Patent Application
20240417407
The present invention covers furoindazole compounds of general formula (I) as described and defined herein, methods of preparing said compounds, intermediate compounds useful for preparing said compounds, pharmaceutical compositions comprising said compounds, and the use of said compounds for manufacturing pharmaceutical compositions for the treatment or prophylaxis of diseases, in particular of autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders.
The present invention covers furoindazole compounds of general formula (I) which are antagonists of the G-protein coupled receptor 84 (also known as GPR84). The relevance of GPR84 for human disease has been described and studied in several publications.
Medium-chain free fatty acids (MCFFAs) are fatty acids with tails of 6 to 12 carbons and can activate GPR84 (Wang J et al., J. Biol. Chem. 2006 Nov. 10, 281(45): 34457-64). There are two sources of FAs for animal metabolism, exogenously derived (dietary) FAs and endogenously synthesized FAs. The biosynthesis of the latter is catalysed by FASN. MCFFAs stimulate release of IL6 from fibroblasts (Smith and Tasi, Nat. Prod. Rep. 2007 October, 24(5): 1041-72) and myristic acid increases IL6 and IL8 levels in human coronary arterial smooth muscle (HCASM) and endothelial (HCEC) cells (Soto-Vaca A. et al., J. Agric. Food Chem. 2013 Oct. 23, 61(42): 10074-9).
GPR84 belongs to the group of Free Fatty Acid (FFA) receptors (Wang J. et al., J. Biol. Chem. 2006 Nov. 10, 281(45): 34457-64). The group of FFA receptors consists of 4 GPCRs (FFA1-FFA2) and the new members GPR42 and GPR84. FFA receptors are involved in biological processes such as metabolic and immune function receptors (Wang J. et al., J. Biol. Chem. 2006 Nov. 10, 281(45): 34457-64).
In contrast to all other FFA receptors which have a broader expression pattern, GPR84 has been described to be expressed primarily in various leukocyte populations and adipocytes (Wang J. et al., J. Biol. Chem. 2006 Nov. 10, 281(45): 34457-64; Lattin J. E. et al., Immunome Res. 2008 Apr. 29, 4: 5; Nagasaki H. et al., FEBS Lett. 2012 Feb. 17, 586(4): 368-72).
Activation of GPR84 promotes a comprehensive fibrotic and inflammatory cellular response, exerted by enhanced migration of macrophages and neutrophils, promoted pro-inflammatory M1 macrophage polarization and response and secretion of key inflammatory cytokines such as IL1beta and TNFalpha (Gagnon L. et al., Am. J. Pathol. 2018 May, 188(5): 1132-1148; Muredda L. et al., Arch. Physiol. Biochem. 2018 May, 124(2): 97-108; Huang Q. et al., Dev. Comp. Immunol. 2014, 45(2): 252-258). Based on the involvement of GPR84 in fibrotic and inflammatory cellular response several diseases have been suggested to be GPR84 dependent.
GPR84 as microglia-associated protein is expressed in neuroinflammatory conditions and is described as a potential target for the treatment of multiple sclerosis (Bouchard C. et al., Glia 2007 June, 55(8): 790-800) and for endometriosis associated and inflammatory pain (Sacher F. et al. 2018, Conference Abstract SRI 2018). Furthermore, inhibition of activity and/or the knockout of GPR84 are also effective in the treatment of neuropathic pain in several preclinical models (Roman et al. 2010, 7th Forum of European Neuroscience (FENS)).
The relevance of GPR84 for inflammatory kidney diseases has been shown in experiments using Gpr84-knockout mice or GPR84 antagonist in models of kidney fibrosis and models for inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases (Puengel et al. 2018, 2018 International Liver Congress (ILC) of the European Association for the Study of the Liver (EASL); Thibodeau J. F. et al. 2018, 51st Annual Meeting and Exposition of the American Society of Nephrology (ASN): Kidney Week 2018).
