 mL reaction flask were sequentially added 4-[6-(4-amino-4-methyl-1-piperidyl)-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 4, 15 mg, 0.030 mmol), 4-ethynylpyridine-2-carboxylic acid (10 mg, 0.067 mmol), 1-(3-dimethylaminopropyl)-3-ethyldithioamide hydrochloride (10 mg, 0.051 mmol) and DCM (2 mL). The mixture was stirred at room temperature overnight. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=0-100:5) to give a white solid 3 mg as the target product (yield: 17.95%). Rf=0.4 (DCM/MeOH=30/1), LC-MS: m/z=550.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.51 (d, J=4.9 Hz, 1H), 8.34 (d, J=2.3 Hz, 1H), 8.23 (s, 1H), 8.19 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 8.09 (s, 1H), 7.70 (dd, J=8.8, 2.4 Hz, 1H), 7.47 (dd, J=4.9, 1.3 Hz, 1H), 7.14 (d, J=1.9 Hz, 1H), 6.80 (d, J=8.9 Hz, 1H), 4.05 (s, 1H), 3.86 (s, 2H), 3.65 (s, 2H), 3.36 (s, 2H), 1.85-1.79 (m, 2H), 1.64 (dd, J=14.5, 7.2 Hz, 2H), 1.39 (s, 6H), 1.37 (s, 3H). HPLC: 94.15%.

Example 295: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-4-methylpiperidin-4-yl)-6-ethynylnicotinamide

Step 1: 6-((trimethylsilyl)ethynyl)pyridine

To a mixture of 6-bromopyridine-3-carbaldehyde (600 mg, 3.2256 mmol), PdCl₂(PPh₃)₂(90 mg, 0.128222 mmol) and CuI (30 mg, 0.15752 mmol) were sequentially added triethylamine (4.8 mL, 34 mmol) and trimethylsilylacetylene (0.92 mL, 6.5 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature for 4 h. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=10:1-8:1) to give a white solid 454 mg (yield: 69.2%) as the target product. LC-MS: m/z=204.20[M+H]⁺.

Step 2: 6-((trimethylsilyl)ethynyl)nicotinic acid

A solution of sodium dihydrogen phosphate (0.15 mL, 0.15 mmol, 1 mol/L) and hydrogen peroxide (0.06 mL, 0.6 mmol) was adjusted with concentrated hydrochloric acid to pH=3 at 0° C., which was added in a solution of 6-(2-trimethylsilylethynyl)pyridine-3-carbaldehyde (100 mg, 0.492 mmol) in acetonitrile (2 mL). The mixture was slowly added with sodium hypochlorite (40 mg, 0.532 mmol) in three portions and reacted at room temperature for 6 h. The mixture was extracted with EA (30 mL×2), washed with water (5 mL) and saturated saline (5 mL), dried over anhydrous sodium sulfate, and filtered. The mother liquid was concentrated in vacuo to give a pale yellow solid 0.108 g as the target product (the yield was 100%). rf=0.5 (DCM/MeOH=2/1), LC-MS: m/z=220.1 [M+H]⁺.

Step 3: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-6-((trimethylsilyl)ethynyl)nicotinamide

To a 5 mL reaction flask were sequentially added 4-[6-(4-amino-4-methyl-1-piperidyl)-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 4, 15 mg, 0.030 mmol), 6-((trimethylsilyl)ethynyl)nicotinic acid (10 mg, 0.046 mmol), EDCI (10 mg, 0.052 mmol), DMAP (1 mg, 0.008 mmol) and DCM (2 mL). The mixture was stirred at room temperature overnight. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM/MeOH=0-100:5) to give a white solid 4 mg as the target product (yield: 21.16%). Rf=0.5 (DCM/MeOH=30/1). LC-MS: m/z=622.3 [M+H]⁺.

Step 4: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-6-ethynyl nicotinamide

To a single-necked flask were sequentially added N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-meth ylpiperidin-4-yl)-6-((trimethylsilyl)ethynyl)nicotinamide (13 mg, 0.021 mmol), methanol (3 mL) and potassium carbonate (10.0 mg, 0.072 mmol). The mixture was stirred at room temperature overnight. The reaction mixture was concentrated in vacuo, and purified by thin layer chromatography (developer DCM/MeOH=30:1) to give a white solid 10 mg as the target product (yield: 87.03%). LC-MS: m/z=550.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.95 (s, 1H), 8.36 (d, J=2.3 Hz, 1H), 8.22 (s, 1H), 8.18 (d, J=2.0 Hz, 1H), 8.09 (dd, J=8.1, 2.2 Hz, 1H), 7.73 (dd, J=8.8, 2.5 Hz, 1H), 7.58 (d, J=8.4 Hz, 1H), 7.17 (d, J=2.0 Hz, 1H), 6.83 (d, J=8.8 Hz, 1H), 6.03 (s, 1H), 3.97 (dt, J=13.4, 4.8 Hz, 2H), 3.88 (s, 2H), 3.66 (s, 1H), 3.54-3.45 (m, 2H), 3.30 (s, 1H), 3.15 (dd, J=14.5, 7.2 Hz, 1H), 2.34 (d, J=14.9 Hz, 2H), 2.07-2.03 (m, 2H), 1.63 (s, 3H), 1.31 (s, 6H). HPLC: 92.42%.

Example 296: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-4-methylpiperidin-4-yl)-4-ethynylbenzamide

Step 1: tert-butyl 4-((4-ethynylbenzoyl)amino)-4-methyl-piperidine-1-carboxylate

To a 25 mL single-necked flask were added tert-butyl 4-amino-4-methyl-piperidine-1-carboxylate (600 mg, 2.7998 mmol), DCM (12 mL), 4-ethynylbenzoic acid (0.50 g, 3.4 mmol), EDCI (0.8 g, 4 mmol) and DMAP (0.034 g, 0.28 mmol). The mixture was stirred and reacted at room temperature overnight. To the reaction mixture were added dichloromethane (20 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (20 mL). The organic phases were combined, washed with 20 mL of saturated brine, dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=20/1-4/1) to give a white foam solid 423 mg (yield 30%) as the target product. LC-MS: m/z=287.1[M-t-Bu+2H], ¹H-NMR (400 MHz, CDCl₃) δ 7.67 (d, J=8.4 Hz, 2H), 7.54 (d, J=8.3 Hz, 2H), 5.78 (s, 1H), 3.71 (s, 2H), 3.26-3.16 (m, 3H), 2.16 (s, 2H), 1.68 (ddd, J=14.1, 10.3, 4.2 Hz, 2H), 1.52 (s, 3H), 1.46 (s, 9H).

Step 2: 4-ethynyl-N-(4-methylpiperidin-4-yl)benzamide-trifluoroacetate

To a 50 mL single-necked flask was added tert-butyl 4-((4-ethynylbenzoyl)amino)-4-methyl-piperidine-1-carboxylate (0.42 g, 1.2 mmol), then DCM (5 mL) and TFA (1.5 mL) were added. The mixture was stirred and reacted at room temperature for 3.5 h. The reaction solution was directly concentrated in vacuo to give a colorless transparent oily liquid product, which was directly used in the next reaction according to the theoretical yield. LC-MS: m/z=243.1[M-CF₃COO].

Step 3: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-4-ethynylbenzamide

To a 10 mL microwave tube were added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.092 mmol) and 4-ethynyl-N-(4-methylpiperidin-4-yl) benzamide-trifluoroacetate (65 mg, 0.182 mmol), then DMSO (1.5 mL) was added. After the mixture was dissolved, DIPEA (0.1 mL, 0.6 mmol) was added, and the mixture was reacted under microwave (temperature 135° C., pressure 10 bar) for 5 h. The reaction mixture was poured into water (20 mL), extracted with EA (40 mL×3), and the organic phases were combined, washed with saturated saline (30 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=100:1-30:1) to give a pale yellow solid 20 mg (yield 27.26%) as the desired product. LC-MS(ESI): m/z=541.1 [M+H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.70 (d, J=8.4 Hz, 3H), 7.54 (d, J=8.3 Hz, 2H), 7.14 (d, J=2.0 Hz, 1H), 6.80 (d, J=8.9 Hz, 1H), 5.92 (s, 1H), 4.03-3.95 (m, 2H), 3.86 (s, 2H), 3.47-3.38 (m, 2H), 3.19 (s, 1H), 2.36-2.29 (m, 2H), 1.89-1.82 (m, 2H), 1.39 (s, 6H), 1.25 (s, 3H). HPLC: 90.64%.

Example 297: 4-(6-(4-(4-ethynylphenoxy)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-(4-iodophenoxy)piperidine-1-carboxylate

To a two-necked flask were sequentially added tert-butyl 4-hydroxypiperidine-1-carboxylate (2.744 g, 13.63 mmol), 4-iodophenol (2 g, 9.09 mmol), triphenylphosphine (3.16 g, 11.8 mmol). The reaction mixture was degassed and refilled with nitrogen. Anhydrous tetrahydrofuran (15 mL) was added, and diisopropylazodicarboxylate (2.4 mL, 12 mmol) was slowly added dropwise at 0° C. After 30 min of dropping, the mixture was warmed to room temperature and then reacted for 4.5 h. To the reaction mixture were added EA (150 mL) and water (50 mL). The organic phases were separated, and the aqueous phase was extracted with EA (150 mL). The combined organic phases were washed with saturated brine (10 mL), concentrated in vacuo, purified by silica gel column chromatography (eluent PE:EA=0-100:5) to give a colorless oily liquid product 3.46 g as the target product (yield: 94.4%). Rf=0.4 (PE/EA=20/1). LC-MS: m/z=403.2 [M]⁺.

Step 2: 4-(4-iodophenoxy)piperidine

To a single-necked flask were added tert-butyl 4-(4-iodophenoxy)piperidine-1-carboxylate (1.00 g, 2.48 mmol) and methanolic hydrochloric acid (15 mL, 60 mmol, 4 mol/L). 2 h. The mixture was reacted at room temperature for 2 h. The reaction mixture was concentrated in vacuo to give a yellow solid 0.842 g as the target product (the yield was 100%). (Rf=0.3, DCM/MeOH=8/1). LC-MS: m/z=304.0 [M]⁺.

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(4-iodophenoxy)piperidin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were sequentially added 4-(4-iodophenoxy)piperidine (31 mg, 0.091284 mmol), 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo [1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 20 mg, 0.06129 mmol), toluene (2 mL) and N,N-diisopropylethylamine (0.1 mL, 0.6 mmol) at room temperature. The mixture was reacted at 120° C. for 36 h. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM/MeOH=0-100:3) to give a white solid 33 mg as the target product (the yield was 88.33%). (Rf=0.4, PE/EA=1/2). LC-MS: m/z=610.0 [M+H]⁺.

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(4-((trimethylsilyl)ethynyl)phenoxy) piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 50 mL two-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(4-iodophenoxy)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (33 mg, 0.054 mmol), Pd(PPh₃)₂Cl₂ (1 mg, 0.0014 mmol), triethylamine (5 mL) and cuprous iodide (1 mg, 0.0052508 mmol). The mixture was stirred under nitrogen for 15 min, then ethynyl (trimethyl)silane (0.05 mL, 0.4 mmol) was added. The mixture was stirred at room temperature for 7 h. The reaction mixture was filtered through a celite pad, then washed with EA (50 mL). The filtrate was concentrated in vacuo, and purified by silica gel column chromatography (eluent PE:EA=0-100:10) to give brown-black liquid 10 mg as the target product (yield: 31.86%). (Rf=0.5, PE/EA=10/1). LC-MS: m/z=580.3 [M+H]⁺.

Step 5: 4-(6-(4-(4-ethynylphenoxy)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(4-((trimethylsilyl)ethynyl)phenoxy)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (10.0 mg, 0.01725 mmol), potassium carbonate (10 mg, 0.072354 mmol) and methanol (2 mL). The mixture was stirred at room temperature for 5 h. The mixture was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE/EA=3/1) to give a pale yellow solid 8.0 mg as the target product (the yield was 91.0%). LC-MS: m/z=508.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.3 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 7.71 (dd, J=8.8, 2.5 Hz, 1H), 7.44 (d, J=8.7 Hz, 2H), 7.15 (d, J=2.0 Hz, 1H), 6.89 (d, J=8.7 Hz, 2H), 6.81 (d, J=8.8 Hz, 1H), 4.65-4.55 (m, 1H), 4.01-3.92 (m, 2H), 3.86 (s, 2H), 3.66-3.55 (m, 2H), 3.01 (s, 1H), 2.12-2.05 (m, 2H), 1.95-1.86 (m, 2H), 1.39 (s, 6H). HPLC: 97.34%.

Example 298: (R)-4-(6-(3-((6-ethynyl-3-yl)oxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl (S)-3-((methylsulfonyl)oxy)pyrrolidine-1-carboxylate

tert-Butyl (3S)-3-hydroxypyrrolidine-1-carboxylate (2.00 g, 10.7 mmol) was dissolved in THF (50 mL) under nitrogen, then NaH (1.284 g, 32.1 mmol) was added. Methanesulfonyl chloride (0.911 mL, 11.8 mmol) was added under ice bath conditions, and the mixture was reacted at this temperature for 4.5 h. The reaction mixture was added with water (10 mL) and EA (50 mL). The aqueous phase was extracted with EA (50 mL×2). The combined organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo to give colorless transparent liquid 2.00 g as the target product (the yield was 100%). (Rf=0.5, PE/EA=4/1). LC-MS: m/z=210.2[M-t-Bu+H]⁺.

Step 2: tert-butyl (R)-3-((6-bromopyridin-3-yl)oxy)pyrrolidine-1-carboxylate

6-Bromopyridin-3-ol (500 mg, 2.8736 mmol) was dissolved in DMSO (6 mL) at room temperature, and potassium tert-butoxide (493 mg, 3.73 mmol) was added with stirring. After stirring for 20 min, the temperature was raised to 100° C. tert-Butyl (S)-3-((methylsulfonyl)oxy)pyrrolidine-1-carboxylate (0.838 g, 3.16 mmol) dissolved in DMSO (30 mL) was added dropwise slowly. After the addition, the mixture was reacted at 120° C. for 5.5 h. Water (10 mL) and EA (200 mL) were added, and the organic phase was washed with saturated sodium chloride (10 mL×3), then the organic phases were separated, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=0-100:10) to give colorless transparent liquid 0.26 g as the objective product (yield 26%). (Rf=0.5, PE/EA=4/1). LC-MS: m/z=287.0 [M-t-Bu]⁺.

Step 3: tert-butyl (R)-3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)pyrrolidine-1-carboxylate

To a 50 mL two-necked flask were sequentially added tert-butyl (3S)-3-[(6-bromo-3-pyridyl)oxy]pyrrolidine-1-carboxylate (0.26 g, 0.76 mmol), Pd(PPh₃)₂Cl₂ (11 mg, 0.0155149 mmol), triethylamine (5 mL) THE (2 mL) and CuI (7 mg, 0.036755 mmol) under nitrogen. After stirring for 15 min, ethynyl (trimethyl)silane (0.21 mL, 1.5 mmol) was added and the mixture was stirred at room temperature for 2.5 h. The reaction mixture was directly concentrated in vacuo, and purified by silica gel column chromatography (PE:EA=0-5:1) to give brown liquid 100 mg as the target product (the yield was 37%). (Rf=0.5, PE/EA=4/1). LC-MS: m/z=361.1[M+H]⁺.

Step 4: tert-butyl (R)-3-((6-ethynylpyridin-3-yl)oxy)pyrrolidine-1-carboxylate

To a single-necked flask were sequentially added tert-butyl (3S)-3-[[6-(2-trimethylsilylethynyl)-3-pyridyl]oxy]pyrrolidine-1-carboxylate (0.10 g, 0.28 mmol), potassium carbonate (77 mg, 0.55712 mmol) and methanol (3 mL). The mixture was stirred at room temperature for 1 h. The reaction mixture was filtered, and the filter cake was washed with EA (50 mL), and the mother liquor was concentrated in vacuo and then purified by silica gel column chromatography (PE:EA=0-5:1) to give pale yellow liquid 0.10 g as the target product. (Rf=0.3, PE/EA=3/1). LC-MS: m/z=289.3 [M+H]⁺.

Step 5: (R)-2-ethynyl-5-(pyrrolidin-3-yloxy)pyridine hydrochloride

tert-Butyl (R)-3-((6-ethynylpyridin-3-yl)oxy)pyrrolidine-1-carboxylate (66 mg, 0.2289 mmol) was dissolved in 1,4-dioxane (1 mL) in a single-necked flask, then a 4 M solution of hydrochloride in 1,4-dioxane (2 mL, 8 mmol, 4 mol/L) was added and the mixture was stirred at room temperature for 0.5 h. The reaction mixture was concentrated in vacuo to give a white solid 51 mg as the target product (the yield was 99.15%). LC-MS: m/z=189.2 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 9.62 (s, 1H), 9.49 (s, 1H), 8.29 (d, J=2.7 Hz, 1H), 7.56 (d, J=8.6 Hz, 1H), 7.48 (dd, J=8.7, 2.9 Hz, 1H), 5.27 (s, 1H), 4.21 (s, 1H), 3.72 (dd, J=15.0, 9.7 Hz, 2H), 3.40-3.29 (m, 2H), 2.29-2.09 (m, 2H).

Step 6: (R)-4-(6-(3-((6-ethynyl-3-yl)oxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo [1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 20 mg, 0.06129 mmol) in DMSO (1.5 mL) were added (R)-2-ethynyl-5-(pyrrolidin-3-yloxy)pyridine hydrochloride (13 mg, 0.069064 mmol) and DIPEA (0.03 mL, 0.2 mmol). After the addition, the mixture was reacted at 130° C. for 5 h under microwave. Water (10 mL) and EA (100 mL) were added, and the organic phase was washed with saturated sodium chloride (6 mL×3), concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give yellow oil 11.0 mg as the objective product (yield 36.3%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=495.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J=2.0 Hz, 1H), 8.29 (d, J=2.4 Hz, 1H), 8.19 (s, 1H), 8.15 (d, J=1.8 Hz, 1H), 7.71 (dd, J=8.7, 2.3 Hz, 1H), 7.45 (d, J=8.6 Hz, 1H), 7.35-7.34 (m, 1H), 7.13 (d, J=1.8 Hz, 1H), 6.54 (d, J=8.8 Hz, 1H), 5.14 (s, 1H), 3.93-3.87 (m, 2H), 3.86 (s, 2H), 3.78-3.68 (m, 2H), 3.64 (s, 1H), 3.09 (s, 1H), 2.39-2.30 (m, 2H), 1.28 (s, 6H). HPLC: 93.38%.

Example 299: 2-((3-cyano-4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridin-6-yl)oxy)acetamide

To a 5 mL single-necked flask was added 4-[6-[3-[(6-ethynyl-3-pyridyl)oxy]azetidin-1-yl]-3-pyridyl]-6-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 27 mg, 0.066 mmol), potassium carbonate (45 mg, 0.31 mmol), 2-chloroacetamide (29 mg, 0.31 mmol) and DMF (0.6 mL). The mixture was reacted at 90° C. After the reaction was completed, the reaction solution was cooled to room temperature, added with water (10 mL) and extracted with EA (20 mL×2). The combined organic phases were washed with water (10 mL×6) and saturated saline (10 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=30:1) to give a yellow solid 10 mg as the target product. LC-MS: m/z=466.10[M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 8.62 (d, J=23.2 Hz, 2H), 8.31 (d, J=17.3 Hz, 2H), 7.80 (d, J=8.1 Hz, 1H), 7.65 (s, 1H), 7.56 (d, J=8.2 Hz, 1H), 7.49 (s, 1H), 7.40 (s, 2H), 6.60 (d, J=8.3 Hz, 1H), 5.34 (s, 1H), 4.61 (s, 2H), 4.54 (s, 2H), 4.19 (s, 1H), 4.03 (d, J=7.0 Hz, 2H). HPLC: 92.99%.

Example 300: 4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-(pyrrolidin-1-yl) thoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 2-(pyrrolidin-1-yl)ethanol

To a 25 mL single-necked flask were sequentially added tetrahydropyrrole (1.2 mL, 14.0 mmol), 2-chloroethanol (1.1 mL, 16.9 mmol) and toluene (10 mL). The mixture was heated to reflux at 120° C. for 5 h. After the reaction was completed, the reaction solution was slowly returned to room temperature, and no post-treatment was carried out. The yield was calculated by 100%, and the mixture was directly used for the next step. Rf=0.3 (EA/MeOH=5/1).

Step 2: 1-(2-chloroethyl)pyrrolidine

To a 25 mL single-necked flask were added a solution of 2-(pyrrolidin-1-yl)ethanol in toluene, then dichlorosulfoxide (2.15 mL, 28.2 mmol) was slowly added in an ice bath. After the addition, the mixture was returned to room temperature and stirred overnight. After the reaction was completed, to the reaction solution was added saturated sodium bicarbonate solution (30 mL) and the resulting mixture was extracted with dichloromethane (50 mL×3). The organic phases were washed with water (50 mL×2), dried over anhydrous sodium sulfate, filtered, and then purified by silica gel column chromatography (eluent DCM:MeOH=20:1) to give a brownish yellow solid 1.56 g as the target product. ¹H NMR (400 MHz, CDCl₃) δ 4.02 (t, J=6.3 Hz, 2H), 3.52 (t, J=6.4 Hz, 2H), 3.42 (s, 4H), 2.14 (s, 4H).

Step 3: 4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-(pyrrolidin-1-yl)ethoxy) yrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask was added 1-(2-chloroethyl)pyrrole (65 mg, 0.49 mmol), 4-[6-[3-[(6-ethynyl-3-pyridyl)oxy]azetidin-1-yl]-3-pyridyl]-6-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 26 mg, 0.064 mmol), potassium carbonate (60 mg, 0.42 mmol), DMF (0.8 mL). The mixture was reacted in an oil bath at 90° C. After the reaction was completed, the reaction solution was cooled to room temperature, water (10 mL) was added and the resulting mixture was extracted with EA (20 mL×3). The organic phases were washed with water (10 mL×6), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=50:1 to 20:1) to give a yellow solid 10 mg as the target product. LC-MS: m/z=506.10[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=1.9 Hz, 1H), 8.21 (d, J=2.7 Hz, 1H), 8.19 (s, 1H), 8.15 (d, J=1.8 Hz, 1H), 7.71 (dd, J=8.6, 2.3 Hz, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.14 (d, J=1.8 Hz, 1H), 7.07 (dd, J=8.6, 2.8 Hz, 1H), 6.47 (d, J=8.6 Hz, 1H), 5.17 (m, 1H), 4.58-4.50 (m, 2H), 4.21-4.17 (m, 4H), 3.10 (s, 1H), 3.01 (t, J=5.5 Hz, 2H), 2.70 (s, 4H), 1.85 (s, 4H). HPLC: 93.60%.

Example 301: 6-(2-(1H-imidazol-1-yl)ethoxy)-4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl) yridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 1-(2-chloroethyl)-1H-imidazole

Imidazole (500 mg, 7.3 mmol) was dissolved in acetonitrile (8 mL) in a 25 mL single-necked flask, then potassium carbonate (5.2 g, 36 mmol) and 1-bromo-2-chloroethane (1.8 mL, 22 mmol) were added with stirring. The mixture was reacted at room temperature. After the reaction was completed, the reaction mixture was filtered by suction. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=20:1) to give colorless liquid 340 mg as the desired product. ¹H NMR (400 MHz, CDCl₃) δ 7.54 (s, 1H), 7.09 (s, 1H), 6.98 (s, 1H), 4.28 (t, J=6.0 Hz, 2H), 3.75 (t, J=6.0 Hz, 2H).

Step 2: 6-(2-(1H-imidazol-1-yl)ethoxy)-4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl) yrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 4-[6-[3-[(6-ethynyl-3-pyridyl)oxy]azetidin-1-yl]-3-pyridyl]-6-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 30 mg, 0.073 mmol), potassium carbonate (50 mg, 0.35 mmol), 1-(2-chloroethyl)-1H-imidazole (35 mg, 0.27 mmol) and DMA (0.5 mL). The mixture was reacted in an oil bath at 90° C. After the reaction was completed, to the reaction solution was added water (5 mL), and the resulting mixture was extracted with EA (15 mL×2). The organic phases were washed with water (5 mL×6) and saturated saline (5 mL), concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=20:1) to give a bright yellow solid 10 mg as the target product. LC-MS: m/z=503.10[M+H]⁺, ¹H NMR (400 MHz, CDCl₃) δ 8.30 (d, J=1.8 Hz, 1H), 8.21 (d, J=2.7 Hz, 1H), 8.19 (s, 1H), 8.09 (d, J=1.7 Hz, 1H), 7.69 (dd, J=8.6, 2.2 Hz, 1H), 7.65 (s, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.13-7.02 (m, 4H), 6.46 (d, J=8.7 Hz, 1H), 5.18 (m, 1H), 4.59-4.51 (m, 2H), 4.43 (t, J=4.7 Hz, 2H), 4.28 (t, J=4.7 Hz, 2H), 4.20 (dd, J=9.2, 3.7 Hz, 2H), 3.10 (s, 1H). HPLC: 94.80%.

Example 302: 4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(oxazol-2-ylmethoxy) yrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 30 mg, 0.073 mmol), 2-(chloromethyl)oxazole (16 mg, 0.14 mmol), potassium carbonate (24 mg, 0.16 mmol) and DMF (0.6 mL). The mixture was reacted in an oil bath at 90° C. After the completion of reaction was monitored by TLC, the reaction solution was cooled to room temperature, added with water (5 mL) and extracted with EA (15 mL×2). The organic phases were washed with water (5 mL×5) and saturated saline (5 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM:MeOH=50:1) to give a yellow solid 7 mg as the target product. LC-MS: m/z=490.90[M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 8.85 (d, J=1.9 Hz, 1H), 8.61 (s, 1H), 8.33 (s, 1H), 8.28 (d, J=2.8 Hz, 1H), 8.23 (s, 1H), 7.80 (dd, J=8.5, 2.4 Hz, 1H), 7.56 (d, J=8.6 Hz, 1H), 7.40-7.38 (m, 1H), 7.38-7.34 (m, 1H), 7.32 (s, 1H), 6.59 (d, J=8.6 Hz, 1H), 5.42 (s, 2H), 5.33 (d, J=4.0 Hz, 1H), 4.53 (dd, J=9.3, 6.6 Hz, 2H), 4.20 (s, 1H), 4.02 (dd, J=9.7, 3.3 Hz, 2H). HPLC: 89.19%.

Example 303: 4-(6-(4-((6-ethynyl-3-yl)oxy)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-ethylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-((6-bromopyridin-3-yl)oxy)piperidine-1-carboxylate

To a two-necked flask were sequentially added tert-butyl 4-hydroxypiperidine-1-carboxylate (868 mg, 4.312 mmol), 6-bromopyridin-3-ol (500 mg, 2.873 mmol), triphenylphosphine (1000 mg, 3.736 mmol). The reaction mixture was degassed and refilled with nitrogen. THF (10 mL) was added. The mixture was cooled to 0° C., and diisopropylazodicarboxylate (0.75 mL, 3.7 mmol) was slowly added dropwise. After 30 min of dropping, the mixture was reacted overnight at room temperature. The reaction mixture was added with water (10 mL) and extracted with EA (150 mL). The organic phases were washed with saturated brine (10 mL), and the mother liquor was concentrated in vacuo, purified by silica gel column chromatography (eluent PE:EA=0-5:1) to give a colorless oily liquid product 0.812 g as the target product (yield: 79.1%). (Rf=0.4, PE/EA=4/1). LC-MS: m/z=301.1 [M-t-Bu]⁺; 303.1 [M-t-Bu+2H]⁺.

Step 2: tert-butyl 4-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy) piperidine-1-carboxylate

To a 50 mL two-necked flask were sequentially added tert-butyl 4-((6-bromopyridin-3-yl)oxy)piperidine-1-carboxylate (0.812 g, 2.27 mmol), Pd(PPh₃)₂Cl₂ (32 mg, 0.045 mmol), triethylamine (5 mL) and THE (5 mL) under nitrogen. After stirring for 15 min, CuI (22 mg, 0.115 mmol) and ethynyl (trimethyl)silane (0.5 mL, 4 mmol) were added and the mixture was stirred at room temperature for 2.5 h. The reaction mixture was directly concentrated in vacuo, and purified by silica gel column chromatography (PE:EA=0-5:1) to give a khaki solid 0.78 g as the target product (the yield was 92%). (Rf=0.4, PE/EA=4/1). LC-MS: m/z=375.2 [M+H]⁺.

Step 3: tert-butyl 4-((6-ethynylpyridin-3-yl)oxy)piperidine-1-carboxylate

To a single-necked flask were sequentially added tert-butyl 4-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)piperidine-1-carboxylate (0.78 g, 2.1 mmol), potassium carbonate (557 mg, 4.0301 mmol) and methanol (10 mL). The mixture was stirred at room temperature for 1 h. The reaction mixture was filtered and washed with EA (50 mL), and the mother liquid was concentrated in vacuo and then purified by silica gel column chromatography (PE:EA=0-5:1) to give a pale yellow solid 0.63 g as the target product. (Rf=0.3, PE/EA=2/1). LC-MS: m/z=303.4 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.27 (d, J=2.7 Hz, 1H), 7.42 (d, J=8.6 Hz, 1H), 7.15 (dd, J=8.6, 2.9 Hz, 1H), 4.53 (tt, J=6.9, 3.3 Hz, 1H), 3.76-3.61 (m, 2H), 3.41-3.29 (m, 2H), 3.07 (s, 1H), 2.00-1.86 (m, 2H), 1.80-1.72 (m, J=13.5, 7.3 Hz, 2H), 1.47 (s, 9H).

Step 4: 2-ethynyl-5-(piperidin-4-yloxy)pyridine hydrochloride

To a single-necked flask were sequentially added tert-butyl 4-((6-ethynylpyridin-3-yl)oxy)piperidine-1-carboxylate (0.63 g, 2.1 mmol) and 4M hydrochloric acid in 1,4-dioxane solution (4 mL, 16 mmol). The mixture was stirred at room temperature for 1 h (a white solid precipitated). The reaction mixture was concentrated in vacuo to give a yellow-white solid 0.41 g as the target product (the yield was 82%). LC-MS: m/z=203.1 [M+H]⁺.

Step 5: 4-6-(4-((6-ethynyl-3-yl)oxy)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy) yrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 26 mg, 0.07968 mmol) in DMSO (1.5 mL) were added 2-ethynyl-5-(piperidin-4-yloxy)pyridine hydrochloride (23 mg, 0.096351 mmol) and DIPEA (0.5 mL, 3 mmol). After the addition, the mixture was reacted for 5 h under microwave (150° C., 5 bar). After the mixture was cooled to room temperature, water (10 mL) and EA (100 mL) were added. The organic phases were washed with saturated sodium chloride (6 mL×3), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=100/3) to give yellow oil 7.5 mg as the objective product (yield 19%). LC-MS: m/z=509.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.35 (d, J=2.3 Hz, 1H), 8.31 (d, J=2.8 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=2.0 Hz, 1H), 7.72 (dd, J=8.8, 2.5 Hz, 1H), 7.45 (d, J=8.6 Hz, 1H), 7.20 (dd, J=8.7, 2.9 Hz, 1H), 7.15 (d, J=2.0 Hz, 1H), 6.82 (d, J=8.8 Hz, 1H), 4.69-4.61 (m, 1H), 3.97 (m, 2H), 3.87 (s, 2H), 3.67-3.60 (m, 3H), 3.09 (s, 1H), 2.12-2.07 (m, 2H), 1.95-1.89 (m, 2H), 1.40 (s, 6H). HPLC: 91.29%.

Example 304: tert-butyl 4-(((3-cyano-4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl) yridin-3-yl)pyrazolo[1,5-a]pyridin-6-yl)oxy)methyl)piperidine-1-carboxylate

To a 25 mL single-necked flask were added 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 100 mg, 0.244 mmol), potassium carbonate (158 mg, 1.11 mmol), tert-butyl 4-(bromomethyl)piperidine-1-carboxylate (280 mg, 1.00 mmol) and DMF (3 mL). The mixture was reacted overnight in an oil bath at 90° C. After the reaction was completed, to the reaction solution was added water (20 mL) and the resulting mixture was extracted with EA (80 mL×2). The organic phases were washed with water (20 mL×8) and saturated saline (20 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=50:1) to give a white solid 142 mg as the target product. LC-MS: m/z=606.20[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=1.8 Hz, 1H), 8.22 (d, J=2.7 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.71 (dd, J=8.6, 2.2 Hz, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.08-7.06 (m, 2H), 6.47 (d, J=8.6 Hz, 1H), 5.18 (s, 1H), 4.55 (dd, J=9.0, 6.6 Hz, 2H), 4.20 (dd, J=9.2, 3.7 Hz, 4H), 3.86 (d, J=6.2 Hz, 2H), 3.10 (s, 1H), 2.76 (m, 2H), 2.09-1.98 (m, 1H), 1.85-1.82 (m, 2H), 1.47 (s, 9H), 1.38-1.32 (m, 2H), HPLC: 98.52%.

Example 305: 6-(2-(dimethylamino)ethoxy)-4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 2-(dimethylamino)ethanol

To a 25 mL single-necked flask were sequentially added dimethylamine tetrahydrofuran solution (8 mL, 16.0 mmol, 2.0 mol/L), 2-chloroethanol (1.3 mL, 19 mmol) and toluene (10 mL). The mixture was heated to reflux at 120° C. for 5 h. After the reaction was completed, the reaction solution was slowly returned to room temperature, and no post-treatment was carried out. The yield was calculated by 100%, and the mixture was directly used for the next step.

Step 2: dimethylaminochloroethane hydrochloride

To a 25 mL single-necked flask were added a solution of 2-(dimethylamino)ethanol in toluene, then dichlorosulfoxide (2.4 mL, 31 mmol) was slowly added in an ice bath. After the addition, the mixture was returned to room temperature and stirred overnight. After the reaction was completed, the mixture was concentrated in vacuo to remove toluene and dichlorosulfoxide to give viscous oil. Anhydrous ethanol (3 mL) was added, and the mixture was stirred and dissolved at 60° C. The solution was cooled to precipitate a white solid, which was filtered and dried to give a white solid as the desired product. ¹H NMR (400 MHz, DMSO-d₆) δ 11.27 (s, 1H), 4.02 (t, J=6.8 Hz, 2H), 3.46 (t, J=6.8 Hz, 2H), 2.78 (s, 6H).

Step 3: 6-(2-(dimethylamino)ethoxy)-4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 20 mg, 0.04897 mmol), potassium carbonate (17 mg, 0.12 mmol), 2-chloro-N,N-dimethyl-ethylamine hydrochloride (10 mg, 0.069 mmol) and DMF (0.4 mL). The mixture was reacted overnight in an oil bath at 90° C. After the reaction was completed, to the reaction mixture was added water (5 mL) and the resulting mixture was extracted with EA (15 mL×2). The organic phases were washed with water (5 mL×5), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography to give a yellow solid 5 mg as the target product. LC-MS: m/z=480.75[M+H]⁺. H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=2.0 Hz, 1H), 8.24-8.14 (m, 3H), 7.70 (dd, J=8.6, 2.4 Hz, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.14 (d, J=1.9 Hz, 1H), 7.07 (dd, J=8.6, 2.9 Hz, 1H), 6.46 (d, J=8.6 Hz, 1H), 5.17 (m, 1H), 4.55 (dd, J=9.2, 6.5 Hz, 2H), 4.24-4.15 (m, 4H), 3.10 (s, 1H), 2.90 (s, 2H), 2.44 (s, 6H). HPLC: 96.71%.

Example 306: 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-hydroxyazetidin-1-carboxylate

To a single-necked flask were added tert-butyl 3-oxoazetidine-1-carboxylate (5.0 g, 29 mmol) and EtOH (50 mL) at room temperature, then NaBH₄ (1.1 g, 29 mmol) was added portionwise with stirring. After the completion of reaction was monitored by TLC, a saturated ammonium chloride solution was added to the reaction solution until no bubbles were generated, and a large amount of white solid was precipitated. The mixture was filtered with suction. The filter cake was washed with ethanol (10 mL), and the filtrate was concentrated in vacuo to remove most of the ethanol. To the mixture was added 30 mL of water and the resulting mixture was extracted with EA (100 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 5.0 g as the target product. LC-MS: m/z=118.10[M-t-Bu+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 4.53 (s, 1H), 4.13-4.09 (m, 2H), 3.78 (dd, J=9.9, 4.1 Hz, 2H), 3.54-3.45 (m, 1H), 1.41 (s, 9H).

Step 2: tert-butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate

To a two-necked flask were added tert-butyl 3-hydroxyazetidine-1-carboxylate (500 mg, 2.89 mmol), DCM (15 mL) and NaH (0.14 g, 5.8 mmol) under nitrogen. The mixture was transferred to 0° C. and MsCl (0.25 mL, 3.2 mmol) was added dropwise with stirring. After the addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, water (20 mL) and DCM (50 mL) were added to the reaction mixture. The organic phase was separated, and the aqueous phase was extracted with EA (50 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquid was purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 566 mg as the target product. LC-MS: m/z=196.10[M-t-Bu+H]⁺, m/z=152.10[M-Boc+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 5.18 (tt, J=6.7, 4.2 Hz, 1H), 4.26 (ddd, J=10.3, 6.7, 1.0 Hz, 2H), 4.11-4.04 (m, 2H), 3.05 (s, 3H), 1.43 (s, 9H).

Step 3: tert-butyl 3-((6-bromopyridin-3-yl)oxy)azetidin-1-carboxylate

6-Bromopyridin-3-ol (200 mg, 1.15 mmol) was dissolved in DMSO (4 mL) at room temperature, and t-BuOK (168 mg, 1.5 mmol) was added to the solution with stirring. After stirring for 20 min, the temperature was raised to 80° C. tert-Butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate (347 mg, 1.4 mmol) dissolved in DMSO (2 mL) was added dropwise slowly. After the addition, the mixture was kept at this temperature with stirring. After the completion of reaction was monitored by TLC, the reaction mixture was poured into water (20 mL). The resulting mixture was extracted with EA (50 mL×2). The combined organic phases were washed with water (20 mL×2) and saturated saline (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a light yellow solid 320 mg as the target product. LC-MS: m/z=329.05[M+H]⁺.

Step 4: tert-butyl 3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)azetidin-1-carboxylate

To a two-necked flask were added tert-butyl 3-((6-bromopyridin-3-yl)oxy)azetidin-1-carboxylate (320 mg, 0.97 mmol), CuI (37 mg, 0.19 mmol), PdCl₂(PPh₃)₂(68 mg, 0.097 mmol), THE (3 mL) and TEA (3 mL) under nitrogen. The mixture was transferred to 50° C. and ethynyl (trimethyl) silane (191 mg, 1.95 mmol) was added dropwise with stirring. After the addition, the mixture was kept at this temperature and reacted. After the completion of reaction was monitored by TLC, the reaction mixture was filtered by suction through a celite pad. The filter cake was washed with a small amount of EA, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a brown solid 240 mg as the desired product. LC-MS: m/z=347.25[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.12 (s, 1H), 7.39 (d, J=8.6 Hz, 1H), 6.97 (dd, J=8.6, 2.9 Hz, 1H), 4.92 (ddd, J=10.4, 6.3, 4.0 Hz, 1H), 4.31 (dd, J=9.6, 6.8 Hz, 2H), 4.00 (dd, J=9.8, 3.4 Hz, 2H), 1.45 (s, 9H), 0.26 (s, 9H).

Step 5: tert-butyl 3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-carboxylate

tert-Butyl 3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)azetidin-1-carboxylate (240 mg, 0.69 mmol) was dissolved in methanol (2 mL) at room temperature, and then potassium carbonate (194 mg, 1.38 mmol) was added with stirring. The reaction solution was reacted at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo. To the residue was added water (10 mL) and the resulting mixture was extracted with EA (30 mL×3). The combined organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a light yellow solid 180 mg as the target product. LC-MS: m/z=275.20[M+H]. ¹H-NMR (400 MHz, CDCl₃) δ 8.14 (d, J=2.8 Hz, 1H), 7.43 (d, J=8.6 Hz, 1H), 6.99 (dd, J=8.6, 2.9 Hz, 1H), 4.92 (tt, J=6.4, 4.1 Hz, 1H), 4.32 (ddd, J=9.7, 6.3, 0.6 Hz, 2H), 4.01 (dd, J=9.9, 3.9 Hz, 2H), 3.09 (s, 1H), 1.45 (s, 9H).

Step 6: 5-(azetidin-3-yloxy)-2-ethynylpyridine hydrochloride

tert-Butyl 3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-carboxylate (180 mg, 0.66 mmol) was dissolved in HCl/dioxane (3 mL, 12 mmol, 4 mol/L) with stirring at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo to give a light yellow solid 158 mg as the target product.

Step 7: 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a microwave tube were added 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.092 mmol) and 5-(azetidin-3-yloxy)-2-ethynyl-pyridine dihydrochloride (34 mg, 0.14 mmol), which were dissolved by adding 2 mL DMSO. Then DIPEA (60 mg, 0.46 mmol) was added. The mixture was reacted at 120° C. for 4 h under microwave. After the reaction was completed, the reaction mixture was added with water (2 mL) and extracted with EA (10 mL×2). The organic phases were washed with water (10 mL) and saturated sodium chloride (10 mL), dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=100:1-20:1) to give a brown solid 15 mg as the target product. Rf=0.5 (DCM/MeOH=20:1). LC-MS: m/z=481.30[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.32 (d, J=1.9 Hz, 1H), 8.21 (d, J=2.4 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=2.0 Hz, 1H), 7.71 (dd, J=8.6, 2.4 Hz, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.14 (d, J=2.0 Hz, 1H), 7.07 (dd, J=8.6, 2.9 Hz, 1H), 6.47 (d, J=8.5 Hz, 1H), 5.17 (ddd, J=10.1, 5.0, 3.1 Hz, 1H), 4.55 (dd, J=9.1, 6.6 Hz, 2H), 4.20 (dd, J=9.5, 3.8 Hz, 2H), 3.86 (s, 2H), 3.10 (s, 1H), 1.39 (s, 6H). HPLC: 92.94%.

Example 307: N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl) pyridin-2-yl)-4-methylpiperidin-4-yl)-3-phenylpropynamide

To a 5 mL reaction flask were sequentially added 4-(6-(4-amino-4-methylpiperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 4, 15 mg, 0.03040 mmol), DCM (2 mL), 3-phenylprop-2-ynyl acid (10 mg, 0.068428 mmol) and N,N′-dicyclohexyl carbon (10 mg, 0.0479812 mmol). The mixture was reacted with stirring at room temperature for 18 h. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM/MeOH=0-100:3) to give a white solid 6.5 mg as the target product (the yield was 39%). (Rf=0.6, DCM/MeOH=10/1). LC-MS: m/z=549.2 [M+H]⁺. HPLC: 94.15%.

Example 308: 6-ethoxy-4-(6-(4-methyl-4-(propargylamino)piperidin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-methyl-4-(prop-2-yn-1-ylamino)piperidine-1-carboxylate

To a solution of tert-butyl 4-amino-4-methyl-piperidine-1-carboxylate (1.00 g, 4.67 mmol) in acetonitrile (23 mL) were added potassium carbonate (967 mg, 7.00 mmol) and 3-bromopropyne (0.44 mL, 5.1 mmol) sequentially at room temperature. The mixture was stirred at room temperature overnight. The reaction mixture was filtered, and the filtrate was concentrated in vacuo to give a crude product, which was pale yellow oil 1.08 g (yield: 91.7%). LC-MS: m/z=253.20 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 3.45-3.35 (m, 4H), 3.33 (d, J=2.4 Hz, 2H), 2.16 (t, J=2.3 Hz, 1H), 1.52-1.42 (m, 4H), 1.41 (s, 9H), 1.10 (s, 3H).

Step 2: tert-butyl 4-methyl-4-(N-(prop-2-yn-1-yl)acetamido)piperidine-1-carboxylate

To a solution of tert-butyl 4-methyl-4-(prop-2-yn-1-ylamino) piperidine-1-carboxylate (1.2 g, 4.8 mmol) in DCM (48 mL) and triethylamine (2.0 mL, 14 mmol) was slowly added dropwise acetyl chloride (0.68 mL, 9.5 mmol) at 0° C. After the addition, the mixture was naturally warmed to room temperature and reacted overnight. The reaction was quenched with water (10 mL) and the mixture was stirred for 20 min. Then the mixture was diluted with DCM (50 mL). The organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=2:1-1:1) to afford a yellow oil 1.25 g (yield: 89%) as the target product. Nuclear magnetic data showed the product was a mixture of stereoisomers (should be a conformational isomer) in a ratio of 2:1. LC-MS: m/z=317.25 [M+Na]⁺; ¹H NMR (600 MHz, CDCl₃) δ 4.01 (d, J=2.4 Hz, 2H), 3.99 (d, J=2.5 Hz, 1H), 3.66-3.53 (m, 3H), 3.28-3.19 (m, 3H), 2.34 (t, J=2.4 Hz, 0.5H), 2.30 (t, J=2.4 Hz, 1H), 2.27 (s, 1.5H), 2.22 (s, 3H), 2.20-2.12 (m, 3H), 2.03-1.94 (m, 3H), 1.50 (s, 1.5H), 1.49 (s, 3H), 1.45 (s, 13.5H).

Step 3: tert-butyl 4-methyl-4-(N-(prop-2-yn-1-yl)acetamido)piperidine-1-ium trifluoroacetate

tert-Butyl 4-methyl-4-(N-(prop-2-yn-1-yl)acetamido)piperidine-1-carboxylate (1.25 g, 4.25 mmol) was dissolved in DCM (42.5 mL) at 0° C., and then trifluoroacetic acid (3.2 mL, 43 mmol) was added with stirring. After the addition, the mixture was removed from the cold bath and naturally warmed to room temperature. The mixture was reacted overnight. The mixture was concentrated in vacuo to remove the solvent, which was used in the next step without further purification. The yield was calculated as 100%. LC-MS: m/z=195.15 [M-CF₃COO]⁺.

Step 4: 6-ethoxy-4-(6-(4-methyl-4-(propargylamino)piperidin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

4-Methyl-4-(N-(prop-2-yn-1-yl)acetamido)piperidine-1-ium trifluoroacetate (98 mg, 0.32 mmol) and 6-ethoxy-4-(6-fluoro-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 1, 30 mg, 0.11 mmol) were dissolved in DMSO (1 mL), then DIPEA (0.10 mL, 0.60 mmol) was added, and the mixture was stirred for 3.5 h under microwave (150° C., 10 bar, pre-mixed for 30 s). After the completion of the reaction, the reaction mixture was cooled to room temperature, then diluted with EA (100 mL), and the organic phases were washed with water (20 mL) and saturated brine (20 mL) in turn, dried over anhydrous sodium, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=1:1) to give a pale yellow solid 20 mg (yield: 45.4%) as the desired product. LC-MS: m/z=415.30 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=2.3 Hz, 1H), 8.18 (s, 1H), 8.09 (d, J=1.8 Hz, 1H), 7.69 (dd, J=8.8, 2.3 Hz, 1H), 7.08 (d, J=1.8 Hz, 1H), 6.77 (d, J=8.9 Hz, 1H), 4.08 (q, J=6.9 Hz, 2H), 3.75-3.62 (m, 4H), 3.43 (d, J=2.3 Hz, 2H), 2.21 (t, J=2.3 Hz, 1H), 1.74-1.60 (m, 4H), 1.49 (t, J=6.9 Hz, 3H), 1.20 (s, 3H).

Example 309: 4-(6-(4-(4-(cyclopropylethynyl)benzoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-(cyclopropylethynyl)benzoate

To a three-necked flask were added methyl 4-iodobenzoate (500 mg, 1.9081 mmol), CuI (44 mg, 0.23103 mmol), PdCl₂(PPh₃)₂(40 mg, 0.05699 mmol) and TEA (5 mL) under nitrogen. After the dissolution, ethynylcyclopropane (150 mg, 2.269 mmol) was added dropwise with stirring at 0° C. The mixture was naturally warmed to room temperature and reacted overnight. The reaction solution was filtered with suction through a celite pad, and then washed with EA (50 mL). The filtrate was added with water (20 mL). The organic phase was separated, and the aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with 30 mL of saturated brine, dried over anhydrous sodium sulfate, filtered, and then purified by silica gel column chromatography (EA:PE=1:200) to give a yellow solid 0.3446 g as the target product (yield 90.210%). ¹H NMR (400 MHz, CDCl₃) δ 7.93 (d, J=8.2 Hz, 2H), 7.41 (d, J=8.2 Hz, 2H), 3.90 (s, 3H), 1.47 (ddd, J=13.1, 8.3, 5.1 Hz, 1H), 0.94-0.80 (m, 4H).

Step 2: 4-(cyclopropylethynyl)benzoic acid

Methyl 4-(cyclopropylethynyl)benzoate (340 mg, 1.698 mmol) was dissolved in methanol (7 mL) under nitrogen in a double-necked flask, and then water (0.7 mL), NaOH (68 mg, 1.7 mmol) were added with stirring at room temperature. The mixture was reacted overnight. To the reaction mixture was added water (20 mL), and the mixture was adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give a yellow solid 0.3055 g as the target product (yield: 96.6%). ¹H NMR (400 MHz, CDCl₃) δ 8.01 (d, J=8.3 Hz, 2H), 7.45 (d, J=8.3 Hz, 2H), 1.52-1.43 (m, 1H), 1.25 (s, 1H), 0.94-0.89 (m, 2H), 0.87-0.83 (m, 2H).