As described previously for macrophages and monocytes, inflammatory changes in adipose tissue enhance expression of GPR84 in adipocytes and modulation of GPR84 regulates adipocyte immune response capabilities (Muredda et al., Archives of Physiology and Biochemistry 2017 August, 124(2): 1-12) indicating the relevance of GPR84 in metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) through normalization of adipose tissue inflammation.
Regulation of neutrophil activity and general inflammation by GPR84 was also described to be relevant for lung diseases like asthma, idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease (Nguyen et al. 2018; Annual Congress Scientific Sessions of the American Heart Association (AHA 2018); Saniere L. et al. 2019; 2019 International Conference of the American Thoracic Society (ATS)).
Few compounds are known as GPR84 antagonists, for example the patent applications WO2013092791 and WO2014095798 disclose dihydropyrimidinoisoquinolinones having activity as GPR84 antagonists. Such compounds find utility in several therapeutic applications including inflammatory conditions.
The patent applications WO2015197550 and WO2016169911 disclose related dihydropyridoisoquinolinones as GPR84 antagonists.
The patent application WO2018161831 discloses dibenzoannulen hydrogen phosphates as GPR84 antagonists.
The patent application WO2009023773 discloses galactokinase inhibitors that were identified by a high throughput screening approach. Among the identified hits were two furoindazole compounds.
The patent application US20090163545 discloses compounds for altering the lifespan of eukaryotic organisms that were identified by a cell-based phenotypic high throughput screening approach. Among the identified hits were two furoindazole compounds.
The patent applications U.S. Pat. No. 6,245,796B1, WO2001083487 and WO2011071136 disclose aromatic tricyclic pyrrole or pyrazole derivatives as 5-HT2c ligands.
The patent application WO2016085990 discloses compounds inhibiting serine hydroxy-methyltransferase 2 activity that were identified by a high throughput screening approach.
Among the identified hits were nine furoindazole compounds.
The patent application WO2019084271 discloses compounds inhibiting the non-canonical poly(A) RNA polymerase associated domain containing protein 5 (PAPD5) originating from diverse compound classes that were identified by a high throughput screening approach. Among the identified hits were eight furoindazole compounds.
However, the state of the art does not describe the furoindazole compounds of general formula (I) of the present invention as described and defined herein.
It has now been found, and this constitutes the basis of the present invention, that the compounds of the present invention have surprising and advantageous properties.
In particular, the compounds of the present invention have surprisingly been found to be effective antagonists of human GPR84 and may be used for the treatment or prophylaxis of diseases, in particular of autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders.
In accordance with a first aspect, the present invention covers compounds of general formula (I):
The term “substituted” means that one or more hydrogen atoms on the designated atom or group are replaced with a selection from the indicated group, provided that the designated atom's normal valency under the existing circumstances is not exceeded. Combinations of substituents and/or variables are permissible.
The term “optionally substituted” means that the number of substituents can be equal to or different from zero. Unless otherwise indicated, it is possible that optionally substituted groups are substituted with as many optional substituents as can be accommodated by replacing a hydrogen atom with a non-hydrogen substituent on any available carbon or nitrogen atom. Commonly, it is possible for the number of optional substituents, when present, to be 1, 2, 3, 4 or 5, in particular 1, 2 or 3.
As used herein, the term “one or more”, e.g. in the definition of the substituents of the compounds of general formula (I) of the present invention, means 1, 2, 3, 4 or 5, particularly 1, 2, 3 or 4, more particularly 1, 2 or 3, even more particularly 1 or 2.
As used herein, an oxo substituent represents an oxygen atom, which is bound to a carbon atom via a double bond.
Should a composite substituent be composed of more than one parts, e.g. (C1-C4-alkoxy)-(C1-C4-alkyl)-, it is possible for the position of a given part to be at any suitable position of said composite substituent, i.e. the C1-C4-alkoxy part can be attached to any carbon atom of the C1-C4-alkyl part of said (C1-C4-alkoxy)-(C1-C4-alkyl)-group. A hyphen at the beginning or at the end of such a composite substituent indicates the point of attachment of said composite substituent to the rest of the molecule. Should a ring, comprising carbon atoms and optionally one or more heteroatoms, such as nitrogen, oxygen or sulphur atoms for example, be substituted with a substituent, it is possible for said substituent to be bound at any suitable position of said ring, be it bound to a suitable carbon atom and/or to a suitable heteroatom.
The term “comprising” when used in the specification includes “consisting of”.
If within the present text any item is referred to as “as mentioned herein”, it means that it may be mentioned anywhere in the present text.
The terms as mentioned in the present text have the following meanings: The term “halogen atom” means a fluorine, chlorine, bromine or iodine atom, particularly a fluorine, chlorine or bromine atom.
The term “C1-C4-alkyl” means a linear or branched, saturated, monovalent hydrocarbon group having 1, 2, 3, or 4 carbon atoms, e.g. a methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl. Particularly, said group has 1, 2, or 3 carbon atoms (“C1-C3-alkyl”), e.g. a methyl, ethyl, propyl, or isopropyl group, more particularly 1 or 2 carbon atoms (“C1-C2-alkyl”), e.g. a methyl or ethyl group.
The term “C1-C4-hydroxyalkyl” means a linear or branched, saturated, monovalent hydrocarbon group in which the term “C1-C4-alkyl” is defined supra, and in which one hydrogen atom is replaced with a hydroxy group, e.g. a hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 1-hydroxypropyl, 1-hydroxypropan-2-yl, 2-hydroxypropan-2-yl, 3-hydroxy-2-methyl-propyl, 2-hydroxy-2-methyl-propyl, 1-hydroxy-2-methyl-propyl group.
The term “C1-C4-haloalkyl” means a linear or branched, saturated, monovalent hydrocarbon group in which the term “C1-C4-alkyl” is as defined supra, and in which one or more of the hydrogen atoms are replaced, identically or differently, with a halogen atom. Particularly, said halogen atom is a fluorine atom. Said C1-C4-haloalkyl group is, for example, fluoromethyl, difluoromethyl, trifluoromethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, 3,3,3-trifluoropropyl or 1,3-difluoropropan-2-yl.
The term “C1-C4-alkoxy” means a linear or branched, saturated, monovalent group of formula (C1-C4-alkyl)-O—, in which the term “C1-C4-alkyl” is as defined supra, e.g. a methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, or tert-butoxy group.
The term “C1-C4-haloalkoxy” means a linear or branched, saturated, monovalent C1-C4-alkoxy group, as defined supra, in which one or more of the hydrogen atoms is replaced, identically or differently, with a halogen atom. Particularly, said halogen atom is a fluorine atom. Said C1-C4-haloalkoxy group is, for example, fluoromethoxy, difluoromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy or pentafluoroethoxy.
The term “C3-C6-cycloalkyl” means a saturated, monovalent, monocyclic hydrocarbon ring which contains 3, 4, 5, or 6 carbon atoms (“C3-C6-cycloalkyl”). Said C3-C6-cycloalkyl group is for example, e.g. a cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl group.
The term “C3-C6-halocycloalkyl” means a saturated, monovalent, monocyclic hydrocarbon ring in which the term “C3-C6-halocycloalkyl” is as defined supra, and in which one or more of the hydrogen atoms are replaced, identically or differently, with a halogen atom. Particularly, said halogen atom is a fluorine atom.
The term “5- to 6-membered heterocycloalkyl” means a monocyclic, saturated heterocycle with 5 or 6 ring atoms in total, which contains one or two identical or different ring heteroatoms from the series N, O and S, it being possible for said heterocycloalkyl group to be attached to the rest of the molecule via any one of the carbon atoms or, if present, a nitrogen atom.