Step 3: 4-(6-(4-(4-(cyclopropylethynyl)benzoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo [1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 30 mg, 0.08611 mmol), 4-(cyclopropylethynyl)benzoic acid (24 mg, 0.12889 mmol), EDCI (33 mg, 0.17214 mmol), DMAP (2 mg, 0.016371 mmol) and DCM (2 mL). The mixture was reacted with stirring at room temperature and monitored by TLC. After the reaction was completed, the reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was extracted with DCM (25 mL×2). The organic phases were combined, washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and then purified by silica gel column chromatography (PE/EA=2/1-1.2/1) to give a yellow solid 29.5 mg as the target product (yield 66.3%). LC-MS(ESI): m/z=572.1[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.1 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.9 Hz, 1H), 7.74 (dd, J=8.8, 2.4 Hz, 1H), 7.43 (d, J=8.2 Hz, 2H), 7.36 (d, J=8.2 Hz, 2H), 7.09 (d, J=1.9 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.92-3.54 (m, 8H), 1.49 (t, J=6.9 Hz, 3H), 1.47-1.41 (m, 1H), 0.90-0.88 (m, 2H), 0.85-0.82 (m, 2H). HPLC: 98.44%.

Example 310: 4-(6-(4-(4-(3-(tert-butoxy)prop-1-yn-1-yl)-3-(trifluoromethyl)benzoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazole [1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-bromo-3-(trifluoromethyl)benzoate

To a 100 mL single-necked flask were added 4-bromo-3-(trifluoromethyl)benzoic acid (2 g, 7.4344 mmol), cesium carbonate (2.75 g, 8.44 mmol), DMF (50 mL) and methyl iodide (0.525 mL, 8.43 mmol). The mixture was reacted at room temperature overnight. The reaction mixture was diluted with EA (50 mL), washed with water (30 mL×2) and saturated brine (30 mL) in turn. The organic phases were dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=100:1-50:1) to give light yellow transparent oily liquid 1.65 g (yield: 78.4%) as the desired product. ¹H NMR (400 MHz, CDCl₃) δ 7.89 (s, 1H), 7.75 (d, J=8.3 Hz, 1H), 7.68 (d, J=8.3 Hz, 1H), 3.93 (s, 3H).

Step 2: methyl 4-(3-(tert-butoxy)prop-1-yn-1-yl)-3-(trifluoromethyl)benzoate

To a three-necked flask were added methyl 4-bromo-3-(trifluoromethyl)benzoate (500 mg, 1.7665 mmol), CuI (40 mg, 0.21003 mmol), PdCl₂(PPh₃)₂(37 mg, 0.05271 mmol) and 1,4 dioxane (5 mL) under nitrogen. After the dissolution, 3-(tert-butoxy)prop-1-yne (240 mg, 2.1396 mmol) was added dropwise at 0° C., then TEA (1.5 mL) was added dropwise. The mixture was reacted at 50° C. overnight. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with 30 mL of saturated brine, dried over anhydrous sodium sulfate, filtered by suction, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:100-1:50) to give yellow oily liquid 355 mg as the target product (yield: 63.94%). ¹H NMR (400 MHz, CDCl₃) δ 7.80 (s, 1H), 7.74 (d, J=8.0 Hz, 1H), 7.63 (d, J=8.0 Hz, 1H), 4.32 (s, 2H), 3.93 (s, 3H), 1.29 (s, 9H).

Step 3: methyl 4-(3-(tert-butoxy)prop-1-yn-1-yl)-3-(trifluoromethyl)benzoic acid

Methyl 4-(3-(tert-butoxy)prop-1-yn-1-yl)-3-(trifluoromethyl)benzoate (300 mg, 0.9545 mmol) was dissolved in methanol (6 mL) under nitrogen in a double-necked flask, and then potassium carbonate (270 mg, 1.9535 mmol) were added in one portion with stirring at room temperature. The mixture was reacted overnight. To the reaction mixture was added water (20 mL), and the mixture was adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give a yellow solid 0.225 g as the target product (yield: 78.6%). ¹H NMR (400 MHz, CDCl₃) δ 7.91 (d, J=8.0 Hz, 1H), 7.84 (s, 1H), 7.66 (d, J=7.8 Hz, 1H), 4.34 (s, 2H), 1.30 (s, 9H) Step 4: 4-(6-(4-(4-(3-(tert-butoxy)prop-1-yn-1-yl)-3-(trifluoromethyl)benzoyl)piperazin-1-yl) pyridin-3-yl)6-ethoxypyrazole [1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 30 mg, 0.08611 mmol), 4-(3-(tert-butoxy)prop-1-yn-1-yl)-3-(trifluoromethyl)benzoic acid (38 mg, 0.1265 mmol), EDCI (33 mg, 0.17214 mmol), DMAP (2 mg, 0.016371 mmol) and DCM (2 mL). The mixture was reacted with stirring at room temperature. To the reaction solution were added DCM (30 mL) and water (15 mL), and the aqueous phase was extracted with EA (25 mL×2). The organic phases were combined, washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=2/1-1.2/1) to give a yellow foamy solid 34.4 mg as the target product (yield: 63.3%). LC-MS(ESI): m/z=631.2[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.33 (d, J=1.6 Hz, 1H), 8.18 (s, 1H), 8.11 (s, 1H), 7.79 (s, 1H), 7.73 (dd, J=8.7, 2.0 Hz, 1H), 7.65 (d, J=7.8 Hz, 1H), 7.30 (d, J=7.8 Hz, 1H), 7.08 (d, J=1.3 Hz, 1H), 6.77 (d, J=8.8 Hz, 1H), 4.32 (s, 2H), 4.08 (dd, J=13.7, 6.8 Hz, 2H), 4.01-3.84 (m, 2H), 3.80-3.68 (m, 2H), 3.63-3.56 (m, 2H), 3.35-3.25 (m, 2H), 1.49 (t, J=6.9 Hz, 3H), 1.29 (s, 9H). HPLC: 95.58%.

Example 311: 4-(6-(4-(3-(cyclopropylethynyl)benzoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 3-(cyclopropylethynyl)benzoate

To a three-necked flask were added methyl 3-bromobenzoate (1.0 g, 4.7 mmol), CuI (180 mg, 0.94513 mmol) and Pd(PPh₃)₄(540 mg, 0.46729 mmol) under nitrogen, which were dissolved by adding acetonitrile (19 mL) with stirring. Then TEA (3.2 mL, 23 mmol) and ethynylcyclopropane (460 mg, 6.959 mmol) were added. The mixture was slowly warmed to 60° C. The completion of reaction was monitored by TLC after reaction for 6 h. The reaction solution was concentrated in vacuo. The residue was added with 60 mL of EA and 20 mL of water, and filtered by suction. The organic phase was separated from the filtrate, washed once with 10 mL of saturated brine, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give yellow oil 920 mg as the desired product (yield: 99.0%). Rf=0.8 (PE:EA=10:1). LC-MS: m/z=201.10[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.04 (s, 1H), 7.91 (d, J=7.8 Hz, 1H), 7.54 (d, J=7.7 Hz, 1H), 7.33 (t, J=7.8 Hz, 1H), 3.90 (s, 3H), 1.48-1.42 (m, 1H), 0.90-0.85 (m, 2H), 0.84-0.80 (m, 2H).

Step 2: 3-(cyclopropylethynyl)benzoic acid

Methyl 3-(cyclopropylethynyl)benzoate (920 mg, 4.595 mmol) was dissolved in THF (36.8 mL) in a single-necked flask, and then LiOH (220 mg, 9.186 mmol), methanol (18.4 mL) and water (18.4 mL) were added with stirring at room temperature. The mixture was reacted overnight. The reaction solution was concentrated in vacuo to remove some of the solvent. To the residue was added 30 mL of water, and the aqueous phase was adjusted with hydrochloric acid to pH=2 under stirring at 0° C. A large amount of solid was precipitated, and to the aqueous phase was added EA (100 mL×2) for extraction. The organic phase was combined, dried over anhydrous sodium sulfate and concentrated in vacuo to give a white solid 836 mg. The yield was 97.7%. Rf=0.01 (PE:EA=10:1). LC-MS: m/z=187.00[M+H]⁺, ¹H-NMR (400 MHz, DMSO-d₆) δ 7.86 (d, J=8.4 Hz, 2H), 7.59 (d, J=7.7 Hz, 1H), 7.46 (t, J=7.7 Hz, 1H), 1.91 (s, 1H), 1.59-1.52 (m, 1H), 0.92-0.87 (m, 2H), 0.78-0.74 (m, 2H).

Step 3: 4-(6-(4-(3-(cyclopropylethynyl)benzoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo [1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 25 mL double-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 20 mg, 0.05741 mmol) and 3-(cyclopropylethynyl)benzoic acid (16 mg, 0.085924 mmol), which were dissolved by adding DCM (5 mL). Then DMAP (2 mg, 0.016371 mmol) and EDCI (22 mg, 0.11476 mmol) were added. The mixture was stirred and reacted at room temperature overnight. To the reaction was added 30 mL of DCM and 10 mL of water. The organic phases were separated, washed with 10 mL of water. The organic phases were dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE=1:1) to give a white solid 4 mg. The yield was 13.49%. Rf=0.3 (PE:EA=1:1). LC-MS: m/z=517.3[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.37 (s, 1H), 8.21 (s, 1H), 8.13 (s, 1H), 7.76 (d, J=9.4 Hz, 1H), 7.48-7.44 (m, 2H), 7.37-7.34 (m, 2H), 7.12 (s, 1H), 6.81 (d, J=8.0 Hz, 1H), 4.10 (dd, J=5.3, 3.6 Hz, 2H), 3.78-3.63 (m, 8H), 1.55-1.54 (m, 1H), 1.28 (s, 3H), 0.82-0.74 (m, 4H). HPLC: 94.29%.

Example 312: 6-ethoxy-4-(6-(4-(3-(prop-2-yn-1-yl)benzoyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 3-(3-(trimethylsilyl)prop-2-yn-1-yl)benzoate

Methyl 3-(bromomethyl)benzoate (1.0 g, 4.4 mmol) was dissolved in THE (20 mL) under nitrogen, then the solution was added with CuI (100 mg, 0.52507 mmol), triphenylphosphine (110 mg, 0.4194 mmol), tris(dibenzylideneacetone)dipalladium (120 mg, 0.1310 mmol), ethynyl trimethylsilane (600 mg, 6.109 mmol) and cesium carbonate (2 g, 6.1384 mmol) under stirring. The mixture was reacted overnight at 50° C. The reaction solution was added with 60 mL of EA and 20 mL of saturated ammonium chloride solution, and filtered by suction. The organic phase was separated from the filtrate, washed once with saturated brine, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give brown oil 320 mg. The yield was 29.7%. Rf=0.9 (PE/EA=10/1). LC-MS: m/z=247.05[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.02 (s, 1H), 7.91 (d, J=7.8 Hz, 1H), 7.56 (d, J=7.4 Hz, 1H), 7.40 (t, J=7.7 Hz, 1H), 3.92 (s, 3H), 1.26 (s, 2H), 0.20 (s, 9H).

Step 2: 3-(prop-2-yn-1-yl)benzoic acid

Methyl 3-(3-(trimethylsilyl)prop-2-yn-1-yl)benzoate (320 mg, 1.299 mmol) was dissolved in THE (12.8 mL) in a single-necked flask, and then LiOH (94 mg, 3.925 mmol), methanol (6.4 mL) and water (6.4 mL) were added with stirring at room temperature. The mixture was reacted overnight. The reaction solution was concentrated in vacuo to remove some of the solvent. To the residue was added 30 mL of water, and the aqueous phase was adjusted with hydrochloric acid to pH=2 under stirring at 0° C. A large amount of solid was precipitated, and the aqueous phase was added with EA (100 mL×2). The organic phase was combined, dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 200 mg. The yield was 96.15%. Rf=0.01 (PE:EA=10:1). LC-MS: m/z=161.10[M+H]⁺, ¹H-NMR (400 MHz, DMSO-d₆) δ 7.88 (s, 1H), 7.78 (d, J=7.5 Hz, 1H), 7.52 (d, J=7.6 Hz, 1H), 7.47 (d, J=7.6 Hz, 1H), 6.46 (t, J=6.8 Hz, 1H), 5.35 (d, J=6.8 Hz, 2H).

Step 3: 6-ethoxy-4-(6-(4-(3-(prop-2-yn-1-yl)benzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 25 mL double-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 20 mg, 0.05741 mmol) and 3-(prop-2-yn-1-yl)benzoic acid (14 mg, 0.087407 mmol), which were dissolved by adding DCM (5 mL). Then DMAP (2 mg, 0.016371 mmol) and EDCI (22 mg, 0.11476 mmol) were added. The mixture was stirred at room temperature overnight. To the reaction mixture were added DCM (30 mL) and water (30 mL). The organic phases were separated and washed with water (10 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:1) to give a white solid 12 mg as the desired product (yield: 42.61%). Rf=0.3 (PE:EA=1:1). LC-MS: m/z=491.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.37 (d, J=2.2 Hz, 1H), 8.22 (s, 1H), 8.14 (d, J=1.9 Hz, 1H), 7.77 (dd, J=8.8, 2.4 Hz, 1H), 7.41 (dd, J=11.2, 5.7 Hz, 4H), 7.12 (d, J=2.0 Hz, 1H), 6.81 (d, J=8.8 Hz, 1H), 6.21 (dd, J=8.7, 4.6 Hz, 1H), 5.22 (s, 2H), 4.10 (q, J=6.5 Hz, 2H), 3.81-3.54 (m, 8H), 1.52 (t, J=6.9 Hz, 3H). HPLC: 97.01%.

Example 313: 6-ethoxy-4-(6-(4-(4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzoyl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzoate

To a two-necked flask were added methyl 4-iodobenzoate (500 mg, 1.9081 mmol) and 2-methylbut-3-yn-2-ol (169 mg, 2.009 mmol) under nitrogen, which were dissolved by adding TEA (20 mL). Then CuI (15 mg, 0.078761 mmol) and PdCl₂(PPh₃)₂(27 mg, 0.03847 mmol) were added and the mixture was stirred at room temperature overnight. The reaction solution was concentrated in vacuo. To the residue was added 30 mL of EA and 30 mL of water. The organic phase was separated from the filtrate, washed with 10 mL of saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a pale yellow solid 400 mg. The yield was 96.07%. Rf=0.4 (PE:EA=10:1). LC-MS: m/z=241.10[M+Na]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 7.97 (d, J=8.0 Hz, 2H), 7.47 (d, J=8.0 Hz, 2H), 3.91 (s, 3H), 2.08 (s, 1H), 1.63 (s, 6H).

Step 2: methyl 4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzoic acid

Methyl 4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzoate (400 mg, 1.833 mmol) was dissolved in methanol (8 mL) in a single-necked flask, and then LiOH (88 mg, 3.674 mmol) and tap water (8 mL) were added with stirring at room temperature. The mixture was stirred at room temperature overnight. The reaction solution was concentrated in vacuo to remove part of methanol. To the residue was added 30 mL of water, and the aqueous phase was adjusted with 2 N hydrochloric acid to pH=2 under stirring at 0° C. A large amount of solid was precipitated, and the aqueous phase was added with EA (100 mL×2). The organic phase was combined, dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 370 mg. The yield was 98.83%. Rf=0.01 (PE:EA=10:1). LC-MS: m/z=203.10[M−H]⁻, ¹H-NMR (400 MHz, CDCl₃) δ 7.81 (d, J=7.3 Hz, 2H), 7.30 (d, J=7.3 Hz, 2H), 4.24 (s, 1H), 1.44 (s, 6H).

Step 3: 6-ethoxy-4-(6-(4-(4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzoyl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 25 mL double-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 20 mg, 0.05741 mmol) and 4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzoic acid (18 mg, 0.088140 mmol), which were dissolved by adding DCM (5 mL). Then EDCI (22 mg, 0.11476 mmol) and DMAP (1 mg, 0.0081853 mmol) were added. The mixture was stirred at room temperature for 5 h and the completion of reaction was monitored by TLC. To the reaction solution was added 30 mL of DCM and 10 mL of water. The organic phases were separated, washed with 10 mL of water once. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent EA:PE=1:1) to give a white solid 21 mg (yield 68.43%). Rf=0.2 (PE/EA=1/1). LC-MS: 535.25[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (s, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.74 (d, J=6.8 Hz, 1H), 7.47 (d, J=8.0 Hz, 2H), 7.40 (d, J=8.1 Hz, 2H), 7.09 (s, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.07 (q, J=6.8 Hz, 2H), 3.89-3.59 (m, 8H), 2.15 (s, 1H), 1.63 (s, 6H), 1.49 (t, J=6.9 Hz, 3H). HPLC: 99.27%.

Example 314: 6-ethoxy-4-(6-(2-(3-ethynyl)-2,8-diazaspiro[4.5]dec-8-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 2-(3-ethynylbenzoyl)-2,8-diazaspiro[4.5]decane-8-carboxylate

To a 25 mL single-necked flask were added tert-butyl 2,8-diazaspiro[4.5]decane-8-carboxylate (500 mg, 2.081 mmol), DCM (10 mL), 3-ethynylbenzoic acid (0.365 g, 2.50 mmol), EDCI (0.6 g, 3 mmol) and DMAP (0.025 g, 0.20 mmol). The mixture was stirred and reacted at room temperature overnight. Dichloromethane (30 mL) and water (20 mL) were added, and the aqueous phase was separated and extracted with DCM (30 mL). The organic phases were combined, washed with 15 mL of saturated brine, dried over anhydrous sodium sulfate, filtered, and then purified by silica gel column chromatography (eluent PE/EA=80/1-2/1) to give a white foam solid 295 mg as the target product (yield 38.47%). ¹H NMR (400 MHz, CDCl₃) δ 7.61 (s, 1H), 7.50 (dd, J=16.7, 7.1 Hz, 2H), 7.36 (s, 1H), 3.78-3.12 (m, 8H), 3.09 (s, 1H), 1.86 (d, J=4.0 Hz, 2H), 1.57 (d, J=16.4 Hz, 4H), 1.44 (d, J=8.4 Hz, 5H), 1.39 (s, 4H), ¹H NMR showed two sets of peaks, which were chiral compounds.

Step 2: (3-ethynylphenyl) (2,8-diazaspiro[4.5]dec-2-yl)methanone trifluoroacetate

To a 50 mL single-necked flask was added tert-butyl 2-(3-ethynylbenzoyl)-2,8-diazaspiro[4.5]decane-8-carboxylate (1.22 g, 3.31 mmol), then DCM (13 mL) and TFA (4 mL) were added. The mixture was stirred at room temperature overnight. The reaction solution was directly concentrated in vacuo to give colorless transparent oily liquid as the target compound (yield 100%), which was directly used for the next reaction without further purification.

Step 3: 6-ethoxy-4-(6-(2-(3-ethynyl)-2,8-diazaspiro[4.5]dec-8-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a 10 mL microwave tube were added 6-ethoxy-4-(6-fluoro-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 1, 20 mg, 0.07085 mmol) and (3-ethynylphenyl)(2,8-diazaspiro[4.5]dec-2-yl) methanone trifluoroacetate (55 mg, 0.1438 mmol), then DMSO (1 mL) was added. After the mixture was dissolved, DIPEA (46 mg, 0.35593 mmol) was added, and the mixture was reacted under microwave (150° C., 10 bar) for 4 h. The reaction mixture was poured into water (10 mL), extracted with EA (30 mL×3), and the organic phases were combined, washed with saturated saline (30 mL). The organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:5-1:1) to give a yellow solid 8 mg as the desired product. Rf=0.3 (PE:EA=2:1). LC-MS: 531.30[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.28 (d, J=17.0 Hz, 1H), 8.19 (s, 1H), 8.10 (s, 1H), 7.70-7.64 (m, 2H), 7.54 (d, J=7.1 Hz, 1H), 7.45 (d, J=8.7 Hz, 2H), 7.09 (d, J=5.3 Hz, 1H), 6.73 (dd, J=32.4, 8.7 Hz, 1H), 4.09 (q, J=7.0, 2.3 Hz, 2H), 3.88-3.51 (m, 7H), 3.47-3.38 (m, 2H), 1.50 (q, J=6.4 Hz, 3H), 1.27-1.24 (m, 6H). HPLC: 91.38%.

Example 315: 4-(6-(4-(2-chloro-5-(cyclopropylethynyl)nicotinoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 2-chloro-5-(cyclopropylethynyl)nicotinate and methyl 2,5-bis(cyclopropylethynyl)nicotinate

To a mixture of methyl 5-bromo-2-chloro-pyridine-3-carboxylate (500 mg, 2.00 mmol), Pd(PPh₃)₂Cl₂ (56 mg, 0.080 mmol) and CuI (19 mg, 0.10 mmol) were sequentially added Et₃N (3.3 mL, 24 mmol), THE (0.2 mL, 99.9 mass %) and cyclopropylacetylene (0.34 mL, 4.0 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was reacted with stirring at room temperature overnight. After the reaction was completed, the mixture was concentrated in vacuo to remove the organic solvent. The residue was purified by silica gel column chromatography (PE:EA=6:1-4:1) to give a pale yellow solid 250 mg of methyl 2-chloro-5-(cyclopropylethynyl)nicotinate (yield 53.1%) as the target product and pale yellow oil 250 mg of methyl 2,5-bis(cyclopropylethynyl)nicotinate (yield 46%) as the target product. methyl 2-chloro-5-(cyclopropylethynyl)nicotinate: LC-MS: m/z=236.05 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.45 (d, J=2.1 Hz, 1H), 8.10 (d, J=2.1 Hz, 1H), 3.94 (s, 3H), 1.50-1.41 (m, 1H), 0.97-0.90 (m, 2H), 0.86-0.82 (m, 2H). methyl 2,5-bis(cyclopropylethynyl)nicotinate: LC-MS: m/z=266.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.59 (d, J=1.9 Hz, 1H), 8.12 (d, J=2.0 Hz, 1H), 3.92 (s, 3H), 1.57-1.52 (m, 1H), 1.51-1.42 (m, 1H), 0.98-0.89 (m, 6H), 0.87-0.81 (m, 2H).

Step 2: 2-chloro-5-(cyclopropylethynyl)nicotinic acid

To a solution of methyl 2-chloro-5-(cyclopropylethynyl)nicotinate (250 mg, 1.06 mmol) in THF/H₂O (3.5/1.5 mL) was added LiOH—H₂O (54 mg, 1.26 mmol) in one portion at room temperature and the mixture was stirred at room temperature overnight. After the reaction was completed, the mixture was concentrated in vacuo to remove the organic solvent, diluted with water (10 mL), and the aqueous phase was washed once with the mixed solvent of DCM/PE (2/3 mL). The aqueous phase was separated, and adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with EA (40 mL×2). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo to give a brown solid 129 mg (54.9%) as a crude material, which was used in the next step without further purification. LC-MS: m/z=222.20 [M+H]⁺.

Step 3: 4-(6-(4-(2-chloro-5-(cyclopropylethynyl)nicotinoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 25 mg, 0.072 mmol), 2-chloro-5-(cyclopropylethynyl)nicotinic acid (37.8 mg, 0.171 mmol) and DMAP (2 mg, 0.016 mmol) in DCM (2 mL, 99.9 mass %) was added EDCI (69 mg, 0.36 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1.5:1-1:1) to give a white solid 32.5 mg (yield: 82.1%) as the desired product. LC-MS: m/z=552.0 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.41 (d, J=2.0 Hz, 1H), 8.34 (d, J=2.0 Hz, 1H), 8.18 (s, 1H), 8.11 (d, J=1.7 Hz, 1H), 7.74 (dd, J=8.8, 2.3 Hz, 1H), 7.62 (d, J=2.1 Hz, 1H), 7.09 (d, J=1.8 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.08 (q, J=6.9 Hz, 2H), 4.04-3.82 (m, 2H), 3.84-3.57 (m, 4H), 3.51-3.28 (m, 2H), 1.49 (t, J=6.9 Hz, 3H), 1.47-1.39 (m, 1H), 0.94-0.82 (m, 4H).

Example 316: 4-(6-(4-(2,5-bis(cyclopropylethynyl)nicotinoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 2-chloro-5-(cyclopropylethynyl)nicotinate and methyl 2,5-bis(cyclopropylethynyl) nicotinate

To a mixture of methyl 5-bromo-2-chloro-pyridine-3-carboxylate (500 mg, 2.00 mmol), Pd(PPh₃)₂Cl₂ (56 mg, 0.080 mmol) and CuI (19 mg, 0.10 mmol) were sequentially added Et₃N (3.3 mL, 24 mmol), THE (0.2 mL, 99.9 mass %) and cyclopropylacetylene (0.34 mL, 4.0 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was reacted with stirring at room temperature overnight. After the reaction was completed, the mixture was concentrated in vacuo to remove the organic solvent. The residue was purified by silica gel column chromatography (PE:EA=6:1-4:1) to give a pale yellow solid 250 mg (chemical name: methyl 2-chloro-5-(cyclopropylethynyl)nicotinate) (yield 53.1%) as the target product and pale yellow oil 250 mg (chemical name: methyl 2,5-bis(cyclopropylethynyl)nicotinate) (yield 46%) as the target product. methyl 2-chloro-5-(cyclopropylethynyl)nicotinate: LC-MS: m/z=236.05 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.45 (d, J=2.1 Hz, 1H), 8.10 (d, J=2.1 Hz, 1H), 3.94 (s, 3H), 1.50-1.41 (m, 1H), 0.97-0.90 (m, 2H), 0.86-0.82 (m, 2H). methyl 2,5-bis(cyclopropylethynyl)nicotinate: LC-MS: m/z=266.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.59 (d, J=1.9 Hz, 1H), 8.12 (d, J=2.0 Hz, 1H), 3.92 (s, 3H), 1.57-1.52 (m, 1H), 1.51-1.42 (m, 1H), 0.98-0.89 (m, 6H), 0.87-0.81 (m, 2H).

Step 2: 2,5-bis(cyclopropylethynyl)nicotinic acid

To a solution of methyl 2,5-bis(cyclopropylethynyl)nicotinate (250 mg, 0.942 mmol) in THF/H₂O (3.5/1.5 mL) was added LiOH—H₂O (80 mg, 1.91 mmol) in one portion at room temperature. The mixture was heated to 40° C. and reacted for 4 h, and then concentrated in vacuo to remove the organic solvent. The resulting mixture was diluted with water (10 mL), and the aqueous phase was washed once with the mixed solvent of DCM/PE (2/3 mL). The aqueous phase was separated, and adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with EA (40 mL×2). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo to give a brown solid 229 mg (96.7%) as a crude material, which was used in the next step without further purification. LC-MS: m/z=252.20 [M+H]⁺.

Step 3: 4-(6-(4-(2,5-bis(cyclopropylethynyl)nicotinoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxy pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 22 mg, 0.063 mmol), 2-chloro-5-(cyclopropylethynyl)nicotinic acid (37.8 mg, 0.15 mmol) and DMAP (2 mg, 0.016 mmol) in DCM (2 mL) was added EDCI (69 mg, 0.36 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1:1-1:1.5) to give a white solid 7.4 mg (yield: 20%) as the desired product. LC-MS: m/z=582.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.53 (s, 1H), 8.34 (d, J=2.0 Hz, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.74 (dd, J=8.7, 2.2 Hz, 1H), 7.58 (d, J=1.6 Hz, 1H), 7.09 (d, J=1.5 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.93 (brs, 2H), 3.78 (brs, 2H), 3.71-3.31 (m, 4H), 1.49 (t, J=6.9 Hz, 3H), 1.48-1.42 (m, 2H), 0.93-0.83 (m, 8H).

Example 317: 4-(6-(4-(2-(cyclopropylethynyl)isonicotinoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 2-bromoisonicotinate

To a solution of 2-bromoisonicotinic acid (513 mg, 2.54 mmol), DMAP (31 mg, 0.25 mmol), EDCI (737 mg, 3.81 mmol) in DCM (25 mL) was added MeOH (0.5 mL, 10 mmol) in one portion at room temperature under nitrogen. The mixture was reacted at room temperature for 6 h. The reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=4:1-1:1) to give pale yellow oil 350 mg (yield: 63.8%), which became a white solid after standing overnight. LC-MS: m/z=218.0[M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.52 (d, J=5.0 Hz, 1H), 8.03 (s, 1H), 7.80 (dd, J=5.0, 1.0 Hz, 1H), 3.96 (s, 3H).

Step 2: methyl 2-(cyclopropylethynyl)isonicotinate

To a mixture of methyl 2-bromoisonicotinate (350 mg, 1.62 mmol), Pd(PPh₃)₂Cl₂ (45 mg, 0.064 mmol) and CuI (15 mg, 0.079 mmol) were sequentially added Et₃N (3 mL, 21.5 mmol), THE (0.2 mL) and cyclopropylacetylene (0.30 mL, 4.0 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was reacted with stirring at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent, and then purified by silica gel column chromatography (PE:EA=6:1-4:1) to give a pale yellow solid 247 mg (yield: 75.8%) as the target product. LC-MS: m/z=202.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.65 (d, J=5.0 Hz, 1H), 7.88 (s, 1H), 7.69 (dd, J=5.0, 1.2 Hz, 1H), 3.94 (s, 3H), 1.53-1.44 (m, 1H), 0.94-0.85 (m, 4H).

Step 3: 2-(cyclopropylethynyl)isonicotinic acid

To a solution of methyl 2-(cyclopropylethynyl)isonicotinate (240 mg, 1.19 mmol) in THF/H₂O (3.5/1.5 mL) was added LiOH—H₂O (76 mg, 1.78 mmol) in one portion at room temperature and the mixture was stirred at room temperature overnight. The mixture was concentrated in vacuo to remove the organic solvent, diluted with water (10 mL), and adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with a mixed solvent of DCM/EtOH (1:1) (40 mL×2). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulting mixture was dried at 50° C. for 11 h under vacuum to give a yellow solid 156 mg (69.9%) as a crude product, which was used in the next step without further purification. LC-MS: m/z=188.05 [M+H]⁺.

Step 4: 4-(6-(4-(2-(cyclopropylethynyl)isonicotinoyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo [1,5-a]pyridine-3-carbonitrile

To a solution of 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 18.4 mg, 0.053 mmol), 2-chloro-5-(cyclopropylethynyl)nicotinic acid (37.0 mg, 0.198 mmol) and DMAP (2 mg, 0.016 mmol) in DCM (2 mL) was added EDCI (69 mg, 0.36 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1:1.5) to give a white solid 17.0 mg (yield: 62.2%) as the desired product. LC-MS: m/z=518.10 [M+H]⁺, 259.6 [M/2+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.61 (d, J=4.9 Hz, 1H), 8.33 (d, J=2.1 Hz, 1H), 8.18 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.74 (dd, J=8.8, 2.4 Hz, 1H), 7.35 (s, 1H), 7.19 (d, J=4.9 Hz, 1H), 7.08 (d, J=1.8 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.08 (q, J=6.9 Hz, 2H), 3.90 (brs, 2H), 3.78-3.61 (m, 4H), 3.49 (brs, 2H), 1.48 (t, J=6.9 Hz, 3H), 1.07-1.02 (m, 1H), 0.94-0.87 (m, 4H).

Example 318: 6-ethoxy-4-(6-(4-(4-ethynyl-3-fluorobenzoyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 3-fluoro-4-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 3-fluoro-4-iodobenzoate (500 mg, 1.7855 mmol), CuI (40 mg, 0.21003 mmol), PdCl₂(PPh₃)₂(37 mg, 0.05271 mmol), TEA (5 mL) and ethynyl (trimethyl) silane (0.4 mL, 2.138 mmol) under nitrogen. The mixture was reacted overnight at room temperature. The reaction mixture was filtered by suction with celite, and the filter cake was washed with EA (20 mL). The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=0:500-1:100) to give pale yellow transparent liquid 442 mg as the desired product (the yield was 98.9%). ¹H NMR (400 MHz, CDCl₃) δ 7.79-7.66 (m, 2H), 7.51 (t, J=7.4 Hz, 1H), 3.92 (s, 3H), 0.27 (s, 9H).

Step 2: 4-ethynyl-3-fluorobenzoic acid

Methyl 3-fluoro-4-((trimethylsilyl)ethynyl)benzoate (440 mg, 1.758 mmol) was dissolved in methanol (9 mL) and water (0.45 mL) in a double-necked flask, and then potassium carbonate (500 mg, 3.6177 mmol) was added in one portion. The mixture was reacted with stirring at room temperature overnight. The reaction mixture was added with water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a pale pink solid 194 mg as the target product (yield: 67.25%). ¹H NMR (400 MHz, DMSO-d₆) δ 13.49 (s, 1H), 7.75 (dd, J=12.2, 9.0 Hz, 2H), 7.69 (t, J=7.5 Hz, 1H), 4.75 (s, 1H).

Step 3: 6-ethoxy-4-(6-(4-(4-ethynyl-3-fluorobenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 25 mg, 0.06495 mmol), 4-ethynyl-3-fluorobenzoic acid (15 mg, 0.091391 mmol), EDCI (25 mg, 0.13041 mmol), DMAP (2 mg, 0.016371 mmol), DIPEA (0.05 mL, 0.3 mmol) and DCM (2 mL). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=4/1-1.5/1) to give a yellow solid 22.9 mg as the target product (yield: 71.3%). LC-MS(ESI): m/z=495.0 [M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.9 Hz, 1H), 7.75 (dd, J=8.8, 2.4 Hz, 1H), 7.56 (t, J=7.5 Hz, 1H), 7.22 (s, 1H), 7.09 (d, J=1.9 Hz, 1H), 6.79 (d, J=8.8 Hz, 1H), 6.53 (d, 1H), 4.09 (q, J=7.0 Hz, 2H), 3.94-3.52 (m, 8H), 3.39 (s, 1H), 1.50 (t, J=6.9 Hz, 3H). HPLC: 94.67%.

Example 319: 6-ethoxy-4-(6-(4-ethynylpicolinoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-bromopyridinecarboxylate

To a 50 mL single-necked flask were sequentially added 4-bromopyridine-2-carboxylic acid (1 g, 4.9505 mmol), DMF (25 mL), cesium carbonate (1.77 g, 5.43 mmol), methyl iodide (0.34 mL, 5.5 mmol). The mixture was reacted with stirring at room temperature overnight. 25 mL of water and 40 mL of ethyl acetate were added. The aqueous phase was extracted with ethyl acetate (40 mL×2), and the combined organic phases were washed with water (25 mL) and saturated sodium chloride (25 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=25/1-8/1) to give a white needle-like crystal solid 805 mg as the desired product (yield: 75.3%). ¹H NMR (400 MHz, CDCl₃) δ 8.56 (d, J=5.2 Hz, 1H), 8.30 (d, J=1.5 Hz, 1H), 7.66 (dd, J=5.2, 1.8 Hz, 1H), 4.02 (s, 3H).

Step 2: methyl 4-((trimethylsilyl)ethynyl)pyridinecarboxylate

To a three-necked flask were added methyl 4-bromopyridinecarboxylate (800 mg, 3.7032 mmol), CuI (84 mg, 0.44106 mmol), PdCl₂(PPh₃)₂(77 mg, 0.1097 mmol), anhydrous THE (5 mL) and ethynyl (trimethyl)silane (436 mg, 4.439 mmol) under nitrogen. TEA (2.4 mL, 100 mass %) was added dropwise with stirring at 0° C. The mixture was reacted overnight at room temperature. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with 30 mL of saturated brine, dried over anhydrous sodium sulfate, filtered by suction, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:7) to give a yellow solid 423 mg as the target product (yield: 48.95%). LC-MS(ESI): m/z=234.2 [M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.68 (d, J=4.9 Hz, 1H), 8.14 (s, 1H), 7.50-7.43 (m, 1H), 4.01 (s, 3H), 0.27 (s, 9H).

Step 3: 4-ethynyl picolinic acid

Methyl 4-((trimethylsilyl)ethynyl)picolinate (420 mg, 1.7999 mmol) was dissolved in anhydrous methanol (8 mL) under nitrogen in a double-necked flask, and then potassium carbonate (500 mg, 3.6177 mmol) was added with stirring in one portion. The mixture was stirred overnight at room temperature. The reaction mixture was added with water (20 mL), adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate, filtered by suction, and concentrated in vacuo to give a yellow solid 95 mg as the target product (yield: 35.9%). ¹H NMR (600 MHz, (CD₃)₂SO) δ 8.73 (d, J=4.9 Hz, 1H), 8.00 (s, 1H), 7.70 (dd, J=4.9, 1.6 Hz, 1H), 4.74 (s, 1H).

Step 4: 6-ethoxy-4-(6-(4-ethynylpicolinoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 25 mg, 0.07176 mmol), 4-ethynyl picolinic acid (15 mg, 0.10195 mmol), EDCI (27 mg, 0.14085 mmol), DMAP (2 mg, 0.016371 mmol), DCM (2 mL) and DIPEA (0.035 mL, 0.21 mmol). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=3/1-1.5/1) to give a yellow solid 19.8 mg as the target product (yield: 57.8%). LC-MS(ESI): m/z=478.0 [M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.59 (d, J=5.0 Hz, 1H), 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.77 (s, 1H), 7.74 (dd, J=8.8, 2.3 Hz, 1H), 7.42 (d, J=5.0 Hz, 1H), 7.09 (d, J=1.9 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.95 (t, J=5.3 Hz, 2H), 3.82-3.75 (m, 4H), 3.73 (t, 2H), 3.36 (s, 1H), 1.50 (t, J=7.0 Hz, 3H). HPLC: 97.85%.

Example 320: 4-(6-(4-(3-chloro-4-ethynyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 3-chloro-4-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 4-bromo-3-chlorobenzoate (500 mg, 2.0041 mmol), CuI (45 mg, 0.23628 mmol), PdCl₂(PPh₃)₂(42 mg, 0.05984 mmol), TEA (5 mL) and ethynyl (trimethyl) silane (240 mg, 2.443 mmol) under nitrogen. The mixture was reacted overnight at 80° C. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with 30 mL of saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:500-1:50) to give pale yellow liquid 500 mg as the target product (yield: 93.5%). ¹H NMR (400 MHz, CDCl₃) δ 8.05 (d, J=1.3 Hz, 1H), 7.85 (dd, J=8.1, 1.6 Hz, 1H), 7.55 (d, J=8.1 Hz, 1H), 3.92 (s, 3H), 0.28 (s, 9H).

Step 2: 3-chloro-4-ethynylbenzoic acid

Methyl 3-chloro-4-((trimethylsilyl)ethynyl)benzoate (500 mg, 1.874 mmol) was dissolved in methanol (10 mL) and water (0.5 mL) in a double-necked flask, and then potassium carbonate (550 mg, 3.9795 mmol, 100 mass %) was added with stirring in one portion. The mixture was stirred to react at room temperature overnight. The reaction mixture was added with water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a white solid 229 mg as the target product (yield: 67.66%). ¹H NMR (400 MHz, CDCl₃) δ 8.13 (d, 1H), 7.93 (dd, J=8.1 Hz, 1H), 7.62 (d, J=8.1 Hz, 1H), 3.56 (s, 1H).

Step 3: 4-(6-(4-(3-chloro-4-ethynyl)piperazin-1-yl)pyridin-3-yl)-6-ethoxypyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile (20 mg, 0.05741 mmol), 3-chloro-4-ethynylbenzoic acid (15 mg, 0.083061 mmol), EDCI (22 mg, 0.11476 mmol), DMAP (2 mg, 0.016371 mmol), DCM (2 mL) and DIPEA (0.5 mL, 3 mmol). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=3/1-1.5/1) to give a yellow solid 17.3 mg as the target product (yield: 59.0%). LC-MS(ESI): m/z=511.0 [M+H]⁺. ¹H-NMR (600 MHz, CDCl₃) δ 8.35 (d, 1H), 8.19 (s, 1H), 8.11 (d, 1H), 7.75 (d, J=8.8 Hz, 1H), 7.60 (d, J=7.9 Hz, 1H), 7.52 (s, 1H), 7.31 (d, J=9.0 Hz, 1H), 7.09 (d, 1H), 6.79 (d, J=8.8 Hz, 1H), 4.09 (q, J=6.8 Hz, 2H), 3.97-3.84 (m, 2H), 3.75-3.66 (m, 4H), 3.63-3.51 (m, 2H), 3.46 (s, 1H), 1.50 (t, J=6.9 Hz, 3H). HPLC: 95.85%.

Example 321: 6-ethoxy-4-(6-(4-(3-ethynyl-4-methylbenzoyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-methyl-3-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 3-iodo-4-methylbenzoate (500 mg, 1.8111 mmol), CuI (41 mg, 0.21528 mmol), PdCl₂(PPh₃)₂(38 mg, 0.05414 mmol), TEA (5 mL) and ethynyl (trimethyl) silane (0.31 mL, 2.2 mmol) under nitrogen. The mixture was reacted overnight at 80° C. The reaction mixture was added with EA (30 mL), then the mixture was filtered by suction through a celite pad. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:500-1:50) to give a white light solid 257 mg as the desired product (the yield was 57.6%). ¹H NMR (400 MHz, CDCl₃) δ 8.10 (d, J=1.1 Hz, 1H), 7.86 (dd, J=8.0, 1.4 Hz, 1H), 7.26 (d, J=2.9 Hz, 1H), 3.90 (s, 3H), 2.48 (s, 3H), 0.26 (s, 9H).

Step 2: 3-ethynyl-4-methylbenzoic acid

Methyl 4-methyl-3-((trimethylsilyl)ethynyl)benzoate (250 mg, 1.015 mmol) was dissolved in methanol (5 mL) and water (0.25 mL) in a double-necked flask, and then NaOH (80 mg, 2 mmol) was added with stirring in one portion. The mixture was stirred to react at room temperature overnight. To the reaction mixture were added water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a white solid 118 mg as the target product (yield: 69.7%).

Step 3: 6-ethoxy-4-(6-(4-(3-ethynyl-4-methylbenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 20 mg, 0.05741 mmol), 3-ethynyl-4-methylbenzoic acid (15 mg, 0.093650 mmol), EDCI (22 mg, 0.11476 mmol), DMAP (2 mg, 0.016371 mmol), DCM (2 mL) and DIPEA (0.5 mL, 3 mmol). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2).

The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=3/1-1.5/1) to give a yellow solid 7.5 mg as the target product (yield: 27.0%). LC-MS(ESI): m/z=491.2 [M+H]⁺. ¹H-NMR (600 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.7 Hz, 1H), 7.74 (dd, J=8.7, 2.3 Hz, 1H), 7.55 (s, 1H), 7.34 (d, J=7.8 Hz, 1H), 7.29 (d, J=7.9 Hz, 1H), 7.09 (d, J=1.8 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.09 (dd, J=13.9, 6.9 Hz, 2H), 3.93-3.55 (m, 8H), 3.32 (s, 1H), 2.49 (s, 3H), 1.50 (t, J=6.9 Hz, 3H). HPLC: 99.09%.

Example 322: 6-ethoxy-4-(6-(4-(3-ethynyl-4-fluorobenzoyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-fluoro-3-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 3-bromo-4-fluorobenzoate (500 mg, 2.1456 mmol), CuI (49 mg, 0.25729 mmol), PdCl₂(PPh₃)₂(45 mg, 0.06411 mmol), TEA (5 mL) and ethynyl (trimethyl) silane (260 mg, 2.647 mmol) under nitrogen. The mixture was reacted overnight at 80° C. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with 30 mL of saturated brine, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:500-1:50) to give pale yellow liquid 352 mg as the target product (yield: 65.5%). ¹H NMR (400 MHz, CDCl₃) δ 8.05 (d, J=1.3 Hz, 1H), 7.85 (dd, J=8.1, 1.6 Hz, 1H), 7.55 (d, J=8.1 Hz, 1H), 3.92 (s, 3H), 0.28 (s, 9H).

Step 2: 3-ethynyl-4-fluorobenzoic acid

Methyl 4-fluoro-3-((trimethylsilyl)ethynyl)benzoate (350 mg, 1.9645 mmol) was dissolved in methanol (7 mL) and water (0.35 mL) in a double-necked flask, and then potassium carbonate (400 mg, 2.8941 mmol) was added with stirring in one portion. The mixture was stirred to react at room temperature overnight. To the reaction mixture were added water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a white solid 219 mg as the target product (yield: 67.9%). ¹H NMR (400 MHz, CDCl₃) δ 8.26 (dd, J=6.7, 2.0 Hz, 1H), 8.13-8.06 (m, 1H), 7.18 (t, J=8.7 Hz, 1H), 3.36 (s, 1H).

Step 3: 6-ethoxy-4-(6-(4-(3-ethynyl-4-fluorobenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 20 mg, 0.05741 mmol), 3-ethynyl-4-fluorobenzoic acid (14 mg, 0.085298 mmol), EDCI (22 mg, 0.11476 mmol), DMAP (2 mg, 0.016371 mmol), DCM (2 mL) and DIPEA (0.5 mL, 3 mmol). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=3/1-1.5/1) to give a yellow solid 26.1 mg as the target product (yield: 84.9%). LC-MS(ESI): m/z=495.0 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.35 (s, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.75 (d, 1H), 7.61 (d, 1H), 7.46 (t, 1H), 7.16 (t, 1H), 7.09 (s, 1H), 6.78 (d, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.97-3.53 (m, 8H), 3.36 (s, 1H), 1.49 (t, J=6.8 Hz, 3H). HPLC: 98.45%.

Example 323: 6-ethoxy-4-(6-(4-(4-ethynyl-2,6-difluorobenzoyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 2,6-difluoro-4-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 4-bromo-2,6-difluorobenzoate (590 mg, 2.3504 mmol), CuI (53 mg, 0.27829 mmol) and PdCl₂(PPh₃)₂(50 mg, 0.07124 mmol) under nitrogen, then TEA (6 mL) and ethynyl (trimethyl) silane (0.4 mL, 3 mmol) were added. The mixture was reacted overnight at 70° C. The reaction mixture was added with EA (30 mL), then the mixture was filtered by suction through a celite pad. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:500-1:50) to give pale yellow liquid 489 mg as the desired product (the yield was 77.54%). ¹H NMR (400 MHz, CDCl₃) δ 7.02 (d, J=8.4 Hz, 2H), 3.94 (s, 3H), 0.25 (s, 9H).

Step 2: 4-ethynyl-2,6-difluorobenzoic acid

Methyl 2,6-difluoro-4-((trimethylsilyl)ethynyl)benzoate (480 mg, 1.789 mmol) was dissolved in methanol (10 mL) and water (0.5 mL) in a double-necked flask, and then NaOH (145 mg, 3.625 mmol) was added with stirring in one portion. The mixture was stirred to react at room temperature overnight. The reaction mixture was added with water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a light yellow solid 304 mg as the target product (yield: 93.3%).

Step 3: 6-ethoxy-4-(6-(4-(4-ethynyl-2,6-difluorobenzoyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 20 mg, 0.05741 mmol), 4-ethynyl-2,6-difluorobenzoic acid (16 mg, 0.087854 mmol), EDCI (22 mg, 0.11476 mmol), DMAP (2 mg, 0.016371 mmol), DCM (2 mL) and DIPEA (0.5 mL, 3 mmol). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=3/1-1.5/1) to give a yellow solid 5.6 mg as the target product (yield: 19%). LC-MS(ESI): m/z=513.0 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.35 (s, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.75 (d, 1H), 7.09 (d, 3H), 6.79 (d, 1H), 4.09 (q, 2H), 4.00-3.91 (m, 2H), 3.80-3.66 (m, 4H), 3.50-3.42 (m, 2H), 3.24 (s, 1H), 1.50 (t, 3H). HPLC: 96.26%.

Example 324: 6-ethoxy-4-(6-(4-(5-(prop-1-yn-1-yl)pyridylcarbonyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 5-(prop-1-yn-1-yl)pyridinecarboxylate

To a mixture of methyl 5-bromopyridinecarboxylate (500 mg, 2.31 mmol), Pd(PPh₃)₂Cl₂ (64 mg, 0.091 mmol) and CuI (22 mg, 0.12 mmol) were sequentially added Et₃N (3.8 mL, 27 mmol), THE (10 mL) and propyne (9.1 mL, 4.6 mmol, 3% n-pentane solution) at room temperature under nitrogen. A black suspension was obtained. The mixture was heated to 50° C. and reacted overnight. The mixture was concentrated in vacuo to remove the solvent. Then to the residual black mixture were added water (30 mL) and ethyl acetate (40 mL). The resulting mixture was filtered through a sand core funnel with celite. The aqueous phase was extracted with EA (20 mL×2). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=6:1-1:4) to afford a yellow solid 73 mg (yield: 18%) as the target product. LC-MS: m/z=176.15 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.71 (s, 1H), 8.06 (d, J=8.1 Hz, 1H), 7.79 (d, J=8.0 Hz, 1H), 4.00 (s, 3H), 2.11 (s, 3H).

Step 2: 5-(prop-1-yn-1-yl)pyridinecarboxylic acid

To a solution of methyl 5-(prop-1-yn-1-yl)pyridinecarboxylate (70 mg, 0.40 mmol) in THF/H₂O (2.0/0.8 mL) was added LiOH—H₂O (25 mg, 0.58 mmol) in one portion at room temperature. The mixture was reacted for 7 h, and then concentrated in vacuo to remove the organic solvent. The resulting mixture was diluted with water (10 mL), and the aqueous phase was washed once with the mixed solvent of DCM/PE (2/3 mL). The aqueous phase was separated, and adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with EA (40 mL×2). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo to give a brown solid 64 mg (96.7%) as a crude material, which was used in the next step without further purification. LC-MS: m/z=162.10 [M+H]⁺.