Said heterocycloalkyl group, without being limited thereto, can be a 5-membered ring, such as tetrahydrofuranyl, 1,3-dioxolanyl, thiolanyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, 1,1-dioxidothiolanyl, 1,2-oxazolidinyl, 1,3-oxazolidinyl or 1,3-thiazolidinyl, for example; or a 6-membered ring, such as tetrahydropyranyl, tetrahydrothiopyranyl, piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl, 1,3-dioxanyl, 1,4-dioxanyl or 1,2-oxazinanyl, for example.
Particularly, “5- to 6-membered heterocycloalkyl” means a 5- to 6-membered heterocycloalkyl as defined supra containing one ring nitrogen or oxygen atom and optionally one further ring heteroatom from the series: N, O, S. More particularly, “5- or 6-membered heterocycloalkyl” means a monocyclic, saturated heterocycle with 5 or 6 ring atoms in total, containing one ring nitrogen or oxygen atom and optionally one further ring heteroatom from the series: N, O.
The term “heterocycloalkyl fused with phenyl or heteroaryl” means a bicyclic heterocycle with 8, 9 or 10 ring atoms in total, in which the two rings share two adjacent ring atoms, and in which the “heterocycloalkyl” part contains one or two identical or different ring heteroatoms from the series: N, O and/or S, and the term “heteroaryl” means a monocyclic aromatic ring having 5 or 6 ring atoms (a “5- to 6-membered heteroaryl” group), which contains at least one ring heteroatom and optionally one, two or three further ring heteroatoms from the series N, O and/or S; it being possible for said fused heterocycloalkyl group to be attached to the rest of the molecule via any one of the carbon atoms or, if present, a nitrogen atom.
The term “heterospirocycloalkyl” means a bicyclic, saturated heterocycle with 6, 7, 8, 9, 10 or 11 ring atoms in total, in which the two rings share one common ring carbon atom, which “heterospirocycloalkyl” contains one or two identical or different ring heteroatoms from the series: N, O, S; it being possible for said heterospirocycloalkyl group to be attached to the rest of the molecule via any one of the carbon atoms, except the spiro carbon atom, or, if present, a nitrogen atom.
Said heterospirocycloalkyl group is, for example, azaspiro[2.3]hexyl, azaspiro[3.3]heptyl, oxaazaspiro[3.3]heptyl, thiaazaspiro[3.3]heptyl, oxaspiro[3.3]heptyl, oxazaspiro[5.3]nonyl, oxazaspiro[4.3]octyl, azaspiro[4,5]decyl, oxazaspiro[5.5]undecyl, diazaspiro[3.3]heptyl, thiazaspiro[3.3]heptyl, thiazaspiro[4.3]octyl, azaspiro[5.5]undecyl, or one of the further homologous scaffolds such as spiro[3.4]-, spiro[4.4]-, spiro[2.4]-, spiro[2.5]-, spiro[2.6]-, spiro[3.5]-, spiro[3.6]-, spiro[4.5]- and spiro[4.6]-.
The term “heteroaryl” means a monovalent, monocyclic, bicyclic or tricyclic aromatic ring having 5, 6, 8, 9, or 10 ring atoms (a “5- to 10-membered heteroaryl” group), particularly 5, 6, 9 or 10 ring atoms, which contains at least one ring heteroatom and optionally one, two or three further ring heteroatoms from the series: N, O and/or S, and which is bound via a ring carbon atom or optionally via a ring nitrogen atom (if allowed by valency).
Said heteroaryl group can be a 5-membered heteroaryl group, such as, for example, thienyl, furanyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl or tetrazolyl; or a 6-membered heteroaryl group, such as, for example, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl or triazinyl; or a tricyclic heteroaryl group, such as, for example, carbazolyl, acridinyl or phenazinyl; or a 9-membered heteroaryl group, such as, for example, benzofuranyl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzothiazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl, indolizinyl or purinyl; or a 10-membered heteroaryl group, such as, for example, quinolinyl, quinazolinyl, isoquinolinyl, cinnolinyl, phthalazinyl, quinoxalinyl or pteridinyl.