Step 3: 6-ethoxy-4-(6-(4-(5-(prop-1-yn-1-yl)pyridylcarbonyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a solution of 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl) piperazine-1-ium chloride (18 mg, 0.047 mmol), 5-(prop-1-yn-1-yl)pyridinecarboxylic acid (15.0 mg, 0.093 mmol) and DMAP (1 mg, 0.008 mmol) in DCM (1 mL) were added DIPEA (0.1 mL, 0.6 mmol) and EDCI (45 mg, 0.23 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1.5:1-1:1) to give a white solid 12.0 mg (yield: 52%) as the desired product. LC-MS: m/z=492.05 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.59 (s, 1H), 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.78 (dd, J=8.1, 1.9 Hz, 1H), 7.74 (dd, J=8.8, 2.4 Hz, 1H), 7.66 (d, J=8.1 Hz, 1H), 7.09 (d, J=1.9 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.08 (q, J=6.9 Hz, 2H), 3.98-3.90 (m, 2H), 3.85-3.75 (m, 4H), 3.74-3.67 (m, 2H), 2.10 (s, 3H), 1.49 (t, J=6.9 Hz, 3H).

Example 325: 6-ethoxy-4-(6-(4-(5-ethynylfuran-2-carbonyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 5-((trimethylsilyl)ethynyl)furan-2-carboxylate

To a mixture of methyl 5-bromofuran-2-carboxylate (600 mg, 2.93 mmol), Pd(PPh₃)₂Cl₂ (102 mg, 0.15 mmol) and CuI (27 mg, 0.14 mmol) in THE (5 mL) were sequentially added Et₃N (3.0 mL, 22 mmol) and trimethylsilylacetylene (0.80 mL, 6 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent. Then to the residual black mixture were added water (30 mL) and ethyl acetate (50 mL). The resulting mixture was filtered through a sand core funnel with celite. The aqueous phase was extracted with EA (20 mL×2). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=10:1) to afford light brown oil 650 mg (yield: 99.9%) as the target product, which was formed into needle crystals after standing overnight. LC-MS: m/z=223.20 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 7.13 (d, J=3.6 Hz, 1H), 6.63 (d, J=3.6 Hz, 1H), 3.89 (s, 3H), 0.25 (s, 9H).

Step 2: 5-ethynylfuran-2-carboxylic acid

To a solution of methyl 5-((trimethylsilyl)ethynyl)furan-2-carboxylate (640 mg, 2.88 mmol) in THF/H₂O (14.0/6.0 mL) was added LiOH—H₂O (308 mg, 7.09 mmol) in one portion at room temperature. The mixture was reacted overnight, and then concentrated in vacuo to remove the organic solvent. The resulting mixture was diluted with water (20 mL), and the aqueous phase was washed once with the mixed solvent of DCM/PE (10/5 mL). The aqueous phase was separated, and adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with saturated brine (40 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo to give a yellow solid 340 mg (yield: 86.8%) as a crude product, which was used in the next step without further purification. LC-MS: m/z=137.10 [M+H]⁺.

Step 3: 6-ethoxy-4-(6-(4-(5-ethynylfuran-2-carbonyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl) piperazine-1-ium chloride (18 mg, 0.047 mmol), 5-ethynylfuran-2-carboxylic acid (12.0 mg, 0.088 mmol) and DMAP (1 mg, 0.008 mmol) in DCM (1 mL) were added DIPEA (0.1 mL, 0.6 mmol) and EDCI (45 mg, 0.23 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1.5:1-1:1) to give a white solid 17.0 mg (yield: 79%) as the desired product. LC-MS: m/z=467.0 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.35 (s, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.75 (d, J=8.6 Hz, 1H), 7.13-7.02 (m, 2H), 6.78 (d, J=8.8 Hz, 1H), 6.72 (s, 1H), 4.09 (q, J=6.7 Hz, 2H), 4.03-3.86 (m, 4H), 3.82-3.65 (m, 4H), 3.45 (s, 1H), 1.50 (t, J=6.7 Hz, 3H).

Example 326: 6-ethoxy-4-(6-(4-(5-ethynylthiophene-2-carbonyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 5-bromothiophene-2-carboxylate

To a solution of 5-bromothiophene-2-carboxylic acid (500 mg, 2.42 mmol) in DMF (9 mL) were sequentially added K₂CO₃ (671 mg, 4.83 mmol) and CH₃I (0.30 mL, 4.8 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature for 5 h. The reaction solution was diluted with EA (50 mL) and water (15 mL). The aqueous phase was extracted with EA (20 mL×2). The organic phase was combined, washed with water (20 mL) and saturated saline (20 mL) in turn, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=6:1) to give a white solid 386 mg (yield: 72%). ¹H NMR (400 MHz, CDCl₃) δ 7.55 (d, J=4.0 Hz, 1H), 7.07 (d, J=3.9 Hz, 1H), 3.87 (s, 3H).

Step 2: methyl 5-((trimethylsilyl)ethynyl)thiophene-2-carboxylate

To a mixture of methyl 5-bromothiophene-2-carboxylate (350 mg, 1.58 mmol), Pd(PPh₃)₂Cl₂ (60 mg, 0.086 mmol) and CuI (16 mg, 0.084 mmol) in THE (5 mL) were sequentially added Et₃N (1.7 mL, 12 mmol) and trimethylsilylacetylene (0.50 mL, 4 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was reacted at 60° C. overnight. The mixture was concentrated in vacuo to remove the solvent. Then to the residual black mixture were added water (30 mL) and ethyl acetate (50 mL). The resulting mixture was filtered through a sand core funnel with celite. The aqueous phase was extracted with EA (20 mL×2). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=50:1-30:1) to afford yellow oil 192 mg (yield: 50.9%) as the target product, which become brown crystals after standing overnight. ¹H NMR (400 MHz, CDCl₃) δ 7.62 (d, J=3.9 Hz, 1H), 7.16 (d, J=3.9 Hz, 1H), 3.88 (s, 3H), 0.26 (s, 9H).

Step 3: 5-ethynylthiophene-2-carboxylic acid

To a solution of methyl 5-((trimethylsilyl)ethynyl)thiophene-2-carboxylate (187 mg, 0.78 mmol) in THF/H₂O (5.0/2.0 mL) was added LiOH—H₂O (83 mg, 1.94 mmol) in one portion at room temperature. The mixture was reacted overnight, and then concentrated in vacuo to remove the organic solvent. The resulting mixture was diluted with water (20 mL), and the aqueous phase was washed once with the mixed solvent of DCM/PE (10/5 mL). The aqueous phase was separated, and adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed with saturated brine (40 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo to give a yellow solid 112 mg (yield: 93.8%) as a crude product, which was used in the next step without further purification. LC-MS: m/z=153.10 [M+H]⁺.

Step 4: 6-ethoxy-4-(6-(4-(5-ethynylthiophene-2-carbonyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a solution of 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl) piperazine-1-ium chloride (20 mg, 0.047 mmol), 5-ethynylthiophene-2-carboxylic acid (23.0 mg, 0.15 mmol) and DMAP (1 mg, 0.008 mmol) in DCM (1 mL) were added DIPEA (0.1 mL, 0.6 mmol) and EDCI (50 mg, 0.26 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1.5:1-1:1) to give a white solid 12.0 mg (yield: 47.8%) as the desired product. LC-MS: m/z=483.30[M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.35 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.9 Hz, 1H), 7.75 (dd, J=8.8, 2.4 Hz, 1H), 7.21 (s, 2H), 7.09 (d, J=1.9 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.94-3.84 (m, 4H), 3.79-3.70 (m, 4H), 3.43 (s, 1H), 1.49 (t, J=6.9 Hz, 3H).

Example 327: 4-(6-(6-(4-ethynylbenzoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 10 mL double-necked flask were added 4-(6-(3,6-diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 20 mg, 0.04189 mmol) and 4-ethynylbenzoic acid (8 mg, 0.054742 mmol), which were dissolved by adding DCM (2 mL). Then DMAP (2 mg, 0.016371 mmol) and EDCI (16 mg, 0.083464 mmol) were added. The mixture was stirred at room temperature overnight. The reaction mixture was added with DCM (30 mL) and water (30 mL). The aqueous phase was extracted with DCM (30 mL×2). The organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=50/1) to give a white solid 13 mg (yield: 58.26%) as the desired product. LC-MS(ESI): m/z=533.0 [M+H]⁺; 1H NMR (400 MHz, CDCl₃) δ 8.33 (d, J=2.1 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=1.8 Hz, 1H), 7.74 (dd, J=8.8, 2.3 Hz, 1H), 7.62-7.50 (m, 4H), 7.14 (d, J=1.8 Hz, 1H), 6.63 (d, J=8.8 Hz, 1H), 4.80-4.66 (m, 2H), 4.30 (s, 1H), 3.86 (s, 2H), 3.83-3.59 (m, 4H), 3.18 (s, 1H), 2.96-2.88 (m, 1H), 2.26-2.17 (m, 1H), 1.39 (s, 6H). HPLC: 99.01%.

Example 328: 4-(6-(6-(3-ethynylbenzoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 10 mL double-necked flask were added 4-(6-(3,6-diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 20 mg, 0.04189 mmol) and 3-ethynylbenzoic acid (8 mg, 0.054742 mmol), which were dissolved by adding DCM (2 mL). Then DMAP (2 mg, 0.016371 mmol) and EDCI (16 mg, 0.083464 mmol) were added. The mixture was stirred at room temperature overnight. The reaction mixture was added with DCM (30 mL) and water (30 mL). The aqueous phase was extracted with DCM (30 mL×2). The organic phase was dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=50/1) to give a white solid 16 mg (yield: 71.71%) as the desired product. LC-MS(ESI): m/z=533.0 [M+H]⁺; 1H NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.77-7.72 (m, 2H), 7.64-7.58 (m, 2H), 7.39 (t, J=7.7 Hz, 1H), 7.14 (d, J=2.0 Hz, 1H), 6.64 (d, J=8.8 Hz, 1H), 4.79-4.69 (m, 2H), 4.30 (s, 1H), 3.86 (s, 2H), 3.80-3.67 (m, 4H), 3.11 (s, 1H), 2.97-2.91 (m, 1H), 2.26-2.18 (m, 1H), 1.39 (s, 6H). HPLC: 98.93%.

Example 329: 4-(6-(6-(4-ethynyl-3-fluorobenzoyl)-3,6-diazabicyclo[3.1.1]hept-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 3-fluoro-4-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 3-fluoro-4-iodobenzoate (500 mg, 1.7855 mmol), CuI (40 mg, 0.21003 mmol), PdCl₂(PPh₃)₂(37 mg, 0.05271 mmol), TEA (5 mL) and ethynyl (trimethyl) silane (0.4 mL, 2.138 mmol) under nitrogen. The mixture was reacted overnight at room temperature. The reaction mixture was filtered by suction with celite, and the filter cake was washed with EA (20 mL). The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=0:500-1:100) to give pale yellow transparent liquid 442 mg as the desired product (the yield was 98.9%). ¹H NMR (400 MHz, CDCl₃) δ 7.79-7.66 (m, 2H), 7.51 (t, J=7.4 Hz, 1H), 3.92 (s, 3H), 0.27 (s, 9H).

Step 2: 4-ethynyl-3-fluorobenzoic acid

Methyl 3-fluoro-4-((trimethylsilyl)ethynyl)benzoate (440 mg, 1.758 mmol) was dissolved in methanol (9 mL) and water (0.45 mL) in a double-necked flask, and then potassium carbonate (500 mg, 3.6177 mmol) was added in one portion. The mixture was reacted with stirring at room temperature overnight. The reaction mixture was added with water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a pale pink solid 194 mg as the target product (yield: 67.25%). ¹H NMR (400 MHz, DMSO-d₆) δ 13.49 (s, 1H), 7.75 (dd, J=12.2, 9.0 Hz, 2H), 7.69 (t, J=7.5 Hz, 1H), 4.75 (s, 1H).

Step 3: 4-(6-(6-(4-ethynyl-3-fluorobenzoyl)-3,6-diazabicyclo[3.1.1]hept-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 25 mL double-necked flask were added 4-(6-(3,6-diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.032 mmol) and 4-ethynyl-3-fluorobenzoic acid (3.8 mg, 0.049 mmol), which were dissolved by adding DCM (5 mL). Then DMAP (2 mg, 0.0164 mmol) and EDCI (12 mg, 0.0626 mmol) were added. The mixture was stirred at room temperature overnight. The reaction solution was added with 30 mL of DCM and 10 mL of water. The organic phases were separated, washed with 10 mL of water once. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by column chromatography (eluent MeOH:DCM=1:50-1:30) to give a white solid 3 mg. The yield was 17.34%. Rf=0.3(MeOH:DCM=1:30). LC-MS: m/z=551.40[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.1 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=1.8 Hz, 1H), 7.74 (dd, J=8.8, 2.2 Hz, 1H), 7.54 (d, J=7.8 Hz, 1H), 7.38 (d, J=4.4 Hz, 1H), 7.35 (d, J=2.1 Hz, 1H), 7.14 (d, J=1.8 Hz, 1H), 6.64 (d, J=8.8 Hz, 1H), 4.73 (d, J=22.3 Hz, 2H), 4.30 (d, J=6.9 Hz, 1H), 3.86 (s, 2H), 3.81-3.76 (m, 1H), 3.74-3.69 (m, 2H), 3.41 (s, 1H), 2.96-2.89 (m, 1H), 2.04-2.01 (m, 1H), 1.25 (s, 6H). HPLC: 93.93%.

Example 330: 4-(6-(6-(4-ethynyl-2,6-difluorobenzoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 2,6-difluoro-4-((trimethylsilyl)ethynyl)benzoate

To a three-necked flask were added methyl 4-bromo-2,6-difluorobenzoate (590 mg, 2.3504 mmol), CuI (53 mg, 0.27829 mmol) and PdCl₂(PPh₃)₂(50 mg, 0.07124 mmol) under nitrogen, then TEA (6 mL) and ethynyl (trimethyl) silane (0.4 mL, 3 mmol) were added. The mixture was reacted overnight at 70° C. The reaction mixture was added with EA (30 mL), then the mixture was filtered by suction through a celite pad. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:500-1:50) to give pale yellow liquid 489 mg as the desired product (the yield was 77.54%). ¹H NMR (400 MHz, CDCl₃) δ 7.02 (d, J=8.4 Hz, 2H), 3.94 (s, 3H), 0.25 (s, 9H).

Step 2: 4-ethynyl-2,6-difluorobenzoic acid

Methyl 2,6-difluoro-4-((trimethylsilyl)ethynyl)benzoate (480 mg, 1.789 mmol) was dissolved in methanol (10 mL) and water (0.5 mL) in a double-necked flask, and then NaOH (145 mg, 3.625 mmol) was added with stirring in one portion. The mixture was stirred to react at room temperature overnight. The reaction mixture was added with water (30 mL) and EA (20 mL). The aqueous phase was separated and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a light yellow solid 304 mg as the target product (yield: 93.3%).

Step 3: 4-(6-(6-(4-ethynyl-2,6-difluorobenzoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.032 mmol) and 4-ethynyl-2,6-difluorobenzoic acid (9 mg, 0.049 mmol) were dissolved with DCM (2 mL) under nitrogen. Then DMAP (2 mg, 0.016 mmol) and EDCI (12 mg, 0.063 mmol) were added. The mixture was reacted at room temperature for 18 h. The reaction mixture was added with DCM (30 mL) and water (10 mL). The organic phase was separated, washed with water (10 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent MeOH:DCM=1:50-1:30) to give a white solid 4 mg as the desired product (yield: 22.39%). Rf=0.3(MeOH:DCM=1:30). LC-MS: m/z=569.30[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.1 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=1.8 Hz, 1H), 7.75 (dd, J=8.8, 2.3 Hz, 1H), 7.17 (d, J=1.9 Hz, 1H), 7.07 (d, J=7.5 Hz, 2H), 6.64 (d, J=8.8 Hz, 1H), 4.87 (s, 1H), 4.36 (s, 1H), 4.23 (d, J=10.6 Hz, 1H), 3.87 (s, 2H), 3.81 (d, J=10.6 Hz, 1H), 3.70 (t, J=10.3 Hz, 2H), 3.23 (s, 1H), 2.92 (dd, J=14.3, 6.6 Hz, 1H), 2.10 (s, 1H), 1.82 (d, J=8.7 Hz, 1H), 1.40 (s, 6H). HPLC: 94.50%.

Example 331: 4-(6-(4-(4-ethynylbenzoyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 25 mL double-necked flask were added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbo nitrile dihydrochloride (see synthesis of intermediate 7, 20 mg, 0.04297 mmol) and 4-ethynylbenzoic acid (10 mg, 0.068428 mmol), which were dissolved by adding DCM (3 mL). Then DMAP (3 mg, 0.024556 mmol) and EDCI (17 mg, 0.088680 mmol) were added. The mixture was reacted at room temperature overnight. The reaction mixture was added with DCM (30 mL) and water (30 mL). The aqueous phase was extracted with DCM (30 mL×2). The organic phase was dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=100/3) to give a white solid 6 mg (yield: 26.82%) as the desired product. LC-MS(ESI): m/z=521.2 [M+H]; ¹H NMR (400 MHz, CDCl₃) δ 8.35 (d, J=2.3 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=2.0 Hz, 1H), 7.74 (dd, J=8.8, 2.4 Hz, 1H), 7.56 (d, J=8.2 Hz, 2H), 7.42 (d, J=8.2 Hz, 2H), 7.15 (d, J=2.0 Hz, 1H), 6.79 (d, J=8.8 Hz, 1H), 3.86 (s, 2H), 3.67 (d, J=23.0 Hz, 8H), 3.17 (s, 1H), 1.39 (s, 6H). HPLC: 98.64%.

Example 332: 4-(6-(6-(5-ethynylpicolinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 5-((trimethylsilyl)ethynyl)picolinate

To a three-necked flask were added methyl 5-bromopyridinecarboxylate (500 mg, 2.3145 mmol), CuI (53 mg, 0.27829 mmol) and PdCl₂(PPh₃)₂(49 mg, 0.06981 mmol) under nitrogen. After the solids were dissolved by adding anhydrous THE (3 mL), ethynyl (trimethyl) silane (273 mg, 2.779 mmol) was added dropwise. The solution was orange and then TEA (1.5 mL) was added dropwise with stirring at room temperature. The solution turned to black. The completion of reaction was monitored by TLC after reaction for 4 h. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. A large amount of brown solid precipitated. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed once with 30 mL of saturated brine. The organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:5) to give a yellow solid 450 mg. The yield was 83.32%. Rf=0.5 (PE:EA=5:1). LC-MS: m/z=234.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.76 (s, 1H), 8.07 (d, J=8.1 Hz, 1H), 7.87 (dd, J=8.1, 1.8 Hz, 1H), 4.00 (s, 3H), 0.27 (s, 9H).

Step 2: 5-ethynyl picolinic acid

Methyl 5-((trimethylsilyl)ethynyl)picolinate (450 mg, 1.9285 mmol) was dissolved in anhydrous methanol (9 mL) under nitrogen in a double-necked flask, and then potassium carbonate (533 mg, 3.8565 mmol) was added with stirring in one portion at room temperature. The mixture was stirred overnight. The reaction mixture was added with water (20 mL) and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed once with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 280 mg. The yield was 98.68%. Rf=0.01 (PE:EA=5:1). LC-MS: m/z=148.10[M+H]⁺. ¹H-NMR (400 MHz, DMSO-d₆) δ 8.78 (s, 1H), 8.08 (d, J=8.1 Hz, 1H), 8.03 (d, J=8.1 Hz, 1H), 4.67 (s, 1H).

Step 3: 5-ethynylpicolinic acid chloride

5-Ethynylpicolinic acid (20 mg, 0.13593 mmol) was dissolved in DCM (5 mL) in a two-necked flask under nitrogen, and DMF (0.01 mL) was added with stirring. After 5 min, SOCl₂ (20 mg, 0.16811 mmol) was added dropwise. After addition, the solution precipitated with a large amount of yellow solid. The mixture was continuously stirred at this temperature. The solid gradually dissolved over time and the solution gradually turned orange, clear and transparent. The mixture was reacted for 0.5 h and then directly concentrated in vacuo, which was directly used for the next step without further purification. The yield was calculated as 100%.

Step 4: 4-(6-(6-(5-ethynylpicolinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were added 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.031 mmol) and 2 mL of DCM at room temperature. After the solids were dissolved, TEA (16 mg, 0.16 mmol) was added with stirring. After 5 min, a solution of 5-ethynyl-2-chloromethylpyridine (8 mg, 0.048 mmol) in 1 mL of DCM was added. After the end of addition, the mixture was reacted continuously at this temperature. After the reaction was completed, the reaction mixture was poured into water (5 mL) and extracted with DCM (10 mL). The organic phases were washed with water (5 mL), dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent MeOH:DCM=1:50-1:30) to give a pale yellow solid 6 mg as the target product. Rf=0.3(DCM:MeOH=30:1). LC-MS: m/z=534.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.66 (s, 1H), 8.33 (d, J=2.3 Hz, 1H), 8.19 (s, 1H), 8.14 (s, 1H), 8.08 (d, J=8.1 Hz, 1H), 7.87 (d, J=8.0 Hz, 1H), 7.71 (dd, J=8.9, 2.3 Hz, 1H), 7.11 (s, 1H), 6.63 (d, J=9.1 Hz, 1H), 4.22 (d, J=10.1 Hz, 1H), 4.05 (d, J=11.2 Hz, 1H), 3.93-3.87 (m, 2H), 3.85 (s, 2H), 3.82-3.73 (m, 2H), 3.32 (s, 1H), 2.94-2.91 (m, 1H), 2.08-2.07 (m, 1H), 1.38 (s, 6H). HPLC: 95.39%.

Example 333: 4-(6-(6-(4-ethynyl-3,5-difluorobenzoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 4-bromo-3,5-benzoate

4-Bromo-3,5-difluoro-benzoic acid (1.50 g, 6.33 mmol) was dissolved in CH₃OH (15 mL) at 0° C., then SOCl₂ (5 mL, 68.5 mmol) was slowly added. The mixture was naturally warmed to room temperature, then heated to 60° C. and reacted with stirring for 3 h. The reaction mixture was cooled to room temperature, concentrated in vacuo to give an off-white solid 1.49 g as the target product (the yield was 94%). ¹H NMR (400 MHz, CDCl₃) δ 7.64 (s, 1H), 7.63 (s, 1H), 3.96 (s, 3H).

Step 2: methyl 3,5-difluoro-4-((trimethylsilyl)ethynyl)benzoate

To a two-necked flask were sequentially added methyl 4-bromo-3,5-benzoate (0.30 g, 1.2 mmol), PdCl₂(PPh₃)₂(84 mg, 0.12 mmol), CuI (23 mg, 0.12 mmol) and PPh₃ (31 mg, 0.12 mmol) under N₂. DMF (2 mL) and Et₃N (2 mL) were added, and then trimethylsilylacetylene (0.23 g, 2.3 mmol) was slowly added. The mixture was reacted with stirring at 50° C. for 24 h. The reaction was stopped. The resulting mixture was cooled to room temperature, added with water (10 mL) and extracted with EA (20 mL×3), then washed with water (10 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo and then purified by silica gel column chromatography (eluent PE) to give a brown solid 0.23 g as the target product (the yield was 72%). ¹H NMR (400 MHz, CDCl₃) δ 7.58 (s, 1H), 7.56 (s, 1H), 3.95 (s, 3H), 0.31 (s, 9H).

Step 3: 4-ethynyl-3,5-difluorobenzoic acid

Methyl 3,5-difluoro-4-((trimethylsilyl)ethynyl)benzoate (0.20 g, 0.75 mmol) was dissolved in ethanol (6 mL) and H₂O (2 mL), then LiOH—H₂O (0.31 g, 7.4 mmol) was slowly added. The mixture was stirred at room temperature for 1 h. The reaction was added with DCM (5 mL) and layered. The aqueous phase was adjusted with hydrochloric acid to pH=2, and extracted with DCM (10 mL×3). The combined organic phases were dried over anhydrous sodium sulfate, filtered and the filtrate was concentrated in vacuo to give a brown solid 0.11 g as the desired product. ¹H NMR (400 MHz, CDCl₃) δ 7.68 (s, 1H), 7.66 (s, 1H), 3.71 (s, 1H).

Step 4: 4-(6-(6-(4-ethynyl-3,5-difluorobenzoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 18 mg, 0.04 mmol) and 4-ethynyl-3,5-difluorobenzoic acid (10 mg, 0.05 mmol) were dissolved with DCM (2 mL) at 0° C. Then EDCI (30 mg, 0.16 mmol) and DMAP (2 mg, 0.02 mmol) were added slowly. The mixture was naturally warmed to room temperature and reacted with stirring for 3 h. The reaction mixture was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/CH₃OH=50/1-20/1) to give a brown solid 2 mg as the target product. LC-MS: m/z=569.1[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.2 Hz, 1H), 8.23 (s, 1H), 8.18 (d, J=1.9 Hz, 1H), 7.80-7.74 (m, 1H), 7.24 (d, J=7.1 Hz, 2H), 7.17 (d, J=1.9 Hz, 1H), 6.67 (d, J=8.8 Hz, 1H), 4.83-4.71 (m, 2H), 4.48-4.19 (m, 2H), 3.89 (s, 2H), 3.79-3.69 (m, 2H), 3.64 (s, 1H), 3.51 (s, 1H), 3.00-2.93 (m, 1H), 1.82 (d, J=8.9 Hz, 1H), 1.42 (s, 6H). HPLC: 91.33%.

Example 334: 4-(6-(4-(5-ethynylpicolinoyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 5-((trimethylsilyl)ethynyl)picolinate

To a three-necked flask were added methyl 5-bromopyridinecarboxylate (500 mg, 2.3145 mmol), CuI (53 mg, 0.27829 mmol) and PdCl₂(PPh₃)₂(49 mg, 0.06981 mmol) under nitrogen. After the solids were dissolved by adding anhydrous THE (3 mL), ethynyl (trimethyl) silane (273 mg, 2.779 mmol) was added dropwise. The solution was orange and then TEA (1.5 mL) was added dropwise with stirring at room temperature. The solution turned to black. The completion of reaction was monitored by TLC after reaction for 4 h. The reaction solution was quenched by the addition of water (20 mL), then EA (50 mL) was added. A large amount of brown solid precipitated. The resulting mixture was filtered by suction through a celite pad. The organic phase was separated from the filtrate. The aqueous phase was extracted with EA (50 mL×2). The organic phases were combined, washed once with 30 mL of saturated brine. The combined organic phases were dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:10-1:5) to give a yellow solid 450 mg. The yield was 83.32%. Rf=0.5 (PE:EA=5:1). LC-MS: m/z=234.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.76 (s, 1H), 8.07 (d, J=8.1 Hz, 1H), 7.87 (dd, J=8.1, 1.8 Hz, 1H), 4.00 (s, 3H), 0.27 (s, 9H).

Step 2: 5-ethynyl picolinic acid

Methyl 5-((trimethylsilyl)ethynyl)picolinate (450 mg, 1.9285 mmol) was dissolved in anhydrous methanol (9 mL) under nitrogen in a double-necked flask, and then potassium carbonate (533 mg, 3.8565 mmol) was added with stirring in one portion at room temperature. The mixture was stirred overnight. The reaction mixture was added with water (20 mL) and adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed once with saturated brine (30 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid 280 mg. The yield was 98.68%. Rf=0.01 (PE:EA=5:1). LC-MS: m/z=148.10[M+H]⁺. ¹H-NMR (400 MHz, DMSO-d₆) δ 8.78 (s, 1H), 8.08 (d, J=8.1 Hz, 1H), 8.03 (d, J=8.1 Hz, 1H), 4.67 (s, 1H).

Step 3: 4-(6-(4-(5-ethynylpicolinoyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile

At room temperature, to a single-necked flask were added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol) and 5-ethynyl picolinic acid (10 mg, 0.068 mmol), which was dissolved by adding 2 mL of DCM. Then DCC (10 mg, 0.048 mmol) was added with stirring. After the end of addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent MeOH:DCM=1:80-1:30) to give a pale yellow solid 4 mg as the target product. Rf=0.3(DCM:MeOH=30:1). LC-MS: m/z=522.10[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.70 (s, 1H), 8.36 (d, J=2.2 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=2.0 Hz, 1H), 7.90 (dd, J=8.1, 2.0 Hz, 1H), 7.76-7.70 (m, 2H), 7.15 (d, J=2.0 Hz, 1H), 6.78 (d, J=8.9 Hz, 1H), 3.98-3.93 (m, 2H), 3.86 (s, 2H), 3.82-3.78 (m, 4H), 3.75-3.71 (m, 2H), 3.31 (s, 1H), 1.39 (s, 6H). HPLC: 94.65%.

Example 335: 6-ethoxy-4-(6-(4-(3-ethynylthiophene-2-carbonyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: methyl 3-((trimethylsilyl)ethynyl)thiophene-2-carboxylate

To a mixture of methyl 3-bromothiophene-2-carboxylate (500 mg, 2.26 mmol), Pd(PPh₃)₂Cl₂ (79 mg, 0.11 mmol) and CuI (21 mg, 0.11 mmol) in Et₃N (2.3 mL, 17 mmol) was added trimethylsilylacetylene (0.64 mL, 4.5 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent. Then to the residual black mixture were added water (30 mL) and ethyl acetate (60 mL). The resulting mixture was filtered through a sand core funnel with celite. The aqueous phase was extracted with EA (20 mL×2). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=30:1) to afford yellow oil 507 mg (yield: 94%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 7.41 (d, J=5.1 Hz, 1H), 7.14 (d, J=5.1 Hz, 1H), 3.90 (s, 3H), 0.28 (s, 9H).

Step 2: 3-ethynylthiophene-2-carboxylic acid

To a solution of methyl 3-((trimethylsilyl)ethynyl)thiophene-2-carboxylate (507 mg, 2.13 mmol) in THF/H₂O (12.8/6.4 mL) was added LiOH—H₂O (227 mg, 5.30 mmol) in one portion at room temperature and the mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the organic solvent, and then diluted with water (10 mL). The aqueous phase was adjusted pH with 2N hydrochloric acid to 3. The aqueous phase was extracted with EA (40 mL×3). The organic phases were combined, washed with saturated brine (50 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo to give a pale yellow solid 256 mg (yield: 79.1%) as a crude product, which was used in the next step without further purification. LC-MS: m/z=153.00 [M+H]⁺.

Step 3: 6-ethoxy-4-(6-(4-(3-ethynylthiophene-2-carbonyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a solution of 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl) piperazine-1-ium chloride (20 mg, 0.052 mmol), 3-ethynylthiophene-2-carboxylic acid (23 mg, 0.15 mmol) and DMAP (1 mg, 0.008 mmol) in DCM (1 mL) were added DIPEA (0.1 mL, 0.6 mmol) and EDCI (50 mg, 0.26 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1.5:1-1:1) to give a white solid 12.4 mg (yield: 49.4%) as the desired product. LC-MS: m/z=483.30 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.9 Hz, 1H), 7.74 (dd, J=8.8, 2.4 Hz, 1H), 7.36 (d, J=5.1 Hz, 1H), 7.12-7.06 (m, 2H), 6.79 (d, J=8.8 Hz, 1H), 4.08 (q, J=6.9 Hz, 2H), 3.87-3.71 (m, 8H), 3.27 (s, 1H), 1.49 (t, J=6.9 Hz, 3H).

Example 336: 6-ethoxy-4-(6-(4-(5-ethynylthiophene-3-carbonyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: ethyl 5-((trimethylsilyl)ethynyl)thiophene-3-carboxylate

To a mixture of ethyl 5-bromothiophene-3-carboxylate (532 mg, 2.26 mmol), Pd(PPh₃)₂Cl₂ (79 mg, 0.11 mmol) and CuI (21 mg, 0.11 mmol) in Et₃N (2.3 mL, 17 mmol) was added trimethylsilylacetylene (0.64 mL, 4.5 mmol) at room temperature under nitrogen. A black suspension was obtained. The mixture was heated to 80° C. and reacted overnight. The mixture was concentrated in vacuo to remove the solvent. Then to the residual black mixture were added water (30 mL) and ethyl acetate (60 mL). The resulting mixture was filtered through a sand core funnel with celite. The aqueous phase was extracted with EA (20 mL×2). The combined organic phases were washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=30:1) to afford light brown oil 484 mg (yield: 84.7%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 7.96 (d, J=1.1 Hz, 1H), 7.61 (d, J=1.1 Hz, 1H), 4.31 (q, J=7.1 Hz, 2H), 1.35 (t, J=7.1 Hz, 3H), 0.25 (s, 9H).

Step 2: 5-ethynylthiophene-3-carboxylic acid

To a solution of ethyl 5-((trimethylsilyl)ethynyl)thiophene-3-carboxylate (484 mg, 1.92 mmol) in THF/H₂O (11.5/5.8 mL) was added LiOH—H₂O (205 mg, 4.79 mmol) in one portion at room temperature. The mixture was reacted overnight, and then concentrated in vacuo to remove the organic solvent. The resulting mixture was diluted with water (10 mL), and the aqueous phase was adjusted pH to 3 with 2N hydrochloric acid, and then was extracted with EA (40 mL×3). The organic phases were combined, washed with saturated brine (50 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give a pale yellow solid 205 mg (yield: 70.3%) as the crude product, which was used in the next step without further purification. LC-MS: m/z=153.05 [M+H]⁺.

Step 3: 6-ethoxy-4-(6-(4-(5-ethynylthiophene-3-carbonyl)piperazin-1-yl)pyridin-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile

To a solution of 4-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl) piperazine-1-ium chloride (20 mg, 0.052 mmol), 5-ethynylthiophene-3-carboxylic acid (23 mg, 0.15 mmol) and DMAP (1 mg, 0.008 mmol) in DCM (1 mL) were added DIPEA (0.1 mL, 0.6 mmol) and EDCI (50 mg, 0.26 mmol) at room temperature under nitrogen. The mixture was stirred at room temperature overnight. After the reaction was completed, the reaction mixture was diluted with DCM (50 mL), washed with water (20 mL) and saturated brine (20 mL) in turn. The organic phases were dried over anhydrous sodium, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=1.5:1-1:1) to give a white solid 15.9 mg (yield: 63.4%) as the desired product. LC-MS: m/z=483.25 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.35 (s, 1H), 8.19 (s, 1H), 8.11 (s, 1H), 7.74 (d, J=8.7 Hz, 1H), 7.49 (s, 1H), 7.36 (s, 1H), 7.09 (s, 1H), 6.78 (d, J=8.7 Hz, 1H), 4.09 (q, 6.7 Hz, 2H), 3.90-3.63 (m, 8H), 3.38 (s, 1H), 1.49 (t, J=6.8 Hz, 3H).

Example 337: 6-ethoxy-4-(6-(4-(3-(4-(trifluoromethyl)phenyl)propioloyl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: ethyl 3-(4-(trifluoromethyl)phenyl)propiolate

To three-necked flask were sequentially added 1-iodo-4-(trifluoromethyl)benzene (500 mg, 1.8382 mmol), CuI (42 mg, 0.22053 mmol) and PdCl₂(PPh₃)₂(38 mg, 0.05414 mmol) and potassium carbonate (0.51 g, 3.7 mmol), then THF (5.5 mL, 100 mass %) was added under nitrogen. Ethyl propiolate (0.76 mL, 7.3 mmol) was slowly injected with the syringe at 65° C. After 3 h of injection, the mixture was reacted at 65° C. for 4 h. The reaction mixture was filtered by suction through a celite pad, and the filter cake was washed with EA (30 mL). The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:200) to give colorless transparent liquid 185 mg as the desired product (the yield was 41.56%). ¹H NMR (400 MHz, CDCl₃) δ 7.67 (dd, J=21.9, 8.3 Hz, 4H), 4.32 (q, J=7.1 Hz, 2H), 1.37 (t, J=7.1 Hz, 3H).

Step 2: 3-(4-(trifluoromethyl)phenyl)propynoic acid

Ethyl 3-(4-(trifluoromethyl)phenyl)propiolate (340 mg, 1.4039 mmol) was dissolved in methanol (7 mL) and water (0.7 mL) in a 50 mL single-necked flask, and then potassium hydroxide (470 mg, 8.376 mmol) were added in one portion with stirring at room temperature. The mixture was reacted overnight. The reaction mixture was added with water (30 mL) and extracted with EA (20 mL). The aqueous phase was adjusted with 1N diluted hydrochloric acid to pH=1, then extracted with EA (50 mL×3). The organic phases were combined and washed with saturated brine (30 mL). The organic phases were dried over anhydrous sodium sulfate, filtered by suction, and concentrated in vacuo to give a white solid 105 mg as the target product (yield: 34.9%).

Step 3: 6-ethoxy-4-(6-(4-(3-(4-(trifluoromethyl)phenyl)propioloyl)piperazin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-ethoxy-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 6, 30 mg, 0.07794 mmol), 3-(4-(trifluoromethyl)phenyl)propynoic acid (20 mg, 0.093397 mmol), EDCI (30 mg, 0.15649 mmol), DMAP (2 mg, 0.016371 mmol), DIPEA (0.06 mL, 0.4 mmol) and DCM (2 mL). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and then purified by silica gel column chromatography (eluent PE/EA=2/1-1.2/1) to give a yellow solid 16.5 mg as the target product (yield: 38.9%). LC-MS(ESI): m/z=545.2[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.36 (d, J=2.1 Hz, 1H), 8.19 (s, 1H), 8.12 (d, J=1.7 Hz, 1H), 7.75 (dd, J=8.7, 2.3 Hz, 1H), 7.67 (q, J=8.5 Hz, 4H), 7.10 (d, J=1.7 Hz, 1H), 6.81 (d, J=8.9 Hz, 1H), 4.09 (q, J=6.9 Hz, 2H), 3.96 (t, 2H), 3.87-3.78 (m, 4H), 3.71 (t, 2H), 1.50 (t, J=6.9 Hz, 3H). HPLC: 97.05%.

Example 338: 6-ethoxy-4-(6-(7-(3-phenylpropioloyl)-2,7-diazaspiro[3.5]nonan-2-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 7-(3-phenylpropioloyl)-2,7-diazaspiro[3,5]nonane-2-carboxylate

To a 25 mL single-necked flask were added tert-butyl 2,7-diazaspiro[3.5]nonane-2-carboxylate (0.12 g, 0.53 mmol), DCM (5 mL), 3-phenylpropynoic acid (0.93 g, 0.64 mmol), EDCI (0.15 g, 0.78 mmol) and DMAP (0.010 g, 0.082 mmol). The mixture was stirred and reacted at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (20 mL), and the aqueous phase was separated and extracted with DCM (30 mL×2). The organic phases were combined and washed with 15 mL of saturated brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=10/1-3/1) to give a yellow solid 52 mg as the target product (yield: 27.7%). ¹H NMR (400 MHz, CDCl₃) δ 7.54 (d, J=6.9 Hz, 2H), 7.43 (t, J=7.3 Hz, 1H), 7.37 (t, J=7.3 Hz, 2H), 3.79-3.73 (m, 2H), 3.73-3.66 (m, 4H), 3.65-3.58 (m, 2H), 1.90-1.71 (m, 4H), 1.45 (s, 9H).

Step 2: 3-phenyl-1-(2,7-diazaspiro[3.5]non-7-yl)prop-2-yn-1-one 2,2,2-trifluoroacetate

To a 50 mL single-necked flask was added tert-butyl 7-(3-phenylpropioloyl)-2,7-diazaspiro[3,5]nonane-2-carboxylate (1.31 g, 3.70 mmol), then DCM (13 mL) and TFA (4 mL) were added. The mixture was stirred to react at room temperature overnight. The reaction solution was directly concentrated in vacuo to obtain colorless transparent oily liquid as the target product (yield 100%), which was used in the next step directly without further purification.

Step 3: 6-ethoxy-4-(6-(7-(3-phenylpropioloyl)-2,7-diazaspiro[3.5]nonan-2-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 25 mL single-necked flask were added 6-ethoxy-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 1, 15 mg, 0.05313 mmol), 3-phenyl-1-(2,7-diazaspiro[3.5]non-7-yl)prop-2-yn-1-one 2,2,2-trifluoroacetate (29 mg, 0.07872 mmol), N,N-diisopropylethylamine (0.026 mL, 0.159 mmol) and DMSO (1 mL). The mixture was reacted under microwave at 150° C. for 3.5 h. The reaction solution was added with EA (30 mL) and water (15 mL), and the aqueous phase was extracted with EA (25 mL×2). The organic phases were combined, washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and then purified by silica gel column chromatography (eluent PE/EA=5/1-1/1.5) to give a yellow solid 7.1 mg as the target product (yield 26%). LC-MS: m/z=517.15[M+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 8.29 (d, 1H), 8.19 (s, 1H), 8.10 (d, 1H), 7.69 (dd, J=8.6, 2.2 Hz, 1H), 7.56 (d, J=7.0 Hz, 2H), 7.42-7.34 (m, 3H), 7.08 (d, J=1.7 Hz, 1H), 6.42 (d, J=8.6 Hz, 1H), 4.08 (q, J=6.9 Hz, 2H), 3.90 (s, 4H), 3.84 (t, 2H), 3.70 (t, J=5.2 Hz, 2H), 1.97 (t, 2H), 1.90 (t, 2H), 1.49 (t, J=6.9 Hz, 3H). HPLC: 94.08%.

Example 339: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-phenylpropioloyl)-3,6-diazabicyclo [3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Under nitrogen, to a 10 mL double-necked flask were added 4-(6-(3,6-diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 20 mg, 0.04189 mmol) and phenylpropynoic acid (8 mg, 0.054742 mmol), which were dissolved by adding DCM (2 mL). Then DMAP (2 mg, 0.016371 mmol) and EDCI (16 mg, 0.083464 mmol) were added. The mixture was stirred at room temperature overnight. The reaction mixture was added with DCM (30 mL) and water (30 mL). The aqueous phase was extracted with DCM (30 mL×2). The organic phase was dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=50/1) to give a pale yellow solid 7.5 mg (yield: 34%) as the desired product. LC-MS(ESI): m/z=533.0 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) 8.37 (d, J=2.1 Hz, 1H), 8.20 (s, 1H), 8.16 (d, J=1.8 Hz, 1H), 7.75 (dd, J=8.8, 2.4 Hz, 1H), 7.54 (d, J=7.0 Hz, 2H), 7.43 (t, J=7.4 Hz, 1H), 7.39-7.35 (m, 2H), 7.15 (d, J=1.9 Hz, 1H), 6.66 (d, J=8.8 Hz, 1H), 4.76 (t, 2H), 4.16 (t, 2H), 3.96 (d, J=11.7 Hz, 1H), 3.86 (s, 2H), 3.74 (d, J=10.9 Hz, 1H), 3.64 (s, 1H), 2.87 (dd, J=14.3, 6.5 Hz, 1H), 2.03-1.99 (m, 1H), 1.39 (s, 6H). HPLC: 94.77%.

Example 340: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(5-methoxypyridin-3-yl)propioloyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol

To a mixture of 3-bromo-5-methoxypyridine (500 mg, 2.6593 mmol), bis(triphenylphosphine)palladium dichloride (93 mg, 0.132496 mmol) and CuI (25 mg, 0.13127 mmol) were sequentially added triethylamine (4.0 mL, 29 mmol) and prop-2-yn-1-ol (0.76 mL, 13 mmol) at room temperature under nitrogen. The resulting mixture was heated to 80° C. and reacted for 5 h. The reaction mixture was diluted with EA (40 mL), and the organic phase was poured out, then the residual black viscous solid was washed with EA (30 mL×3). The organic phases were combined, concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=4:1-2:1) to give a pale yellow solid as the target product (the yield was 64.54%). LC-MS: m/z=164.15 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (s, 1H), 8.25 (s, 1H), 7.23 (s, 1H), 4.51 (s, 2H), 3.85 (s, 3H).

Step 2: 3-(5-methoxypyridin-3-yl)propynal

To a solution of 3-(5-methoxy-3-pyridyl)prop-2-yn-1-ol (280 mg, 1.7160 mmol) in dichloromethane (17.2 mL) were sequentially added sodium bicarbonate (724 mg, 8.58 mmol) and Dess Martin reagent (1.102 g, 2.572 mmol) at room temperature. The mixture was reacted for 1 h at room temperature. The reaction mixture was added with 20 mL of saturated sodium thiosulfate solution to quench the reaction. The aqueous phase was extracted with DCM (50 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, then purified by silica gel column chromatography (PE/EA=3:1) to give a white solid 202 mg (yield: 73.0%) as the target product. LC-MS: m/z=162.10 [M+H]⁺. ¹H NMR (600 MHz, CDCl₃) δ 9.42 (s, 1H), 8.42 (s, 1H), 8.38 (d, J=2.5 Hz, 1H), 7.34 (s, 1H), 3.87 (s, 3H).

Step 3: 3-(5-methoxypyridin-3-yl)propynoic acid

To a solution of 3-(5-methoxypyridin-3-yl)propynal (150 mg, 0.93075 mmol) in acetonitrile (0.76 mL) were added aqueous sodium dihydrogen phosphate solution (0.31 mL, 0.28 mmol, 0.91 mol/L, concentrated hydrochloric acid adjusted to pH=2), hydrogen peroxide (0.11 mL, 1.1 mmol, 30 mass %) in a 10 mL single-necked flask. An aqueous solution of sodium chlorite (1.1 mL, 1.1 mmol, 1 mol/L) was slowly added to the above solution under ice bath conditions. The temperature was kept below 10° C. and the mixture was reacted for 2 h. The reaction was stopped. The aqueous phase was separated and extracted with EA (20 mL×3). The combined organic phases were back-extracted with saturated sodium bicarbonate solution (20 mL×3). The combined aqueous phases were adjusted to pH 1 with concentrated hydrochloric acid and extracted with EA (20 mL×3). The combined organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and concentrated in vacuo to give a white solid 0.84 mg as the target product (yield: 51%). LC-MS: m/z=178.2 [M+H]⁺. ¹H NMR (400 MHz, MeOD) δ 8.37-8.31 (m, 2H), 7.63 (s, 1H), 3.91 (s, 3H).

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(5-methoxypyridin-3-yl)propioloyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were sequentially added 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 25 mg, 0.05237 mmol), 3-(5-methoxypyridin-3-yl)propynoic acid (15 mg, 0.084669 mmol), DMAP (1 mg, 0.0081853 mmol), EDCI (30 mg, 0.15649 mmol), DCM (1 mL), N,N-diisopropylethylamine (0.05 mL, 0.3 mmol). The mixture was reacted with stirring at room temperature overnight. The reaction solution was added with DCM (30 mL) and water (15 mL), and the aqueous phase was separated and extracted with DCM (25 mL×2). The organic phases were combined and washed with 15 mL of saturated brine. The organic phases were separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/3) to give a white solid 6.3 mg as the target product (yield: 21.0%). LC-MS (ESI): m/z=564.2[M+1]. ¹H NMR (400 MHz, CDCl₃) δ 8.39-8.35 (m, 2H), 8.20 (s, 1H), 8.16 (d, 1H), 7.76 (dd, 1H), 7.37-7.30 (m, 2H), 7.15 (d, 1H), 6.66 (d, J=8.9 Hz, 1H), 4.82-4.71 (m, 2H), 4.15 (d, J=11.6 Hz, 2H), 3.98 (d, J=10.6 Hz, 1H), 3.89-3.84 (m, 5H), 3.75 (d, J=10.0 Hz, 1H), 3.64 (s, 1H), 2.93-2.84 (m, 1H), 2.04-2.00 (m, 1H), 1.28 (s, 6H). HPLC: 91.73%.

Example 341: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(6-methoxypyridin-3-yl)propioloyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(6-methoxypyridin-3-yl)prop-2-yn-1-ol

To a 25 mL two-necked flask under nitrogen were sequentially added 5-bromo-2-methoxypyridine (600 mg, 3.19 mmol), cuprous iodide (33 mg, 0.17 mmol) and bistriphenylphosphine palladium dichloride (121 mg, 0.17 mmol). Then triethylamine (5 mL) and propargyl alcohol (0.6 mL, 10 mmol) were slowly added. The mixture was heated to 80° C. and stirred to react overnight. The reaction mixture was returned to room temperature slowly, then diluted with water (100 mL) and filtered. The black paste was washed with EA (100 mL×3), and the organic phases were extracted, separated and combined. Then the organic phases were washed with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=4:1) to give a white solid 350 mg as the target product (yield: 67.217%). LC-MS(ES-API): m/z=164.00 [M+H]⁺.

Step 2: 3-(6-methoxypyridin-3-yl)prop-2-yn-1-yl

To a 50 mL single-necked flask were sequentially added 3-(6-methoxypyridin-3-yl)prop-2-yn-1-ol (0.35 g, 2.1 mmol), Dess Martin reagent (1.25 g, 2.95 mmol), sodium bicarbonate (0.95 g, 11 mmol) and dichloromethane (25 mL). The mixture was stirred at room temperature overnight. The reaction mixture was quenched with saturated sodium thiosulfate solution (50 mL). The organic phase was separated, and the aqueous phase was extracted with DCM (100 ml×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=10:1) to give a yellow solid 290 mg, which was the target product (yield: 84.0%, Rf=0.7 (PE/EA=4/1)).

Step 3: 3-(6-methoxypyridin-3-yl)propynoic acid

A solution of sodium dihydrogen phosphate (0.55 mL, 0.55 mmol, 1.0 mol/L) and hydrogen peroxide (0.25 mL, 2.4 mmol, 30 mass %) was adjusted pH with hydrochloric acid (12 mol/L) to 2 under ice bath conditions, and a solution of 3-(6-methoxypyridin-3-yl)prop-2-yn-1-yl (290 mg, 1.7995 mmol) in acetonitrile (2 mL) was added. Sodium chlorite (180 mg, 1.9902 mmol) was then added slowly in three portions and the mixture was kept at this temperature and stirred continuously for 2 h. The reaction mixture was returned to room temperature slowly, then added with water (50 mL). The resulting mixture was extracted with EA (100 mL×3). The organic phases were combined, washed with saturated brine (200 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo to give a yellow solid 275 mg as the target product. (yield: 86.263%, Rf=0.15 (EA)). LC-MS(ES-API): m/z=178.10 [M+H]⁺.

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(6-methoxypyridin-3-yl)propioloyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15.8 mg, 0.033 mmol), DIPEA (0.05 mL, 0.3 mmol), EDCI (31 mg, 0.161 mmol) and DMAP (1 mg, 0.008 mmol) were sequentially added in dichloromethane (1.5 mL) in a 5 mL single-necked flask, then 3-(6-methoxypyridin-3-yl)propynoic acid (17 mg, 0.095958 mmol) was added. The resulting mixture was stirred at room temperature overnight. The reaction solution was filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=100/1-40/1) to give a white solid 11.2 mg, which was the target product. (Rf=0.4, DCM/MeOH=30/1). LC-MS ES-API): m/z=564.20 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.41 (d, J=2.2 Hz, 1H), 8.23 (s, 1H), 8.18 (d, J=2.0 Hz, 1H), 7.79 (dd, J=8.8, 2.4 Hz, 1H), 7.17 (d, J=2.0 Hz, 1H), 6.70 (d, J=8.8 Hz, 1H), 3.91 (d, J=6.1 Hz, 2H), 3.89 (s, 2H), 3.82 (d, J=12.0 Hz, 2H), 3.63 (d, J=11.6 Hz, 2H), 3.29 (d, J=2.2 Hz, 2H), 2.73 (dd, J=13.7, 6.3 Hz, 1H), 2.23 (t, J=2.4 Hz, 1H), 2.03 (s, 1H), 1.42 (s, 6H). HPLC: 90.19%.

Example 342: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(5-methoxypyridin-3-yl)propionyl) piperazin-1-yl)pyridine-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol

To a mixture of 3-bromo-5-methoxypyridine (500 mg, 2.6593 mmol), bis(triphenylphosphine)palladium dichloride (93 mg, 0.132496 mmol) and CuI (25 mg, 0.13127 mmol) were sequentially added triethylamine (4.0 mL, 29 mmol) and prop-2-yn-1-ol (0.76 mL, 13 mmol) at room temperature under nitrogen. The resulting mixture was heated to 80° C. and reacted for 5 h. The reaction mixture was diluted with EA (40 mL), and the organic phase was poured out, then the residual black viscous solid was washed with EA (30 mL×3). The organic phases were combined, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=4:1-2:1) to give a pale yellow solid 280 mg as the target product (the yield was 64.54%). LC-MS: m/z=164.15 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (s, 1H), 8.25 (s, 1H), 7.23 (s, 1H), 4.51 (s, 2H), 3.85 (s, 3H).

Step 2: 3-(5-methoxypyridin-3-yl)propynal

To a solution of 3-(5-methoxy-3-pyridyl)prop-2-yn-1-ol (280 mg, 1.7160 mmol) in dichloromethane (17.2 mL) were sequentially added sodium bicarbonate (724 mg, 8.58 mmol) and Dess Martin reagent (1.102 g, 2.572 mmol) at room temperature. The mixture was reacted for 1 h at room temperature. The reaction mixture was added with 20 mL of saturated sodium thiosulfate solution to quench the reaction. The aqueous phase was extracted with DCM (50 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, then purified by silica gel column chromatography (PE/EA=3:1) to give a white solid 202 mg (yield: 73.0%) as the target product. LC-MS: m/z=162.10 [M+H]⁺. ¹H NMR (600 MHz, CDCl₃) δ 9.42 (s, 1H), 8.42 (s, 1H), 8.38 (d, J=2.5 Hz, 1H), 7.34 (s, 1H), 3.87 (s, 3H).

Step 3: 3-(5-methoxypyridin-3-yl)propynoic acid

To a solution of 3-(5-methoxypyridin-3-yl)propynal (150 mg, 0.93075 mmol) in acetonitrile (0.76 mL) were added aqueous sodium dihydrogen phosphate solution (0.31 mL, 0.28 mmol, 0.91 mol/L, concentrated hydrochloric acid adjusted to pH=2), hydrogen peroxide (0.11 mL, 1.1 mmol, 30 mass %) in a 10 mL single-necked flask. An aqueous solution of sodium chlorite (1.1 mL, 1.1 mmol, 1 mol/L) was slowly added to the above solution under ice bath conditions. The temperature was kept below 10° C. and the mixture was reacted for 2 h. The reaction was stopped. The aqueous phase was separated and extracted with EA (20 mL×3). The combined organic phases were back-extracted with saturated sodium bicarbonate solution (20 mL×3). The combined aqueous phases were adjusted to pH 1 with concentrated hydrochloric acid and extracted with EA (20 mL×3). The combined organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and concentrated in vacuo to give a white solid 0.84 mg as the target product (yield: 51%). LC-MS: m/z=178.2 [M+H]⁺. ¹H NMR (400 MHz, MeOD) δ 8.37-8.31 (m, 2H), 7.63 (s, 1H), 3.91 (s, 3H).

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(5-methoxypyridin-3-yl)propionyl) piperazin-1-yl)pyridine-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol) and 3-(5-methoxypyridin-3-yl)propanoic acid (9 mg, 0.051 mmol) in DCM (2 mL) were added DMAP (2 mg, 0.016 mmol) and EDCI (12 mg, 0.063 mmol) under nitrogen. The mixture was stirred and reacted at room temperature overnight. The reaction mixture was added with DCM (30 mL) and water (10 mL). The organic phase was separated, washed with water (10 mL), dried over anhydrous sodium sulfate, concentrated in vacuo and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent MeOH:DCM=1:50-1:30) to give a white solid 9 mg as the desired product. The yield was 50.62%. Rf=0.3 (MeOH:DCM=1:30). LC-MS: m/z=552.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.39 (s, 1H), 8.36 (dd, J=4.9, 2.5 Hz, 2H), 8.21 (s, 1H), 8.17 (d, J=2.0 Hz, 1H), 7.76 (dd, J=8.8, 2.4 Hz, 1H), 7.36 (dd, J=2.6, 1.7 Hz, 1H), 7.16 (d, J=2.0 Hz, 1H), 6.81 (d, J=9.1 Hz, 1H), 3.99-3.95 (m, 2H), 3.89 (s, 3H), 3.87 (s, 2H), 3.85-3.80 (m, 4H), 3.73-3.70 (m, 2H), 1.40 (s, 6H). HPLC: 98.95%.

Example 343: 6-(2-hydroxy-2-methyl-propoxy)-4-(6-(4-(3-(pyridin-3-yl)propioloyl) piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(3-pyridyl)prop-2-yn-1-ol

To a 25 mL two-necked flask were added CuI (72 mg, 0.378 mmol) and PdCl₂(PPh₃)₂ (270 mg, 0.385 mmol) at room temperature. The reaction mixture was degassed and refilled with nitrogen. Then triethylamine (11 mL, 78.9 mmol), propynyl alcohol (0.89 mL, 15 mmol) and 3-bromopyridine (0.73 mL, 7.6 mmol) were added. The mixture was reacted at 50° C. overnight. TLC showed the reaction was completed. The mixture was quenched with saturated ammonium chloride (20 mL) and filtered by suction. The filter cake was washed with 40 mL of EA. The organic phase was separated, and then the aqueous phase was extracted with EA (40 mL×2). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=3:1-1:1) to give a brownish yellow solid 0.705 g (the yield was 70%), which was the target product. LC-MS(ES-API): m/z=134.20 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.76 (d, J=1.3 Hz, 1H), 8.51 (dd, J=4.9, 1.5 Hz, 1H), 7.73 (dt, J=7.9, 1.8 Hz, 1H), 7.31-7.26 (m, 1H), 4.50 (s, 2H), 3.72 (s, 1H).

Step 2: 3-(3-pyridyl)prop-2-ynaldehyde

To a 100 mL single-necked flask were added 3-(3-pyridyl)prop-2-yn-1-ol (200 mg, 1.502 mmol), NaHCO₃ (0.634 g, 7.51 mmol) and Dess Martin oxidant (0.83 g, 2.0 mmol), which were dissolved by adding DCM (15 mL). The mixture was stirred and reacted at room temperature for 3 h. TLC showed the reaction was completed. The resulting mixture was added with 10 mL of saturated sodium thiosulfate solution to quench the reaction. The organic phase was separated and the aqueous phase was extracted with DCM (20 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE/EA=6:1-3:1) to give a brownish yellow solid 60 mg (yield: 30.46%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 9.43 (s, 1H), 8.83 (d, J=1.1 Hz, 1H), 8.69 (dd, J=4.8, 1.2 Hz, 1H), 7.89 (dd, J=7.9, 1.6 Hz, 1H), 7.37 (dd, J=7.9, 5.0 Hz, 1H).

Step 3: 3-(3-pyridyl)prop-2-ynoic acid

A concentrated hydrochloric acid solution was added to adjust the pH of a solution of NaH₂PO₄ (0.14 mL, 0.14 mmol) and H₂O₂(0.051 mL, 0.50 mmol) to 3 in a 10 ml single-necked flask at 0° C., then a solution of 3-(3-pyridyl)prop-2-ynaldehyde (60 mg, 0.458 mmol) in acetonitrile (1.5 mL) was added. NaClO₂ (46 mg, 0.504 mmol) was added slowly in three portions. The mixture was reacted at 0° C. for 20 min, and then transferred to room temperature for reaction. TLC showed the reaction was completed. The resulting mixture was added with 1 mL of water to quench the reaction, then extracted with EA (5 mL×3). The organic phases were combined, washed with saturated saline (5 mL), dried over anhydrous sodium sulfate. The mixture was filtered, and concentrated in vacuo to give a yellow solid 0.042 g (yield: 62%) as the target product. LC-MS(ES-API): m/z=148.2 [M+H]⁺.

Step 4: 6-(2-hydroxy-2-methyl-propoxy)-4-(6-(4-(3-(pyridin-3-yl)propioloyl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were sequentially added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol), 3-(3-pyridyl)prop-2-ynoic acid (16.8 mg, 0.114 mmol), EDCI (36 mg, 0.188 mmol) and DMAP (1.0 mg, 0.008 mmol), which were dissolved by adding DCM (2 mL). The mixture was reacted with stirring at room temperature overnight. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM-DCM:MeOH=25:1) to give a pale yellow solid 0.008 g (the yield was 50%), which was the target product. LC-MS(ES-API): m/z=522.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.81 (s, 1H), 8.66 (s, 1H), 8.37 (d, J=2.2 Hz, 1H), 8.20 (s, 1H), 8.17 (d, J=1.9 Hz, 1H), 7.88 (d, J=7.7 Hz, 1H), 7.76 (dd, J=8.7, 2.4 Hz, 1H), 7.35 (s, 1H), 7.16 (d, J=1.9 Hz, 1H), 6.81 (d, J=9.0 Hz, 1H), 3.96 (d, J=5.4 Hz, 2H), 3.87 (s, 2H), 3.85-3.78 (m, 4H), 3.74-3.68 (m, 2H), 2.11 (s, 1H), 1.39 (s, 6H). HPLC: 98.71%.

Example 344: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-phenylpropioloyl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL reaction flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridin-3-carbonitrile dihydrochloride (15 mg, 0.032 mmol) and DCM (2 mL), then 3-phenylprop-2-ynyl acid (10 mg, 0.068 mmol) and N,N′-dicyclohexylcarbodiimide (10 mg, 0.048 mmol) were added under ice bath conditions. The mixture was stirred at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was directly concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give a white solid 4.0 mg as the target product (yield: 59.63%). LC-MS: m/z=521.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.39 (d, J=2.4 Hz, 1H), 8.23 (s, 1H), 8.19 (d, J=2.0 Hz, 1H), 7.78 (dd, J=8.7, 2.4 Hz, 1H), 7.60 (d, J=6.9 Hz, 2H), 7.46 (d, J=7.1 Hz, 1H), 7.42 (d, J=7.5 Hz, 1H), 7.37 (d, J=2.3 Hz, 1H), 7.18 (d, J=1.9 Hz, 1H), 6.83 (d, J=8.8 Hz, 1H), 4.05-3.97 (m, 2H), 3.89 (s, 1H), 3.86 (d, J=5.7 Hz, 2H), 3.85-3.80 (m, 2H), 3.76-3.71 (m, 2H), 3.67 (s, 2H), 1.27 (s, 6H). HPLC: 95.36%.

Example 345: 4-(5-fluoro-6-(4-(3-phenylpropioloyl)piperazin-1-yl)pyridin-3-yl)-6-methoxy [1,5-a]pyridine-3-carbonitrile

Step 1: 6-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-Bromo-6-methoxypyrazolo[1,5-a]pyridine-3-carbonitrile (800 mg, 3.1737 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bis(1,3,2-dioxaborolane) (1.5 g, 5.9 mmol), [1,1′-bis(diphenylphosphino)ferrocene]palladium dichloride dichloromethane complex (0.3 g, 0.3 mmol), potassium acetate (0.95 g, 9.6 mmol, 99.0 mass %) and 1,4-dioxane (8 mL) were sequentially added to a reaction flask under nitrogen. The mixture was reacted at 90° C. overnight. The completion of reaction was monitored by TLC. Then the reaction mixture was added with water (25 mL) and EA (40 mL). The separated aqueous phase was extracted with EA (40 mL). The combined organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE/EA=10/1-4/1) to give a white solid 788 mg as the target product (the yield was 57.94%). LC-MS: m/z=217.10 [M-t-Bu]⁺.

Step 2: 4-(5,6-difluoropyridin-3-yl)-6-methoxy[1,5-a]pyridine-3-carbonitrile

To a 25 mL two-necked flask were sequentially added 6-methoxy-4-(4,4,5,5-tetramethyl-1,3-dioxaborolane-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (326 mg, 1.082 mmol), 5-bromo-2,3-difluoro-pyridine (150 mg, 0.773 mmol), XantPhos (90 mg, 0.155 mmol), Na₂CO₃ aq (1 mL, 2 mmol, 2 mol/L) and dioxane (4 mL). The mixture was refilled with nitrogen for 5 min and then Pd₂(dba)₃ (36 mg, 0.039 mmol) was added. Then the mixture was refilled with nitrogen for 10 min and reacted at 90° C. overnight after sealing. The reaction mixture was added with water (15 mL) and EA (30 mL). The separated aqueous phase was extracted with EA (30 mL×2). The combined organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=20/1-5/1) to give a white solid 25 mg as the target product (the yield was 11.30%). LC-MS: m/z=287.00[M+1]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.22 (s, 2H), 8.16 (s, 1H), 7.78 (t, J=8.9 Hz, 1H), 7.18 (s, 1H), 3.93 (s, 3H).

Step 3: tert-butyl 4-(3-phenylprop-2-ynyl)piperazine-1-carboxylate

To a 25 mL single-necked flask was added 3-phenylprop-2-ynoic acid (500 mg, 3.422 mmol), which was dissolved by adding DMF (5 mL). The mixture was placed in a low temperature bath at 0° C. Then tert-butyl piperazine-1-carboxylate (637 mg, 3.420 mmol) was added. N,N-dicyclohexylcarbodiimide (706 mg, 3.422 mmol) was added in portions. The resulting mixture was reacted for 4 h at 0° C. TLC showed the reaction was completed. The reaction mixture was added with water (25 mL), then extracted with EA (10 mL×2), washed with saturated saline (40 mL). The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=8:1-2:1) to give a yellow-white solid 0.985 g (the yield was 91.6%), which was the target product. LC-MS(ES-API): m/z=315.3[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.57-7.52 (m, 2H), 7.39 (ddd, J=15.9, 7.2, 1.9 Hz, 3H), 3.84-3.78 (m, 2H), 3.70-3.63 (m, 2H), 3.5-3.50 (m, 2H), 3.48-3.42 (m, 2H), 1.48 (s, 9H).

Step 4: 3-phenyl-1-piperazin-1-yl-prop-2-yn-1-one hydrochloride

To a 100 mL single-necked flask were added tert-butyl 4-(3-phenylprop-2-ynyl)piperazine-1-carboxylate (0.985 g, 3.13 mmol) and a solution of hydrogen chloride in ethyl acetate (9.85 mL, 39.4 mmol). The mixture was stirred at room temperature, and the solid was dissolved, then a white solid was precipitated. The solution was changed to a white suspension, and the reaction was continued for 3 h. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo to give yellow oil, which was dried in an oven at 60° C. to obtain a theoretical amount of yellow white solid 0.785 g as the target product. LC-MS(ES-API): m/z=215.3[M+H]⁺.

Step 5: 4-(5-fluoro-6-(4-(3-phenylpropioloyl)piperazin-1-yl)pyridin-3-yl)-6-methoxy[1,5-a]pyridine-3-carbonitrile

4-(5,6-Difluoro-3-pyridyl)-6-methoxypyrazolo[1,5-a]pyridine-3-carbonitrile (25 mg, 0.087 mmol), DIPEA (0.07 mL, 0.4 mmol) and 3-phenyl-1-piperazin-1-yl-prop-2-yn-1-one hydrochloride (30 mg, 0.119 mmol) were dissolved in DMSO (2 mL) in the microwave tube. The mixture was reacted under microwave at 135° C. for 5 h under 5 pressures. To the reaction solution were added with EA (20 mL) and water (10 mL), and the aqueous phase was separated and extracted with EA (20 mL×2). The organic phases were combined and washed with 10 mL of saturated brine, dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=200/1-50/1) to give a white solid 12 mg as the target product (yield: 28.59%). LC-MS: m/z=481.1[M+1]⁺. ¹H NMR (600 MHz, CDCl₃) δ 8.24 (s, 1H), 8.21 (s, 1H), 8.19 (d, J=2.0 Hz, 1H), 7.61-7.58 (m, 2H), 7.51 (dd, J=13.3, 1.9 Hz, 1H), 7.46 (t, J=7.4 Hz, 1H), 7.41 (t, J=7.4 Hz, 2H), 7.16-7.14 (m, 1H), 4.04-4.01 (m, 2H), 3.94 (s, 3H), 3.90-3.87 (m, 2H), 3.78-3.75 (m, 2H), 3.72-3.69 (m, 2H). HPLC: 97.19%.

Example 346: 1-[4-[4-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)phenyl]piperazin-1-yl]-3-phenyl-prop-2-yn-1-one

Step 1: 6-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine

To a 25 mL two-necked flask were added 4-bromo-6-methoxypyrazolo[1,5-a]pyridine (800 mg, 3.523 mmol), potassium acetate (1.037 g, 10.57 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bis(1,3,2-dioxaborolane) (1.342 g, 5.286 mmol) and PdCl₂(dppf)CH₂Cl₂ (291 mg, 0.353 mmol) under nitrogen. 1,4-Dioxane (6.4 mL) was then added, and the mixture was heated to reflux at 90° C. overnight. TLC showed that the reaction was complete. The resulting mixture was filtered by suction, washed with 80 mL of EA several times, and the organic phases were washed with 20 mL of saturated saline, dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, then purified by silica gel column chromatography (eluent PE/EA=10:1-1:1) to give brown oil 0.82 g (yield: 84.87%) as the target product. LC-MS(ES-API): m/z=275.10[M+H]⁺.

Step 2: tert-butyl 4-(4-bromophenyl)piperazine-1-carboxylate

To a 25 mL single-necked flask were sequentially added 1-bromo-4-iodobenzene (956 mg, 3.379 mmol), tert-butyl piperazine-1-carboxylate (600 mg, 3.221 mmol), Pd₂(dba)₃ (300 mg, 0.327 mmol), XantPhos (56 mg, 0.096 mmol), sodium tert-butoxide (1.24 g, 12.9 mmol) and toluene (12 mL). The mixture was refilled with nitrogen for 5 min, sealed and stirred to react at 60° C. for 5 h. The reaction mixture was added with water (25 mL) and EA (40 mL). The separated aqueous phase was extracted with EA (40 mL×2). The combined organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=20/1-10/1) to give a white light solid 305 mg as the target product (the yield was 27.75%). LC-MS: m/z=341.10[M+1]⁺. ¹H NMR (600 MHz, CDCl₃) δ 7.35 (d, J=9.0 Hz, 2H), 6.79 (d, J=8.8 Hz, 2H), 3.60-3.55 (m, 4H), 3.13-3.06 (m, 4H), 1.48 (s, 9H).

Step 3: tert-butyl 4-[4-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)phenyl]piperazine-1-carboxylate

To a 10 mL two-necked flask were added 6-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine (100 mg, 0.3648 mmol), potassium acetate (108 mg, 1.100 mmol) PdCl₂(dppf)CH₂Cl₂ (31 mg, 0.0376 mmol) and tert-butyl 4-(4-bromophenyl)piperazine-1-carboxylate (187 mg, 0.5481 mmol). The reaction mixture was degassed and refilled with nitrogen. Then the mixture was dissolved in 1,4-dioxane (2 mL), and heated to reflux at 90° C. overnight. TLC showed that the reaction was complete. The resulting mixture was filtered by suction, washed with 40 mL of EA several times, and the organic phases were washed with 15 mL of saturated saline, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, then purified by silica gel column chromatography (eluent PE/EA=8:1-1:1) to give a white solid 0.122 g (yield: 82%) as the target product. LC-MS(ES-API): m/z=409.30[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (s, 1H), 7.88 (d, J=2.1 Hz, 1H), 7.51 (d, J=8.6 Hz, 2H), 7.05 (d, J=7.2 Hz, 2H), 6.61 (d, J=12.2 Hz, 2H), 4.01 (s, 3H), 3.66-3.59 (m, 4H), 3.24-3.18 (m, 4H), 1.49 (s, 9H).

Step 4: 6-methoxy-4-(4-piperazin-1-ylphenyl)pyrazolo[1,5-a]pyridine dihydrochloride

To a 25 mL single-necked flask were added tert-butyl 4-[4-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)phenyl]piperazine-1-carboxylate (122.3 mg, 0.2994 mmol) and a solution of hydrogen chloride in ethyl acetate (4 mL, 16 mmol). The mixture was reacted with stirring at room temperature for 2 h. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo, dried in an oven at 60° C. to obtain a theoretical amount of yellow white solid. LC-MS(ES-API): m/z=309.10[M+H]⁺.

Step 5: 1-[4-[4-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)phenyl]piperazin-1-yl]-3-phenyl-prop-2-yn-1-one

To a 5 mL single-necked flask were sequentially added 6-methoxy-4-(4-piperazin-1-ylphenyl)pyrazolo[1,5-a]pyridine dihydrochloride (40 mg, 0.105 mmol), EDCI (100.6 mg, 0.5248 mmol) and DMAP (2.6 mg, 0.021 mmol). Then DCM (2 mL) was added. After the mixture was dissolved, 3-phenylprop-2-ynoic acid (46 mg, 0.315 mmol) was added. The mixture was stirred at room temperature for 8 h. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=25:1) to give an off-white solid 27.3 mg (the yield was 59.6%), which was the target product. LC-MS(ES-API): m/z=437.10[M+H]⁺. H NMR (400 MHz, CDCl₃) δ 8.32 (s, 1H), 7.88 (d, J=2.1 Hz, 1H), 7.60-7.56 (m, 2H), 7.52 (d, J=8.7 Hz, 2H), 7.44 (d, J=7.3 Hz, 1H), 7.40 (d, J=7.4 Hz, 2H), 7.04 (d, J=8.7 Hz, 2H), 6.64-6.59 (m, 2H), 4.04 (d, J=5.1 Hz, 2H), 4.02 (s, 3H), 3.91-3.87 (m, 2H), 3.35-3.31 (m, 2H), 3.30-3.25 (m, 2H). HPLC: 97.53%.

Example 347:1-(4-(5-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)piperazin-1-yl)-3-phenylprop-2-yn-1-one

Step 1: 6-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine

To a 25 mL two-necked flask were added 4-bromo-6-methoxypyrazolo[1,5-a]pyridine (1 g, 4.404 mmol), potassium acetate (1.297 g, 13.22 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bis(1,3,2-dioxaborolane) (1.677 g, 6.605 mmol) and PdCl₂(dppf)CH₂Cl₂ (363 mg, 0.440 mmol). The reaction mixture was degassed and refilled with nitrogen. 1,4-Dioxane (8 mL) was then added, and the mixture was heated to reflux at 90° C. overnight. TLC showed that the reaction was complete. The resulting mixture was filtered by suction, washed with 80 mL of EA, and the organic phases were washed with 20 mL of saturated saline, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, then purified by silica gel column chromatography (eluent PE/EA=10:1-1:1) to give brown oil 0.785 g (yield: 65.06%) as the target product. LC-MS(ES-API): m/z=275.20[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.52 (s, 1H), 7.90 (d, J=2.1 Hz, 1H), 6.60 (s, 2H), 3.97 (s, 3H), 1.35 (s, 12H).

Step 2: 4-(6-fluoro-3-pyridyl)-6-methoxypyrazolo[1,5-a]pyridine

To a 25 mL two-necked flask were added 6-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine (785 mg, 2.864 mmol), potassium acetate (843 g, 8590 mmol) and PdCl₂(dppf)CH₂Cl₂ (236 mg, 0.286 mmol). The reaction mixture was degassed and refilled with nitrogen. Then 1,4-dioxane (6.4 mL) was added to dissolve the solids. 5-Bromo-2-fluoro-pyridine (0.442 mL, 4.29 mmol) was then added. The mixture was heated to reflux at 90° C. overnight. The resulting mixture was filtered by suction. The filter cake was washed with 80 mL of EA several times, and the organic phases were washed with 20 mL of saturated saline. The organic phases were then separated, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=8:1-1:1) to give a brown solid 0.6754 g (yield: 96.97%) as the target product. LC-MS(ES-API): m/z=244.10[M+H]⁺. ¹H NMR (600 MHz, CDCl₃) δ 8.44 (d, J=2.1 Hz, 1H), 8.33 (s, 1H), 7.98 (td, J=8.2, 2.6 Hz, 1H), 7.93 (d, J=1.6 Hz, 1H), 7.05 (dd, J=8.4, 3.0 Hz, 1H), 6.68 (s, 1H), 6.51 (s, 1H), 4.03 (s, 3H).

Step 3: tert-butyl 4-(3-phenylprop-2-ynyl)piperazine-1-carboxylate

To a 25 mL single-necked flask was added 3-phenylprop-2-ynoic acid (500 mg, 3.422 mmol), which was dissolved by adding DMF (5 mL). The mixture was placed in a low temperature bath at 0° C. Then tert-butyl piperazine-1-carboxylate (637 mg, 3.420 mmol) was added. N,N-dicyclohexylcarbodiimide (706 mg, 3.422 mmol) was added in portions. The resulting mixture was reacted for 4 h at 0° C. TLC showed the reaction was completed. The reaction mixture was added with water (25 mL), then extracted with EA (10 mL×2), washed with saturated saline (40 mL). The organic phases were separated, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=8:1-2:1) to give a yellow-white solid 0.985 g (the yield was 91.6%), which was the target product. LC-MS(ES-API): m/z=315.3[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.57-7.52 (m, 2H), 7.39 (ddd, J=15.9, 7.2, 1.9 Hz, 3H), 3.84-3.78 (m, 2H), 3.70-3.63 (m, 2H), 3.5-3.50 (m, 2H), 3.48-3.42 (m, 2H), 1.48 (s, 9H).

Step 4: 3-phenyl-1-piperazin-1-yl-prop-2-yn-1-one hydrochloride

To a 100 mL single-necked flask were added tert-butyl 4-(3-phenylprop-2-ynyl)piperazine-1-carboxylate (0.985 g, 3.13 mmol) and a solution of hydrogen chloride in ethyl acetate (9.85 mL, 39.4 mmol). The mixture was stirred at room temperature, and the solid was dissolved, then a white solid was precipitated. The solution was changed to a white suspension, and the reaction was continued for 3 h. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo to give yellow oil, which was dried in an oven at 60° C. to obtain a theoretical amount of yellow white solid 0.785 g as the target product. LC-MS(ES-API): m/z=215.3[M+H]⁺.

Step 5: 1-(4-(5-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)-2-pyridyl)piperazin-1-yl)-3-phenyl-prop-2-yn-1-one

To a 10 mL microwave tube were sequentially added 4-(6-fluoro-3-pyridyl)-6-methoxypyrazolo[1,5-a]pyridine (100 mg, 0.411 mmol), 3-phenyl-1-piperazin-1-yl-prop-2-yn-1-one hydrochloride (155 mg, 0.618 mmol), potassium carbonate (227 mg, 1.642 mmol) and DMSO (3 mL). The mixture was heated in a microwave at 150° C. for 5 h. The resulting mixture was added with 20 mL of water and extracted with EA (100 mL×3). The organic phases were washed with saturated saline (80 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=20:1) to give a pale yellow solid 12.5 mg (yield: 6.95%) as the target product. LC-MS(ES-API): m/z=438.10[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.45 (d, 1H), 8.29 (s, 1H), 7.89 (d, J=1.9 Hz, 1H), 7.74 (dd, J=8.8, 2.4 Hz, 1H), 7.58 (d, J=6.9 Hz, 2H), 7.44 (d, J=7.2 Hz, 1H), 7.40 (d, J=7.4 Hz, 2H), 6.78 (d, J=8.8 Hz, 1H), 6.64 (d, J=1.3 Hz, 1H), 6.54 (s, 1H), 4.02 (s, 3H), 4.00-3.98 (m, 2H), 3.87-3.83 (m, 2H), 3.78-3.75 (m, 2H), 3.67-3.64 (m, 2H). HPLC: 82.47%.

Example 348:1-(4-(5-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)pyrimidin-2-yl)piperazin-1-yl)-3-phenyl-prop-2-yn-1-one

Step 1: 4-(2-chloropyrimidin-5-yl)-6-methoxypyrazolo[1,5-a]pyridine

To a 25 mL two-necked flask were added 4-bromo-6-methoxypyrazolo[1,5-a]pyridine (500 mg, 2.202 mmol), (2-chloropyrimidin-5-yl)boronic acid (366 mg, 2.311 mmol) and PdCl₂(dppf)CH₂Cl₂ (182 mg, 0.221 mmol). The reaction mixture was degassed and refilled with nitrogen. Then 1,4-dioxane (7.5 mL) was added with stirring to dissolve the solids. An aqueous solution of potassium acetate (4.4 mL, 4.4 mmol) was added under ice bath conditions. The mixture was reacted in an oil bath at 85° C. overnight. The resulting mixture was filtered by suction, and the filter cake was washed with EA (40 mL). The organic phases were washed with saturated saline (15 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=8:1-1:2) to give a yellow solid 105.5 mg (yield: 20%) as the target product. LC-MS(ES-API): m/z=261.20[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.85 (s, 2H), 8.36 (s, 1H), 7.96 (d, J=2.0 Hz, 1H), 6.72 (d, J=1.4 Hz, 1H), 6.47 (s, 1H), 4.05 (s, 3H).

Step 2: tert-butyl 4-(3-phenylprop-2-ynyl)piperazine-1-carboxylate

To a 25 mL single-necked flask were added 3-phenylprop-2-ynoic acid (500 mg, 3.422 mmol) and DMF (5 mL). Then tert-butyl piperazine-1-carboxylate (637 mg, 3.420 mmol) was added at 0° C. N,N-dicyclohexylcarbodiimide (706 mg, 3.422 mmol) was added in portions. The resulting mixture was reacted for 4 h at 0° C. The reaction mixture was added with water (25 mL), then extracted with EA (100 mL×2). The combined organic phases were washed with saturated saline (40 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo. The residue was purified by silica gel column chromatography (eluent PE:EA=8:1-2:1) to give a yellow-white solid 0.985 g (the yield was 91.6%), which was the target product. LC-MS(ES-API): m/z=315.3[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.57-7.52 (m, 2H), 7.39 (ddd, J=15.9, 7.2, 1.9 Hz, 3H), 3.84-3.78 (m, 2H), 3.70-3.63 (m, 2H), 3.5-3.50 (m, 2H), 3.48-3.42 (m, 2H), 1.48 (s, 9H).

Step 3: 3-phenyl-1-piperazin-1-yl-prop-2-yn-1-one hydrochloride

To a 100 mL single-necked flask were added tert-butyl 4-(3-phenylprop-2-ynyl)piperazine-1-carboxylate (0.985 g, 3.13 mmol) and a solution of hydrogen chloride in ethyl acetate (9.85 mL, 39.4 mmol). The mixture was reacted with stirring at room temperature for 3 h. The reaction solution was directly concentrated in vacuo to give yellow oil, which was dried in an oven at 60° C. to obtain a theoretical amount of yellow white solid 0.785 g as the target product. LC-MS(ES-API): m/z=215.3[M+H]⁺.

Step 4: 1-(4-(5-(6-methoxypyrazolo[1,5-a]pyridin-4-yl)pyrimidin-2-yl)piperazin-1-yl)-3-phenyl-prop-2-yn-1-one

To a 25 mL single-necked flask were added 4-(2-chloropyrimidin-5-yl)-6-methoxypyrazolo[1,5-a]pyridine (35 mg, 0.134 mmol), 3-phenyl-1-piperazin-1-yl-prop-2-yn-1-one hydrochloride (36 mg, 0.144 mmol) and potassium carbonate (56 mg, 0.405 mmol), which were dissolved by adding acetonitrile (3.5 mL). The mixture was reacted in an 80° C. oil bath overnight. The resulting mixture was added with 4 mL of water and extracted with EA (20 mL×3). The organic phases were washed with saturated saline (10 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=10:1) to give an off-white solid 15.8 mg (yield: 26.8%) as the target product. LC-MS(ES-API): m/z=439.2[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.57 (s, 2H), 8.26 (s, 1H), 7.90 (d, J=2.0 Hz, 1H), 7.58 (d, J=6.9 Hz, 2H), 7.44 (d, J=7.2 Hz, 1H), 7.40 (d, J=7.5 Hz, 2H), 6.66 (s, 1H), 6.46 (s, 1H), 4.02 (s, 3H), 4.01-3.99 (m, 2H), 3.95 (q, J=4.9 Hz, 4H), 3.83-3.79 (m, 2H). HPLC: 98.44%.

Example 349: 4-(6-(6-(3-ethynyl-4-fluorobenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-fluoro-3-((trimethylsilyl)ethynyl)benzaldehyde

To a mixture of 3-bromo-4-fluoro-benzaldehyde (600 mg, 2.9555 mmol), bis(triphenylphosphine)palladium dichloride (82 mg, 0.12 mmol) and cuprous iodide (28 mg, 0.14702 mmol) were sequentially added triethylamine (4.4 mL, 32 mmol) and trimethylsilylacetylene (0.84 mL, 5.9 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=20:1) to give a yellow solid 367 mg (yield: 56.4%) as the target product.

Step 2: 3-ethynyl-4-fluorobenzaldehyde

To a solution of 4-fluoro-3-((trimethylsilyl)ethynyl)benzaldehyde (367 mg, 1.6658 mmol) in methanol (4.2 mL) was added K₂CO₃ (23 mg, 0.16641 mmol) at room temperature, and the mixture was reacted at room temperature for 2 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=20:1) to afford a white solid 184 mg (yield: 74.6%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 9.94 (s, 1H), 8.02 (dd, J=6.7, 2.0 Hz, 1H), 7.89 (ddd, J=8.2, 5.0, 2.0 Hz, 1H), 7.25 (t, J=8.6 Hz, 1H), 3.40 (s, 1H).

Step 4: 4-(6-(6-(3-ethynyl-4-fluorobenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.03708 mmol), 3-ethynyl-4-fluorobenzaldehyde (11 mg, 0.074259 mmol), sodium triacetoxyborohydride (24 mg, 0.11324 mmol) and DCE (2 mL). The mixture was reacted at 35° C. overnight. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/2) to give a white solid 13 mg (the yield was 63.78%), which was the target product. LC-MS(ESI): m/z=537.2 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 8.41 (d, J=1.9 Hz, 1H), 8.22 (s, 1H), 8.16 (d, J=1.9 Hz, 1H), 7.80-7.76 (m, 1H), 7.51 (d, J=6.3 Hz, 1H), 7.35 (s, 1H), 7.17 (d, J=1.7 Hz, 1H), 7.02 (d, J=8.9 Hz, 1H), 6.69 (d, J=8.7 Hz, 1H), 3.87 (s, 2H), 3.84-3.77 (m, 4H), 3.65-3.57 (m, 4H), 3.29 (s, 1H), 2.77-2.70 (m, 1H), 2.05-2.00 (m, 1H), 1.40 (s, 6H). HPLC: 92.88%.

Example 350: 4-(6-(6-(4-ethynyl-2,6-difluorobenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxyl-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol

To a 100 mL double-necked flask were sequentially added 4-bromo-2,6-difluoro-benzoic acid (1 g, 4.2194 mmol) and THE (40 mL) under nitrogen, then a mixture of dimethyl sulfide borane (4.3 mL, 45 mmol) in 100 ml of THE was slowly added. After the completion of the dropwise addition, the mixture was reacted for 6 h at room temperature. The reaction mixture was added with methanol until no air bubbles were generated, and the mixture was transferred to a 500 mL single-necked flask to concentrate in vacuo. The residue was added with ethyl acetate (200 mL) and water (80 mL). The organic phase was separated, and washed with water (80 mL) and saturated saline (80 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=100/1-100-5) to give a white solid 880 mg as the target product (the yield was 93.5%). ¹H NMR (400 MHz, CDCl₃) δ 7.13 (d, J=6.7 Hz, 2H), 4.76 (d, J=6.3 Hz, 2H), 1.90 (t, J=6.5 Hz, 1H).

Step 2: (2,6-difluoro-4-((trimethylsilyl)ethynyl)phenyl)methanol

To a three-necked flask were added 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol (500 mg, 2.2420 mmol), CuI (51 mg, 0.268 mmol), PdCl₂(PPh₃)₂(47 mg, 0.067 mmol), TEA (5 mL) and ethynyl (trimethyl) silane (0.4 mL, 3 mmol) under nitrogen. The mixture was reacted overnight at 70° C. The reaction mixture was added with EA (30 mL). Then the mixture was filtered by suction with celite, and washed with appropriate amount of EA. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (EA:PE=0:100-3:100) to give pale yellow liquid 158 mg as the desired product (the yield was 29.3%). ¹H NMR (400 MHz, CDCl₃) δ 7.03-6.95 (m, 2H), 4.75 (s, 2H), 1.93 (s, 1H), 0.25 (s, 9H).

Step 3: (4-ethynyl-2,6-difluorophenyl)methanol

To a 10 mL single-necked flask were added 2,6-difluoro-4-((trimethylsilyl)ethynyl)phenyl)methanol (150 mg, 0.624 mmol) and methanol (5 mL). After the solid was dissolved, K₂CO₃ (170 mg, 1.23 mmol) was added, and the mixture was stirred at room temperature for 3 h. The reaction solution was added with EA (15 mL) and water (10 mL), then partitioned. The aqueous phase was extracted with EA (10 mL×3), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=100/0-100/3) to give a white solid 88 mg as the target product (the yield was 83.85%). ¹H NMR (400 MHz, CDCl₃) δ 7.03 (d, J=7.5 Hz, 2H), 4.77 (d, J=6.2 Hz, 2H), 3.16 (s, 1H), 1.90 (t, J=6.5 Hz, 1H).

Step 4: 2-(bromomethyl)-5-ethynyl-1,3-difluorobenzene

To a 10 mL single-necked flask were added 4-ethynyl-2,6-difluorophenyl)methanol (85 mg, 0.50553 mmol) and DCM (2.5 mL). After the solid was dissolved, PBr₃ (0.1 mL, 1 mmol) was slowly added in the ice salt bath. The mixture was reacted with stirring for 5 h in an ice bath. After the reaction was stopped, DCM (15 mL) and saturated sodium bicarbonate solution (5 mL) were added. The mixture was partitioned, and the aqueous phase was extracted with DCM (10 mL). The combined organic phases were washed with saturated saline (10 mL), dried over anhydrous sodium sulfate, concentrated in vacuo, and then used for the next step without further purification.

Step 5: 4-(6-(6-(4-ethynyl-2,6-difluorobenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 4-(6-(3,6-diazabicyclo[3.1.1]heptane-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 20 mg, 0.04189 mmol), 2-(bromomethyl)-5-ethynyl-1,3-difluorobenzene (14 mg, 0.060596 mmol), DMF (2 mL) and potassium carbonate (23 mg, 0.170 mmol). The resulting mixture was reacted with stirring at room temperature overnight. The reaction mixture was added with water (8 mL) and EA (20 mL). The separated aqueous phase was extracted with EA (20 mL). The combined organic phases were washed with water (10 mL×2) and saturated saline (10 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=100/0-100/3) to give a white solid 4.8 mg (the yield was 21%) as the target product. LC-MS (ESI): m/z=555.2[M+1]. ¹H NMR (400 MHz, CDCl₃) δ 8.42 (d, J=2.2 Hz, 1H), 8.21 (s, 1H), 8.16 (d, J=1.6 Hz, 1H), 7.79 (dd, 1H), 7.16 (d, J=1.7 Hz, 1H), 7.01 (d, J=7.4 Hz, 2H), 6.73 (d, J=8.8 Hz, 1H), 4.05 (d, J=11.8 Hz, 2H), 3.98-3.90 (m, 2H), 3.87 (s, 2H), 3.73-3.66 (m, 4H), 3.14 (s, 1H), 2.84-2.74 (m, 1H), 2.24-2.15 (m, 1H), 1.28 (s, 6H). HPLC: 94.26%.

Example 351: 4-(6-(4-(4-ethynylbenzyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-((trimethylsilyl)ethynyl)benzaldehyde

To a mixture of 4-bromobenzaldehyde (600 mg, 3.2429 mmol), bis(triphenylphosphine)palladium dichloride (91 mg, 0.129647 mmol) and cuprous iodide (30 mg, 0.15752 mmol) were sequentially added triethylamine (4.9 mL, 35 mmol) and trimethylsilylacetylene (0.92 mL, 6.5 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature overnight. The mixture was concentrated in vacuo to remove the solvent, and the residue was purified by silica gel column chromatography (PE:EA=20:1) to give a yellow solid 631 mg (yield: 96.2%) as the target product.

Step 2: 4-ethynyl benzaldehyde

To a solution of 4-((trimethylsilyl)ethynyl)benzaldehyde (631 mg, 3.1188 mmol) in methanol (7.8 mL) was added K₂CO₃ (43 mg, 0.31112 mmol) at room temperature. The mixture was reacted at room temperature for 4 h. The reaction was quenched with saturated NH₄Cl (10 mL). The organic solvent was evaporated under reduced pressure, and the residue was extracted with EA (40 mL×2). The organic phases were combined, and then washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=15:1) to afford a white solid 378 mg (yield: 93.1%) as the target product. LC-MS(ESI): m/z=131.10 [M+H]⁺; ¹H NMR (400 MHz, CDCl₃) δ 9.99 (s, 1H), 7.82 (d, J=8.2 Hz, 2H), 7.61 (d, J=8.1 Hz, 2H), 3.29 (s, 1H).

Step 3: 4-(6-(4-(4-ethynylbenzyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbo nitrile dihydrochloride (see synthesis of intermediate 7, 20 mg, 0.04297 mmol), 4-ethynylbenzaldehyde (10 mg, 0.076840 mmol), DCM (2 mL) and sodium triacetylborohydride (36 mg, 0.16986 mmol). The mixture was reacted overnight at room temperature. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/3) to give a white solid 15 mg (the yield was 68.9%), which was the target product. LC-MS(ESI): m/z=507.2 [M+H]; ¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J=2.4 Hz, 1H), 8.19 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 7.70 (dd, J=8.8, 2.4 Hz, 1H), 7.50-7.45 (m, 2H), 7.36-7.32 (m, 2H), 7.13 (d, J=1.9 Hz, 1H), 6.75 (d, J=8.9 Hz, 1H), 3.85 (s, 2H), 3.74-3.62 (m, 5H), 3.60 (s, 2H), 3.07 (s, 1H), 2.63-2.56 (m, 4H), 1.38 (s, 6H). HPLC: 98.15%.

Example 352: 4-(6-(6-(4-ethynyl-2,3,5,6-tetrafluorobenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-bromo-2,3,5,6-tetrafluorobenzaldehyde

To a 50 mL two-necked flask were sequentially added LiBr (333 mg, 3.83 mmol), NMP (5 mL) and 2,3,4,5,6-pentafluorobenzaldehyde (0.31 mL, 2.5 mmol) under N₂. The mixture was heated in a 160° C. oil bath and stirred overnight. The reaction mixture was cooled, and then EA (25 mL) was added and the resulting mixture was washed with water (8 mL×4). The organic phases were dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE/EA=15/1) to give a pale yellow solid 340 mg as the target product (yield 53%). LC-MS: (ESI-MS): m/z=255.0 [M−H]⁻. ¹H NMR (400 MHz, CDCl₃): δ 10.30 (s). ¹⁹F NMR (375 MHz, CDCl₃): δ −144.0 (mc, 2F, Ar-o-F), −131.2(mc, 2F, Ar-m-F).

Step 2: 2,3,5,6-tetrafluoro-4-((trimethylsilyl)ethynyl)benzaldehyde

To a 50 mL two-necked flask under N₂ were sequentially added PdCl₂(PPh₃)₃(29 mg, 0.041 mmol), CuI (29 mg, 0.15 mmol), 4-bromo-2,3,5,6-tetrafluorobenzaldehyde (150 mg, 0.58 mmol), TEA (5 mL) and trimethylsilylacetylene (0.14 mL, 0.99 mmol). The mixture was stirred and heated for 4 h in a 60° C. oil bath. The reaction mixture was cooled, and then added with water (25 mL) and extracted with EA (20 mL×2). The combined organic phases were washed with saturated ammonium chloride solution (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (eluent PE/EA=15/1) to give a pale yellow solid 130 mg as the target product (yield 80%). ¹H NMR (400 MHz, CDCl₃) δ 10.29 (s, 1H), 0.07 (s, 9H). ¹⁹F NMR (376 MHz, CDCl₃) δ −135.35 (dd, J=19.5, 12.6 Hz, 2F), −145.84 (dd, J=19.5, 12.6 Hz, 2F).

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(2,3,5,6-tetrafluoro-4-((trimethylsilyl) ethynyl)benzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)-3-pyridyl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 25 mg, 0.057 mmol), 2,3,5,6-tetrafluoro-4-((trimethylsilyl)ethynyl)benzaldehyde (46 mg, 0.17 mmol), sodium triacetoxyborohydride (63 mg, 0.30 mmol) and DCE (4 mL). The mixture was stirred at rt overnight. The reaction solution was added with 15 mL of ammonium chloride solution and extracted with EA (20 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo, which was directly used in the next reaction.

Step 4: 4-(6-(6-(4-ethynyl-2,3,5,6-tetrafluorobenzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 50 mL single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(2,3,5,6-tetrafluoro-4-((trimethylsilyl)ethynyl)benzyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (0.056 mmol), K₂CO₃ (33 mg, 0.24 mmol) and MeOH (4 mL). The mixture was stirred at rt for 1 h. The reaction solution was added with 20 mL of ammonium chloride solution, extracted with EA (15 mL×2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (eluent DCM/MeOH=25/1) to give a white solid 5 mg, which was the target product. LC-MS: (ESI-MS): m/z=591.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.42 (d, J=2.3 Hz, 1H), 8.22 (s, 1H), 8.16 (d, J=1.8 Hz, 1H), 7.79 (dd, J=8.8, 2.4 Hz, 1H), 7.16 (d, J=1.8 Hz, 1H), 6.73 (d, J=8.8 Hz, 1H), 3.99 (d, J=12.1 Hz, 2H), 3.90-3.81 (m, 4H), 3.70-3.61 (m, 5H), 2.68 (m, 1H), 2.08 (m, 1H), 1.40 (s, 6H). HPLC: 99.57%.

Example 353: 4-(6-(6-((6-ethynyl-5-fluoropyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: (6-ethynyl-5-fluoropyridin-3-yl)methanol

To a two-necked flask were added (6-bromo-5-fluoro-3-pyridyl)methanol (150 mg, 0.73 mmol), CuI (28 mg, 0.15 mmol) and PdCl₂(PPh₃)₂(51 mg, 0.073 mmol) under nitrogen, which were dissolved in THE (3 mL) and TEA (3 mL). Ethyl (trimethyl)silane (108 mg, 1.1 mmol) was added with stirring at 70° C. and the mixture was kept at this temperature and reacted. After the completion of reaction was monitored by TLC, the reaction mixture was filtered by suction through a celite pad. The filter cake was washed with a small amount of EA, and the filtrate was dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:5-1:2) to give a brown solid 100 mg as the desired product. ¹H-NMR (400 MHz, CDCl₃) δ 8.30 (s, 1H), 7.46 (d, J=9.4 Hz, 1H), 4.64 (s, 2H), 4.57 (s, 1H), 3.37 (s, 1H).