In general, and unless otherwise mentioned, the heteroaryl groups include all possible isomeric forms thereof, e.g.: tautomers and positional isomers with respect to the point of linkage to the rest of the molecule. Thus, for some illustrative non-restricting examples, the term pyridinyl includes pyridin-2-yl, pyridin-3-yl and pyridin-4-yl; or the term thienyl includes thien-2-yl and thien-3-yl.
Particularly, the heteroaryl group is a pyridinyl group.
The term “C1-C6”, as used in the present text, e.g. in the context of the definition of “C1-C6-alkyl”, “C1-C6-haloalkyl”, “C1-C6-hydroxyalkyl”, “C1-C6-alkoxy” or “C1-C6-haloalkoxy” means an alkyl group having a finite number of carbon atoms of 1 to 6, i.e. 1, 2, 3, 4, 5 or 6 carbon atoms.
Further, as used herein, the term “C3-C8”, as used in the present text, e.g. in the context of the definition of “C3-C8-cycloalkyl”, means a cycloalkyl group having a finite number of carbon atoms of 3 to 8, i.e. 3, 4, 5, 6, 7 or 8 carbon atoms.
When a range of values is given, said range encompasses each value and sub-range within said range.
For example:
As used herein, the term “leaving group” means an atom or a group of atoms that is displaced in a chemical reaction as stable species taking with it the bonding electrons. In particular, such a leaving group is selected from the group comprising: halide, in particular fluoride, chloride, bromide or iodide, (methylsulfonyl)oxy, [(trifluoromethyl)sulfonyl]oxy, [(nonafluorobutyl)sulfonyl]oxy, (phenylsulfonyl)oxy, [(4-methylphenyl)sulfonyl]oxy, [(4-bromophenyl)sulfonyl]oxy, [(4-nitrophenyl)sulfonyl]oxy, [(2-nitrophenyl)sulfonyl]oxy, [(4-isopropylphenyl)sulfonyl]oxy, [(2,4,6-triisopropylphenyl)sulfonyl]oxy, [(2,4,6-trimethylphenyl)sulfonyl]oxy, [(4-tert-butylphenyl)sulfonyl]oxy and [(4-methoxyphenyl)sulfonyl]oxy.
It is possible for the compounds of general formula (I) to exist as isotopic variants. The invention therefore includes one or more isotopic variant(s) of the compounds of general formula (I), particularly deuterium-containing compounds of general formula (I).
The term “Isotopic variant” of a compound or a reagent is defined as a compound exhibiting an unnatural proportion of one or more of the isotopes that constitute such a compound.
The term “Isotopic variant of the compound of general formula (I)” is defined as a compound of general formula (I) exhibiting an unnatural proportion of one or more of the isotopes that constitute such a compound.
The expression “unnatural proportion” means a proportion of such isotope which is higher than its natural abundance. The natural abundances of isotopes to be applied in this context are described in “Isotopic Compositions of the Elements 1997”, Pure Appl. Chem., 70(1), 217-235, 1998.
Examples of such isotopes include stable and radioactive isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulphur, fluorine, chlorine, bromine and iodine, such as 2H (deuterium), 3H (tritium), 11C, 13C, 14C, 15N, 17O, 18O, 32P, 33P, 33S, 34S, 35S, 36S, 18F, 36Cl, 82Br, 123I, 124I, 125I, 129I and 131I, respectively.
With respect to the treatment and/or prophylaxis of the disorders specified herein the isotopic variant(s) of the compounds of general formula (I) preferably contain deuterium (“deuterium-containing compounds of general formula (I)”). Isotopic variants of the compounds of general formula (I) in which one or more radioactive isotopes, such as 3H or 14C, are incorporated are useful e.g. in drug and/or substrate tissue distribution studies.
These isotopes are particularly preferred for the ease of their incorporation and detectability. Positron emitting isotopes such as 18F or 11C may be incorporated into a compound of general formula (I). These isotopic variants of the compounds of general formula (I) are useful for in vivo imaging applications. Deuterium-containing and 13C-containing compounds of general formula (I) can be used in mass spectrometry analyses in the context of preclinical or clinical studies.