Step 2: 5-(bromomethyl)-2-ethynyl-3-fluoropyridine

(6-Ethynyl-5-fluoropyridin-3-yl)methanol (30 mg, 0.20 mmol) was dissolved in 2 mL of DCM in a single-necked flask at 0° C., and PBr₃ (0.03 mL, 0.3 mmol) was added dropwise with stirring. After the addition, the mixture was continuously stirred at this temperature. After the completion of reaction was monitored by TLC, the reaction mixture was added with saturated sodium bicarbonate with stirring to adjust the pH of the aqueous phase to 8. The resulting mixture was diluted with DCM (10 mL), and the organic phase was separated, washed with water (5 mL) once, dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo to remove most of DCM. The residue was directly used for the next reaction and was calculated according to the theoretical yield.

Step 3: 4-(6-(6-((6-ethynyl-5-fluoropyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

At room temperature, to a single-necked flask were added 4-[6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.031 mmol) and potassium carbonate (22 mg, 0.16 mmol), which were dissolved by adding 2 mL of DMF. After 5 min, 5-(bromomethyl)-2-ethynyl-3-fluoropyridine (10 mg, 0.047 mmol) dissolved in 1 mL of DCM was added with stirring. After the end of addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, the mixture was poured into water (10 mL) and the resulting mixture was extracted with EA (30 mL×2). The organic phases were washed with water (20 mL×3) and saturated saline (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent MeOH:DCM=1:80-1:20) to give a light yellow solid 4 mg as the target product. Rf=0.3(DCM:MeOH=30:1). LC-MS: m/z=538.10[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.41 (d, J=2.4 Hz, 1H), 8.39 (s, 1H), 8.22 (s, 1H), 8.16 (d, J=2.1 Hz, 1H), 7.79 (dd, J=8.6, 2.3 Hz, 1H), 7.57 (s, 1H), 7.16 (d, J=2.0 Hz, 1H), 6.69 (d, J=8.8 Hz, 1H), 3.87 (s, 2H), 3.80 (d, J=5.1 Hz, 4H), 3.69 (s, 2H), 3.66-3.61 (m, 2H), 3.41 (s, 1H), 2.75-2.71 (m, 1H), 2.07-2.05 (m, 1H), 1.40 (s, 6H). HPLC: 95.71%.

Example 354: 4-(6-(4-((6-ethynyl-pyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 6-(2-trimethylsilylethynyl)pyridin-3-carbaldehyde

To a 25 mL two-necked flask were sequentially added with 6-bromopyridine-3-carbaldehyde (1000 mg, 5.376 mmol), PdCl₂(PPh₃)₂(151 mg, 0.215 mmol) and CuI (52 mg, 0.273 mmol) at room temperature. The reaction mixture was degassed and refilled with nitrogen. Triethylamine (8.1 mL, 58 mmol) and ethynyl (trimethyl)silane (1.52 mL, 10.8 mmol) were added. The resulting mixture was reacted overnight. TLC showed the reaction was completed. The mixture was directly concentrated in vacuo and purified by silica gel column chromatography (eluent PE:EA=10:1-8:1) to give a yellow-white product 0.66 g (the yield was 60%), which was the target product. LC-MS(ES-API): m/z=204.2 [M+H]⁺.

Step 2: 6-ethynylpyridine-3-carbaldehyde

To a 25 mL single-necked flask were sequentially added 6-(2-trimethylsilylethynyl)pyridine-3-carbaldehyde (660 mg, 3.246 mmol), K₂CO₃ (897 mg, 6.490 mmol) and MeOH (8.12 mL). The mixture was stirred to react at room temperature. TLC showed the reaction was completed. The reaction was quenched by dropwise addition of saturated ammonium chloride (10 mL). Methanol was removed under reduced pressure. The residue was extracted with EA (20 mL×2). The organic phases were washed with saturated brine (10 mL×2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=10:1-4:1) to give a yellow-white product 0.240 g (the yield was 56.4%), which was the target product. LC-MS(ES-API): m/z=132.1 [M+H]⁺.

Step 3: 4-(6-(4-((6-ethynyl-pyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were sequentially added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mol), 6-ethynylpyridine-3-carbaldehyde (10 mg, 0.076 mol), STAB (33.4 mg, 0.153 mmol) and DCE (2 mL). The mixture was stirred to react at room temperature overnight. The reaction solution was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM-DCM:MeOH=20:1) to give a pale yellow solid 0.005 g (the yield was 30%), which was the target product. LC-MS(ES-API): m/z=508.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.57 (s, 1H), 8.33 (d, J=2.3 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.71 (dd, J=8.8, 2.6 Hz, 2H), 7.48 (d, J=7.8 Hz, 1H), 7.14 (d, J=1.9 Hz, 1H), 6.75 (d, J=8.6 Hz, 1H), 3.86 (s, 2H), 3.66 (t, 4H), 3.59 (s, 2H), 3.15 (s, 1H), 2.57 (t, 4H), 1.28 (s, 6H). HPLC: 92.42%.

Example 355: 4-(6-(6-((4-ethynyl-3-fluorophenyl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxyl-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: (3-fluoro-4-iodo-phenyl)methanol

To a 25 mL two-necked flask was added LiAlH₄ (295 mg, 7.539 mmol). The flask was degassed and refilled with nitrogen. Anhydrous THE (10 mL) was added to dissolve the solid at 0° C. 3-Fluoro-4-iodo-benzoic acid (1000 mg, 3.759 mmol) was added in portions with continuously flowing nitrogen. After the end of addition, the mixture was kept reacting for 30 minutes at 0° C., and then was reacted with stirring at room temperature. TLC showed the reaction was completed.

The resulting mixture was added with 15 mL of water to quench the reaction in an ice bath, then extracted with EA (40 mL×3). The organic phases were combined, washed with saturated saline (40 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, then purified by silica gel column chromatography (eluent PE/EA=30:1-8:1) to give yellow oil 0.54 g (yield: 57%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 7.69 (dd, J=8.0, 6.5 Hz, 1H), 7.07 (dd, J=5.6, 4.8 Hz, 1H), 6.88 (d, J=8.1 Hz, 1H), 4.63 (s, 2H), 2.25 (s, 1H).

Step 2: 3-fluoro-4-iodo-benzaldehyde

To a 25 mL single-necked flask were added (3-fluoro-4-iodo-phenyl)methanol (540 mg, 2.143 mmol), NaHCO₃ (0.9 g, 10 mmol) and Dess Martin oxidant (1.2 g, 2.8 mmol), which were dissolved by adding DCM (15 mL). The mixture was stirred for reaction at room temperature. TLC showed the reaction was completed. The resulting mixture was added with 10 mL of saturated sodium thiosulfate solution to quench the reaction. After the mixture was partitioned, the organic phase was separated and the aqueous phase was extracted with DCM (20 mL×2). The organic phases were combined, washed with saturated saline (15 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, then purified by silica gel column chromatography (eluent PE/EA=10:1-2:1) to give a yellow-white solid 0.45 g (yield: 84%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 9.95 (d, J=1.6 Hz, 1H), 7.97 (dd, J=8.0, 6.0 Hz, 1H), 7.52 (dd, J=7.6, 1.6 Hz, 1H), 7.41 (dd, J=8.0, 1.7 Hz, 1H).

Step 3: 3-fluoro-4-(2-trimethylsiloxy)benzaldehyde

To a 25 mL two-necked flask were added 3-fluoro-4-iodo-benzaldehyde (450 mg, 1.80 mmol), CuI (35 mg, 0.184 mmol) and PdCl₂ (PPh₃)₂ (64 mg, 0.091 mmol). The reaction mixture was degassed and refilled with nitrogen. Then anhydrous THF (4.5 mL) and triethylamine (4.5 mL, 32 mmol) were added. After the dissolution, ethynyl (trimethyl)silane (0.51 mL, 3.6 mmol) was added. The mixture was stirred for reaction at room temperature. TLC showed the reaction was completed. The resulting mixture was filtered by suction. The filter cake was washed with 120 mL of EA several times, and the filtrate with washed with 30 mL of saturated saline, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, then purified by silica gel column chromatography (eluent PE/EA=100:1-30:1) to give brownish yellow oil 0.195 g (yield: 49.2%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 9.95 (d, J=1.7 Hz, 1H), 7.61-7.59 (m, 2H), 7.55 (d, J=9.1 Hz, 1H), 0.27 (s, 9H).

Step 4: 4-ethynyl-3-fluoro-benzaldehyde

To a 10 mL single-necked flask were sequentially added 3-fluoro-4-(2-trimethylsiloxy)benzaldehyde (195 mg, 0.885 mmol), K₂CO₃ (245 mg, 1.773 mmol) and MeOH (2.5 mL). The mixture was stirred to react at room temperature. TLC showed the reaction was completed. The mixture was added with water (2 mL), then extracted with EA (10 mL×3), washed with saturated saline (8 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent pure PE-PE:EA=50:1) to give a white solid 0.071 g (the yield was 54%), which was the target product. ¹H NMR (400 MHz, CDCl₃) δ 9.98 (d, J=1.7 Hz, 1H), 7.68-7.62 (m, 2H), 7.59 (d, J=9.2 Hz, 1H), 3.51 (s, 1H).

Step 5: 4-(6-(6-((4-ethynyl-3-fluorophenyl)methyl))-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were sequentially added 4-[6-(3,6-diazabicyclo[3.1.1]heptan-3-yl-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 20 mg, 0.042 mmol) and 4-ethynyl-3-fluoro-benzaldehyde (25 mg, 0.169 mmol), which were dissolved by adding DCE (2 mL). Then a drop of glacial acetic acid was added. The mixture was stirred for reaction at room temperature for 30 min, then sodium triacetoxyborohydride (36 mg, 0.165 mmol) was added and the mixture was stirred for reaction at room temperature. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=20:1) to give a white solid 0.011 g (the yield was 49%), which was the target product. LC-MS(ES-API): m/z=537.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.40 (d, J=2.1 Hz, 1H), 8.22 (s, 1H), 8.16 (d, J=1.9 Hz, 1H), 7.78 (dd, J=8.8, 2.4 Hz, 1H), 7.41 (t, J=7.5 Hz, 1H), 7.19-7.15 (m, 2H), 7.10 (d, J=8.4 Hz, 1H), 6.68 (d, J=8.8 Hz, 1H), 3.87 (s, 2H), 3.84-3.77 (m, 4H), 3.64 (s, 2H), 3.63-3.55 (m, 2H), 3.27 (s, 1H), 2.73 (d, J=6.3 Hz, 1H), 2.02 (d, J=6.7 Hz, 1H), 1.28 (s, 6H). HPLC: 97.72%.

Example 356: 4-(6-(6-((6-ethynyl-5-fluoropyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: (6-ethynyl-5-fluoropyridin-3-yl)methanol

To a two-necked flask were added (6-bromo-5-fluoro-3-pyridyl)methanol (150 mg, 0.73 mmol), CuI (28 mg, 0.15 mmol) and PdCl₂(PPh₃)₂(51 mg, 0.073 mmol) under nitrogen, which were dissolved in THE (3 mL) and TEA (3 mL). Ethyl (trimethyl)silane (108 mg, 1.1 mmol) was added with stirring at 70° C. and the mixture was kept at this temperature and reacted. After the completion of reaction was monitored by TLC, the reaction mixture was filtered by suction through a celite pad. The filter cake was washed with a small amount of EA, and the filtrate was dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:5-1:2) to give a brown solid 100 mg as the desired product. ¹H-NMR (400 MHz, CDCl₃) δ 8.30 (s, 1H), 7.46 (d, J=9.4 Hz, 1H), 4.64 (s, 2H), 4.57 (s, 1H), 3.37 (s, 1H).

Step 2: 5-(bromomethyl)-2-ethynyl-3-fluoropyridine

(6-Ethynyl-5-fluoropyridin-3-yl)methanol (30 mg, 0.20 mmol) was dissolved in 2 mL of DCM in a single-necked flask at 0° C., and PBr₃ (0.03 mL, 0.3 mmol) was added dropwise with stirring. After the addition, the mixture was continuously stirred at this temperature. After the completion of reaction was monitored by TLC, the reaction mixture was added with saturated sodium bicarbonate with stirring to adjust the pH of the aqueous phase to 8. The resulting mixture was diluted with DCM (10 mL), and the organic phase was separated, washed with water (5 mL) once, dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo to remove most of DCM. The residue was directly used for the next reaction and was calculated according to the theoretical yield.

Step 3: 4-(6-(6-((6-ethynyl-5-fluoropyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

At room temperature, to a single-necked flask were added 4-[6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.031 mmol) and potassium carbonate (22 mg, 0.16 mmol), which were dissolved by adding 2 mL of DMF. After 5 min, 5-(bromomethyl)-2-ethynyl-3-fluoropyridine (10 mg, 0.047 mmol) dissolved in 1 mL of DCM was added with stirring. After the end of addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, the mixture was poured into water (10 mL) and the resulting mixture was extracted with EA (30 mL×2). The organic phases were washed with water (20 mL×3) and saturated saline (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent MeOH:DCM=1:80-1:20) to give a light yellow solid 4 mg as the target product. Rf=0.3(DCM:MeOH=30:1). LC-MS: m/z=538.10[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.41 (d, J=2.4 Hz, 1H), 8.39 (s, 1H), 8.22 (s, 1H), 8.16 (d, J=2.1 Hz, 1H), 7.79 (dd, J=8.6, 2.3 Hz, 1H), 7.57 (s, 1H), 7.16 (d, J=2.0 Hz, 1H), 6.69 (d, J=8.8 Hz, 1H), 3.87 (s, 2H), 3.80 (d, J=5.1 Hz, 4H), 3.69 (s, 2H), 3.66-3.61 (m, 2H), 3.41 (s, 1H), 2.75-2.71 (m, 1H), 2.07-2.05 (m, 1H), 1.40 (s, 6H). HPLC: 95.71%.

Example 357: 6-ethoxy-4-(6-(6(6-ethynyl-pyridin-3-yl)methyl]-3,6-diazabicyclo[3.1.1]heptan-3-yl]-pyridin-3-yl]pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 6-(2-trimethylsilylethynyl)pyridin-3-carbaldehyde

To a 25 mL two-necked flask were sequentially added with 6-bromopyridine-3-carbaldehyde (1000 mg, 5.376 mmol), PdCl₂(PPh₃)₂(151 mg, 0.215 mmol) and CuI (52 mg, 0.273 mmol) at room temperature. The reaction mixture was degassed and refilled with nitrogen. Triethylamine (8.1 mL, 58 mmol) and ethynyl (trimethyl)silane (1.52 mL, 10.8 mmol) were added to the mixture and a black turbid liquid was obtained. The resulting mixture was reacted overnight. TLC showed the reaction was completed. The mixture was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=10:1-8:1) to give a yellow-white product 0.66 g (the yield was 60%), which was the target product. LC-MS(ES-API): m/z=204.2[M+H]⁺.

Step 2: 6-ethynylpyridine-3-carbaldehyde

To a 25 mL single-necked flask were sequentially added 6-(2-trimethylsilylethynyl)pyridine-3-carbaldehyde (1.0 g, 4.919 mmol), K₂CO₃ (1.36 g, 9.84 mmol) and MeOH (12.3 mL). The mixture was stirred to react at room temperature. TLC showed the reaction was completed. The reaction was quenched by dropwise addition of saturated ammonium chloride (15 mL). Most of the methanol was removed under reduced pressure. The resulting turbid liquid was extracted with EA (40 mL×2). The organic phase was washed with saturated brine (15 mL×2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=8:1-4:1) to give a yellow-white product 0.3 g (the yield was 50%), which was the target product. LC-MS(ES-API): m/z=132.1 [M+H]⁺.

Step 3: (6-ethynyl-3-pyridyl)methanol

To a 25 mL two-necked flask were added 6-ethynylpyridine-3-carbaldehyde (150 mg, 1.144 mmol) and sodium borohydride (66 mg, 1.71 mmol). The reaction mixture was degassed and refilled with nitrogen. Then anhydrous THE (7.5 mL) was added. The mixture was reacted at 0° C. with stirring for 15 min in a cryogenic tank, and then placed at room temperature for reaction. TLC showed the reaction was completed. The mixture was quenched with water (10 mL) and extracted with EA (10 mL×2). The organic phase was washed with saturated brine (15 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=2:1-1:2) to give a yellow-white solid 0.06 g (the yield was 40%), which was the target product. LC-MS(ES-API): m/z=134.1 [M+H]⁺.

Step 4: 5-(bromomethyl)-2-ethynyl-pyridine

To a 10 mL single-necked flask was added a solution of (6-ethynyl-3-pyridyl)methanol (23 mg, 0.173 mmol) in DCM (2 mL) at 0° C. in the cryogenic tank, then PBr₃ (0.033 mL, 0.35 mmol) was added slowly. After 30 minutes of reaction, TLC showed that the reaction was completed. The mixture was slowly added with water (2 mL) to quench the reaction. Saturated potassium carbonate solution (5 mL) was added dropwise to adjust the pH to alkaline. The resulting mixture was extracted with DCM (15 mL×2), concentrated in vacuo to remove part of DCM, and then directly used for the next step. The yield was calculated by 100%.

Step 5: 6-ethoxy-4-(6-(6(6-ethynyl-pyridin-3-yl)methyl]-3,6-diazabicyclo[3.1.1]heptan-3-yl]-pyridin-3-yl]pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask was added 4-[6-(3,6-diazabicyclo[3.1.1]hept-3-yl)-3-pyridyl]-6-ethoxy-pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 8, 25 mg, 0.058 mmol), K₂CO₃ (32 mg, 0.229 mmol), N,N-dimethylformamide (3 mL) and 5-(bromomethyl)-2-ethynyl-pyridine (26.5 mg, 0.135 mmol). The mixture was slowly warmed to 40° C. and reacted overnight. TLC showed the reaction was completed. The mixture was quenched with water (10 mL) and extracted with EA (10 mL×2). The combined organic phases were washed with saturated saline (10 mL×2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent DCM-DCM:MeOH=20:1) to give a pale yellow solid 0.011 g (the yield was 40%), which was the target product. LC-MS(ES-API): m/z=476.20[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.61 (s, 1H), 8.42 (d, J=2.0 Hz, 1H), 8.23 (s, 1H), 8.14 (d, J=1.8 Hz, 1H), 7.81 (dd, J=8.8, 2.3 Hz, 1H), 7.75 (d, J=7.9 Hz, 1H), 7.47 (d, J=8.0 Hz, 1H), 7.14 (s, 1H), 6.71 (d, J=8.8 Hz, 1H), 4.12 (q, J=6.9 Hz, 2H), 3.83 (d, J=5.8 Hz, 4H), 3.70 (s, 2H), 3.65 (d, J=14.2 Hz, 2H), 3.15 (s, 1H), 2.79-2.72 (m, 1H), 2.06 (d, J=7.4 Hz, 1H), 1.35 (s, 3H). HPLC: 90.44%.

Example 358: 4-(6-(4-(4-ethynylbenzyl)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-(4-bromobenzyl)piperidine-1-carboxylate

To a 25 mL two-necked flask under nitrogen were sequentially added tert-butyl 4-methylenepiperidine-1-carboxylate (450 mg, 2.2811 mmol) and 9-bisbicyclo[3.3.1]nonane (4.6 mL, 2 mmol, 0.5 mol/L). The mixture was refluxed at 70° C. for 1 h. The mixture was cooled to room temperature and was sequentially added with 1-bromo-4-iodo-benzene (600 mg, 2.12 mmol), potassium carbonate (380 mg, 2.72206 mmol), DMF (6 mL), water (0.6 mL) and [1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (50 mg, 0.068 mmol) under nitrogen. The resulting mixture was warmed to 60° C. and reacted for 3 h. The reaction mixture was added with EA (60 mL), washed with water (20 mL×3) and saturated saline (20 mL). The organic phases were separated, dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=100/0-100/2) to give a white solid 239 mg (yield 31.81%) as the desired product. ¹H NMR (400 MHz, CDCl₃) δ 7.42 (d, J=8.3 Hz, 2H), 7.03 (d, J=8.3 Hz, 2H), 4.19-3.99 (m, 2H), 2.65 (t, J=12.3 Hz, 2H), 2.51 (d, J=6.9 Hz, 2H), 1.72-1.62 (m, 2H), 1.60-1.58 (m, 1H), 1.47 (s, 9H), 1.22-1.08 (m, 2H).

Step 2: tert-butyl 4-(4-((trimethylsilyl)ethynyl)benzyl)piperidine-1-carboxylate

To a 10 mL two-necked flask under nitrogen were sequentially added tert-butyl 4-(4-bromobenzyl)piperidine-1-carboxylate (190 mg, 0.5363 mmol), bis(triphenylphosphine)palladium dichloride (40 mg, 0.0564177 mmol), DMF (3 mL) and triethylamine (0.25 mL, 1.8 mmol). After stirring for 15 min, cuprous iodide (10 mg, 0.052508 mmol) and trimethylsilylacetylene (0.16 mL, 1.1 mmol) were added. The mixture was reacted overnight at 50° C. The reaction mixture was filtered through a celite pad, and the filter cake was washed with EA (40 mL). The mother liquor was added with water (20 mL). The aqueous phase was separated and extracted with EA (50 mL×3). The organic phases were washed with water (50 mL) and saturated saline (50 mL×2), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=100/2-100/6) to give pale yellow viscous liquid 152 mg as the target product (the yield was 76.28%). ¹H NMR (400 MHz, CDCl₃) δ 7.38 (d, J=8.1 Hz, 2H), 7.06 (d, J=8.1 Hz, 2H), 4.15-3.98 (m, 2H), 2.62 (t, J=12.6 Hz, 2H), 2.51 (d, J=7.0 Hz, 2H), 1.68-1.62 (m, 1H), 1.59-1.54 (m, 2H), 1.44 (s, 9H), 1.17-1.06 (m, 2H), 0.24 (s, 9H).

Step 3: 4-(4-((trimethylsilyl)ethynyl)benzyl)piperidine hydrochloride

To a 10 mL single-necked flask were sequentially added tert-butyl 4-(4-((trimethylsilyl)ethynyl)benzyl)piperidine-1-carboxylate (150 mg, 0.4037 mmol) and HCl/EA (5 mL, 20 mmol, 4 mol/L). The mixture was reacted at room temperature for 6 h. The mixture was directly concentrated in vacuo at 35° C. to give a light brown solid 130 mg as the desired product, which was used in the next step directly without further purification.

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(4-((trimethylsilyl)ethynyl)benzyl)piperidin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a mixture of 4-(4-((trimethylsilyl)ethynyl)benzyl)piperidine hydrochloride (65 mg, 0.1882 mmol) and 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.09194 mmol) were added toluene (2 mL) and DIPEA (0.1 mL, 0.6 mmol) at room temperature. The mixture was reacted at 120° C. overnight. The mixture was cooled to room temperature and concentrated in vacuo to remove the solvent, which was used in the next step directly without further purification.

Step 5: 4-(6-(4-(4-ethynylbenzyl)piperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(4-((trimethylsilyl)ethynyl)benzyl)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (53 mg, 0.09173 mmol), MeOH (2 mL) and K₂CO₃ (16 mg, 0.11577 mmol). The mixture was stirred and reacted at room temperature overnight. The resulting mixture was directly concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=100/1-30/1) to give a light yellow solid 30.1 mg, which was the target product (the yield was 64.9%). LC-MS(ESI): m/z==506.30 [M+H]; ¹H NMR (400 MHz, CDCl₃) δ 8.37 (d, J=2.2 Hz, 1H), 8.28 (d, 1H), 8.24 (s, 1H), 7.74 (dd, J=9.0, 2.4 Hz, 1H), 7.43 (d, J=8.1 Hz, 2H), 7.27 (d, 1H), 7.12 (d, J=8.1 Hz, 2H), 6.82 (d, J=9.0 Hz, 1H), 4.37 (d, J=13.3 Hz, 2H), 3.88 (s, 2H), 3.05 (s, 1H), 2.93 (t, J=12.0 Hz, 2H), 2.59 (d, J=7.0 Hz, 2H), 2.37-2.16 (m, 4H), 2.07-1.99 (m, 1H), 1.38 (s, 6H). HPLC: 97.24%.

Example 359: 4-(6-(4-(4-ethynylbenzyl)-4-hydroxypiperidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-bromobenzyl magnesium bromide

To a 50 mL two-necked flask under N₂ were sequentially added Mg (205 mg, 8.433 mmol) and diethyl ether (anhydrous) (5 mL) at −5° C., then 1-bromo-4-bromomethylbenzene (1380 mg, 5.52 mmol) dissolved in 9 ml of diethyl ether was slowly added. After the addition was completed, the mixture was stirred at rt and the reaction liquid gradually became milky white. After stirring for 1 hour, the mixture was transferred to 0° C. and directly used for the next reaction.

Step 2: tert-butyl 4-(4-bromophenyl)-4-hydroxypiperidine-1-carboxylate

4-Bromobenzylmagnesium bromide (5.52 mmol) was slowly added (in 15-20 min) to a solution of tert-butyl 4-oxopiperidine-1-carboxylate (1050 mg, 5.27 mmol) in anhydrous ether solution (10 mL) at 0° C. After 5 min, the mixture was moved to rt and stirred for 3 h. The reaction mixture was quenched with a saturated aqueous solution of ammonium chloride (15 mL) at −5° C. Then the mixture was extracted with EA (25 mL×2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (eluent PE/EA=5:1) to give a white solid 350 mg (2 steps total yield 18%). LC-MS(ESI-MS): m/z=392.2; 394.2 [M+Na]⁺. ¹H NMR (600 MHz, CDCl₃) δ 7.41 (d, J=8.0 Hz, 2H), 7.05 (d, J=8.1 Hz, 2H), 3.82 (s, 2H), 3.06 (s, 2H), 2.69 (s, 2H), 1.53 (m, 2H), 1.45 (m, 2H), 1.43 (s, 9H).

Step 3: tert-butyl 4-hydroxy-4-(4-((trimethylsilyl)ethynyl)benzyl)piperidine-1-carboxylate

To a 50 mL two-necked flask under N₂ were sequentially added PdCl₂(PPh₃)₃(36 mg, 0.051 mmol), CuI (9.5 mg, 0.050 mmol), tert-butyl 4-(4-bromophenyl)-4-hydroxypiperidine-1-carboxylate (185 mg, 0.50 mmol), TEA (4 mL) and trimethylsilylacetylene (0.25 mL, 1.80 mmol). The mixture was stirred and reacted in a 45° C. oil bath overnight. The reaction mixture was cooled, filtered, and then washed with EA (5 mL×3). The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=5/1) to give a pale yellow solid 105 mg (yield 54%). LC-MS(ESI-MS): m/z=388.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.45-7.38 (m, 1H), 7.30 (dd, J=15.6, 8.2 Hz, 1H), 7.18 (dd, J=11.0, 4.3 Hz, 1H), 7.08 (dd, J=14.5, 8.4 Hz, 1H), 3.83 (s, 2H), 3.24 (s, 1H), 3.08 (s, 2H), 2.77-2.65 (m, 2H), 1.63-1.50 (m, 2H), 1.48 (s, 2H), 1.45 (s, 9H), 0.24 (s, 9H).

Step 4: tert-butyl 4-hydroxy-4-(4-ethynylbenzyl)-4-hydroxypiperidine-1-carboxylate

To a 50 mL single-necked flask were sequentially added tert-butyl 4-hydroxy-4-(4-((trimethylsilyl)ethynyl)benzyl)piperidine-1-carboxylate (305 mg, 0.79 mmol), MeOH (12 mL) and K₂CO₃ (610 mg, 4.41 mmol). The mixture was stirred at rt for 4 h. The reaction solution was added with 10 mL of ammonium chloride solution and extracted with EA (25 mL×2). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo to give 250 mg of oil, which was directly used in the next reaction without further purification. LC-MS: (ESI-MS): m/z=338.2 [M+Na]⁺.

Step 5: 4-(4-ethynylbenzyl)piperidin-4-ol

To a 50 mL single-necked flask were sequentially added tert-butyl 4-hydroxy-4-(4-ethynylbenzyl)-4-hydroxypiperidine-1-carboxylate (73 mg, 0.23 mmol) and DCM (5.0 mL). TFA (0.32 mL) was added at 0° C. The mixture was reacted overnight, then added with saturated sodium bicarbonate solution (30 mL) and extracted with EA (15 mL×4). The organic phases were combined, dried, concentrated in vacuo, then purified by silica gel column chromatography (eluent DCM/MeOH=8:1 (1% Et₃N)) to give 55 mg of crude product, which was directly used in the next reaction. LC-MS: (ESI-MS): m/z=216.3 [M+H]⁺.

Step 6: 4-(6-(4-(4-ethynylbenzyl)-4-hydroxypiperidin-1-yl)pyridine-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL microwave tube were sequentially added 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 36 mg, 0.11 mmol), 4-(4-ethynylbenzyl)piperidin-4-ol (28 mg, 0.13 mmol), DMSO (3.5 mL) and N,N-diisopropylethylamine (0.16 mL, 0.97 mmol). The mixture was reacted under microwave at 110° C. for 3.5 h. The reaction solution was cooled, then added with EA (20 mL) and washed with ammonium chloride solution (10 mL×2). The aqueous phases were combined and extracted with EA (15 mL). The combined organic layers were dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, purified by silica gel column chromatography (eluent PE/EA=2:3) to give a light yellow solid 5 mg, which was the target product. LC-MS: (ESI-MS): m/z=522.4[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J=1.8 Hz, 1H), 8.19 (s, 1H), 8.14 (m, 1H), 7.69 (dd, J=8.8, 2.1 Hz, 1H), 7.46 (d, J=7.8 Hz, 2H), 7.19 (d, J=7.9 Hz, 2H), 7.14 (m, 1H), 6.78 (d, J=8.9 Hz, 1H), 4.16 (d, J=13.1 Hz, 2H), 4.11 (s, 1H), 3.86 (s, 2H), 3.33 (m, 2H), 3.08 (s, 1H), 2.98 (s, 1H), 2.80 (s, 2H), 1.76-1.70 (m, 4H), 1.39 (s, 6H). HPLC: 88.63%.

Example 360: 4-(6-(4-(3,5-difluoro-4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzyl)piperazin-1-yl)pyridine-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: (4-bromo-3,5-difluorophenyl)methanol

4-Bromo-3,5-difluorobenzoic acid (3 g, 12.658 mmol) was dissolved in THE (60 mL) at 0° C. under N₂, then BH₃.Me₂S (25 mL, 250 mmol, 10 mol/L) was slowly added. The mixture was stirred under the ice bath, then naturally warmed to room temperature and reacted overnight. The reaction was quenched by the addition of methanol slowly until no bubbles were produced. The resulting mixture was concentrated in vacuo and the residue was purified by silica gel column chromatography (eluent PE/EA=15/1-10/1) to give a white solid 2.672 g as the target product (the yield was 94.65%).

Step 2: 4-bromo-3,5-difluorobenzaldehyde

(4-Bromo-3,5-difluorophenyl)methanol (3 g, 13.45 mmol) was dissolved in DCM (60 mL) under the ice bath, and dess-Martin (11.4 g, 26.9 mmol) was added slowly. The mixture was stirred for 0.5 h under the ice bath, then warmed to room temperature and reacted with stirring overnight. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE/EA=100/1-50/1) to give a white solid 2.024 g, which was the target product (the yield was 68.08%).

Step 3: tert-butyl 4-(4-bromo-3,5-difluorobenzyl)piperazine-1-carboxylate

To a 25 mL single-necked flask were sequentially added tert-butyl piperazine-1-carboxylate (480 mg, 2.577 mmol), 4-bromo-3,5-difluorobenzaldehyde (600 mg, 2.714 mmol), DCE (20 mL, 100 mass %) and glacial acetic acid (0.16 mL, 2.8 mmol). After the mixture was reacted for 30 min, sodium triacetoxyborohydride (1.65 g, 7.79 mmol) was added, and the mixture was reacted at room temperature for 5 h. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE/EA=100/2-100/5) to give colorless transparent liquid 750 mg as the target product (the yield was 74.4%).

Step 4: tert-butyl 4-(3,5-difluoro-4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzyl) piperazine-1-carboxylate

tert-butyl 4-(4-bromo-3,5-difluorobenzyl)piperazine-1-carboxylate (600 mg, 1.534 mmol), PdCl₂(PPh₃)₂(215 mg, 0.306 mmol), CuI (30 mg, 0.157 mmol), PPh₃ (40 mg, 0.15250 mmol), DMF (12 mL) and Et₃N (0.85 mL, 6.1 mmol) were sequentially added under N₂, then 2-methylbut-3-yn-2-ol (0.4 mL, 4 mmol) was slowly added. The reaction was stirred and reacted at 80° C. overnight. The reaction was stopped, and the mixture was cooled to room temperature, added with water (10 mL) and extracted with EA (30 mL×3). The combined organic phases were washed with water (20 mL) and saturated saline (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE/EA=100/4-100/10) to give a pale yellow crystal 410 mg as the target product (the yield was 67.8%). LC-MS: m/z=395.10[M+1]⁺. ¹H NMR (400 MHz, CDCl₃) δ 6.90 (d, J=7.9 Hz, 2H), 3.46 (s, 2H), 3.45-3.39 (m, 4H), 2.42-2.30 (m, 4H), 2.12 (s, 1H), 1.64 (s, 6H), 1.45 (s, 9H).

Step 5: 4-(2,6-difluoro-4-(piperazin-1-ylmethyl)phenyl)-2-methylbut-3-yl-2-ol hydrochloride

To a 10 mL single-necked flask were sequentially added tert-butyl 4-(3,5-difluoro-4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzyl)piperazine-1-carboxylate (100 mg, 0.2535 mmol) and HCl/EA (5 mL, 20 mmol, 4 mol/L). The mixture was stirred at room temperature overnight. The mixture was directly concentrated in vacuo to give a dark yellow solid which was used in the next step without further purification and was calculated on theoretical yield. LC-MS: m/z=295.2[M−HCl+H]⁺.

Step 6: 4-(6-(4-(3,5-difluoro-4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzyl)piperazin-1-yl) pyridine-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a mixture of 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 60 mg, 0.184 mmol) and 4-(2,6-difluoro-4-(piperazin-1-ylmethyl)phenyl)-2-methylbut-3-yl-2-ol hydrochloride (84 mg, 0.254 mmol) were added toluene (3 mL) and DIPEA (0.2 mL, 1 mmol) at room temperature. The mixture was stirred under reflux at 120° C. for 8 days. Post-treatment: the reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=50/1) to give a yellow solid 58 mg, which was the target product (the yield was 52.51%). LC-MS: m/z=601.20[M+1]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.33 (d, J=2.2 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.71 (dd, J=8.8, 2.4 Hz, 1H), 7.14 (d, J=2.1 Hz, 1H), 6.95 (d, J=7.8 Hz, 2H), 6.75 (d, J=8.9 Hz, 1H), 3.86 (s, 2H), 3.67 (t, J=4.8 Hz, 4H), 3.53 (s, 2H), 2.56 (t, J=4.8 Hz, 4H), 1.65 (s, 6H), 1.39 (s, 6H). HPLC: 94.67%.

Example 361: 4-(6-(4-(4-ethynyl-3,5-difluorobenzyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(4-(3,5-Difluoro-4-(3-hydroxy-3-methylbut-1-yn-1-yl)benzyl)piperazin-1-yl)pyri dine-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of Example 360, 40 mg, 0.066 mmol) was dissolved in toluene (2 mL). The mixture was stirred at rt for 10 min. KOH (10 mg, 0.178 mmol) was added and the mixture was stirred under reflux for 11 h.

The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=50:1) to give a white solid 12.5 mg as the target product (the yield was 34.6%). LC-MS: m/z=543.15[M+1]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.33 (d, J=2.1 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.71 (dd, J=8.8, 2.5 Hz, 1H), 7.14 (d, J=2.0 Hz, 1H), 6.99 (d, J=8.0 Hz, 2H), 6.76 (d, J=8.8 Hz, 1H), 3.86 (s, 2H), 3.68 (t, J=4.4 Hz, 4H), 3.54 (s, 2H), 3.49 (s, 1H), 2.57 (t, J=4.8 Hz, 4H), 1.39 (s, 6H). HPLC: 99.51%.

Example 362: 4-(6-(6-(3-(2-fluorophenyl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(2-fluorophenyl)prop-2-yn-1-ol

To a mixture of 1-fluoro-2-iodobenzene (800 mg, 3.6036 mmol), bis(triphenylphosphine)palladium dichloride (126 mg, 0.179511 mmol) and cuprous iodide (34 mg, 0.17853 mmol) were sequentially added triethylamine (5.4 mL, 39 mmol) and prop-2-yn-1-ol (0.43 mL, 7.3 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature overnight. The reaction mixture was diluted with EA (40 mL), and the organic phase was poured out, then the residual black viscous solid was washed with EA (30 mL×3). The organic phases were combined, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=2:1) to give a pale yellow solid 505 mg (yield: 93.3%) as the target product.

Step 2: 3-(2-fluorophenyl)propynal

To a solution of 3-(2-fluorophenyl)prop-2-yn-1-ol (505 mg, 3.3633 mmol) in dichloromethane (33.6 mL) were sequentially added sodium bicarbonate (1.42 g, 16.8 mmol) and Dess Martin reagent (1.73 g, 4.04 mmol) at room temperature. The mixture was reacted at room temperature for 1.5 h. The reaction was quenched with saturated Na₂S₂O₂ (20 mL). The mixture was extracted with DCM (50 mL×2). The organic phases were combined and dried over anhydrous sodium sulfate, filtered by suction, and concentrated in vacuo. The residue was purified by silica gel column chromatography (PE:EA=10:1) to give pale yellow liquid 445 mg (yield: 89.3%) as the target product. ¹H NMR (400 MHz, CDCl₃) δ 9.45 (s, 1H), 7.62-7.53 (m, 1H), 7.48 (dd, J=7.8, 5.8 Hz, 1H), 7.23-7.11 (m, 2H).

Step 3: 4-(6-(6-(3-(2-fluorophenyl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 12 mg, 0.02967 mmol), 3-(2-fluorophenyl)propynal (10 mg, 0.067508 mmol), sodium triacetoxyborohydride (19 mg, 0.089648 mmol) and DCE (2 mL). The mixture was reacted at 35° C. for 4.5 h. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/2) to give a white solid 5.5 mg (the yield was 32.0%), which was the target product. LC-MS(ESI): m/z=537.0 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.60 (d, J=18.1 Hz, 2H), 8.42 (d, J=2.2 Hz, 1H), 8.22 (s, 1H), 8.17 (d, J=1.9 Hz, 1H), 7.82-7.78 (m, 1H), 7.35 (d, J=2.4 Hz, 1H), 7.17 (d, J=1.9 Hz, 1H), 7.10-7.06 (m, 1H), 6.71 (d, J=8.8 Hz, 1H), 3.92-3.83 (m, 4H), 3.78-3.63 (m, 6H), 3.53 (s, 1H), 2.37-2.31 (m, 1H), 2.25-2.19 (m, 1H), 1.37 (s, 6H). HPLC: 91.02%.

Example 363: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(pyridin-3-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(pyridin-3-yl)prop-2-yn-1-ol

To a mixture of 3-iodopyridine (400 mg, 1.9512 mmol), bis(triphenylphosphine)palladium dichloride (68 mg, 0.097 mmol) and cuprous iodide (18 mg, 0.094514 mmol) were sequentially added triethylamine (2.9 mL, 21 mmol) and prop-2-yn-1-ol (0.23 mL, 3.9 mmol) at room temperature under nitrogen. The mixture was reacted at room temperature for 4.5 h. The reaction mixture was diluted with EA (40 mL), and the organic phase was poured out, then the residual black viscous solid was washed with EA (30 mL×3). The organic phases were combined, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=3:1-4:1) to give a pale yellow solid 242.4 mg (yield: 93.3%) as the target product. LC-MS(ESI): m/z=134.15 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.75 (s, 1H), 8.53 (d, J=4.2 Hz, 1H), 7.74 (d, J=7.8 Hz, 1H), 7.29-7.24 (m, 1H), 4.52 (s, 2H), 3.33 (br s, 1H).

Step 2: 3-(pyridin-3-yl)propynal

To a 50 ml single-necked flask were added 3-(pyridin-3-yl)prop-2-yn-1-ol (50 mg, 0.37552 mmol) and DCM (2 mL) at room temperature. Then a solution of Dess Martin reagent (240 mg, 0.5659 mmol) in 2 ml of DCM was added. The mixture was reacted for 4 h under ice bath. The reaction was quenched with saturated Na₂S₂O₂ (20 mL). The mixture was extracted with DCM (30 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo at room temperature to give a pale yellow viscous solid, which was used in the next step directly without further purification. The yield was calculated as 100%.

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(pyridin-3-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added sequentially 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 25 mg, 0.05237 mmol), 3-(pyridin-3-yl)propynyl aldehyde (10 mg, 0.076260 mmol), DCM (2 mL) and sodium triacetylborohydride (45 mg, 0.21232 mmol). The mixture was reacted overnight. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=100/0-100/3) to give a white solid 8 mg (the yield was 29.4%), which was the target product. LC-MS(ESI): m/z=520.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.65 (s, 1H), 8.52 (d, 1H), 8.40 (d, J=2.2 Hz, 1H), 8.22 (s, 1H), 8.16 (d, J=1.9 Hz, 1H), 7.78 (dd, J=8.8, 2.4 Hz, 1H), 7.71 (d, J=7.9 Hz, 1H), 7.25-7.20 (m, 1H), 7.16 (d, J=1.9 Hz, 1H), 6.71 (d, J=8.8 Hz, 1H), 4.01 (d, J=4.9 Hz, 2H), 3.91-3.85 (m, 4H), 3.79-3.59 (m, 3H), 3.56 (s, 2H), 2.85-2.75 (m, 1H), 2.06-1.97 (m, 1H), 1.40 (s, 6H). HPLC: 95.90%.

Example 364: 6-(2-hydroxy-2-methyl-propoxy)-4-(6-(4-(3-(pyridin-2-yl)prop-2-ynyl) piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(2-pyridyl)prop-2-yn-1-ol

To a 25 mL two-necked flask were added CuI (60 mg, 0.315 mmol) and PdCl₂(PPh₃)₂ (222 mg, 0.316 mmol) at room temperature. The reaction mixture was degassed and refilled with nitrogen. Then triethylamine (9.5 mL, 68 mmol), propynyl alcohol (0.744 mL, 12.7 mmol) and 2-bromopyridine (0.6 mL, 6 mmol) were added. The mixture was reacted at 50° C. overnight. TLC showed the reaction was completed. The reaction solution was concentrated in vacuo, washed with 15 mL of saturated ammonium chloride, extracted with EA (40 mL×2), and filtered by suction.

The solid was washed with EA (10 mL×3). The combined organic phases were washed with saturated saline (15 mL×2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=3:1-1:1) to give a yellow-white product 0.664 g (the yield was 80%), which was the target product. LC-MS(ES-API): m/z=134.25 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.56 (d, J=4.3 Hz, 1H), 7.66 (td, J=7.8, 1.7 Hz, 1H), 7.43 (d, J=7.8 Hz, 1H), 7.24 (dd, J=4.6, 3.0 Hz, 1H), 4.53 (s, 2H), 2.63 (s, 1H).

Step 2: 2-(3-bromoprop-1-ynyl)pyridine

10-(2-Pyridyl)prop-2-yn-1-ol (100 mg, 0.225 mmol) was dissolved in DCM (3 mL) in a 25 mL single-necked flask at 0° C., then PBr₃ (0.141 mL, 0.45 mmol) was slowly added. The mixture was continuously reacted at this temperature. TLC showed the reaction was completed. The reaction was quenched by the addition of water (5 mL) slowly. Saturated potassium carbonate solution (15 mL) was added dropwise to adjust the pH to alkaline. The mixture was extracted with DCM (30 mL×2) and saturated brine (20 mL), then dried over anhydrous sodium sulfate. The resulting mixture was filtered and concentrated in vacuo, which was directly used for the next step. The yield was calculated as 100%.

Step 3: 6-(2-hydroxy-2-methyl-propoxy)-4-(6-(4-(3-(pyridin-2-yl)prop-2-ynyl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol) and K₂CO₃ (18.3 mg, 0.131 mmol), and DMF (2 mL) was added to dissolve the solids. Then 2-(3-bromoprop-1-ynyl)pyridine (25 mg, 0.128 mmol) was added. The mixture was stirred for reaction at room temperature. After TLC showed the reaction was completed, the mixture was quenched with water (9 mL) and extracted with EA (20 mL×2). The organic phases were washed with saturated saline (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=20:1) to give a yellow-white solid 0.011 g (the yield was 67%), which was the target product. LC-MS(ES-API): [M+H]⁺=508.2. ¹H NMR (400 MHz, CDCl₃) δ 8.56 (s, 1H), 8.34 (d, J=2.4 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.72 (dd, J=8.8, 2.5 Hz, 1H), 7.64 (t, J=7.7 Hz, 1H), 7.45 (d, J=7.8 Hz, 1H), 7.22 (d, J=6.3 Hz, 1H), 7.14 (d, J=2.0 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 3.86 (s, 2H), 3.78-3.68 (m, 4H), 3.66 (s, 2H), 2.90-2.62 (m, 4H), 2.01 (s, 1H), 1.39 (s, 6H). HPLC: 88.56%.

Example 365: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(pyridin-2-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 2-(3-bromopropan-1-yn-1-yl)pyridine

To a 25 mL single-necked flask were sequentially added 3-(pyridin-2-yl)prop-2-yn-1-ol (21 mg, 0.16 mmol) and DCM (5 mL) at −5° C., then PBr₃ (0.04 mL, 0.40 mmol) was added slowly. After 5 min of addition, the mixture was reacted at −5° C. for 2 h. To the reaction solution was slowly added 10 mL of 5% K₂CO₃ solution, and the organic phases were collected. The aqueous phase was extracted with DCM (10 mL×2). The organic phases were combined, dried over sodium sulfate, filtered, and concentrated in vacuo, which was directly used for the next reaction in equivalent amounts. LC-MS(ESI-MS): m/z=196.1, 198.1 [M+H]⁺.

Step 2: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(pyridin-2-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 4-(6-(3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 5 mg, 0.011 mmol), DMF (2 mL), K₂CO₃ (16 mg, 0.12 mmol) and 2-(3-bromopropan-1-yn-1-yl)pyridine (29 mg, 0.15 mmol). The mixture was reacted at 40° C. overnight. The reaction solution was added with EA (10 mL), washed with water (5 mL×4), and the combined aqueous phases were extracted with EA (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM/MeOH=30:1) to give a pale yellow solid 4 mg (yield: 65%) as the target product. LC-MS(ESI-MS): m/z=520.2 [M+H]⁺. HPLC: 90.90%.

Example 366: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(5-methoxypyridin-3-yl)prop-2-yn-1-yl) piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-methoxypyridin-3-yl)prop-2-yn-1-ol

To a two-necked flask under nitrogen were added 3-bromo-5-methoxy-pyridine (600 mg, 3.2 mmol), PdCl₂(PPh₃)₂(224 mg, 0.32 mmol) and copper iodide (122 mg, 0.64 mmol), which were dissolved by adding 5 mL of TEA. Then prop-2-yn-1-ol (0.23 mL, 4.0 mmol) was added with stirring, and the mixture was reacted in an oil bath at 70° C. for heating. After the reaction was completed, the reaction mixture was filtered by suction through a celite pad. The filter cake was washed with a small amount of EA, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:5-1:2) to give a white solid 233 mg as the desired product. ¹H-NMR (400 MHz, CDCl₃) δ 8.34 (d, J=1.0 Hz, 1H), 8.23 (d, J=2.7 Hz, 1H), 7.23 (s, 1H), 4.50 (s, 2H), 3.84 (s, 3H), 3.08 (s, 1H).

Step 2: 3-(3-bromoprop-1-yn-1-yl)-5-methoxypyridine

3-(5-Methoxypyridin-3-yl)prop-2-yn-1-ol (60 mg, 0.37 mmol) was dissolved in 2 mL of DCM in a single-necked flask at 0° C., and PBr₃ (10 mg, 0.037 mmol) was added dropwise with stirring. After the addition, the mixture was continuously stirred at this temperature. After the raw materials were consumed completely monitored by TLC, the reaction mixture was added with saturated sodium bicarbonate with stirring to adjust the pH of the aqueous phase to 8. The resulting mixture was diluted with DCM (10 mL), and the organic phase was separated, washed with water (5 mL) once, dried over anhydrous sodium sulfate, concentrated in vacuo to remove part of DCM to obtain a thick material, which was directly used for the next reaction and was calculated according to the theoretical yield.

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(5-methoxypyridin-3-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol) and K₂CO₃ (14 mg, 0.10 mmol), which were dissolved by adding DMF (2 mL). The reaction solution was transferred to 0° C., and 3-(3-bromoprop-1-ynyl)-5-methoxy-pyridine (11 mg, 0.049 mmol) was added with stirring. After the addition, the mixture was reacted continuously at this temperature. After the reaction was completed, the reaction mixture was added with water (10 mL) and extracted with EA (30 mL×2). The organic phases were washed with water (10 mL×2) and saturated saline (10 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent MeOH:DCM=1:50-1:30) to give an off-white solid 1.5 mg as the target product. Rf=0.3(DCM:MeOH=20:1). LC-MS: m/z=538.20[M+H]⁺. ¹H-NMR (400 MHz, CDCl₃) δ 8.35 (d, J=2.3 Hz, 1H), 8.28 (s, 1H), 8.24 (s, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.72 (dd, J=8.8, 2.5 Hz, 1H), 7.35 (d, J=2.3 Hz, 1H), 7.14 (d, J=2.1 Hz, 1H), 6.79 (d, J=8.8 Hz, 1H), 3.86 (s, 2H), 3.85 (s, 3H), 3.76-3.73 (m, 4H), 3.63 (s, 2H), 2.81-2.77 (m, 4H), 1.28 (s, 6H).