Isotopic variants of the compounds of general formula (I) can generally be prepared by methods known to a person skilled in the art, such as those described in the schemes and/or examples herein, by substituting a reagent for an isotopic variant of said reagent, preferably for a deuterium-containing reagent. Depending on the desired sites of deuteration, in some cases deuterium from D2O can be incorporated either directly into the compounds or into reagents that are useful for synthesizing such compounds. Deuterium gas is also a useful reagent for incorporating deuterium into molecules. Catalytic deuteration of olefinic bonds and acetylenic bonds is a rapid route for incorporation of deuterium. Metal catalysts (i.e. Pd, Pt, and Rh) in the presence of deuterium gas can be used to directly exchange deuterium for hydrogen in functional groups containing hydrocarbons. A variety of deuterated reagents and synthetic building blocks are commercially available from companies such as for example C/D/N Isotopes, Quebec, Canada; Cambridge Isotope Laboratories Inc., Andover, MA, USA; and CombiPhos Catalysts, Inc., Princeton, NJ, USA.
The term “deuterium-containing compound of general formula (I)” is defined as a compound of general formula (I), in which one or more hydrogen atom(s) is/are replaced by one or more deuterium atom(s) and in which the abundance of deuterium at each deuterated position of the compound of general formula (I) is higher than the natural abundance of deuterium, which is about 0.015%. Particularly, in a deuterium-containing compound of general formula (I) the abundance of deuterium at each deuterated position of the compound of general formula (I) is higher than 10%, 20%, 30%, 40%, 50%, 60%, 70% or 80%, preferably higher than 90%, 95%, 96% or 97%, even more preferably higher than 98% or 99% at said position(s). It is understood that the abundance of deuterium at each deuterated position is independent of the abundance of deuterium at other deuterated position(s).
The selective incorporation of one or more deuterium atom(s) into a compound of general formula (I) may alter the physicochemical properties (such as for example acidity [C. L. Perrin, et al., J. Am. Chem. Soc., 2007, 129, 4490], basicity [C. L. Perrin et al., J. Am. Chem. Soc., 2005, 127, 9641], lipophilicity [B. Testa et al., Int. J. Pharm., 1984, 19(3), 271]) and/or the metabolic profile of the molecule and may result in changes in the ratio of parent compound to metabolites or in the amounts of metabolites formed. Such changes may result in certain therapeutic advantages and hence may be preferred in some circumstances. Reduced rates of metabolism and metabolic switching, where the ratio of metabolites is changed, have been reported (A. E. Mutlib et al., Toxicol. Appl. Pharmacol., 2000, 169, 102). These changes in the exposure to parent drug and metabolites can have important consequences with respect to the pharmacodynamics, tolerability and efficacy of a deuterium-containing compound of general formula (I). In some cases, deuterium substitution reduces or eliminates the formation of an undesired or toxic metabolite and enhances the formation of a desired metabolite (e.g. Nevirapine: A. M. Sharma et al., Chem. Res. Toxicol., 2013, 26, 410; Efavirenz: A. E. Mutlib et al., Toxicol. Appl. Pharmacol., 2000, 169, 102). In other cases, the major effect of deuteration is to reduce the rate of systemic clearance. As a result, the biological half-life of the compound is increased. The potential clinical benefits would include the ability to maintain similar systemic exposure with decreased peak levels and increased trough levels. This could result in lower side effects and enhanced efficacy, depending on the particular compound's pharmacokinetic/pharmacodynamic relationship. ML-337 (C. J. Wenthur et al., J. Med. Chem., 2013, 56, 5208) and Odanacatib (K. Kassahun et al., WO2012/112363) are examples for this deuterium effect. Still other cases have been reported in which reduced rates of metabolism result in an increase in exposure of the drug without changing the rate of systemic clearance (e.g. Rofecoxib: F. Schneider et al., Arzneim. Forsch./Drug. Res., 2006, 56, 295; Telaprevir: F. Maltais et al., J. Med. Chem., 2009, 52, 7993). Deuterated drugs showing this effect may have reduced dosing requirements (e.g. lower number of doses or lower dosage to achieve the desired effect) and/or may produce lower metabolite loads.