Example 367: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(pyridin-3-yl)prop-2-yn-1-yl) piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(3-pyridyl)prop-2-yn-1-ol

To a 25 mL two-necked flask were added CuI (72 mg, 0.378 mmol) and PdCl₂(PPh₃)₂ (270 mg, 0.385 mmol) at room temperature. The reaction mixture was degassed and refilled with nitrogen. Then triethylamine (11 mL, 78.9 mmol), propynyl alcohol (0.89 mL, 15 mmol) and 3-bromopyridine (0.73 mL, 7.6 mmol) were added. The mixture was reacted at 50° C. overnight. TLC showed the reaction was completed. The mixture was quenched with saturated ammonium chloride (20 mL) and filtered by suction. The filter cake was washed with 40 mL of EA. The organic phase was separated, and then the aqueous phase was extracted with EA (40 mL×2). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent PE:EA=3:1-1:1) to give a brownish yellow solid 0.705 g (the yield was 70%), which was the target product. LC-MS(ES-API): m/z=134.20 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.76 (d, J=1.3 Hz, 1H), 8.51 (dd, J=4.9, 1.5 Hz, 1H), 7.73 (dt, J=7.9, 1.8 Hz, 1H), 7.31-7.26 (m, 1H), 4.50 (s, 2H), 3.72 (s, 1H).

Step 2: 3-(3-bromoprop-1-ynyl)pyridine

3-(3-Pyridyl)prop-2-yn-1-ol (200 mg, 1.502 mmol) was dissolved in DCM (15 mL) in a 25 mL single-necked flask at 0° C., then PBr₃ (0.282 mL, 3.00 mmol) was slowly added. The mixture was reacted at this temperature. TLC showed the reaction was completed. The reaction was quenched by the addition of water (5 mL) slowly, and saturated potassium carbonate solution was added dropwise to adjust the pH to alkaline. The mixture was extracted with DCM (20 mL×2) and saturated brine (15 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, which was directly used in the next step. The yield was calculated as 100%.

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(pyridin-3-yl)prop-2-yn-1-yl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol), K₂CO₃ (18.3 mg, 0.131 mmol) and 3-(3-bromoprop-1-ynyl)pyridine (25 mg, 0.128 mmol), which was dissolved by adding DMF (1.5 mL). The mixture was stirred for reaction at room temperature overnight. The mixture was quenched with water (9 mL) and extracted with EA (20 mL×2). The organic phases were washed with saturated saline (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The mixture was purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=25:1) to give a yellow-white solid 8.9 mg (the yield was 54%), which was the target product. LC-MS(ES-API): m/z=508.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.68 (s, 1H), 8.53 (s, 1H), 8.34 (d, J=2.2 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.77-7.69 (m, 2H), 7.14 (d, J=2.0 Hz, 1H), 6.83 (d, J=7.7 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 3.85 (s, 2H), 3.80-3.68 (m, 4H), 3.63 (s, 2H), 2.86-2.68 (m, 4H), 1.39 (s, 6H). HPLC: 96.21%.

Example 368: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-phenylprop-2-yn-1-yl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-phenylpropan-2-yn-1-ol

To a 50 mL two-necked bottle were sequentially added bistriphenylphosphine palladium dichloride (209 mg, 0.294783 mmol) and cuprous iodide (112 mg, 0.58809 mmol). The reaction mixture was degassed and refilled with nitrogen. triethylamine (20 mL), iodobenzene (1.64 mL, 14.7 mmol) and prop-2-yn-1-ol (1.71 mL, 29.4 mmol) were then added. The mixture was stirred at room temperature for 12 h. The reaction mixture was filtered, then washed with EA (100 mL). The filtrate was concentrated in vacuo, and purified by silica gel column chromatography (PE:EA=50:1-20:1) to give pale yellow oil 1.94 g as the target product (yield: 99.8%), Rf=0.5 (PE:EA=20:1). ¹H NMR (600 MHz, CDCl₃) δ 7.47-7.41 (m, 2H), 7.35-7.28 (m, 3H), 4.50 (d, J=3.8 Hz, 2H), 1.96 (s, 1H).

Step 2: (3-bromoprop-1-yn-1-yl)benzene

3-Phenylprop-2-yn-1-ol (50 mg, 0.37833 mmol) was dissolved in DCM (4 mL) at 0° C., and phosphorus tribromide (0.1 mL, 1 mmol) was slowly added. The mixture was reacted at 0° C. for 6 h. The reaction was quenched by the addition of water. The mixture was added with saturated potassium carbonate to adjust pH to alkaline, extracted with DCM (20 mL×2) and concentrated in vacuo to 4 mL, which was directly used for the next step. The yield was calculated as 100%.

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-phenylprop-2-yn-1-yl)piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

6-(2-Hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.03223 mmol) was dissolved in DMF (1 mL). Potassium carbonate (18 mg, 0.128940 mmol) was added, then a solution of 3-bromoprop-1-ynylbenzene (0.18 mg, 0.00092 mmol) in DCM (1 mL) was added. The mixture was reacted at rt overnight. The reaction mixture was added with water (10 mL) and extracted with EA (20 mL). The organic layers were washed with water (5 mL×2), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=0-100:3.5) to give a yellow solid 13 mg as the target product (the yield was 79.62%). LC-MS: m/z=507.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.37 (d, J=2.4 Hz, 1H), 8.22 (s, 1H), 8.18 (d, J=1.9 Hz, 1H), 7.75 (dd, J=8.8, 2.4 Hz, 1H), 7.47 (dd, J=6.4, 2.9 Hz, 2H), 7.37 (d, J=2.3 Hz, 1H), 7.34-7.31 (m, 2H), 7.16 (d, J=1.9 Hz, 1H), 6.81 (d, J=8.9 Hz, 1H), 3.88 (s, 2H), 3.77 (s, 4H), 3.67 (s, 1H), 3.65 (s, 2H), 2.83 (s, 4H), 1.31 (s, 6H). HPLC: 98.75%.

Example 369: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-phenylprop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-[6-(3,6-Diazabicyclo[3.1.1]heptan-3-yl)-3-pyridyl]-6-(2-hydroxy-2-methyl-propoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.03142 mmol) and 3-phenylprop-2-ynaldehyde (12 mg, 0.138 mmol) were dissolved in DCE (2 mL) in a single-necked flask, then sodium triacetoxyborohydride (19 mg, 0.086959 mmol) was added. The mixture was stirred at room temperature overnight. The reaction solution was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM:MeOH=0-100:3.5) to give a pale yellow solid 8 mg (the yield was 49.10%), which was the target product. Rf=0.5(DCM/MeOH=10:1). LC-MS: m/z=519.2 [M+H]⁺, HPLC: 96.76%. H NMR (400 MHz, CDCl₃) δ 8.42 (d, J=2.2 Hz, 1H), 8.24 (s, 1H), 8.18 (d, J=2.0 Hz, 1H), 7.80 (dd, J=8.8, 2.5 Hz, 1H), 7.45 (dd, J=6.6, 3.0 Hz, 2H), 7.35-7.29 (m, 3H), 7.18 (d, J=2.1 Hz, 1H), 6.72 (d, J=8.8 Hz, 1H), 3.98 (d, J=5.4 Hz, 2H), 3.93-3.83 (m, 4H), 3.72-3.62 (m, 2H), 3.53 (s, 2H), 2.79-2.76 (m, 1H), 2.29-2.19 (m, 1H), 1.42 (s, 6H).

Example 370: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(4-methoxyphenyl)prop-2-yn-1-yl) piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(4-methoxyphenyl)prop-2-yn-1-ol

To a 25 mL three-necked flask under nitrogen were sequentially added 4-iodoanisole (2.5 g, 11 mmol), cuprous iodide (0.24 g, 1.3 mmol) and bistriphenylphosphine palladium dichloride (0.22 g, 0.31 mmol), which were dissolved by adding triethylamine (25 mL). Then propargyl alcohol (0.93 mL, 16 mmol) was added dropwise at 0° C. After the dropwise addition, the mixture was reacted at this temperature. The completion of reaction was monitored by TLC. The mixture was filtered through a celite pad. The filter cake was washed with EA (50 mL), filtered, concentrated in vacuo, and then purified by silica gel column chromatography (eluent: PE/EA=20:1-10:1) to give a yellow solid 1.56 g as the target product (yield: 90.0%, Rf=0.1 (PE/EA=20/1)). ¹H NMR (400 MHz, CDCl₃) δ 7.38 (d, J=8.8 Hz, 2H), 6.84 (d, J=8.8 Hz, 2H), 4.48 (s, 2H), 3.81 (s, 3H).

Step 2: 3-(4-methoxyphenyl)propiolaldehyde

To a 50 mL single-necked flask were sequentially added 3-(4-methoxyphenyl)prop-2-yn-1-ol (600 mg, 3.6996 mmol), Dess Martin reagent (2.1 g, 5.0 mmol), sodium bicarbonate (1.6 g, 19 mmol) and dichloromethane solution (30 mL). The mixture was stirred at room temperature overnight. The reaction mixture was quenched with saturated sodium thiosulfate solution (50 mL). After static stratification, the organic phase was separated, and the aqueous phase was extracted with DCM (100 ml×2). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE/EA=15:1) to give yellow liquid 510 mg, which was the target product (yield: 86.067%, Rf=0.7 (PE/EA=8/1)). ¹H NMR (400 MHz, CDCl₃) δ 9.39 (s, 1H), 7.62-7.52 (m, 2H), 6.92 (d, J=8.9 Hz, 2H), 3.85 (s, 3H).

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-(3-(4-methoxyphenyl)prop-2-yn-1-yl) piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were sequentially added 6-(1-methyl-1H-pyrazol-4-yl)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.0322 mmol), STAB (23 mg, 0.1085 mmol), DCE (2 mL) and 3-(4-methoxyphenyl)propiolaldehyde (25 mg, 0.156 mmol). The mixture was stirred at room temperature overnight. The reaction solution was filtered. The mother liquor was concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM/MeOH=50/1-30/1) to give a yellow solid 10.2 mg, which was the target product. (Rf=0.15, DCM/MeOH=50/1). LC-MS(ES-API): m/z=537.20 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.34 (d, J=2.3 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 7.72 (dd, J=8.8, 2.5 Hz, 1H), 7.38 (d, J=8.6 Hz, 2H), 7.14 (d, J=1.9 Hz, 1H), 6.83 (d, J=8.7 Hz, 2H), 6.78 (d, J=8.9 Hz, 1H), 3.86 (s, 2H), 3.80 (s, 3H), 3.76-3.71 (m, 4H), 3.58 (s, 2H), 2.81-2.74 (m, 4H), 1.39 (s, 6H). HPLC: 93.73%.

Example 371: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(pyridin-4-yl)prop-2-yn-1-yl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(pyridin-4-yl)prop-2-yn-1-ol

4-Iodopyridine (1.00 g, 4.88 mmol), PdCl₂(PPh₃)₂(0.34 g, 0.48 mmol), CuI (93 mg, 0.48832 mmol) and PPh₃ (128 mg, 0.48801 mmol) were dissolved in THE (15 mL) under N₂ at room temperature, then propargyl alcohol (0.55 g, 9.8 mmol) and Et3N (0.99 g, 9.8 mmol) were added. The mixture was reacted with stirring at room temperature for 5.5 h. The reaction was quenched with saturated NH₄Cl. The resulting mixture was extracted with EA (10 mL×3), washed with water (10 mL), dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo and then purified by silica gel column chromatography (eluent PE/EA=10/1-3/1) to give a yellow-brown solid 0.52 g as the target product. LC-MS: m/z=134.1[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.59 (s, 2H), 7.34-7.27 (m, 2H), 4.53 (s, 2H).

Step 2: 4-(3-bromopropan-1-yn-1-yl)pyridine

3-(4-Pyridyl)prop-2-yn-1-ol (100 mg, 0.75103 mmol) was dissolved in dichloromethane (6 mL) at 0° C., and phosphorus tribromide (0.141 mL, 1.50 mmol) was slowly added. The mixture was reacted at 0° C. for 1 h. The reaction was quenched by the addition of water (5 mL). The mixture was added with saturated potassium carbonate to adjust pH to alkaline, extracted with DCM (50 mL×2) and concentrated in vacuo to 4 mL, which was directly used for the next step. The yield was calculated as 100%. LC-MS: m/z=196.1 [M+H]⁺.

Step 3: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(3-(pyridin-4-yl)prop-2-yn-1-yl)-3,6-diazabicyclo [3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

4-(6-(3,6-Diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile dihydrochloride (see synthesis of intermediate 3, 15 mg, 0.03142 mmol) was dissolved in DMF (0.5 mL) in a single-necked flask. Potassium carbonate (17 mg, 0.121777 mmol) was added, then a solution of 4-(3-bromoprop-1-ynyl)pyridine (0.18 mg, 0.00092 mmol) in dichloromethane was added. The mixture was stirred for reaction at rt overnight. The mixture was extracted with ethyl acetate (50 mL), washed with water (5 mL×2) and saturated brine (5 mL) respectively, concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=0-100/3.5) to give a pale yellow solid (3 mg, 0.005774 mmol). The yield was 18.38%. Rf=0.4(DCM/MeOH=30/1). LC-MS: m/z=520.0 [M+H]⁺. HPLC: 92.03%. ¹H NMR (400 MHz, CDCl₃) δ 8.54 (d, J=5.7 Hz, 2H), 8.40 (s, 1H), 8.22 (s, 1H), 8.16 (s, 1H), 7.78 (d, J=6.0 Hz, 1H), 7.28 (s, 2H), 7.15 (s, 1H), 6.70 (d, J=8.7 Hz, 1H), 5.34 (s, 1H), 3.94 (d, J=5.7 Hz, 2H), 3.86 (d, J=14.6 Hz, 4H), 3.64 (s, 4H), 3.52 (s, 2H), 1.40 (s, 6H).

Example 372: 4-(6-(4-(3-(5-fluoropyridin-3-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-fluoropyridin-3-yl)prop-2-yn-1-ol

To a 25 mL two-necked flask were added 3-bromo-5-fluoropyridine (300 mg, 1.704 mmol), cuprous iodide (35 mg, 0.18 mmol), PdCl₂(PPh₃)₂(60 mg, 0.085 mmol) at room temperature. The reaction mixture was degassed and refilled with nitrogen. Then triethylamine (3 mL, 21.5 mmol) and prop-2-yn-1-ol (0.2 mL, 3 mmol) were added. The mixture was reacted at 60° C. overnight. The reaction mixture was added with EA (40 mL) and saturated ammonium chloride solution (20 mL), and then filtered by suction. The filter cake was washed with EA (20 mL). The combined organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=3/1-1/1) to give a pale yellow solid 89 mg (yield 34.54%) as the desired product. ¹H NMR (400 MHz, CDCl₃) δ 8.51 (s, 1H), 8.41 (d, J=2.6 Hz, 1H), 7.44 (d, J=8.2 Hz, 1H), 4.51 (s, 2H), 2.47 (s, 1H).

Step 2: 3-(3-bromopropan-1-yn-1-yl)-5-fluoropyridine

3-(5-Fluoropyridin-3-yl)prop-2-yn-1-ol (80 mg, 0.53 mmol) was dissolved in DCM (2 mL) at 0° C., and then PBr₃ (0.1 mL, 1 mmol) was added slowly. The mixture was stirred for reaction at low temperature for 2 h. The reaction was stopped and quenched with water (10 mL). Saturated NaHCO₃ solution was added to adjust the pH to alkaline. The mixture was extracted with DCM (20 mL×3), washed with water, dried over anhydrous sodium sulfate, concentrated in vacuo at 30° C. to give a pale yellow concentrate, which was used in the next step directly without further purification.

Step 3: 4-(6-(4-(3-(5-fluoropyridin-3-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbo nitrile dihydrochloride (see synthesis of intermediate 7, 20 mg, 0.04297 mmol), 3-(3-bromoprop-1-yn-1-yl)-5-fluoropyridine (19 mg, 0.088773 mmol), DMF (2 mL) and potassium carbonate (0.024 g, 0.17 mmol). The mixture was reacted overnight at room temperature. The reaction mixture were added with EA (20 mL) and water (20 mL). The aqueous layer was separated and extracted with EA (20 mL). The combined organic phases were washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=100/0-100/3) to give a light red solid 5 mg (yield: 22.14%) as the desired product. LC-MS: m/z=526.3 [M+H]; ¹H NMR (400 MHz, CDCl₃) δ 8.49 (s, 1H), 8.40 (s, 1H), 8.35 (d, 1H), 8.20 (s, 1H), 8.15 (d, 1H), 7.73 (dd, 1H), 7.48-7.43 (m, 1H), 7.14 (d, 1H), 6.79 (d, 1H), 3.86 (s, 2H), 3.77-3.72 (m, 4H), 3.69 (s, 1H), 3.64 (s, 2H), 2.81-2.75 (m, 4H), 1.39 (s, 6H). HPLC: 94.13%.

Example 373: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-hydroxy-4-(propan-2-yn-1-yl)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-hydroxy-4-(3-(trimethylsilyl)prop-2-yn-1-yl)piperidine-1-carboxylate

To a two-necked flask was added CeCl₃ (2 g, 8.1146 mmol), then THE (16 mL) was added by injection under nitrogen. The mixture was stirred at room temperature for 1 h and ready for use. To the other two-necked flask under nitrogen were added trimethyl(prop-1-ynyl)silane (0.9 g, 8 mmol) and THF (16 mL) with a syringe. After the mixture was dropped to −78° C., n-BuLi (3.2 mL, 8.0 mmol, 2.5 mol/L) was slowly added with a syringe. The reaction solution was reacted at −78° C. for 1 h and ready for use. After 1 h, the CeCl₃ solution was slowly added to the above reaction solution at −78° C., and the mixed solution was further reacted at −78° C. for 1.5 h and ready for use. To the other two-necked flask was added tert-butyl 4-oxopiperidine-1-carboxylate (800 mg, 4.0151 mmol) was added, and THE (5.8 mL) was added by injection under nitrogen. After completely dissolved, the mixture was slowly added to the above mixed solution with a syringe. The mixture was reacted at −78° C. for 2 h, and the reaction was monitored by TLC. After the reaction was completed, a saturated ammonium chloride solution (20 mL) was added, and the mixture was removed at −78° C. and stirred at room temperature overnight. The resulting mixture was added with 1M diluted hydrochloric acid (9.5 mL) and EA (16 mL). After stirring for 5 min, the mixture was filtered through a celite pad. The filtrate was separated and the aqueous phase was extracted with EA (30 mL). The organic phases were combined, dried over anhydrous sodium sulfate and then purified by silica gel column chromatography (PE/EA=100/2-100/6) to give a white solid 555 mg. LC-MS: m/z=256.2[m+1-Bu]⁺. ¹H-NMR (400 MHz, MeOD) δ 4.46 (s, 2H), 3.80-3.71 (m, 2H), 3.18 (s, 2H), 1.78-1.65 (m, 4H), 1.46 (s, 9H), 0.17 (s, 9H).

Step 2: tert-butyl 4-hydroxy-4-(prop-2-yn-1-yl)piperidine-1-carboxylate

To a 50 mL single-necked flask were sequentially added tert-butyl 4-hydroxy-4-(3-(trimethylsilyl)prop-2-yn-1-yl)piperidine-1-carboxylate (550 mg, 1.766 mmol), MeOH (18 mL) and K₂CO₃ (0.3 g, 2 mmol). The mixture was stirred for reaction at room temperature and monitored by TLC. After completion of the reaction, the mixture was concentrated in vacuo and then purified by silica gel column chromatography (PE/EA=5/1-2/1) to give colorless oily liquid 400 mg.

Step 3: 4-(prop-2-yn-1-yl)piperidin-4-ol hydrochloride

To a 100 mL single-necked flask were sequentially added tert-butyl 4-ethynyl-4-hydroxypiperidine-1-carboxylate (400 mg, 1.672 mmol) and HCl/MeOH (25 mL, 100 mmol, 4 mol/L). The mixture was stirred at room temperature overnight. The reaction solution was concentrated in vacuo to give pale yellow oil 240 mg, which was used in the next step according to the theoretical yield without further purification. The yield was calculated as 100%. Rf=0.01 (PE:EA=4:1).

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-hydroxy-4-(propan-2-yn-1-yl)piperidin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL microwave tube were added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 25 mg, 0.07662 mmol) and 4-(prop-2-yn-1-yl)piperidin-4-ol hydrochloride (26 mg, 0.14801 mmol), then DMSO (1.5 mL) was added. After the mixture was dissolved, DIPEA (0.1 mL, 0.6 mmol, 100 mass %) was added, and the mixture was reacted under microwave (temperature 135° C., pressure 10 bar) for 5 h. The completion of reaction was monitored by TLC. Then the reaction solution was diluted with 10 mL of water and extracted with EA (30 mL×3). The organic phases were combined and washed with 30 mL of saturated saline once, dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=100:1-30:1) to give a light yellow solid 12 mg. The yield was 12.10% (the reaction was not optimized). Rf=0.2 (DCM/MeOH=30:1). LC-MS: m/z=446.20 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.33 (d, J=2.0 Hz, 1H), 8.19 (s, 1H), 8.15 (d, J=1.7 Hz, 1H), 7.70 (dd, J=8.8, 2.4 Hz, 1H), 7.14 (d, J=1.7 Hz, 1H), 6.80 (d, J=8.8 Hz, 1H), 4.11-4.04 (m, 2H), 3.86 (s, 2H), 3.54-3.48 (m, 2H), 2.57 (s, 1H), 2.14 (s, 2H), 2.06-2.03 (m, 2H), 1.88-1.85 (m, 2H), 1.39 (s, 6H). HPLC: 93.33%.

Example 374: 4-(6-(4-(3-(5-fluoropyridin-2-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(5-fluoropyridin-2-yl)prop-2-yn-1-ol

To a 50 mL two-necked flask were sequentially added 2-bromo-5-fluoro-pyridine (570 mg, 3.2388 mmol), Pd(PPh₃)₂Cl₂ (114 mg, 0.160791 mmol) and CuI (24 mg, 0.12602 mmol). The reaction mixture was degassed and refilled with nitrogen, and then prop-2-yn-1-ol (0.33 mL, 5.7 mmol) and triethylamine (3 mL) were added. The resulting mixture was reacted at room temperature overnight. The reaction mixture was filtered, then washed with EA (100 mL). The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=50:1-20:1) to give a pale yellow solid 435 mg as the target product (yield: 88.863%). (RF=0.2, PE/EA=5/1). LC-MS: m/z=152.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.43 (d, J=2.7 Hz, 1H), 7.46 (dd, J=8.6, 4.5 Hz, 1H), 7.39 (td, J=8.2, 2.8 Hz, 1H), 4.52 (s, 2H), 2.76 (s, 1H).

Step 2: 2-(3-bromoprop-1-yn-1-yl)-5-fluoropyridine

3-(5-Fluoro-2-pyridinyl)prop-2-yn-1-ol (120 mg, 0.79397 mmol) was dissolved in dichloromethane (6 mL) at 0° C., and phosphorus tribromide (0.15 mL, 1.6 mmol) was slowly added. The mixture was reacted at low temperature for 1 h. The reaction was quenched by the addition of water (20 mL) slowly. The mixture was added with saturated potassium carbonate to adjust pH to alkaline, extracted with DCM (50 mL) and concentrated in vacuo to 4 mL, which was directly used for the next step. The yield was calculated as 100%.

Step 3: 4-(6-(4-(3-(5-fluoropyridin-2-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

6-(2-Hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyri dine-3-carbonitrile dihydrochloride (see synthesis of intermediate 7, 15 mg, 0.032 mmol) was dissolved in DMF (0.5 mL) in a single-necked flask. Then potassium carbonate (17 mg, 0.122 mmol) and a solution of 2-(3-bromoprop-1-ynyl)-5-fluoropyridine (0.18 mg, 0.00084 mmol) in DCM were added. The mixture was reacted at rt overnight. The reaction mixture was extracted with EA (20 mL) and washed with water (5 mL×3). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=0-100:3.5) to give a pale yellow solid 7.0 mg as the target product (the yield was 41.32%). Rf=0.5 (DCM/MeOH=30/1). LC-MS: m/z=526.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ=8.44 (d, J=2.6 Hz, 1H), 8.36 (d, J=2.2 Hz, 1H), 8.22 (s, 1H), 8.18 (d, J=2.0 Hz, 1H), 7.74 (dd, J=8.8, 2.5 Hz, 1H), 7.49 (dd, J=8.6, 4.4 Hz, 1H), 7.43-7.35 (m, 2H), 7.16 (d, J=2.0 Hz, 1H), 6.80 (d, J=8.9 Hz, 1H), 3.88 (s, 2H), 3.76 (s, 4H), 3.68 (s, 2H), 3.66 (s, 1H), 2.84 (s, 4H), 1.31 (s, 6H). HPLC: 91.63%.

Example 375: 4-(6-(4-(3-(3-(3-fluoropyridin-2-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 3-(3-fluoropyridin-2-yl)prop-2-yn-1-ol

To a 50 mL two-necked flask under N₂ were sequentially added PdCl₂(PPh₃)₂(180 mg, 0.26 mmol), CuI (136 mg, 0.71 mmol), 2-bromo-3-fluoro-pyridine (830 mg, 4.72 mmol), TEA (12 mL) and propargyl alcohol (0.35 mL, 6.0 mmol). The mixture was stirred and heated for reaction for 6 h in a 60° C. oil bath. After the reaction mixture was cooled, water (25 mL) was added, and the resulting mixture was extracted with EA (25 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE/EA=1/1) to give a yellow-white solid 600 mg as the target product (yield 84%). LC-MS(ESI-MS): m/z=152.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.39 (m, 1H), 7.43 (td, J=8.5, 1.0 Hz, 1H), 7.29 (m, 1H), 4.57 (d, J=5.1 Hz, 2H), 2.82 (t, J=5.6 Hz, 1H).

Step 2: 2-(3-bromopropan-1-yn-1-yl)-3-fluoropyridine

To a 25 mL single-necked flask were sequentially added 3-(3-fluoropyridin-2-yl)prop-2-yn-1-ol (91 mg, 0.60 mmol) and DCM (6 mL), then PBr₃ (0.11 mL, 1.2 mmol) was added slowly at −10° C. After 20 min of addition, the mixture was continuously stirring for 1.5 h. To the reaction solution was slowly added 20 mL of 5% K₂CO₃ aqueous solution. The aqueous phase was extracted with DCM (30 mL×3). The organic phases were combined, dried over sodium sulfate, filtered, and concentrated in vacuo, which was directly used for the next reaction in equivalent amounts. LC-MS(ESI-MS): m/z=214.0, 216.0 [M+H]⁺.

Step 3: 4-(6-(4-(3-(3-(3-fluoropyridin-2-yl)prop-2-yn-1-yl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(piperazin-1-yl)pyridin-3-yl)pyrazole[1,5-a]pyridine-3-carbonitrile hydrochloride (see synthesis of intermediate 7, 25 mg, 0.058 mmol), DMF (2 mL), K₂CO₃ (30 mg, 0.22 mmol) and 2-(3-bromopropan-1-yn-1-yl)-3-fluoropyridine (60 mg, 0.28 mmol). The mixture was stirred for reaction at rt overnight. The reaction solution was added with EA (20 mL), washed with water (8 mL×3), and the combined aqueous phases were extracted with EA (15 mL). The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent DCM/MeOH=20:1) to give a pale yellow solid 13 mg. The yield was 42%. LC-MS(ESI-MS): m/z=526.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.39 (m, 1H), 8.34 (d, J=2.2 Hz, 1H), 8.19 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 7.72 (dd, J=8.8, 2.5 Hz, 1H), 7.42 (td, J=8.6, 1.3 Hz, 1H), 7.28 (m, 1H), 7.14 (d, J=2.0 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 3.86 (s, 2H), 3.75-3.70 (m, 6H), 2.86-2.71 (m, 4H), 1.39 (s, 6H). HPLC: 91.70%.

Example 376: 4-(6-(3-(4-ethynylphenoxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-hydroxyazetidin-1-carboxylate

To a 100 mL single-necked flask were added tert-butyl 3-oxoazetidine-1-carboxylate (2.0 g, 12 mmol) and EtOH (20 mL) at room temperature, then NaBH₄ (0.88 g, 23 mmol) was added portionwise with stirring. After the completion of reaction was monitored by TLC, a saturated ammonium chloride solution was added to the reaction solution until no bubbles were generated, and a large amount of white solid was precipitated. The mixture was filtered with suction. The filter cake was washed with ethanol (10 mL), and the filtrate was concentrated in vacuo to remove most of the ethanol. The mixture was added with 30 mL of water and extracted with EA (100 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 2.0 g as the target product. LC-MS: m/z=118.10[M-t-Bu+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 4.53 (s, 1H), 4.13-4.09 (m, 2H), 3.78 (dd, J=9.9, 4.1 Hz, 2H), 3.54-3.45 (m, 1H), 1.41 (s, 9H).

Step 2: tert-butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate

To a two-necked flask were added tert-butyl 3-hydroxyazetidine-1-carboxylate (500 mg, 2.89 mmol), DCM (15 mL) and NaH (0.14 g, 5.8 mmol) under nitrogen. The mixture was transferred to 0° C. and MsCl (0.25 mL, 3.2 mmol) was added dropwise with stirring. After the addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, water (20 mL) and DCM (50 mL) were added to the reaction mixture. The organic phase was separated, and the aqueous phase was extracted with EA (50 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL), dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo and purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 680 mg as the target product. LC-MS: m/z=196.10[M-t-Bu+H]⁺, m/z=152.10[M-Boc+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 5.18 (tt, J=6.7, 4.2 Hz, 1H), 4.26 (ddd, J=10.3, 6.7, 1.0 Hz, 2H), 4.11-4.04 (m, 2H), 3.05 (s, 3H), 1.43 (s, 9H).

Step 3: tert-butyl 3-(4-iodophenoxy)azetidin-1-carboxylate

P-iodophenol (550 mg, 2.5 mmol) was dissolved in DMF (4 mL) at room temperature, and t-BuOK (320 mg, 2.85 mmol) was added to the solution with stirring. After stirring for 20 min, the temperature was raised to 80° C. tert-Butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate (680 mg, 2.75 mmol) dissolved in DMF (1.5 mL) was added dropwise slowly. After the addition, the mixture was kept at this temperature with stirring. After the completion of reaction was monitored by TLC, the reaction mixture was poured into water (20 mL). The resulting mixture was extracted with EA (50 mL×2). The combined organic phases were washed with water (20 mL×2) and saturated saline (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and then purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a white solid 615 mg as the target product. LC-MS: m/z=319.9[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.56 (d, J=8.8 Hz, 2H), 6.52 (d, J=8.8 Hz, 2H), 4.83 (ddd, J=10.4, 6.3, 4.1 Hz, 1H), 4.28 (dd, J=9.6, 6.5 Hz, 2H), 3.98 (dd, J=9.7, 4.0 Hz, 2H), 1.44 (s, 9H).

Step 4: 3-(4-iodophenoxy)azetidine hydrochloride

tert-Butyl 3-(4-iodophenoxy)azetidin-1-carboxylate (615 mg, 1.64 mmol) was dissolved in HCl/EA (3 mL, 12 mmol, 4 mol/L) with stirring at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was concentrated in vacuo to give a white solid 510 mg as the target product. ¹H NMR (400 MHz, DMSO-d₆) δ 11.96 (s, 1H), 7.64 (d, J=8.9 Hz, 2H), 6.73 (d, J=8.9 Hz, 2H), 5.11-5.02 (m, 1H), 4.41 (dd, J=12.3, 6.6 Hz, 2H), 3.96 (dd, J=12.3, 4.7 Hz, 2H), 1.91 (s, 1H).

Step 5: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-iodophenoxy)azetidin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(4-fluorophenyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo [1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 48 mg, 0.1471 mmol) in DMSO (2 mL) were added 3-(4-iodophenoxy)azetidine hydrochloride (69 mg, 0.22147 mmol) and DIPEA (0.08 mL, 0.5 mmol) at room temperature. After the addition, the mixture was reacted for 10 h under microwave (100° C., 10 bar, preheating for 30 s). The reaction mixture was added with water (10 mL) and EA (50 mL). The organic layers were separated, washed with saturated brine (10 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give brown liquid 660 mg as the target product (the yield was 70.15%). LC-MS: m/z=582.2 [M+H]⁺.

Step 6: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-(((trimethylsilyl)ethynyl)phenoxy) azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a two-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-iodophenoxy)azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (60 mg, 0.1032 mmol), Pd(PPh₃)₂Cl₂ (1.5 mg, 0.0021 mmol), triethylamine (2 mL) and THE (2 mL). The reaction mixture was degassed and refilled with nitrogen. After stirring for 15 min, cuprous iodide (1.0 mg, 0.0053 mmol) and ethynyl (trimethyl)silane (0.05 mL, 0.4 mmol) were added. The mixture was stirred at room temperature overnight. The reaction mixture was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=0-100/3) to give brown liquid 57 mg as the target product (the yield was 68.5%). (Rf=0.5, DCM/MeOH=20/1). LC-MS: m/z=552.3 [M+H]⁺.

Step 7: 4-(6-(3-(4-ethynylphenoxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-((trimethylsilyl)ethynyl)phenoxy)azetidine-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (57 mg, 0.1033 mmol), potassium carbonate (29 mg, 0.209 mmol) and methanol (3 mL). The mixture was stirred at room temperature for 3 h. The reaction mixture was directly concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=0-10/3) to give a white solid 21 mg as the target product (the yield was 42.39%). (Rf=0.5, DCM/MeOH=20/1). LC-MS: m/z=480.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=1.9 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 7.71 (dd, J=8.6, 2.3 Hz, 1H), 7.46 (d, J=8.7 Hz, 2H), 7.14 (d, J=1.9 Hz, 1H), 6.76 (d, J=8.7 Hz, 2H), 6.46 (d, J=8.6 Hz, 1H), 5.19-5.08 (m, 1H), 4.60-4.49 (m, 2H), 4.19 (dd, J=9.3, 3.8 Hz, 2H), 3.86 (s, 2H), 3.02 (s, 1H), 2.07 (s, 1H), 1.39 (s, 6H). HPLC: 95.09%.

Example 377: (R)-4-(6-(3-(4-ethynylphenoxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl (S)-3-((methylsulfonyl)oxy)pyrrolidine-1-carboxylate

tert-Butyl (3S)-3-hydroxypyrrolidine-1-carboxylate (2.00 g, 10.7 mmol) was dissolved in THF (50 mL) in a double-necked flask under nitrogen, then NaH (0.856 g, 21.4 mmol, 60 mass %) was added. Methanesulfonyl chloride (0.911 mL, 11.8 mmol) was added under ice bath conditions, and the mixture was reacted at room temperature for 4.5 h. The reaction mixture was added with water (10 mL) and EA (100 mL). The organic phase was separated and the aqueous phase was extracted with EA (50 mL×2). The combined organic phases were washed with saturated brine (10 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to give colorless transparent liquid 2.84 g as the target product (the yield was 100%). (Rf=0.4, PE/EA=2/1). LC-MS: m/z=210.2[M-t-Bu+H]⁺.

Step 2: tert-butyl (R)-3-(4-iodophenoxy)pyrrolidine-1-carboxylate

To a single-necked flask were sequentially added tert-butyl (S)-3-(methanesulfonyl)oxypyrrolidine-1-carboxylate (470 mg, 1.7714 mmol), 4-iodophenol (300 mg, 1.3636 mmol), potassium carbonate (565 mg, 4.0880 mmol) and DMF (6 mL). The mixture was stirred at 80° C. overnight. The reaction mixture was added with water (10 mL) and extracted with EA (50 mL). The organic layers were washed with saturated brine (10 mL×2), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE/EA=0-20/1) to give colorless transparent liquid 424 mg as the target product (the yield was 79.89%). LC-MS: m/z=334.0[M-t-Bu+H]⁺. ¹H NMR (600 MHz, CDCl₃) δ 7.61-7.51 (m, 2H), 6.64 (d, J=8.6 Hz, 2H), 4.83 (s, 1H), 3.65-3.55 (m, 2H), 3.54-3.40 (m, 2H), 2.19-2.05 (m, 2H), 1.46 (s, 9H).

Step 3: (R)-3-(4-iodophenoxy)pyrrolidine hydrochloride

tert-Butyl (R)-3-(4-iodophenoxy)pyrrolidine-1-carboxylate (434 mg, 1.115 mmol) was dissolved in EA (2 mL) in a single-necked flask, then a solution of 4M hydrochloric acid in EA (5 mL, 20 mmol) was added. The mixture was stirred at room temperature for 1 h. The reaction mixture was directly concentrated in vacuo to give a khaki solid 363 mg as the target product (the yield was 99.99%). ¹H NMR (400 MHz, DMSO-d₆) δ 9.39 (s, 2H), 7.63 (d, J=8.8 Hz, 2H), 6.83 (d, J=8.8 Hz, 2H), 5.12 (s, 1H), 3.48-3.40 (m, 1H), 3.31-3.27 (m, 2H), 3.27-3.19 (m, 1H), 2.24-2.05 (m, 2H).

Step 4: (R)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-iodophenoxy)pyrrolidin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 50 mg, 0.1532 mmol) in DMSO (2 mL) were added (R)-3-(4-iodophenoxy)pyrrolidine hydrochloride (55 mg, 0.16893 mmol) and DIPEA (0.08 mL, 0.5 mmol) at room temperature. After the addition, the mixture was reacted for 8 h under microwave (100° C., 10 bar, preheating for 30 s). After the reaction was completed, the reaction mixture was cooled to room temperature, added with water (10 mL) and EA (50 mL). The organic layers were washed with saturated brine (6 mL×3), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give yellow liquid 91 mg as the target product (the yield was 99.74%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=596.7 [M+H]⁺.

Step 5: (R)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-(((trimethylsilyl))ethynyl)phenoxy) pyrrolidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a two-necked flask were sequentially added (R)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-iodophenoxy)pyrrolidin-1-yl)-pyridyl-3-yl)pyrazolo [1,5-a]pyridine-3-carbonitrile (92 mg, 0.1545 mmol), Pd(PPh₃)₂Cl₂ (2.2 mg, 0.0031 mmol) and triethylamine (2 mL). The reaction mixture was degassed and refilled with nitrogen. THE (5 mL) was added by injection. After stirring for 15 min, cuprous iodide (1.5 mg, 0.0079 mmol) and ethynyl (trimethyl)silane (0.1 mL, 0.7 mmol) were added. The mixture was stirred at room temperature for 5 h. The reaction mixture was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=0-100/3) to give brown liquid 87.4 mg as the target product (the yield was 100%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=566.9[M+H]⁺.

Step 6: (R)-4-(6-(3-(4-ethynylphenoxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were sequentially added (R)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-(((trimethylsilyl))ethynyl)phenoxy)pyrrolidin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (87 mg, 0.1538 mmol), potassium carbonate (43 mg, 0.31112 mmol) and methanol (3 mL). The mixture was stirred at room temperature overnight. The reaction mixture was directly concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=0-100/3) to give a yellow-white solid 46 mg as the target product (the yield was 60.60%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=494.3 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.32 (s, 1H), 8.20 (s, 1H), 8.15 (s, 1H), 7.71 (dd, J=8.7, 2.0 Hz, 1H), 7.44 (d, J=8.4 Hz, 2H), 7.13 (s, 1H), 6.86 (d, J=8.5 Hz, 2H), 6.54 (d, J=8.7 Hz, 1H), 5.10 (s, 1H), 3.96-3.80 (m, 4H), 3.80-3.65 (m, 2H), 3.01 (s, 1H), 2.62 (s, 1H), 2.47-2.26 (m, 2H), 1.39 (s, 6H). HPLC: 94.84%.

Example 378: 4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(N-Bocpiperidin-4-methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 25 mL single-necked flask were added 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 100 mg, 0.244 mmol), potassium carbonate (158 mg, 1.11 mmol), tert-butyl 4-(bromomethyl)piperidine-1-carboxylate (280 mg, 1.00 mmol) and DMF (3 mL). The mixture was reacted overnight in an oil bath at 90° C. After the reaction was completed, the reaction solution was added with water (20 mL) and extracted with EA (80 mL×2). The organic phases were washed with water (50 mL×5) and saturated saline (50 mL), dried over anhydrous sodium sulfate, concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=50:1) to give a white solid 142 mg as the target product. LC-MS: m/z=606.20[M+H]⁺, ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=1.8 Hz, 1H), 8.22 (d, J=2.7 Hz, 1H), 8.19 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.71 (dd, J=8.6, 2.2 Hz, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.08-7.06 (m, 2H), 6.47 (d, J=8.6 Hz, 1H), 5.18 (s, 1H), 4.55 (dd, J=9.0, 6.6 Hz, 2H), 4.20 (dd, J=9.2, 3.7 Hz, 4H), 3.86 (d, J=6.2 Hz, 2H), 3.10 (s, 1H), 2.76 (m, 2H), 2.09-1.98 (m, 1H), 1.85-1.82 (m, 2H), 1.47 (s, 9H), 1.38-1.32 (m, 2H). HPLC: 98.52%.

Example 379: 6-(2-(dimethylamino)ethoxy)-4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 2-(dim ethyl amino)ethanol

To a 25 mL single-necked flask were sequentially added dimethylamine tetrahydrofuran solution (8 mL, 16.0 mmol, 2.0 mol/L), 2-chloroethanol (1.3 mL, 19 mmol) and toluene (10 mL). The mixture was heated to reflux at 120° C. for 5 h. After the reaction was completed, the reaction solution was slowly returned to room temperature, and no post-treatment was carried out. The yield was calculated by 100%, and the mixture was directly used for the next step.

Step 2: dimethylaminochloroethane hydrochloride

To a 25 mL single-necked flask were sequentially added 2-(dimethylamino)ethanol, then dichlorosulfoxide (2.4 mL, 31 mmol) was slowly added in an ice bath. After the addition, the mixture was returned to room temperature and stirred overnight. After the reaction was completed, the mixture was concentrated in vacuo to remove toluene and dichlorosulfoxide to give viscous oil. A small amount of anhydrous ethanol was added to recrystallize. A white solid precipitated which was filtered while hot to give a white solid as the target product. ¹H NMR (400 MHz, DMSO-d₆) δ 11.27 (s, 1H), 4.02 (t, J=6.8 Hz, 2H), 3.46 (t, J=6.8 Hz, 2H), 2.78 (s, 6H).

Step 3: 6-(2-(dimethylamino)ethoxy)-4-(6-(3-((6-ethynyl-3-yl)oxy)azetidin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 4-(6-(3-((6-ethynylpyridin-3-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 5, 20 mg, 0.049 mmol), potassium carbonate (17 mg, 0.12 mmol), 2-chloro-N,N-dimethyl-ethylamine hydrochloride (10 mg, 0.069 mmol) and DMF (0.4 mL). The mixture was reacted overnight in an oil bath at 90° C. After the reaction was completed, the reaction mixture was added with water (5 mL) and extracted with EA (15 mL×2). The organic phases were washed with water (10 mL×5), dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and then purified by silica gel column chromatography to give a yellow solid 5 mg as the target product. LC-MS: m/z=480.75[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=2.0 Hz, 1H), 8.24-8.14 (m, 3H), 7.70 (dd, J=8.6, 2.4 Hz, 1H), 7.46 (d, J=8.6 Hz, 1H), 7.14 (d, J=1.9 Hz, 1H), 7.07 (dd, J=8.6, 2.9 Hz, 1H), 6.46 (d, J=8.6 Hz, 1H), 5.17 (m, 1H), 4.55 (dd, J=9.2, 6.5 Hz, 2H), 4.24-4.15 (m, 4H), 3.10 (s, 1H), 2.90 (s, 2H), 2.44 (s, 6H). HPLC: 96.71%.

Example 380: 6-(2-(1H-imidazol-1-yl)ethoxy)-4-(6-(4-((6-ethynylpyridin-3-yl)oxy)piperidine-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 4-((6-bromopyridin-3-yl)oxy)piperidine-1-carboxylate

To a two-necked flask were sequentially added tert-butyl 4-hydroxypiperidine-1-carboxylate (868 mg, 4.312 mmol), 6-bromopyridin-3-ol (500 mg, 2.873 mmol), triphenylphosphine (1000 mg, 3.736 mmol). The reaction mixture was degassed and refilled with nitrogen. THF (10 mL) was added. The mixture was cooled to 0° C., and diisopropylazodicarboxylate (0.75 mL, 3.7 mmol) was slowly added dropwise. After 30 min of dropping, the mixture was reacted overnight at room temperature. The reaction mixture was added with water (10 mL) and extracted with EA (150 mL). The organic phases were washed with saturated brine (10 mL), and the mother liquid was concentrated in vacuo, purified by silica gel column chromatography (eluent PE:EA=0-5:1) to give a colorless oily liquid product 0.812 g as the target product (yield: 79.1%). (Rf=0.4, PE/EA=4/1). LC-MS: m/z=301.1 [M-t-Bu]⁺; 303.1 [M-t-Bu+2H]⁺.

Step 2: tert-butyl 4-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy) piperidine-1-carboxylate

To a 50 mL two-necked flask were sequentially added tert-butyl 4-((6-bromopyridin-3-yl)oxy)piperidine-1-carboxylate (0.812 g, 2.27 mmol), Pd(PPh₃)₂Cl₂ (32 mg, 0.045 mmol), triethylamine (5 mL) and THE (5 mL) under nitrogen. After stirring for 15 min, CuI (22 mg, 0.115 mmol) and ethynyl (trimethyl)silane (0.5 mL, 4 mmol) were added and the mixture was stirred at room temperature for 2.5 h. The reaction mixture was directly concentrated in vacuo, and purified by silica gel column chromatography (PE:EA=0-5:1) to give a khaki solid 0.78 g as the target product (the yield was 92%). (Rf=0.4, PE/EA=4/1). LC-MS: m/z=375.2 [M+H]⁺.

Step 3: tert-butyl 4-((6-ethynylpyridin-3-yl)oxy)piperidine-1-carboxylate

To a single-necked flask were sequentially added tert-butyl 4-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)piperidine-1-carboxylate (0.78 g, 2.1 mmol), potassium carbonate (557 mg, 4.0301 mmol) and methanol (10 mL). The mixture was stirred at room temperature for 1 h. The reaction mixture was filtered and washed with EA (50 mL), and the mother liquor was concentrated in vacuo and then purified by silica gel column chromatography (PE:EA=0-5:1) to give a pale yellow solid 0.63 g as the target product. (Rf=0.3, PE/EA=2/1). LC-MS: m/z=303.4 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.27 (d, J=2.7 Hz, 1H), 7.42 (d, J=8.6 Hz, 1H), 7.15 (dd, J=8.6, 2.9 Hz, 1H), 4.53 (tt, J=6.9, 3.3 Hz, 1H), 3.76-3.61 (m, 2H), 3.41-3.29 (m, 2H), 3.07 (s, 1H), 2.00-1.86 (m, 2H), 1.80-1.72 (m, 2H), 1.47 (s, 9H).

Step 4: 2-ethynyl-5-(piperidin-4-yloxy)pyridine hydrochloride

To a single-necked flask were sequentially added tert-butyl 4-((6-ethynylpyridin-3-yl)oxy)piperidine-1-carboxylate (0.63 g, 2.1 mmol) and 4M hydrochloric acid in 1,4-dioxane solution (4 mL, 16 mmol). The mixture was stirred at room temperature for 1 h (a white solid precipitated). The reaction mixture was concentrated in vacuo to give a yellow-white solid 0.41 g as the target product (the yield was 82%). LC-MS: m/z=203.1 [M+H]⁺.

Step 5: 6-(2-(1H-imidazol-1-yl)ethoxy)-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added 4-(6-fluoro-3-pyridyl)-6-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile (98 mg, 0.39 mmol), potassium carbonate (123 mg, 0.86 mmol) and 1-(2-chloroethyl)imidazole (85 mg, 0.65 mmol), which were dissolved by adding DMF. The mixture was reacted in an oil bath at 80° C. After the completion of reaction was monitored by TLC, the reaction solution was cooled to room temperature, added with water (10 mL) and extracted with EA (20 mL×2). The organic phases were washed with water (10 mL×6) and saturated saline (10 mL×3), dried over anhydrous sodium sulfate and filtered. The filtrate was purified by silica gel column chromatography (eluent DCM:MeOH=100: 1-25:1) to give a yellow solid 66 mg. ¹H NMR (400 MHz, CDCl₃) δ 8.38 (s, 1H), 8.22 (s, 1H), 8.16 (d, J=2.0 Hz, 1H), 8.02-7.96 (m, 1H), 7.64 (s, 1H), 7.13 (dd, J=6.6, 4.5 Hz, 3H), 7.09-7.02 (m, 1H), 4.44 (t, J=4.8 Hz, 2H), 4.30 (t, J=4.9 Hz, 2H).

Step 6: 6-(2-(1H-imidazol-1-yl)ethoxy)-4-(6-(4-((6-ethynylpyridin-3-yl)oxy)piperidine-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL microwave tube were added 6-(2-(1H-imidazol-1-yl)ethoxy)-4-(6-fluoropyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (30 mg, 0.086 mmol) and 2-ethynyl-5-(4-piperidinyloxy)pyridine hydrochloride (25 mg, 0.10 mmol), which were dissolved by adding DMSO (0.6 mL). Then DIPEA (0.06 mL, 0.4 mmol) was added. The mixture was reacted at 110° C. for 5 h. Additional E (35 mg) was added and the mixture was reacted in an oil bath at 100° C. After the completion of reaction was monitored by TLC, the reaction solution was cooled to room temperature, added with water (5 mL) and extracted with EA (20 mL×2). The organic phases were washed with water (10 mL×4) and saturated saline (10 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent DCM:MeOH=20:1) to give a yellow solid 3 mg. LC-MS: m/z=531.20[M+H]⁺, HPLC: 92.18%, ¹H NMR (400 MHz, CDCl₃) δ 8.33 (dd, J=4.8, 2.6 Hz, 2H), 8.22 (s, 1H), 8.11 (d, J=1.8 Hz, 1H), 7.71 (dd, J=8.8, 2.5 Hz, 2H), 7.46 (d, J=8.6 Hz, 1H), 7.21 (dd, J=8.7, 2.9 Hz, 1H), 7.15 (s, 1H), 7.09 (dd, J=13.7, 2.1 Hz, 2H), 6.83 (d, J=8.8 Hz, 1H), 4.71-4.62 (m, 1H), 4.46 (t, J=4.8 Hz, 2H), 4.31 (t, J=4.8 Hz, 2H), 4.03-3.94 (m, 2H), 3.68-3.61 (m, 2H), 3.10 (s, 1H), 2.12-2.06 (m, 2H), 1.95-1.90 (m, 2H).

Example 381: (S)-4-(6-(3-((6-ethynylpyridin-3-yl)oxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl (R)-3-((methylsulfonyl)oxy)pyrrolidine-1-carboxylate

To a two-necked flask were added tert-butyl (3R)-3-hydroxypyrrolidine-1-carboxylate (2.00 g, 10.7 mmol) and DCM (50 mL) under nitrogen, then NaH (0.856 g, 21.4 mmol) was added. Methanesulfonyl chloride (0.911 mL, 11.8 mmol) was added under ice bath conditions, and the mixture was reacted at this temperature for 5.5 h. The reaction mixture was added with water (10 mL) and EA (100 mL). The aqueous phase was extracted with EA (50 mL×2). The combined organic phases were washed with saturated brine (10 mL), dried over anhydrous sodium sulfate, concentrated in vacuo to give colorless transparent liquid 2.84 g as the target product (the yield was 100%). (Iodine color development Rf=0.5, PE/EA=4/1). LC-MS: m/z=210.1[M-t-Bu+H]⁺.

Step 2: tert-butyl (S)-3-((6-bromopyridin-3-yl)oxy)pyrrolidine-1-carboxylate

6-Bromopyridin-3-ol (590 mg, 3.3908 mmol) was dissolved in DMSO (6 mL) at room temperature, and potassium tert-butoxide (580 mg, 4.39 mmol) was added with stirring. After stirring for 20 min, the temperature was raised to 100° C. tert-Butyl (S)-3-((methylsulfonyl)oxy)pyrrolidine-1-carboxylate (1.00 g, 3.77 mmol) dissolved in DMSO (30 mL) was added dropwise slowly. After the addition, the mixture was reacted at 100° C. for 12 h. The reaction mixture was added with water (10 mL) and EA (100 mL). The organic layers were separated, washed with saturated brine (10 mL×4), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=0-100:10) to give a white solid 0.72 g as the target product (the yield was 62%). (Rf=0.5, PE/EA=4/1). LC-MS: m/z=289.0 [M-t-Bu+2H]⁺.

Step 3: tert-butyl (S)-3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)pyrrolidine-1-carboxylate

To a 50 mL two-necked flask were sequentially added tert-butyl (S)-3-((6-bromo-3-pyridyl)oxy)pyrrolidine-1-carboxylate (0.72 g, 2.1 mmol), Pd(PPh₃)₂Cl₂ (30 mg, 0.0423133 mmol), triethylamine (5 mL) and THE (5 mL) under nitrogen. After stirring for 15 min, CuI (20 mg, 0.10502 mmol) and ethynyl (trimethyl)silane (0.59 mL, 4.2 mmol) were added and the mixture was stirred overnight. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=0-5:1) to give brown liquid 341 mg as the target product (the yield was 45%). (Rf=0.5 PE/EA=4/1). LC-MS: m/z=361.1[M+H]⁺.

Step 4: tert-butyl (S)-3-((6-ethynylpyridin-3-yl)oxy)pyrrolidine-1-carboxylate

To a single-necked flask were sequentially added tert-butyl (S)-3-((6-((trimethylsilyl)ethynyl)pyridin-3-yl)oxy)pyrrolidine-1-carboxylate (340 mg, 0.9431 mmol), potassium carbonate (261 mg, 1.8884 mmol) and methanol (3 mL). The mixture was stirred at room temperature for 0.5 h. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=0-3:1) to give pale yellow liquid 272 mg as the target product (the yield was 100%). (Rf=0.3, PE/EA=3/1). LC-MS: m/z=289.5 [M+H]⁺.

Step 5: (S)-2-ethynyl-5-(pyrrolidin-3-yloxy)pyridine hydrochloride

To a single-necked flask were sequentially added tert-butyl (S)-3-((6-ethynylpyridin-3-yl)oxy)pyrrolidine-1-carboxylate (272 mg, 0.9435 mmol) and a solution of 4N hydrochloric acid in EA (4 mL, 16 mmol, 4 mol/L). The mixture was stirred at room temperature for 0.5 h. The reaction mixture was directly concentrated in vacuo to give a khaki solid 212 mg as the target product (the yield was 100%). LC-MS: m/z=189.2 [M+H]⁺.

Step 6: (S)-4-(6-(3-((6-ethynyl-3-yl)oxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methyl-propoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 25 mg, 0.07662 mmol) in DMSO (1.5 mL) were added (S)-2-ethynyl-5-(pyrrolidin-3-yloxy)pyridine hydrochloride (21 mg, 0.093462 mmol) and DIPEA (0.04 mL, 0.2 mmol) at room temperature. The mixture was reacted for 5 h under microwave (100° C., 10 bar, preheating for 30 s). After the reaction was completed, the reaction mixture was cooled to room temperature, added with water (10 mL) and EA (50 mL). The organic layers were washed with saturated brine (6 mL×3), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give a white solid 12 mg as the target product (the yield was 31.36%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=495.1 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ=8.34 (s, 1H), 8.30 (s, 1H), 8.20 (s, 1H), 8.16 (d, J=1.8 Hz, 1H), 7.75 (dd, J=8.4, 1.8 Hz, 1H), 7.45 (d, J=8.4 Hz, 1H), 7.19 (dd, J=8.6, 2.8 Hz, 1H), 7.15 (d, J=1.8 Hz, 1H), 6.58 (d, J=8.7 Hz, 1H), 5.15 (s, 1H), 3.92 (s, 2H), 3.86 (s, 2H), 3.81-3.71 (m, 2H), 3.65 (s, 1H), 3.09 (s, 1H), 2.44-2.32 (m, 2H), 1.39 (s, 6H). HPLC: 91.10%.

Example 382: (S)-4-(6-(3-(4-ethynylphenoxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl (R)-3-((methylsulfonyl)oxy)pyrrolidine-1-carboxylate

tert-Butyl (3R)-3-hydroxypyrrolidine-1-carboxylate (2.00 g, 10.7 mmol) was dissolved in THF (50 mL) in a double-necked flask under nitrogen, then NaH (0.856 g, 21.4 mmol, 60 mass %) was added (a large amount of bubbles were generated). Methanesulfonyl chloride (0.911 mL, 11.8 mmol) was added under ice bath conditions, and the mixture was reacted at room temperature for 4.5 h (the reaction liquid had a white solid suspension). The reaction mixture was added with water (10 mL) and EA (100 mL). The organic phases were separated and the aqueous phase was extracted with EA (50 mL). The combined organic phases were washed with saturated brine (10 mL), dried over anhydrous sodium sulfate, concentrated in vacuo to give colorless transparent liquid 2.84 g as the target product (the yield was 100%). (Rf=0.4, PE/EA=2/1). LC-MS: m/z=210.2[M-t-Bu+H]⁺.

Step 2: tert-butyl (S)-3-(4-iodophenoxy)pyrrolidine-1-carboxylate

To a single-necked flask were sequentially added tert-butyl (R)-3-((methanesulfonyl)oxy)pyrrolidine-1-carboxylate (470 mg, 1.7714 mmol), 4-iodophenol (300 mg, 1.3636 mmol), potassium carbonate (565 mg, 4.0880 mmol) and DMF (6 mL). The mixture was stirred at 80° C. overnight. The reaction mixture was added with water (10 mL) and extracted with EA (100 mL). The organic layers were washed with saturated brine (10 mL×2), dried over anhydrous sodium, purified by silica gel column chromatography (PE/EA=0-20/1) to give colorless transparent liquid 424 mg as the target product (the yield was 61.50%). LC-MS: m/z: 334.0[M-t-Bu+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.56 (d, J=8.3 Hz, 2H), 6.64 (d, J=8.8 Hz, 2H), 4.83 (s, 1H), 3.66-3.55 (m, 2H), 3.55-3.41 (m, 2H), 2.21-2.06 (m, 2H), 1.46 (s, 9H).

Step 3: (S)-3-(4-iodophenoxy)pyrrolidine hydrochloride

tert-Butyl (S)-3-(4-iodophenoxy)pyrrolidine-1-carboxylate (434 mg, 1.115 mmol) was dissolved in EA (2 mL) in a single-necked flask, then a solution of 4M hydrochloric acid in EA (5 mL, 20 mmol, 4 mol/L) was added. The mixture was stirred at room temperature for 2.5 h. The reaction mixture was directly concentrated in vacuo to give a white solid 320 mg as the target product (the yield was 88.14%). ¹H NMR (400 MHz, DMSO-d₆) δ 9.64-9.06 (m, 2H), 7.63 (d, J=8.8 Hz, 2H), 6.83 (d, J=8.8 Hz, 2H), 5.12 (s, 1H), 3.48-3.40 (m, 1H), 3.31-3.26 (m, 2H), 3.26-3.18 (m, 1H), 2.25-2.03 (m, 2H).

Step 4: (S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-iodophenoxy)pyrrolidin-1-yl)pyridin-3-yl) pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 50 mg, 0.1532 mmol) in DMSO (2 mL) were added (3S)-3-(4-iodophenoxy)pyrrolidine hydrochloride (55 mg, 0.16893 mmol) and DIPEA (0.08 mL, 0.5 mmol) at room temperature. After the addition, the mixture was reacted for 8 h under microwave (100° C., 10 bar, preheating for 30 s). After the reaction was completed, the reaction mixture was cooled to the room temperature. Water (10 mL) and EA (100 mL) were added, and the organic phase was washed with saturated sodium chloride (6 mL×3), concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give light brown liquid 91 mg as the objective product (yield 99.74%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=596.0 [M+H]⁺.

Step 5: (S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-(((trimethylsilyl))ethynyl)phenoxy) pyrrolidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a two-necked flask were sequentially added (S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-iodophenoxy)pyrrolidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (92 mg, 0.1545 mmol), Pd(PPh₃)₂Cl₂ (2.2 mg, 0.0031 mmol), triethylamine (2 mL) and THE (5 mL). The reaction mixture was degassed and refilled with nitrogen. After stirring for 15 min, cuprous iodide (1.5 mg, 0.0079 mmol) and ethynyl (trimethyl)silane (0.1 mL, 0.7 mmol) were added. The mixture was stirred at room temperature overnight. The reaction mixture was concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=0-100/3) to give brown liquid 87.4 mg as the target product (the yield was 100%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=566.2[M+H]⁺.

Step 6: (S)-4-(6-(3-(4-ethynylphenoxy)pyrrolidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were sequentially added (S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(4-(((trimethylsilyl))ethynyl)phenoxy)pyrrolidine-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (87 mg, 0.1538 mmol), potassium carbonate (43 mg, 0.31112 mmol) and methanol (3 mL). The mixture was stirred at room temperature overnight. The reaction mixture was directly concentrated in vacuo, and then purified by silica gel column chromatography (DCM/MeOH=100/0-100/3) to give a yellow-white solid 40 mg as the target product (the yield was 52.69%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=494.3[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.33 (s, 1H), 8.20 (s, 1H), 8.15 (s, 1H), 7.73 (d, J=8.4 Hz, 1H), 7.44 (d, J=8.7 Hz, 2H), 7.14 (s, 1H), 6.86 (d, J=8.7 Hz, 2H), 6.56 (d, J=8.7 Hz, 1H), 5.10 (s, 1H), 3.94-3.86 (m, 2H), 3.86 (s, 2H), 3.82-3.63 (m, 3H), 3.01 (s, 1H), 2.45-2.30 (m, 2H), 1.39 (s, 6H). HPLC: 95.88%.

Example 383: 4-(6-(5-((6-ethynylpyridin-3-yl)oxy)hexahydrocyclopentyl[c]pyrrole-2(1H)-yl) pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 5-hydroxyhexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

LiAlH₄ (0.35 g, 9.2 mmol) was slowly added to anhydrous THE (15 mL) under ice water bath. After the mixture was stirred at low temperature for 15 min, tert-butyl 5-oxohexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (1.03 g, 4.57 mmol) was slowly added. The mixture was naturally warmed to room temperature and stirred for 2 h. The reaction was quenched with a saturated Na₂SO₄ solution, then the mixture was filtered by suction and concentrated in vacuo to give brownish yellow viscous liquid 0.89 g with a yield of 86%. ¹H NMR (400 MHz, CDCl₃) δ 4.34-4.23 (m, 1H), 3.54-3.45 (m, 2H), 3.38-3.28 (m, 2H), 2.81-2.64 (m, 1H), 2.62-2.52 (m, 2H), 2.20-2.12 (m, 2H), 1.75-1.57 (m, 1H), 1.45 (s, 9H).

Step 2: tert-butyl 5-((methylsulfonyl)oxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

tert-Butyl 5-hydroxyhexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (0.50 g, 2.2 mmol) dissolved in DCM (20 mL) in an ice water bath, then NaH (0.18 g, 4.5 mmol, 60 mass %) was added. After stirring for 10 min, methylsulfonyl chloride (0.2 mL, 3 mmol) was slowly added. The mixture was naturally warmed to room temperature and stirred for 3 h. The reaction was quenched by the addition of water slowly. The resulting mixture was extracted with DCM (20 mL×3), washed with water, dried over anhydrous sodium sulfate, concentrated in vacuo and then purified by silica gel column chromatography (eluent PE/EA=10/1-5/1) to give colorless viscous liquid 0.48 g (the yield was 71%).

Step 3: tert-butyl 5-(4-bromophenoxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

To a single-necked flask were sequentially added tert-butyl 5-((methylsulfonyl)oxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (100 mg, 0.3274 mmol), 6-bromopyridin-3-ol (56 mg, 0.32184 mmol), potassium carbonate (136 mg, 0.98401 mmol) and DMF (2 mL). The mixture was stirred at 80° C. for 1 day. Water (5 mL) and EA (150 mL) were added, and the organic phases were separated, washed with saturated saline (5 mL×3), concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=0-2:1) to give colorless transparent liquid 116 mg as the objective product (yield 92.67%). (Rf=0.5, PE/EA=2/1). MS: m/z=383.5 [M]⁺, 385.5 [M+H]⁺.

Step 4: tert-butyl 5-(4-(((trimethylsilyl)ethynyl)phenoxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

To a 50 mL two-necked flask were sequentially added tert-butyl 5-(4-bromophenoxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (0.116 g, 0.303 mmol), Pd(PPh₃)₂Cl₂ (4.3 mg, 0.0061 mmol), triethylamine (2 mL) and THE (2 mL). The reaction mixture was degassed and refilled with nitrogen. After stirring for 15 min, cuprous iodide (3 mg, 0.015752 mmol) and ethynyl (trimethyl)silane (0.07 mL, 0.5 mmol) were added and the mixture was stirred overnight. The reaction mixture was concentrated in vacuo, and then purified by silica gel column chromatography (PE:EA=0-5:1) to give a khaki solid 83 mg as the target product (the yield was 68.5%). (Rf=0.5, PE/EA=4/1). LC-MS: m/z=401.7 [M+H]⁺.

Step 5: tert-butyl 5-(4-ethynylphenoxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

To a single-necked flask were sequentially added tert-butyl 5-(4-(((trimethylsilyl)ethynyl)phenoxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (83 mg, 0.2077 mmol), potassium carbonate (60 mg, 0.43412 mmol) and methanol (4 mL). The mixture was stirred at room temperature for 2 h. The reaction mixture was filtered and washed with EA (50 mL), and the mother liquid was concentrated in vacuo and then purified by silica gel column chromatography (PE:EA=0-5:1) to give pale yellow liquid 11 mg as the target product (yield 16.18%). (Rf=0.3, PE/EA=2/1).

Step 6: 5-(4-ethynylphenoxy)octahydrocyclopenta[c]pyrrole hydrochloride

To a single-necked flask were sequentially added tert-butyl 5-(4-ethynylphenoxy)hexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (11 mg, 0.03360 mmol) and a solution of 4N hydrochloric acid in 1,4-dioxane (3 mL, 12 mmol, 4 mol/L). The mixture was stirred at room temperature. The completion of reaction was monitored by TLC. The reaction mixture was concentrated in vacuo to give a yellow-white solid 8.8 mg as the target product (the yield was 100%).

Step 7: 4-(6-(5-((6-ethynylpyridin-3-yl)oxy)hexahydrocyclopenta[c]pyrrole-2(1H)-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo [1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 26 mg, 0.07968 mmol) in DMSO (1.5 mL) were added 5-(4-ethynylphenoxy)octahydrocyclopenta[c]pyrrole hydrochloride (26 mg, 0.09819 mmol) and DIPEA (0.5 mL, 3 mmol) at room temperature. The mixture was reacted for 5 h under microwave (100° C., 5 bar, preheating for 30 s). After the reaction was completed, the reaction mixture was cooled to the room temperature. The reaction mixture was added with EA (50 mL) and washed with water (10 mL×3). The mother liquor was directly concentrated in vacuo, and purified by silica gel column chromatography (DCM/MeOH=0-100:3) to give a yellow-white solid 2 mg as the target product (the yield was 5.0%). (Rf=0.4, DCM/MeOH=20/1). LC-MS: m/z=535.2 [M+H]⁺.

Example 384: 4-(6-(3-((5-ethynylpyridin-2-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-hydroxyazetidine-1-carboxylate

To a 100 mL single-necked flask were added tert-butyl 3-oxoazetidine-1-carboxylate (2.0 g, 12 mmol) and EtOH (20 mL) at room temperature, then NaBH₄ (0.88 g, 23 mmol) was added portionwise with stirring. The mixture was stirred at room temperature for reaction. After the completion of reaction was monitored by TLC, a saturated ammonium chloride solution was added to the reaction solution until no bubbles were generated. The mixture was filtered with suction. The filter cake was washed with ethanol (10 mL), and the filtrate was concentrated in vacuo to remove most of the ethanol. To the mixture was added 30 mL of water and the resulting mixture was extracted with EA (100 mL×2). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquid was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 2.0 g as the target product. LC-MS: m/z=118.10[M-t-Bu+H]⁺, ¹H-NMR (400 MHz, CDCl₃) δ 4.53 (s, 1H), 4.13-4.09 (m, 2H), 3.78 (dd, J=9.9, 4.1 Hz, 2H), 3.54-3.45 (m, 1H), 1.41 (s, 9H).

Step 2: tert-butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate

To a two-necked flask were added tert-butyl 3-hydroxyazetidine-1-carboxylate (500 mg, 2.89 mmol), DCM (15 mL) and NaH (0.14 g, 5.8 mmol) under nitrogen. The mixture was transferred to 0° C. and MsCl (0.25 mL, 3.2 mmol) was added dropwise with stirring. After the addition, the mixture was reacted continuously at this temperature. After the completion of reaction was monitored by TLC, the reaction solution was quenched with water (20 mL) and then DCM (50 mL) were added. The organic phase was separated, and the aqueous phase was extracted with DCM (50 mL). The combined organic phases were washed with water (20 mL×2) and saturated sodium chloride (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The mother liquor was concentrated in vacuo and purified by silica gel column chromatography (eluent EA:PE=1:5) to give colorless oil 680 mg as the target product. LC-MS: m/z=196.10[M-t-Bu+H]⁺, m/z=152.10[M-Boc+H]⁺; ¹H-NMR (400 MHz, CDCl₃) δ 5.18 (tt, J=6.7, 4.2 Hz, 1H), 4.26 (ddd, J=10.3, 6.7, 1.0 Hz, 2H), 4.11-4.04 (m, 2H), 3.05 (s, 3H), 1.43 (s, 9H).

Step 3: tert-butyl 3-((5-iodopyridin-2-yl)oxy)azetidin-1-carboxylate

To a 25 mL single-necked flask were added tert-butyl 3-methylsulfonyloxyazetidine-1-carboxylate (410 mg, 1.63 mmol), 5-iodo-2-olpyridine (300 mg, 1.36 mmol) and potassium tert-butoxide (195 mg, 1.65 mmol). DMF (5 mL) was added to dissolve the solids, and the mixture was reacted in an oil bath at 100° C. After the completion of reaction was monitored by TLC, to the reaction solution was added water (10 mL) and the resulting mixture was extracted with EA (40 mL×2). The organic phases were washed with water (15 mL×6) and saturated saline (15 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was purified by silica gel column chromatography (eluent PE:EA=10:1) to give a white solid 283 mg as the target product. LC-MS: m/z=377.10[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.29 (d, J=1.9 Hz, 1H), 7.82 (dd, J=8.7, 2.3 Hz, 1H), 6.62 (d, J=8.7 Hz, 1H), 5.26 (tt, J=6.6, 4.3 Hz, 1H), 4.34-4.24 (m, 2H), 3.95 (dd, J=10.0, 4.1 Hz, 2H), 1.44 (s, 9H).

Step 4: tert-butyl 3-((5-((trimethylsilyl)ethynyl)pyridin-2-yl)oxy)azetidin-1-carboxylate

To a 50 mL double-necked flask were added tert-butyl 3-((5-iodopyridin-2-yl) oxy) azetidine-1-carboxylate (283 mg, 0.75 mmol), Pd(PPh₃)Cl₂ (15 mg, 0.021 mmol), triethylamine (1.5 mL, 11.0 mmol) and THE (8 mL). The reaction mixture was degassed and refilled with nitrogen. Then cuprous iodide (40 mg, 0.21 mmol), trimethylchlorosilane (1.5 mL, 11.0 mmol) were added. The mixture was reacted at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE/EA=100/1) to give colorless transparent liquid 250 mg, which was the target product. LC-MS: m/z=347.20[M+H]⁺.

Step 5: tert-butyl 3-((5-ethynylpyridin-2-yl)oxy)azetidin-1-carboxylate

To a 25 mL single-necked flask was added tert-butyl 3-((5-((trimethylsilyl)ethynyl)pyridin-2-yl)oxy)azetidin-1-carboxylate (250 mg, 0.72 mmol), which was dissolved by adding methanol (3 mL). Then potassium carbonate (300 mg, 2.17 mmol) was added at room temperature. The mixture was reacted at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE/EA=20/1) to give a pale yellow solid 146 mg, which was the target product. LC-MS: m/z=275.20[M+H]⁺.

Step 6: 2-(azetidin-3-oxy)-5-ethynylpyridine hydrochloride

To a 25 mL single-necked flask was added tert-butyl 3-((5-ethynylpyridin-2-yl)oxy)azetidin-1-carboxylate (146 mg, 0.53 mmol), then HCl/EA (5 mL, 4N) was added with stirring. The mixture was stirred at room temperature for reaction. After the completion of reaction was monitored by TLC, the reaction solution was concentrated in vacuo to remove the solvent and dried in a vacuum drying oven at 60° C. to obtain an off-white solid 112 mg as the target product. LC-MS: m/z=211.20[M+H]⁺; m/z=175.20[M+H-HCl]⁺.

Step 7: 4-(6-(3-((5-ethynylpyridin-2-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methyl propyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL microwave tube were added 4-(6-fluoropyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy) pyrazolo [1,5-a] pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.092 mmol), 2-(azetidin-3-oxy)-5-ethynylpyridine hydrochloride (85 mg, 0.40 mmol), DIPEA (0.1 mL, 0.6 mmol) and DMSO (0.6 mL). The mixture was reacted at 110° C. for 12 h. After the completion of reaction was monitored by TLC, to the reaction solution was added water (10 mL) and the resulting mixture was extracted with EA (25 mL×2). The combined organic phases were washed with water (5 mL×3) and saturated saline (5 mL×2), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and purified by silica gel column chromatography (eluent PE:EA=50:1) to give a yellow solid 5 mg as the target product. LC-MS: m/z=481.20[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.30 (d, J=9.2 Hz, 2H), 8.19 (s, 1H), 8.15 (s, 1H), 7.69 (d, J=8.6 Hz, 2H), 7.13 (d, J=1.8 Hz, 1H), 6.77 (d, J=8.6 Hz, 1H), 6.44 (d, J=8.6 Hz, 1H), 5.61-5.53 (s, 1H), 4.58-4.50 (m, 2H), 4.15 (dd, J=9.4, 4.0 Hz, 2H), 3.86 (s, 2H), 3.13 (s, 1H), 1.39 (s, 6H). HPLC: 90.41%.

Example 385: 4-(6-(3-(4-ethynyl-3-fluorophenoxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-(3-fluoro-4-iodo-phenoxy)azetidin-1-carboxylate

To a 10 mL single-necked flask were added 3-fluoro-4-iodo-phenol (400 mg, 1.681 mmol), tert-butyl 3-((methylsulfonyl) oxy)azetidin-1-carboxylate (507 mg, 2.018 mmol) and t-BuOK (377.2 mg, 3.361 mmol). Then DMF (6 mL) was added to dissolve the solids. The mixture was reacted in an oil bath at 100° C. overnight. TLC showed the reaction was completed. To the mixture was added water (25 mL) and to the resulting mixture was extracted with EA (50 mL×2). The organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (pure PE-PE:EA=10:1) to give a white crystalline solid (yield: 69%) as the target product. LC-MS(ES-API): m/z=338.00[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.60 (dd, J=8.6, 7.4 Hz, 1H), 6.50 (dd, J=9.4, 2.7 Hz, 1H), 6.36 (dd, J=8.7, 2.3 Hz, 1H), 4.83 (qd, J=6.4, 4.1 Hz, 1H), 4.29 (dd, J=9.6, 6.8 Hz, 2H), 3.98 (dd, J=9.9, 3.8 Hz, 2H), 1.45 (s, 9H).

Step 2: tert-butyl 3-(3-fluoro-4-(2-trimethylsilylethynyl) phenoxy)azetidin-1-carboxylate

To a 25 mL two-necked flask were added tert-butyl 3-(3-fluoro-4-iodo-phenoxy) azetidine-1-carboxylate (450 mg, 1.144 mmol), CuI (22 mg, 0.116 mmol) and PdCl₂ (PPh₃)₂ (41 mg, 0.058 mmol). The reaction mixture was degassed and refilled with nitrogen. Then anhydrous THE (4.5 mL) and TEA (4.5 mL, 32 mmol) were added. After the dissolution, ethynyl (trimethyl)silane (0.323 mL, 2.29 mmol) was added. The mixture was stirred for reaction at room temperature overnight. TLC showed the reaction was completed. The resulting mixture was filtered by suction through a celite pad. The filter cake was washed with EA (60 mL) several times, and the filtrate was washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=100: 1-10:1) to give a brown solid 0.398 g (yield: 95.7%) as the target product. LC-MS(ES-API): m/z=308.10[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.36 (t, J=8.5 Hz, 1H), 6.51-6.41 (m, 2H), 4.88-4.81 (m, 1H), 4.29 (dd, J=9.6, 6.7 Hz, 2H), 3.98 (dd, J=9.9, 3.9 Hz, 2H), 1.45 (s, 9H), 0.25 (s, 9H).

Step 3: tert-butyl 3-(4-ethynyl-3-fluorophenoxy)azetidin-1-carboxylate

To a 10 mL single-necked flask were sequentially added tert-butyl 3-(3-fluoro-4-(2-trimethylsilylethynyl) phenoxy) azetidine-1-carboxylate (400 mg, 1.100 mmol), K₂CO₃ (305 mg, 2.207 mmol) and MeOH (3 mL). The mixture was stirred to react at room temperature overnight. After TLC showed the reaction was completed, the mixture was quenched by adding 10 mL of saturated ammonium chloride dropwise and then concentrated in vacuo to remove part of methanol. The resulting mixture was extracted with EA (30 mL×2). The organic phases were washed with saturated saline (15 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=100:1-5:1) to give a white solid 0.364 g (the yield was 82.3%), which was the target product. LC-MS(ES-API): m/z=236.10[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.39 (t, J=8.4 Hz, 1H), 6.51-6.45 (m, 2H), 4.89-4.82 (m, 1H), 4.30 (dd, J=9.4, 6.8 Hz, 2H), 3.99 (dd, J=9.9, 3.7 Hz, 2H), 3.23 (s, 1H), 1.45 (s, 9H).

Step 4: 3-(4-ethynyl-3-fluoro-phenoxy)azetidin hydrochloride

To a 10 mL single-necked flask were added tert-butyl 3-(4-ethynyl-3-fluorophenoxy) azetidine-1-carboxylate (254 mg, 0.872 mmol) and a solution of hydrogen chloride in ethyl acetate (6 mL, 24 mmol, 4 mol/L). The mixture was reacted with stirring at room temperature for 1 h.

TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo, dried in an oven at 60° C. to obtain a theoretical amount of yellow white solid. LC-MS(ES-API): m/z=192.15[M+H]⁺.

Step 5: 4-(6-(3-(4-ethynyl-3-fluorophenoxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.092 mmol) and 3-(4-ethynyl-3-fluoro-phenoxy) azetidine hydrochloride (63 mg, 0.277 mmol), which were dissolved by adding DMAC (1.4 mL, 15 mmol). Then triethylamine (0.08 mL, 0.6 mmol) and DMAP (1.2 mg, 0.01 mmol) were added. The mixture was reacted at 90° C. in an oil bath overnight. TLC showed the reaction was completed. The reaction solution was cooled to room temperature, then to the resulting mixture was added water (15 mL) and the resulting mixture was extracted with EA (30 mL×3). The organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=10:1) to give a white solid 0.02 g (yield: 40%) as the target product. LC-MS(ES-API): m/z=498.50[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J=1.8 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 7.71 (dd, J=8.6, 2.3 Hz, 1H), 7.42 (t, J=8.4 Hz, 1H), 7.14 (d, J=1.9 Hz, 1H), 6.60-6.53 (m, 2H), 6.46 (d, J=8.5 Hz, 1H), 5.14-5.08 (m, 1H), 4.54 (dd, J=9.0, 6.7 Hz, 2H), 4.18 (dd, J=9.4, 3.7 Hz, 2H), 3.86 (s, 2H), 3.24 (s, 1H), 1.39 (s, 6H). HPLC: 89.77%.

Example 386: 4-(6-(3-(4-ethynyl-3-fluoro-phenoxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxyl-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-(3-fluoro-4-iodo-phenoxy)azetidin-1-carboxylate

To a 10 mL single-necked flask were added 3-fluoro-4-iodo-phenol (400 mg, 1.681 mmol), tert-butyl 3-((methylsulfonyl) oxy)azetidin-1-carboxylate (507 mg, 2.018 mmol) and t-BuOK (377.2 mg, 3.361 mmol). Then DMF (6 mL) was added to dissolve the solids. The mixture was reacted in an oil bath at 100° C. overnight. TLC showed the reaction was completed. To the mixture was added water (25 mL) and to the resulting mixture was extracted with EA (50 mL×2). The organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (pure PE-PE:EA=10:1) to give a white crystalline solid (yield: 69%) as the target product. LC-MS(ES-API): m/z=338.00[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.60 (dd, J=8.6, 7.4 Hz, 1H), 6.50 (dd, J=9.4, 2.7 Hz, 1H), 6.36 (dd, J=8.7, 2.3 Hz, 1H), 4.83 (qd, J=6.4, 4.1 Hz, 1H), 4.29 (dd, J=9.6, 6.8 Hz, 2H), 3.98 (dd, J=9.9, 3.8 Hz, 2H), 1.45 (s, 9H).

Step 2: tert-butyl 3-(3-fluoro-4-(2-trimethylsilylethynyl) phenoxy)azetidin-1-carboxylate

To a 25 mL two-necked flask were added tert-butyl 3-(3-fluoro-4-iodo-phenoxy) azetidine-1-carboxylate (450 mg, 1.144 mmol), CuI (22 mg, 0.116 mmol) and PdCl₂ (PPh₃) 2 (41 mg, 0.058 mmol). The reaction mixture was degassed and refilled with nitrogen. Then anhydrous THE (4.5 mL) and TEA (4.5 mL, 32 mmol) were added. After the dissolution, ethynyl (trimethyl)silane (0.323 mL, 2.29 mmol) was added. The mixture was stirred for reaction at room temperature overnight. TLC showed the reaction was completed. The resulting mixture was filtered by suction through a celite pad. The filter cake was washed with EA (60 mL) several times, and the filtrate was washed with saturated brine (20 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=100: 1-10:1) to give a brown solid 0.398 g (yield: 95.7%) as the target product. LC-MS(ES-API): m/z=308.10[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.36 (t, J=8.5 Hz, 1H), 6.51-6.41 (m, 2H), 4.88-4.81 (m, 1H), 4.29 (dd, J=9.6, 6.7 Hz, 2H), 3.98 (dd, J=9.9, 3.9 Hz, 2H), 1.45 (s, 9H), 0.25 (s, 9H).

Step 3: tert-butyl 3-(4-ethynyl-3-fluorophenoxy)azetidin-1-carboxylate

To a 10 mL single-necked flask were sequentially added tert-butyl 3-(3-fluoro-4-(2-trimethylsilylethynyl) phenoxy) azetidine-1-carboxylate (400 mg, 1.100 mmol), K₂CO₃ (305 mg, 2.207 mmol) and MeOH (3 mL). The mixture was stirred to react at room temperature overnight. After TLC showed the reaction was completed, the mixture was quenched by adding 10 mL of saturated ammonium chloride dropwise and then concentrated in vacuo to remove part of methanol. The resulting mixture was extracted with EA (30 mL×2). The organic phases were washed with saturated saline (15 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=100:1-5:1) to give a white solid 0.364 g (the yield was 82.3%), which was the target product. LC-MS(ES-API): m/z=236.10[M-56+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 7.39 (t, J=8.4 Hz, 1H), 6.51-6.45 (m, 2H), 4.89-4.82 (m, 1H), 4.30 (dd, J=9.4, 6.8 Hz, 2H), 3.99 (dd, J=9.9, 3.7 Hz, 2H), 3.23 (s, 1H), 1.45 (s, 9H).

Step 4: 3-(4-ethynyl-3-fluoro-phenoxy)azetidine hydrochloride

To a 10 mL single-necked flask were added tert-butyl 3-(4-ethynyl-3-fluorophenoxy) azetidine-1-carboxylate (254 mg, 0.872 mmol) and a solution of hydrogen chloride in ethyl acetate (6 mL, 24 mmol, 4 mol/L). The mixture was reacted with stirring at room temperature for 1 h. TLC showed the reaction was completed. The reaction solution was directly concentrated in vacuo, dried in an oven at 60° C. to obtain a theoretical amount of yellow white solid. LC-MS(ES-API): m/z=192.15[M+H]⁺.

Step 5: 4-(6-(3-(4-ethynyl-3-fluoro-phenoxy)azetidin-1-yl)-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were sequentially added 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 30 mg, 0.092 mmol) and 3-(4-ethynyl-3-fluoro-phenoxy) azetidine hydrochloride (63 mg, 0.277 mmol), which were dissolved by adding DMAC (1.4 mL, 15 mmol). Then triethylamine (0.08 mL, 0.6 mmol) and DMAP (1.2 mg, 0.01 mmol) were added. The mixture was reacted at 90° C. in an oil bath overnight. TLC showed the reaction was completed. The reaction solution was cooled to room temperature, then to the resulting mixture was added water (15 mL) and the resulting mixture was extracted with EA (30 mL×3). The organic phases were washed with saturated saline (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent pure DCM-DCM:MeOH=10:1) to give a white solid 0.02 g (yield: 40%) as the target product. LC-MS(ES-API): m/z=498.50[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J=1.8 Hz, 1H), 8.20 (s, 1H), 8.15 (d, J=1.9 Hz, 1H), 7.71 (dd, J=8.6, 2.3 Hz, 1H), 7.42 (t, J=8.4 Hz, 1H), 7.14 (d, J=1.9 Hz, 1H), 6.60-6.53 (m, 2H), 6.46 (d, J=8.5 Hz, 1H), 5.14-5.08 (m, 1H), 4.54 (dd, J=9.0, 6.7 Hz, 2H), 4.18 (dd, J=9.4, 3.7 Hz, 2H), 3.86 (s, 2H), 3.24 (s, 1H), 1.39 (s, 6H). HPLC: 89.77%.

Example 387: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-((6-(prop-1-yn-1-yl) pyridin-3-yl) oxy)azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-((6-bromopyridin-3-yl)oxy)azetidin-1-carboxylate

6-Bromopyridin-3-ol (200 mg, 1.15 mmol) was dissolved in DMSO (4 mL) at room temperature, and t-BuOK (168 mg, 1.5 mmol) was added to the solution with stirring. After stirring for 20 min, the temperature was raised to 80° C. tert-Butyl 3-((methylsulfonyl)oxy)azetidin-1-carboxylate (347 mg, 1.4 mmol) dissolved in DMSO (2 mL) was added dropwise slowly. After the addition, the mixture was kept at this temperature with stirring. After the reaction was completed, the reaction mixture was poured into water (20 mL). The resulting mixture was extracted with EA (50 mL×2). The combined organic phases were washed with water (20 mL×2) and saturated saline (20 mL). The organic phases were dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent EA:PE=1:20-1:10) to give a pale yellow solid 320 mg as the target product. LC-MS: m/z=329.05 [M+H]⁺.

Step 2: tert-butyl 3-(((6-(propynyl) pyridin-3-yl) oxy) azetidine-1-carboxylate

To a 50 mL two-necked flask were sequentially added tert-butyl 3-[((6-bromo-3-pyridyl) oxy] azetidine-1-carboxylate (0.573 g, 1.74 mmol), PdCl₂(PPh₃)₂(25 mg, 0.0352611 mmol), triethylamine (2 mL) and THE (2 mL). The reaction mixture was degassed and refilled with nitrogen. After stirring for 15 min, cuprous iodide (17 mg, 0.089263 mmol) and propyne (3.5 mL, 3.5 mmol, 1 mol/L) were added and the mixture was stirred at 50° C. for reaction. After the completion of reaction was monitored by TLC, the reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=0-5:1) to give a pale brown solid 326 mg as the target product (the yield was 65.0%). LC-MS: m/z=289.1[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.10 (d, J=2.7 Hz, 1H), 7.32 (d, J=8.6 Hz, 1H), 6.99 (dd, J=8.6, 2.9 Hz, 1H), 4.99-4.89 (m, 1H), 4.33 (dd, J=9.8, 6.6 Hz, 2H), 4.03 (dd, J=9.9, 3.7 Hz, 2H), 2.08 (s, 3H), 1.47 (s, 9H).

Step 3: 5-(azetidin-3-yloxy)-2-(prop-1-yn-1-yl) pyridine hydrochloride

To a single-necked flask were sequentially added tert-butyl 3-[((6-prop-1-ynyl-3-pyridyl) oxy] azetidine-1-carboxylate (326 mg, 1.131 mmol) and a solution of 4N hydrochloric acid in EA (4 mL, 16 mmol). The mixture was stirred at room temperature for 1 h. The reaction mixture was concentrated in vacuo to give a yellow-white solid 254 mg as the target product (the yield was 99.97%). LC-MS: m/z=189.1 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆) δ 9.56 (s, 1H), 9.46 (s, 1H), 8.21 (d, J=2.8 Hz, 1H), 7.45 (d, J=8.6 Hz, 1H), 7.34 (dd, J=8.7, 3.0 Hz, 1H), 5.18 (dd, J=10.8, 5.7 Hz, 1H), 4.43 (td, J=11.7, 6.4 Hz, 2H), 4.06-3.95 (m, 2H), 2.05 (s, 3H).

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-((6-(prop-1-yn-1-yl) pyridin-3-yl) oxy)azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a solution of 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 50 mg, 0.153 mmol) in DMSO (2 mL) were added 5-(azetidin-3-yloxy)-2-prop-1-ynyl-pyridine hydrochloride (45 mg, 0.200 mmol) and N,N-diisopropylethylamine (0.1 mL, 0.6 mmol). After the addition, the mixture was reacted for 5 h under microwave (130° C., 10 bar). The reaction mixture was cooled to room temperature, then to the mixture were added water (30 mL) and EA (100 mL). The organic layers were washed with saturated brine (20 mL×3) and concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give a yellow solid 30 mg as the target product (the yield was 39.59%). LC-MS: m/z=495.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.34 (d, J=1.7 Hz, 1H), 8.22 (s, 1H), 8.18 (d, J=1.6 Hz, 2H), 7.74 (dd, J=8.5, 2.0 Hz, 1H), 7.35 (d, J=8.8 Hz, 1H), 7.17 (d, J=1.6 Hz, 1H), 7.07 (dd, J=8.6, 2.7 Hz, 1H), 6.50 (d, J=8.6 Hz, 1H), 5.23-5.13 (m, 1H), 4.58 (dd, J=8.8, 6.7 Hz, 2H), 4.23 (dd, J=9.2, 3.6 Hz, 2H), 3.88 (s, 2H), 3.68 (s, 1H), 2.09 (s, 3H), 1.41 (s, 6H). HPLC: 89.36%.

Example 388: 4-(6-(3-((2-ethynylpyridin-4-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: tert-butyl 3-((2-bromo-4-pyridyl) oxy) azetidine-1-carboxylate

To a 25 mL single-necked flask were added 2-bromopyridin-4-ol (1 g, 5.74 mmol), tert-butyl 3-((methylsulfonyl) oxy) azetidine-1-carboxylate (1.74 g, 6.92 mmol), tert-butyl potassium (815 mg, 6.90 mmol) and DMF (10 mL). The mixture was reacted in an oil bath at 100° C. overnight. The reaction solution was cooled to room temperature, added with water (50 mL) and extracted with EA (150 mL×2). The combined organic phases were washed with water (50 mL×4) and saturated saline (50 mL×2), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo, and then purified by silica gel column chromatography (eluent PE:EA=4:1) to give colorless liquid 490 mg as the target product.

Step 2: 4-(azetidin-3-yloxy)-2-bromopyridine hydrochloride

To a single-necked flask were sequentially added tert-butyl 3-((2-bromo-4-pyridyl) oxy) azetidine-1-carboxylate (140 mg, 0.425 mmol) and a solution of hydrochloric acid in EA (4 mL, 16 mmol, 4 mol/L). The mixture was stirred at room temperature for 1 h. The reaction mixture was directly filtered to give a white solid 113 mg as the target product (the yield was 99.98%). MS: m/z=228.9[M+H]⁺, 231.0[M+2H]⁺. 1H NMR (400 MHz, DMSO-d₆) δ 9.54 (s, 1H), 9.45 (s, 1H), 8.24 (d, J=5.7 Hz, 1H), 7.21 (d, J=2.2 Hz, 1H), 7.02 (dd, J=5.7, 2.3 Hz, 1H), 5.28-5.19 (m, 1H), 4.53-4.40 (m, 2H), 4.00-3.94 (m, 2H).

Step 3: 4-(6-(3-((2-bromopyridin-4-yl)oxy))azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL single-necked flask were added 4-(6-fluoro-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy) pyrazolo[1,5-a]pyridine-3-carbonitrile (see synthesis of intermediate 2, 53 mg, 0.1624 mmol), 4-(azetidin-3-yloxy)-2-bromopyridine hydrochloride (65 mg, 0.24478 mmol), potassium carbonate (45 mg, 0.32559 mmol), DMAP (2 mg, 0.016371 mmol) and DMSO (2 mL). The mixture was reacted with stirring at 90° C. overnight. Water (20 mL) and EA (200 mL) were added, and the organic phases were washed with saturated sodium chloride (30 mL×3), concentrated in vacuo, and then purified by silica gel column chromatography (DCM:MeOH=0-100:3) to give yellow solid 87 mg as the objective product (yield 100%). MS(ESI, pos.ion): m/z=535.7 [M]⁺, 537.7 [M+2H]⁺.

Step 4: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(2-(((trimethylsilyl)ethynyl)pyridin-4-yl) oxy)azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 50 mL two-necked flask were sequentially added 4-(6-(3-((2-bromo-4-pyridyl) oxy)azetidin-1-yl)-3-pyridyl)-6-(2-hydroxy-2-methyl-propoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (87 mg, 0.1625 mmol), Pd(PPh₃)₂Cl₂ (2.3 mg, 0.0032 mmol), triethylamine (4 mL) and THE (4 mL). The reaction mixture was degassed and refilled with nitrogen. After stirring for 15 min, cuprous iodide (2 mg, 0.010502 mmol) and ethynyl (trimethyl)silane (0.1 mL, 0.7 mmol) were added. The mixture was stirred at room temperature overnight. The reaction mixture was concentrated in vacuo, and the residue was purified by silica gel column chromatography (PE:EA=0-5:1) to give brown liquid 89.8 mg as the target product (the yield was 100%). LC-MS: m/z=554.2[M+H]⁺.

Step 5: 4-(6-(3-((2-ethynylpyridin-4-yl)oxy)azetidin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropyloxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a single-necked flask were sequentially added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-((2-(((trimethylsilyl)ethynyl)pyridin-4-yl)oxy)azetidine-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile (60 mg, 0.1086 mmol), potassium carbonate (30 mg, 0.21706 mmol) and methanol (5 mL). The mixture was stirred at room temperature for 5 h. The reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (DCM/MeOH=0-100:3) to give a white solid 28 mg as the target product. LC-MS: m/z=481.2 [M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.46 (d, J=5.7 Hz, 1H), 8.34 (d, J=1.9 Hz, 1H), 8.22 (s, 1H), 8.18 (d, J=1.9 Hz, 1H), 7.75 (dd, J=8.5, 2.3 Hz, 1H), 7.17 (d, J=1.9 Hz, 1H), 6.95 (d, J=2.2 Hz, 1H), 6.76 (dd, J=5.7, 2.4 Hz, 1H), 6.50 (d, J=8.6 Hz, 1H), 5.23-5.16 (m, 1H), 4.60 (dd, 2H), 4.23 (dd, J=9.3, 3.6 Hz, 2H), 3.89 (s, 2H), 3.51 (s, 1H), 3.18 (s, 1H), 1.42 (s, 6H). HPLC: 92.92%.

Example 389: 4-(6-(4-(((3-ethynylphenyl)sulfonyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

Step 1: 4-(6-(4-((3-bromophenyl)sulfonyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask were added 6-(2-hydroxy-2-methyl-propoxy)-4-(6-piperazin-1-yl-3-pyridyl) pyrazolo [1,5-a] pyridine-3-carbonitrile hydrochloride (see synthesis of intermediate 4, 72 mg, 0.15 mmol) and potassium carbonate (100 mg, 0.72 mmol), which were dissolved by adding DMF (1 mL). Then 3-bromobenzenesulfonyl chloride (0.1 mL, 0.75 mmol) was added. The mixture was reacted in an oil bath at 60° C. After the completion of reaction was monitored by TLC, to the reaction solution was added water (15 mL) and the resulting mixture was extracted with EA (20 mL×2). The organic phases were washed with water (5 mL×3) and saturated saline (5 mL×2), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and the residue was purified by silica gel column chromatography (eluent PE:EA=1:1) to give a yellow solid 35 mg as the target product. LC-MS: m/z=612.10[M+H]⁺.

Step 2: 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-((3-(((trimethylsilyl) ethynyl) phenyl) sulfonyl) piperazin-1-yl) pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 10 mL double-necked flask was added Pd(PPh₃)₂Cl₂ (12 mg, 0.017 mmol). The reaction flask was degassed and refilled with nitrogen. Then a solution of 4-(6-(4-((3-bromophenyl) sulfonyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile (35 mg, 0.057 mmol) in THE (2 mL) and triethylamine (0.1 mL, 0.7 mmol) were added. Cuprous iodide (6 mg, 0.03 mmol) and ethynyltrimethylsilane (0.1 mL, 0.7 mmol) were added with stirring. After the addition, the mixture was reacted at 40° C. in an oil bath. After the completion of reaction was monitored by TLC, the reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography (eluent PE:EA=1:1-EA) to give a yellow solid 15 mg, which was the target product. LC-MS: m/z=629.20[M+H]⁺.

Step 3: 4-(6-(4-(((3-ethynylphenyl)sulfonyl)piperazin-1-yl)pyridin-3-yl)-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile

To a 5 mL single-necked flask was added 6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-((3-(((trimethylsilyl)ethynyl)phenyl)sulfonyl)piperazin-1-yl)pyridin-3-yl)pyrazole[1,5-a]pyridine-3-carbonitrile (15 mg, 0.024 mmol), which was dissolved by adding methanol. Then potassium carbonate (12 mg, 0.087 mmol) was added. The mixture was reacted at room temperature. After the completion of reaction was monitored by TLC, the reaction mixture was directly concentrated in vacuo, and the residue was purified by silica gel column chromatography to give a white solid 4 mg, which was the target product. LC-MS: m/z=557.20[M+H]⁺. ¹H NMR (400 MHz, CDCl₃) δ 8.32 (s, 1H), 8.20 (s, 1H), 8.17 (s, 1H), 7.93 (d, J=13.7 Hz, 1H), 7.78-7.75 (m, 1H), 7.67 (s, 1H), 7.49-7.47 (m, 2H), 7.14 (s, 1H), 6.74 (d, J=8.7 Hz, 1H), 3.87 (s, 2H), 3.83-3.74 (m, 4H), 3.22 (s, 1H), 3.20-3.12 (m, 4H), 1.40 (s, 6H).

Examples 10-49, Example 54, Example 59

Using suitable raw materials, the target compounds (10)-(49) of Examples 10-49, the target compound (54) of Example 54, and the target compound (59) of Example 59 can be prepared by referring to the synthetic route of Example 1 or Example 2. The specific structures and characterization data are described in Table 1 below:

TABLE 1
Structures and characterization data of compounds (10)-(49), compound (54) and
compound (59)
(10)
LC-MS: m/z = 415.2 [M + H]+
(11)
LC-MS: m/z = 457.23 [M + H]+
(12)
LC-MS: m/z = 469.2 [M + H]+
(13)
LC-MS: m/z = 469.2 [M + H]+
(14)
LC-MS: m/z = 483.2 [M + H]+
(15)
LC-MS: m/z = 470.2 [M + H]+
(16)
LC-MS: m/z = 537.3 [M + H]+
(17)
LC-MS: m/z = 484.2 [M + H]+
(18)
LC-MS: m/z = 507.2 [M + H]+
(19)
LC-MS: m/z = 522.2 [M + H]+
(20)
LC-MS: m/z = 441.2 [M + H]+
(21)
LC-MS: m/z = 509.2 [M + H]+
(22)
LC-MS: m/z = 502.2 [M + H]+
(23)
LC-MS: m/z = 495.2 [M + H]+
(24)
LC-MS: m/z = 525.2 [M + H]+
(25)
LC-MS: m/z = 545.2 [M + H]+
(26)
LC-MS: m/z = 530.1 [M + H]+
(27)
LC-MS: m/z = 478.2 [M + H]+
(28)
LC-MS: m/z = 508.2 [M + H]+
(29)
LC-MS: m/z = 523.2 [M + H]+
(30)
LC-MS: m/z = 503.2 [M + H]+
(31)
LC-MS: m/z = 496.2 [M + H]+
(32)
LC-MS: m/z = 526.2 [M + H]+
(33)
LC-MS: m/z = 546.2 [M + H]+
(34)
LC-MS: m/z = 531.1 [M + H]+
(35)
LC-MS: m/z = 427.2 [M + H]+
(36)
LC-MS: m/z = 413.2 [M + H]+
(37)
LC-MS: m/z = 427.2 [M + H]+
(38)
LC-MS: m/z = 427.2 [M + H]+
(39)
LC-MS: m/z = 415.2 [M + H]+
(40)
LC-MS: m/z = 427.2 [M + H]+
(41)
LC-MS: m/z = 455.2 [M + H]+
(42)
LC-MS: m/z = 455.2 [M + H]+
(43)
LC-MS: m/z = 441.2 [M + H]+
(44)
LC-MS: m/z = 441.2 [M + H]+
(45)
LC-MS: m/z = 400.2 [M + H]+
(46)
LC-MS: m/z = 372.1 [M + H]+
(47)
LC-MS: m/z = 386.2 [M + H]+
(48)
LC-MS: m/z = 412.2 [M + H]+
(49)
LC-MS: m/z = 442.2 [M + H]+
(54)
LC-MS: m/z = 413.2 [M + H]+
(59)
LC-MS: m/z = 441.2 [M + H]+

Examples 50-53, Examples 55-58, Examples 60-65

Using suitable raw materials, the target compounds (50)-(53) of Examples 50-53, the target compounds (55)-(58) of Examples 55-58 and the target compounds (60)-(65) of Examples 60-65 can be prepared by referring to the synthetic route of synthesis scheme 6 or synthesis scheme 4. The specific structures and characterization data are described in Table 2 below:

TABLE 2
Structures and characterization data of compounds (50)-(53), compounds (55)-(58) and
compounds (60)-(65)
(50)
LC-MS: m/z = 415.2 [M + H]+
(51)
LC-MS: m/z = 429.2 [M + H]+
(52)
LC-MS: m/z = 455.2 [M + H]+
(53)
LC-MS: m/z = 459.2 [M + H]+
(55)
LC-MS: m/z = 483.2 [M + H]+
(56)
LC-MS: m/z = 516.3 [M + H]+
(57)
LC-MS: m/z = 541.3 [M + H]+
(58)
LC-MS: m/z = 487.2 [M + H]+
(60)
LC-MS: m/z = 500.3 [M + H]+
(61)
LC-MS: m/z = 493.2 [M + H]+
(62)
LC-MS: m/z = 538.2 [M + H]+
(63)
LC-MS: m/z = 532.2 [M + H]+
(64)
LC-MS: m/z = 565.2 [M + H]+
(65)
LC-MS: m/z = 505.2 [M + H]+

Examples 66-73, Examples 90-91

Using suitable raw materials, the target compounds (66)-(73) of Examples 66-73 and the target compounds (90)-(91) of Examples 90-91 can be prepared by referring to the synthetic route of synthesis scheme 1 or synthesis scheme 2. The specific structures and characterization data are described in Table 3 below:

TABLE 3
Structures and characterization data of compounds (66)-(73) and
compounds (90)-(91)
(66)
LC-MS: m/z = 429.2 [M + H]+
(67)
LC-MS: m/z = 415.2 [M + H]+
(68)
LC-MS: m/z = 441.2 [M + H]+
(69)
LC-MS: m/z = 483.2 [M + H]+
(70)
LC-MS: m/z = 427.2 [M + H]+
(71)
LC-MS: m/z = 427.2 [M + H]+
(72)
LC-MS: m/z = 441.2 [M + H]+
(73)
LC-MS: m/z = 441.2 [M + H]+
(90)
LC-MS: m/z = 444.2 [M + H]+
(91)
LC-MS: m/z = 472.2 [M + H]+

Examples 74-89, Examples 92-109

Using suitable raw materials, the target compounds (74)-(89) of Examples 74-89 and the target compounds (92)-(109) of Examples 92-109 can be prepared by referring to the synthetic route of synthesis scheme 2 or synthesis scheme 3. The specific structures and characterization data are described in Table 4 below:

TABLE 4
Structures and characterization data of compounds (74)-(89) and compounds
(92)-(109)
(74)
LC-MS: m/z = 451.2 [M + H]+
(75)
LC-MS: m/z = 505.2 [M + H]+
(76)
LC-MS: m/z = 597.2 [M + H]+
(77)
LC-MS: m/z = 587.2 [M + H]+
(78)
LC-MS: m/z = 574.2 [M + H]+
(79)
LC-MS: m/z = 466.2 [M + H]+
(80)
LC-MS: m/z = 529.2 [M + H]+
(81)
LC-MS: m/z = 547.2 [M + H]+
(82)
LC-MS: m/z = 506.2 [M + H]+
(83)
LC-MS: m/z = 430.2 [M + H]+
(84)
LC-MS: m/z = 493.2 [M + H]+
(85)
LC-MS: m/z = 527.2 [M + H]+
(86)
LC-MS: m/z = 552.2 [M + H]+
(87)
LC-MS: m/z = 486.2 [M + H]+
(88)
LC-MS: m/z = 444.2 [M + H]+
(89)
LC-MS: m/z = 458.2 [M + H]+
(92)
LC-MS: m/z = 472.2 [M + H]+
(93)
LC-MS: m/z = 491.2 [M + H]+
(94)
LC-MS: m/z = 483.2 [M + H]+
(95)
LC-MS: m/z = 506.2 [M + H]+
(96)
LC-MS: m/z = 523.2 [M + H]+
(97)
LC-MS: m/z = 478.2 [M + H]+
(98)
LC-MS: m/z = 464.2 [M + H]+
(99)
LC-MS: m/z = 564.2 [M + H]+
(100)
LC-MS: m/z = 519.2 [M + H]+
(101)
LC-MS: m/z = 469.2 [M + H]+
(102)
LC-MS: m/z = 455.2 [M + H]+
(103)
LC-MS: m/z = 455.2 [M + H]+
(104)
LC-MS: m/z = 455.2 [M + H]+
(105)
LC-MS: m/z = 469.2 [M + H]+
(106)
LC-MS: m/z = 469.2 [M + H]+
(107)
LC-MS: m/z = 469.2 [M + H]+
(108)
LC-MS: m/z = 444.2 [M + H]+
(109)
LC-MS: m/z = 443.2 [M + H]+

Examples 110-141

Using suitable raw materials, the target compounds (110)-(141) of Examples 110-141 can be prepared by referring to the synthetic route of Example 3, synthesis scheme 3 or synthesis scheme 11. The specific structures and characterization data are described in Table 5 below:

TABLE 5
Structures and characterization data of compounds (110)-(141)
LC-MS: m/z = 415.2 [M + H]+
LC-MS: m/z = 429.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 427.2 [M + H]+
LC-MS: m/z = 427.2 [M + H]+
LC-MS: m/z = 441.2 [M + H]+
LC-MS: m/z = 441.2 [M + H]+
LC-MS: m/z = 441.2 [M + H]+
LC-MS: m/z = 441.2 [M + H]+
LC-MS: m/z = 441.2 [M + H]+
LC-MS: m/z = 469.2 [M + H]+
LC-MS: m/z = 483.2 [M + H]+
LC-MS: m/z = 481.2 [M + H]+
LC-MS: m/z = 455.2 [M + H]+
LC-MS: m/z = 483.2 [M + H]+
LC-MS: m/z = 459.2 [M + H]+
LC-MS: m/z = 469.2 [M + H]+
LC-MS: m/z = 493.2 [M + H]+
LC-MS: m/z = 414.2 [M + H]+
LC-MS: m/z = 428.2 [M + H]+
LC-MS: m/z = 440.2 [M + H]+
LC-MS: m/z = 415.2 [M + H]+
LC-MS: m/z = 429.2 [M + H]+
LC-MS: m/z = 440.2 [M + H]+
LC-MS: m/z = 477.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 431.2 [M + H]+
LC-MS: m/z = 473.2 [M + H]+
LC-MS: m/z = 492.2 [M + H]+
LC-MS: m/z = 460.2 [M + H]+
LC-MS: m/z = 485.2 [M + H]+

Examples 142-146

Using suitable raw materials, the target compounds (142)-(146) of Examples 142-146 can be prepared by referring to the synthetic route of Example 297, Example 298 or synthesis scheme 3. The specific structures and characterization data are described in Table 6 below:

TABLE 6
Structures and characterization data of compounds (142)-(146)
LC-MS: m/z = 464.2 [M + H]+
LC-MS: m/z = 465.2 [M + H]+
LC-MS: m/z = 466.2 [M + H]+
LC-MS: m/z = 482.2 [M + H]+
LC-MS: m/z = 494.2 [M + H]+

Examples 148-256

Using suitable raw materials, the target compounds (148)-(256) of Examples 148-256 can be prepared by referring to the synthetic route of Example 1, synthesis scheme 3 or synthesis scheme 12. The specific structures and characterization data are described in Table 7 below:

TABLE 7
Structures and characterization data of compounds (148)-(256)
LC-MS: m/z = 376.2 [M + H]+
LC-MS: m/z = 390.2 [M + H]+
LC-MS: m/z = 316.2 [M + H]+
LC-MS: m/z = 411.1 [M + H]+
LC-MS: m/z = 404.2 [M + H]+
LC-MS: m/z = 455.1 [M + H]+
LC-MS: m/z = 402.2 [M + H]+
LC-MS: m/z = 401.2 [M + H]+
LC-MS: m/z = 417.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 373.1 [M + H]+
LC-MS: m/z = 387.1 [M + H]+
LC-MS: m/z = 460.2 [M + H]+
LC-MS: m/z = 474.2 [M + H]+
LC-MS: m/z = 444.2 [M + H]+
LC-MS: m/z = 470.2 [M + H]+
LC-MS: m/z = 486.2 [M + H]+
LC-MS: m/z = 485.2 [M + H]+
LC-MS: m/z = 470.2 [M + H]+
LC-MS: m/z = 456.2 [M + H]+
LC-MS: m/z = 499.2 [M + H]+
LC-MS: m/z = 472.2 [M + H]+
LC-MS: m/z = 467.2 [M + H]+
LC-MS: m/z = 516.2 [M + H]+
LC-MS: m/z = 416.2 [M + H]+
LC-MS: m/z = 458.2 [M + H]+
LC-MS: m/z = 480.2 [M + H]+
LC-MS: m/z = 470.2 [M + H]+
LC-MS: m/z = 486.2 [M + H]+
LC-MS: m/z = 430.2 [M + H]+
LC-MS: m/z = 484.2 [M + H]+
LC-MS: m/z = 458.2 [M + H]+
LC-MS: m/z = 442.2 [M + H]+
LC-MS: m/z = 513.2 [M + H]+
LC-MS: m/z = 527.2 [M + H]+
LC-MS: m/z = 431.2 [M + H]+
LC-MS: m/z = 431.2 [M + H]+
LC-MS: m/z = 431.2 [M + H]+
LC-MS: m/z = 484.2 [M + H]+
LC-MS: m/z = 500.2 [M + H]+
LC-MS: m/z = 467.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 467.2 [M + H]+
LC-MS: m/z = 572.3 [M + H]+
LC-MS: m/z = 486.2 [M + H]+
LC-MS: m/z = 486.2 [M + H]+
LC-MS: m/z = 500.2 [M + H]+
LC-MS: m/z = 456.2 [M + H]+
LC-MS: m/z = 488.2 [M + H]+
LC-MS: m/z = 492.2 [M + H]+
LC-MS: m/z = 484.2 [M + H]+
LC-MS: m/z = 455.1 [M + H]+
LC-MS: m/z = 437.1 [M + H]+
LC-MS: m/z = 415.1 [M + H]+
LC-MS: m/z = 487.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 432.2 [M + H]+
LC-MS: m/z = 415.2 [M + H]+
LC-MS: m/z = 459.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 441.1 [M + H]+
LC-MS: m/z = 457.2 [M + H]+
LC-MS: m/z = 471.2 [M + H]+
LC-MS: m/z = 429.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 457.2 [M + H]+
LC-MS: m/z = 441.2 [M + H]+
LC-MS: m/z = 454.2 [M + H]+
LC-MS: m/z = 469.2 [M + H]+
LC-MS: m/z = 464.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 431.2 [M + H]+
LC-MS: m/z = 447.2 [M + H]+
LC-MS: m/z = 447.2 [M + H]+
LC-MS: m/z = 473.2 [M + H]+
LC-MS: m/z = 459.2 [M + H]+
LC-MS: m/z = 486.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 445.2 [M + H]+
LC-MS: m/z = 500.2 [M + H]+
LC-MS: m/z = 499.2 [M + H]+
LC-MS: m/z = 528.3 [M + H]+
LC-MS: m/z = 485.2 [M + H]+
LC-MS: m/z = 484.2 [M + H]+
LC-MS: m/z = 498.2 [M + H]+
LC-MS: m/z = 514.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 467.2 [M + H]+
LC-MS: m/z = 430.2 [M + H]+
LC-MS: m/z = 444.2 [M + H]+
LC-MS: m/z = 458.2 [M + H]+
LC-MS: m/z = 468.2 [M + H]+
LC-MS: m/z = 485.2 [M + H]+
LC-MS: m/z = 474.2 [M + H]+
LC-MS: m/z = 443.2 [M + H]+
LC-MS: m/z = 459.2 [M + H]+
LC-MS: m/z = 401.2 [M + H]+
LC-MS: m/z = 402.2 [M + H]+
LC-MS: m/z = 415.2 [M + H]+
LC-MS: m/z = 402.2 [M + H]+
LC-MS: m/z = 400.2 [M + H]+
LC-MS: m/z = 419.2 [M + H]+
LC-MS: m/z = 436.1 [M + H]+
LC-MS: m/z = 431.2 [M + H]+

Example 262, Examples 271-274, Examples 276-279

Using suitable raw materials, the target compound (262) of Example 262, the target compounds (271)-(274) of Examples 271-274 and the target compounds (276)-(279) of Examples 276-279 can be prepared by referring to the synthetic route of Example 261, synthesis scheme 8 or synthesis scheme 3. The specific structures and characterization data are described in Table 8 below:

TABLE 8
Structures and characterization data of compound (262), compounds
(271)-(274) and compounds (276)-(279)
LC-MS: m/z = 537.2 [M + H]+
LC-MS: m/z = 534.3 [M + H]+
LC-MS: m/z = 562.3 [M + H]+
LC-MS: m/z = 578.3 [M + H]+
LC-MS: m/z = 560.3 [M + H]+
LC-MS: m/z = 534.3 [M + H]+
LC-MS: m/z = 546.3 [M + H]+
LC-MS: m/z = 544.2 [M + H]+
LC-MS: m/z = 558.2 [M + H]+

Example 264, Examples 281-284

Using suitable raw materials, the target compound (264) of Example 264 and the target compounds (281)-(284) of Examples 281-284 can be prepared by referring to the synthetic route of Example 263 or synthesis scheme 3. The specific structures and characterization data are described in Table 9 below:

TABLE 9
Structures and characterization data of compound (264) and
compounds (281)-(284)
LC-MS: m/z = 550.2 [M + H]+
LC-MS: m/z = 564.3 [M + H]+
LC-MS: m/z = 592.3 [M + H]+
LC-MS: m/z = 608.3 [M + H]+
LC-MS: m/z = 590.3 [M + H]+

Examples 267-270, Example 280

Using suitable raw materials, the target compounds (267)-(270) of Examples 267-270 and the target compound (280) of Example 280 can be prepared by referring to the synthetic route of Example 266, Example 285 or synthesis scheme 3. The specific structures and characterization data are described in Table 10 below:

TABLE 10
Structures and characterization data of compound (267)-(270)
and compound (280)
LC-MS: m/z = 499.2 [M + H]+
LC-MS: m/z = 457.2 [M + H]+
LC-MS: m/z = 501.2 [M + H]+
LC-MS: m/z = 515.3 [M + H]+
LC-MS: m/z = 431.2 [M + H]+

Biological Activities Test Example:

Test Example 1

• 1. Experimental Purpose:
  • The inhibitory activities of the series of compounds against Ret wt, VEGFR2, CCDC6-RET, Ret M918T, Ret V804L, and Ret V804M were tested by HTRF method, and IC₅₀ values were determined.
• 2. The assay agents and consumables used are as shown below:
• 1) HTRF KinEASE-TK kit (Cisbio, 62TK0PEC)
• 2) Ret wt (Invitrogen, PV3082)
• 3) VEGFR2 (invitrogen, PV3660)
• 4) CCDC6-RET (Signalchem, R02-19BG-10)
• 5) Ret M918T (Signalchem, R02-12JG-10)
• 6) Ret V804L (Signalchem, R02-12BG-10)
• 7) Ret V804M (Signalchem, R02-12GG-10)
• 8) MgCl₂ (Sigma, M1028)
• 9) ATP (Promega, V910B)
• 10) DTT (Invitrogen, P2325)
• 11) DMSO (Sigma, D8418)
• 12) 384-well plate, white, low volume, round-bottom (Greiner, 784075)
• 13) 384-Well Polypropylene microplate, Clear, Flatt Bottom, Bar Code (Labcyte, P-05525-BC)
• 14) 96-well polypropylene plate (Nunc, 249944)
• 15) Plate shaker (Thermo, 4625-1 CECN/THZ Q)
• 16) Centrifuge (Eppendorf, 5810R)
• 17) Envision 2104 multi-label Reader (PerkinElmer, 2104-10-1)
• 18) Echo (Labcyte, 550)
• 3. Experimental procedure
• 3.1 Preparation of 1× Kinase Reaction Buffer:

1 volume of 5× kinase reaction buffer and 4 volumes of water; 5 mM MgCl₂; 1 mM DTT; 1 mM MnCl₂.

• 3.2 10 nl of diluted compound was transferred to per well in the Echo 550 reaction plate (784075, Greiner);
• 3.3 The reaction plate was sealed with a sealing film and centrifuged at 1000 g for 1 minute.
• 3.4 1× Enzyme reaction buffer was used to prepare 2× Kinase.
• 3.5 5 μl of kinase was added to each well in the reaction plate (prepared in step 3). The plate was sealed with a sealing film, centrifuged at 1000 g for 30 seconds, and then left at room temperature for 10 minutes.
• 3.6 4× TK-substrate-biotin and 4×ATP were prepared with 1× enzyme reaction buffer, and then mixed uniformly. To the reaction plate was added 5 μl of the mixture of K-substrate-biotin/ATP.
• 3.7 The plate was sealed with a sealing film, centrifuged at 1000 g for 30 seconds, and then left for reaction at room temperature for 40 minutes.
• 3.8 4× Sa-XL 665 (250 nM) was prepared using HTRF assay buffer.
• 3.9 5 μl of Sa-XL 665 and 5 μl of TK-antibody-Cryptate were added to each well, centrifuged at 1000 g for 30 seconds, and reacted at room temperature for 1 hour.
• 3.10 Fluorescence signals at 615 nm (Cryptate) and 665 nm (XL665) were read with Envision 2104.
• 4. Data Analysis

4.1 Calculation of the ratio of each well (Ratio_665/615 nm)

4.2 The inhibition rate was calculated as follows:

$\mathrm{The}\mathrm{inhibition}\mathrm{rate}\mathrm{rate}\mathrm{of}\mathrm{the}\mathrm{compound}\left(\%\mathrm{inhibition}\right)=\hspace{1em}\left[1-\frac{{\mathrm{Ratio}}_{\mathrm{compound}}-{\stackrel{\_}{\mathrm{Ratio}}}_{\mathrm{positive}\mathrm{control}}}{{\stackrel{\_}{\mathrm{Ratio}}}_{\mathrm{negative}\mathrm{control}}-{\stackrel{\_}{\mathrm{Ratio}}}_{\mathrm{positive}\mathrm{control}}}\right]*100$

Ratio _{positive control}: average of CEP-32496 readings in all positive control wells

Ratio _{negative control}: average of DMSO readings in all negative control wells

Wherein, the chemical name of CEP-32496 is:

• N-[3-[(6,7-dimethoxy-4-quinazolinyl)oxy]phenyl]-N′-[5-(2,2,2-trifluoro-1,1-dimethylethyl)-3-isoxazolyl]urea.

4.3 Calculation of the IC₅₀ and Drawing of the inhibition curve of the compound:

The IC₅₀ (half inhibitory concentration) of the compound was obtained using the following non-linear fit formula: Data analysis was performed using Graphpad 6.0 software.

Y=Bottom+(Top−Bottom)/(1+10{circumflex over ( )}((LogIC₅₀−X)*Hill Slope))

X: compound concentration log value Y: inhibition, %

• 5. Results were as shown in Table A-1 to Table A-4.

TABLE A-1
Kinase inhibitory activity of the compounds of the invention
	IC50	IC50 (nM),	IC50 (nM),	IC50 (nM),	IC50 (nM),
	(nM),	Ret	Ret	Ret	Ret
Example	Ret wt	CCDC6	M918T	V804L	V804M
Example 1	4.57	10.38	7.47	25.12	79.60
Example 5	15.96	6.32	18.15	10.57	62.36
Example 6	16.34	4.80	25.61	27.47	84.31
Example 265	4.22	2.88	6.28	2.08	45.94
Example 286	0.90	0.45	0.96	0.74	14.44
Example 287	4.64	1.89	4.44	0.97	47.66
Example 288	2.21	1.80	3.27	21.94	25.51
Example 290	34.63	55.09	45.60	47.38	123.30
Example 318	7.25	6.12	11.20	3.63	91.79
Example 320	5.929	2.977	5.983	2.42	59.93
Example 323	3.891	3.60	4.70	2.45	51.24

TABLE A-2
Kinase inhibitory activity of the compounds of the invention
	IC50 (nM),	IC50 (nM),	IC50 (nM),	IC50 (nM),
	Ret	Ret	Ret	Ret
Example	wt	CCDC6	M918T	V804L
Example 8	2.80	8.83	2.64	4.64
Example 9	0.64	3.3	0.7	1.1
Example 308	19.29	34.7	10.3	26

TABLE A-3
Kinase inhibitory activity of the compounds of the invention
		IC50			IC50
	IC50	(nM),		IC50	(nM),
	(nM),	Ret		(nM),	Ret
Example	Ret wt	V804M	Example	Ret wt	V804M
Example 257	0.88	12.74	Example 350	0.94	46.32
Example 260	1.72	12.16	Example 351	0.83	11.6
Example 263	34.06	60.21	Example 352	0.75	28.37
Example 291	1.47	14.74	Example 353	0.76	9.33
Example 292	53.6	156.82	Example 354	14.69	83.90
Example 295	28.13	188.30	Example 355	0.33	2.83
Example 296	3.93	99.27	Example 358	6.30	61.50
Example 297	0.64	4.23	Example 359	1.025	6.71
Example 298	0.38	5.05	Example 361	9.90	50.00
Example 299	3.26	36.61	Example 363	2.51	39.02
Example 300	1.76	20.65	Example 364	3.34	57.37
Example 301	0.08	1.11	Example 365	5.25	64.68
Example 306	0.18	4.81	Example 366	22.69	195.80
Example 307	34.77	171.20	Example 367	11.31	140.70
Example 329	1.16	24.59	Example 368	1.75	28.66
Example 330	4.18	81.87	Example 369	0.37	4.68
Example 331	0.30	2.54	Example 370	29.10	112.3
Example 332	3.18	21.00	Example 376	0.35	0.60
Example 333	0.81	8.35	Example 377	0.41	2.08
Example 334	4.30	64.37	Example 378	9.18	18.74
Example 340	20.93	62.82	Example 379	4.01	28.73
Example 342	5.81	79.99	Example 380	0.30	0.46
Example 343	2.79	63.26	Example 381	1.75	32.59
Example 344	16.36	77.59	Example 382	1.1	21.61
Example 384	0.48	2.42	Example 385	0.35	0.43

TABLE A-4
Kinase inhibitory activity of the compounds of the invention
	IC50		IC50		IC50
	(nM),		(nM),		(nM),
Example	Ret wt	Example	Ret wt	Example	Ret wt
Example 2	23.35	Example 261	9.31	Example 321	20.76
Example 3	24.39	Example 266	7.51	Example 322	17.25
Example 4	49.95	Example 285	3.20	Example 324	23.71
Example 7	8.80	Example 289	41.59	Example 325	13.55
Example 258	1.25	Example 317	40.40	Example 326	25.40
Example 259	0.17	Example 319	9.013	Example 327	1.11
Example 341	20.62	Example 338	78.8	Example 328	2.82
Example 349	1.59	Example 362	6.99

It can be seen from Table A-1 to Table A-4 that the compounds of the present invention have a good inhibitory effect on Ret wt. In addition, the compounds of the present invention have good inhibitory effects on Ret CCDC-6, Ret M918T, Ret V804L, and Ret V804M.

In addition to the compounds of the examples in Table A-1 to Table A-4, the other compounds of the present invention also have a good inhibitory effect on Ret wt, with IC₅₀ values ranging from 0 to 50 nM; In addition, the other compounds of the present invention have good inhibitory effects on Ret CCDC-6, Ret M918T, Ret V804L, and Ret V804M, with IC₅₀ values ranging from 0 to 100 nM.

Reference throughout this specification to “an embodiment”, “some embodiments”, “one embodiment”, “another example”, “an example”, “a specific example”, or “some examples” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as “in some embodiments”, “in one embodiment”, “in an embodiment”, “in another example”, “in an example”, “in a specific example” or “in some examples” in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can integrate and combine different embodiments, examples or the features of them as long as they are not contradictory to one another.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1-33. (canceled)

34. A compound having Formula (I) or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

35. The compound of claim 34, wherein G is H, D, C1-6 alkyl, 3-12 membered hetCyc, 3-12 membered Cyc, (3-12 membered hetCyc)-C1-6 alkyl, (3-12 membered Cyc)-C1-6 alkyl, (5-10 membered heteroaryl)-C1-6 alkyl, amino C1-6 alkyl, C1-6 alkylamino-C1-6 alkyl, di(C1-6 alkyl)amino-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, R5O(C═O)NR6C1-6 alkyl, R5(C═O)NR6C1-6 alkyl, NR5R6(C═O)C1-6 alkyl, R5(C═O)C1-6 alkyl, NR5R6(C═O)—, R5OC1-6 alkyl, wherein each of C1-6 alkyl, 3-12 membered hetCyc, 3-12 membered Cyc, (3-12 membered hetCyc)-C1-6 alkyl, (3-12 membered Cyc)-C1-6 alkyl, (5-10 membered heteroaryl)-C1-6 alkyl, amino C1-6 alkyl, C1-6 alkylamino-C1-6 alkyl, di(C1-6 alkyl)amino-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, and a C1-6 alkyl moiety in R5O(C═O)NR6C1-6 alkyl, R5(C═O)NR6C1-6 alkyl, NR5R6(C═O)C1-6 alkyl, R5(C═O)C1-6 alkyl, R5OC1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, C3-6 cycloalkylidene, 3-6 membered heterocyclylidene, C1-6 alkyl, C1-6 alkoxy, C1-6 alkoxy C1-6 alkyl, R5(C═O)— and R5O(C═O)—; or,G is H, D, C1-4 alkyl, 3-10 membered hetCyc, 3-10 membered Cyc, (3-10 membered hetCyc)-C1-4 alkyl, (3-10 membered Cyc)-C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl, amino C1-4 alkyl, C1-4 alkylamino-C1-4 alkyl, di(C1-4 alkyl)amino-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, R5O(C═O)NR6C1-4 alkyl, R5(C═O)NR6C1-4 alkyl, NR5R6(C═O)C1-4 alkyl, R5(C═O)C1-4 alkyl, NR5R6(C═O)—, R5OC1-4 alkyl, wherein each of C1-4 alkyl, 3-10 membered hetCyc, 3-10 membered Cyc, (3-10 membered hetCyc)-C1-4 alkyl, (3-10 membered Cyc)-C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl, amino C1-4 alkyl, C1-4 alkylamino-C1-4 alkyl, di(C1-4 alkyl)amino-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, and a C1-4 alkyl moiety in R5O(C═O)NR6C1-4 alkyl, R5(C═O)NR6C1-4 alkyl, NR5R6(C═O)C1-4 alkyl, R5(C═O)C1-4 alkyl, R5OC1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, C3-6 cycloalkylidene, 3-6 membered heterocyclylidene, C1-4 alkyl, C1-4 alkoxy, C1-4 alkoxy C1-4 alkyl, R5(C═O)— and R5O(C═O)—; or,G is H, D, C1-4 alkyl, 3-6 membered hetCyc, 3-6 membered Cyc, (3-6 membered hetCyc)-C1-4 alkyl, (3-6 membered Cyc)-C1-4 alkyl, (5-6 membered heteroaryl)-C1-4 alkyl, amino C1-4 alkyl, C1-4 alkylamino-C1-4 alkyl, di(C1-4 alkyl)amino-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, R5O(C═O)NR6C1-4 alkyl, R5(C═O)NR6C1-4 alkyl, NR5R6(C═O)C1-4 alkyl, R5(C═O)C1-4 alkyl, NR5R6(C═O)— or R5OC1-4 alkyl, wherein each of C1-4 alkyl, 3-6 membered hetCyc, 3-6 membered Cyc, (3-6 membered hetCyc)-C1-4 alkyl, (3-6 membered Cyc)-C1-4 alkyl, (5-6 membered heteroaryl)-C1-4 alkyl, amino C1-4 alkyl, C1-4 alkylamino-C1-4 alkyl, di(C1-4 alkyl)amino-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, and a C1-4 alkyl moiety in R5O(C═O)NR6C1-4 alkyl, R5(C═O)NR6C1-4 alkyl, NR5R6(C═O)C1-4 alkyl, R5(C═O)C1-4 alkyl and R5OC1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from oxo, F, Cl, Br, OH, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, azetanylidene, oxetanylidene, pyrrolidinylidene, pyrazolidinylidene, tetrahydrofuranylidene, methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, isobutyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, methoxymethyl, ethoxymethyl, n-propoxymethyl, isopropoxymethyl, methoxyethyl, ethoxyethyl, n-propoxyethyl, isopropoxyethyl, methoxypropyl, ethoxypropyl, n-propoxypropyl, isopropoxypropyl, CH3(C═O)—, CH3O(C═O)—, CH3CH2O(C═O)— and (CH3)3CO(C═O)—.

36. The compound of claim 34, wherein A is 3-12 membered Cyc or 3-12 membered hetCyc, wherein each of 3-12 membered Cyc and 3-12 membered hetCyc is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, oxo, NR5R6, R5O—, R5(C═O)NR6—, NR5R6C1-6 alkyl, NR5R6(C═O)C1-6 alkoxy C1-6 alkyl, NR6R7C1-6 alkoxy, NR6R7C1-6 alkoxy C1-6 alkyl, C1-6alkyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, 3-12 membered Cyc, 3-12 membered hetCyc, 3-12 membered hetCyc-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, 3-12 membered hetCyc-C1-6 alkoxy C1-6 alkyl, C3-6 cycloalkylidene and 3-6 membered heterocyclylidene; or,A is one of the following sub-formulae:

37. The compound according to claim 34, wherein A is one of the following sub-formulae:

38. The compound of claim 34, wherein M is —(C═O)—, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkyl-C6-10 aryl, C1-6 alkyl-(5-10 membered heteroaryl), C2-6 alkenyl-C6-10 aryl, C2-6 alkynyl-C6-10 aryl, C2-6 alkenyl-(5-10 membered heteroaryl), C2-6 alkynyl-(5-10 membered heteroaryl), C6-10 aryl, 5-10 membered heteroaryl, 3-12 membered hetCyc, 3-12 membered Cyc, C6-10 aryl-C1-6 alkyl, (5-10 membered heteroaryl)-C1-6 alkyl, (3-12 membered hetCyc)-C1-6 alkyl or (3-12 membered Cyc)-C1-6 alkyl, wherein each of C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkyl-C6-10 aryl, C1-6 alkyl-(5-10 membered heteroaryl), C2-6 alkenyl-C6-10 aryl, C2-6 alkynyl-C6-10 aryl, C2-6 alkenyl-(5-10 membered heteroaryl), C2-6 alkynyl-(5-10 membered heteroaryl), C6-10 aryl, 5-10 membered heteroaryl, 3-12 membered hetCyc, 3-12 membered Cyc, C6-10 aryl-C1-6 alkyl, (5-10 membered heteroaryl)-C1-6 alkyl, (3-12 membered hetCyc)-C1-6 alkyl and (3-12 membered Cyc)-C1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF3, NR5R6, oxo, C1-6 alkoxy, C3-6 cycloalkylidene, 3-6 membered heterocyclylidene, hydroxy C1-6 alkyl, C1-6 alkyl, C3-6 cycloalkyl, C3-6 cycloalkyl C2-6 alkynyl and 3-7 membered heterocyclic group; or,M is —(C═O)—, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 alkylphenyl, C1-4 alkyl-(5-10 membered heteroaryl), C2-4 alkenylphenyl, C2-4 alkynylphenyl, C2-4 alkenyl-(5-10 membered heteroaryl), C2-4 alkynyl-(5-10 membered heteroaryl), phenyl, 5-10 membered heteroaryl, 3-10 membered hetCyc, 3-10 membered Cyc, phenyl-C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl, (3-10 membered hetCyc)-C1-4 alkyl or (3-10 membered Cyc)-C1-4 alkyl, wherein each of C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 alkylphenyl, C1-4 alkyl-(5-10 membered heteroaryl), C2-4 alkenylphenyl, C2-4 alkynylphenyl, C2-4 alkenyl-(5-10 membered heteroaryl), C2-4 alkynyl-(5-10 membered heteroaryl), phenyl, 5-10 membered heteroaryl, 3-10 membered hetCyc, 3-10 membered Cyc, phenyl-C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl, (3-10 membered hetCyc)-C1-4 alkyl and (3-10 membered Cyc)-C1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF3, NR5R6, oxo, C1-4 alkoxy, C3-6 cycloalkylidene, 3-6 membered heterocyclylidene, hydroxy C1-4 alkyl, C1-4 alkyl, C3-6 cycloalkyl, C3-6 cycloalkyl C2-4 alkynyl and 3-6 membered heterocyclic group; orM is —(C═O)—, —CH2—, —(CH2)2—, —(CH2)3—, —(CH2)4—, —CH═CH2—, —CH2CH═CH—, —CH2CH═CHCH2—, —C≡C—, —CH2CH≡CH—, —CH2CH≡CHCH2—, —CH═CH-phenyl, —CH2CH═CH-phenyl, —CH2CH═CH—CH2-phenyl, —C≡C-phenyl, —CH2C≡C-phenyl, —CH2C≡C—CH2-phenyl, —CH═CH-pyridyl, —CH2CH═CH-pyridyl, —CH2CH═CH—CH2-pyridyl, —CH═CH-pyrazolyl, —CH2CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, —C≡C-pyridyl, —CH2C≡C-pyridyl, —CH2C≡C—CH2-pyridyl, —C≡C-pyrazolyl, —CH2C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, phenyl, pyridyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, furyl, thienyl, —CH2-pyridyl, —CH2CH2-pyridyl, —CH2-phenyl, —CH2CH2-phenyl, —CH2-pyrimidinyl, —CH2-pyrazinyl, —CH2-imidazolyl, —CH2-pyrazolyl, phenyl-CH2—, phenyl-CH2CH2—, pyridyl-CH2—, pyridyl-CH2CH2—, pyrimidinyl-CH2—, pyrazinyl-CH2—, imidazolyl-CH2— or pyrazolyl-CH2—, wherein each of —CH2—, —(CH2)2—, —(CH2)3—, —(CH2)4—, —CH═CH2—, —CH2CH═CH—, —CH2CH═CHCH2—, —C≡C—, —CH2CH≡CH—, —CH2CH≡CHCH2—, —CH═CH-phenyl, —CH2CH═CH-phenyl, —CH2CH═CH—CH2-phenyl, —C≡C-phenyl, —CH2C≡C-phenyl, —CH2C≡C—CH2-phenyl, —CH═CH-pyridyl, —CH2CH═CH-pyridyl, —CH2CH═CH—CH2-pyridyl, —CH═CH-pyrazolyl, —CH2CH═CH-pyrazolyl, —CH═CH-pyrimidinyl, —CH═CH-pyrazinyl, —CH═CH-benzimidazolyl, —CH═CH-benzopyrazolyl, —C≡C-pyridyl, —CH2C≡C-pyridyl, —CH2C≡C—CH2-pyridyl, —C≡C-pyrazolyl, —CH2C≡C-pyrazolyl, —C≡C-pyrimidinyl, —C≡C-pyrazinyl, —C≡C-benzimidazolyl, —C≡C-benzopyrazolyl, phenyl, pyridyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, furyl, thienyl, —CH2-pyridyl, —CH2CH2-pyridyl, —CH2-phenyl, —CH2CH2-phenyl, —CH2-pyrimidinyl, —CH2-pyrazinyl, —CH2-imidazolyl, —CH2-pyrazolyl, phenyl-CH2—, phenyl-CH2CH2—, pyridyl-CH2—, pyridyl-CH2CH2—, pyrimidinyl-CH2—, pyrazinyl-CH2—, imidazolyl-CH2— and pyrazolyl-CH2— is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, CF3, NH2, oxo, methoxy, ethoxy, n-propoxy, isopropoxy, cyclopropylidene, cyclobutylidene, cyclopentylidene, azetidinylidene, hydroxymethyl, hydroxyethyl, 2-hydroxy-2-propyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylethynyl, pyrrolidinyl, morpholinyl.

39. The compound of claim 34, wherein R3 is H, D, C1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C6-10 aryl, 5-10 membered heteroaryl, (3-12 membered Cyc)-C1-6 alkyl, (3-12 membered hetCyc)-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, C6-10 aryl C1-6 alkyl, (5-10 membered heteroaryl) C1-6 alkyl or amino C1-6 alkyl, wherein each of C1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C6-10 aryl, 5-10 membered heteroaryl, (3-12 membered Cyc)-C1-6 alkyl, (3-12 membered hetCyc)-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, C6-10 aryl C1-6 alkyl, (5-10 membered heteroaryl) C1-6 alkyl and amino C1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR5R6, R5O—, R5O(C═O)—, R5(C═O)—, NR5R6(C═O)NR5—, R5S(═O)2—, NO2, CN, CF3, C1-6 alkyl and C3-6 cycloalkyl; or,R3 is H, D, C1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, (3-10 membered Cyc)-C1-4 alkyl, (3-10 membered hetCyc)-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, phenyl C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl or amino C1-4 alkyl, wherein each of C1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, (3-10 membered Cyc)-C1-4 alkyl, (3-10 membered hetCyc)-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, phenyl C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl and amino C1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, NR5R6, R5O—, R5O(C═O)—, R5(C═O)—, NR5R6(C═O)NR5—, R5S(═O)2—, NO2, CN, CF3, C1-4 alkyl and C3-6 cycloalkyl; or,R3 is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopropylmethyl, cyclobutylmethyl, cyclohexylmethyl, spiro[4.4]decylmethyl, bicyclo[3.3.0]octyl, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, azetidinylmethyl, piperidinylmethyl, morpholinylmethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, isopropoxymethyl, isopropoxyethyl, n-butoxymethyl, isobutoxymethyl, tert-butoxymethyl, tert-butoxyethyl, phenyl, pyridyl, imidazolyl, pyrazolyl, pyrimidinyl, 3H-indolyl, indolyl, benzimidazolyl, 3,8a-dihydroindolizinyl, phenylmethyl, 3,8a-dihydroindolizinyl methyl, pyridylmethyl, imidazolylmethyl, pyrazolylmethyl, pyrimidinylmethyl, 3H-indolylmethyl, indolylmethyl, benzimidazolylmethyl, NH2CH2—, NH(CH3)CH2—, N(CH3)2CH2—, NH2(CH2)2—, NH(CH3)CH2—, NH(CH3)(CH2)2— or N(CH3)2(CH2)2—, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trifluoromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopropylmethyl, cyclobutylmethyl, cyclohexylmethyl, spiro[4.4]decylmethyl, bicyclo[3.3.0]octyl, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, azetidinylmethyl, piperidinylmethyl, morpholinylmethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, isopropoxymethyl, isopropoxyethyl, n-butoxymethyl, isobutoxymethyl, tert-butoxy methyl, tert-butoxyethyl, phenyl, pyridyl, imidazolyl, pyrazolyl, pyrimidinyl, 3H-indolyl, indolyl, benzimidazolyl, 3,8a-dihydroindolizinyl, phenylmethyl, 3,8a-dihydroindolizinylmethyl, pyridylmethyl, imidazolylmethyl, pyrazolylmethyl, pyrimidinylmethyl, 3H-indolyl methyl, indolylmethyl, benzimidazolylmethyl, NH2CH2—, NH(CH3)CH2—, N(CH3)2CH2—, NH2(CH2)2—, NH(CH3)CH2—, NH(CH3)(CH2)2— and N(CH3)2(CH2)2— is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NH2, NO2, CN, CF3, C(CH3)3O(C═O)—, CH3(C═O)—, NH2(C═O)NH—, NHCH3(C═O)NH—, CH3S(═O)2—, methyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenoxy, pyridyloxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl.

40. The compound of claim 34, wherein R1 is H, D, CN, F, Cl, Br, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, vinyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, vinyl, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH2, OH and NO2; andR4 is H, D, F, Cl, Br, CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butylmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy, wherein each of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butylmethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy and tert-butoxy is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, CN, NH2, OH and NO2.

41. The compound of claim 34, wherein R5 is H, D, C1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C6-10 aryl, 5-10 membered heteroaryl, C6-10 aryl C1-6 alkyl, (5-10 membered heteroaryl)-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, C6-10 aryloxy C1-6 alkyl, amino C1-6 alkyl, C1-6 alkylamino C1-6 alkyl, di(C1-6 alkyl)amino C1-6 alkyl, (3-12 membered Cyc)-C1-6 alkyl or (3-12 membered hetCyc)-C1-6 alkyl, wherein each of C1-6 alkyl, 3-12 membered Cyc, 3-12 membered hetCyc, C6-10 aryl, 5-10 membered heteroaryl, C6-10 aryl C1-6 alkyl, (5-10 membered heteroaryl)-C1-6 alkyl, C1-6 alkoxy C1-6 alkyl, C6-10 aryloxy C1-6 alkyl, amino C1-6 alkyl, C1-6 alkylamino C1-6 alkyl, di(C1-6 alkyl)amino C1-6 alkyl, (3-12 membered Cyc)-C1-6 alkyl and (3-12 membered hetCyc)-C1-6 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR6R7, C1-6 alkyl, C1-6 alkylsulfonyl, C1-6 alkoxy, C6-10 aryl and 5-10 membered heteroaryl;R6 is H, D or C1-6 alkyl; andR7 is H, D, C1-6 alkyl, C6-10 aryl C1-6 alkyl or (5-10 membered heteroaryl) C1-6 alkyl;or,R5 is H, D, C1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, phenyl C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, phenoxy C1-4 alkyl, amino C1-4 alkyl, C1-4 alkylamino C1-4 alkyl, di(C1-4 alkyl)amino C1-4 alkyl, (3-10 membered Cyc)-C1-4 alkyl or hetCyc-C1-4 alkyl, wherein each of C1-4 alkyl, 3-10 membered Cyc, 3-10 membered hetCyc, phenyl, 5-10 membered heteroaryl, phenyl C1-4 alkyl, (5-10 membered heteroaryl)-C1-4 alkyl, C1-4 alkoxy C1-4 alkyl, phenoxy C1-4 alkyl, amino C1-4 alkyl, C1-4 alkylamino C1-4 alkyl, di(C1-4 alkyl)amino C1-4 alkyl, (3-10 membered Cyc)-C1-4 alkyl and hetCyc-C1-4 alkyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NR6R7, C1-6 alkyl, C1-4 alkylsulfonyl, C1-4 alkoxy, phenyl and 5-10 membered heteroaryl;R6 is H, D or C1-4 alkyl; andR7 is H, D, C1-4 alkyl, phenyl C1-4 alkyl or (5-10 membered heteroaryl) C1-4 alkyl;or,R5 is H, D, NH2CH2—, NH2(CH2)2—, NH(CH3)CH2—, NH(CH3)(CH2)2—, N(CH3)2CH2—, NH(CH3)2(CH2)2—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylethyl, cyclobutyl methyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methoxymethyl, methoxyethyl, ethoxyethyl, phenylmethyl, phenylethyl, phenyl-n-propyl, pyridylmethyl, pyridylethyl, pyridyl-n-propyl, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, azetidinyl, oxetanyl or tetrahydropyranyl, wherein each of NH2CH2—, NH2(CH2)2—, NH(CH3)CH2—, NH(CH3)(CH2)2—, N(CH3)2CH2—, NH(CH3)2(CH2)2—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylethyl, cyclobutylmethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methoxymethyl, methoxyethyl, ethoxyethyl, phenylmethyl, phenylethyl, phenyl-n-propyl, pyridylmethyl, pyridylethyl, pyridyl-n-propyl, phenoxymethyl, phenoxyethyl, phenoxy-n-propyl, azetidinyl, oxetanyl and tetrahydropyranyl is independently and optionally substituted by 1, 2, 3 or 4 substituents selected from F, Cl, Br, OH, NH2, NH(CH3), CH3S(═O)2—, CH3CH2S(═O)2—, CH(CH3)2S(═O)2—, C(CH3)3S(═O)2—, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, n-propoxy, phenyl, pyridyl, pyrazolyl, pyrimidinyl;R6 is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; andR7 is H, D, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenylmethyl, phenylethyl, phenyl-n-propyl, imidazolylmethyl, pyrazolylmethyl, pyridylmethyl, pyridylethyl, pyrimidinylmethyl or pyrimidinylethyl.

42. The compound of claim 34 having Formula (I-1), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

43. The compound of claim 42, wherein

44. The compound of claim 34 having Formula (I-2), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

45. The compound of claim 44, wherein A1 is one of the following sub-formulae:

46. The compound of claim 34 having Formula (I-3) or (I-4), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

47. The compound of claim 46, wherein

48. The compound of claim 34 having one of the following structures, or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof,

49. A pharmaceutical composition comprising the compound of claim 34 and a pharmaceutically acceptable adjuvant.

50. A method of preventing or treating a RET-related disease in a patient, comprising administering a therapeutically effective amount of the compound of claim 34 to the patient.

51. The method of claim 50, wherein the RET-related disease is cancer, irritable bowel syndrome and/or pain associated with irritable bowel syndrome.

52. A method of preventing or treating a RET-related disease in a patient, comprising administering a therapeutically effective amount of the pharmaceutical composition of claim 49 to the patient.

53. The method of claim 52, wherein the RET-related disease is cancer, irritable bowel syndrome and/or pain associated with irritable bowel syndrome.