A compound of general formula (I) may have multiple potential sites of attack for metabolism. To optimize the above-described effects on physicochemical properties and metabolic profile, deuterium-containing compounds of general formula (I) having a certain pattern of one or more deuterium-hydrogen exchange(s) can be selected. Particularly, the deuterium atom(s) of deuterium-containing compound(s) of general formula (I) is/are attached to a carbon atom and/or is/are located at those positions of the compound of general formula (I), which are sites of attack for metabolizing enzymes such as e.g. cytochrome P450.
Where the plural form of the word compounds, salts, polymorphs, hydrates, solvates and the like, is used herein, this is taken to mean also a single compound, salt, polymorph, isomer, hydrate, solvate or the like.
By “stable compound’ or “stable structure” is meant a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent.
The compounds of the present invention optionally contain one or more asymmetric centres, depending upon the location and nature of the various substituents desired. It is possible that one or more asymmetric carbon atoms are present in the (R) or (S) configuration, which can result in racemic mixtures in the case of a single asymmetric centre, and in diastereomeric mixtures in the case of multiple asymmetric centres. In certain instances, it is possible that asymmetry also be present due to restricted rotation about a given bond, for example, the central bond adjoining two substituted aromatic rings of the specified compounds.
Preferred compounds are those which produce the more desirable biological activity. Separated, pure or partially purified isomers and stereoisomers or racemic or diastereomeric mixtures of the compounds of the present invention are also included within the scope of the present invention. The purification and the separation of such materials can be accomplished by standard techniques known in the art.
Preferred isomers are those which produce the more desirable biological activity. These separated, pure or partially purified isomers or racemic mixtures of the compounds of this invention are also included within the scope of the present invention. The purification and the separation of such materials can be accomplished by standard techniques known in the art.
The optical isomers can be obtained by resolution of the racemic mixtures according to conventional processes, for example, by the formation of diastereoisomeric salts using an optically active acid or base or formation of covalent diastereomers. Examples of appropriate acids are tartaric, diacetyltartaric, ditoluoyltartaric and camphorsulfonic acid. Mixtures of diastereoisomers can be separated into their individual diastereomers on the basis of their physical and/or chemical differences by methods known in the art, for example, by chromatography or fractional crystallisation. The optically active bases or acids are then liberated from the separated diastereomeric salts. A different process for separation of optical isomers involves the use of chiral chromatography (e.g., HPLC columns using a chiral phase), with or without conventional derivatisation, optimally chosen to maximise the separation of the enantiomers. Suitable HPLC columns using a chiral phase are commercially available, such as those manufactured by Daicel, e.g., Chiracel OD and Chiracel OJ, for example, among many others, which are all routinely selectable. Enzymatic separations, with or without derivatisation, are also useful. The optically active compounds of the present invention can likewise be obtained by chiral syntheses utilizing optically active starting materials.
In order to distinguish different types of isomers from each other reference is made to IUPAC Rules Section E (Pure Appl Chem 45, 11-30, 1976).
The present invention includes all possible stereoisomers of the compounds of the present invention as single stereoisomers, or as any mixture of said stereoisomers, e.g. (R)- or (S)-isomers, in any ratio. Isolation of a single stereoisomer, e.g. a single enantiomer or a single diastereomer, of a compound of the present invention is achieved by any suitable state of the art method, such as chromatography, especially chiral chromatography, for example.
Further, it is possible for the compounds of the present invention to exist as tautomers. For example, any compound of the present invention which contains an indazole moiety can exist as a 1H tautomer, or a 2H tautomer, or even a mixture in any amount of the two tautomers, namely:
The present invention includes all possible tautomers of the compounds of the present invention as single tautomers, or as any mixture of said tautomers, in any ratio.
Further, the compounds of the present invention can exist as N-oxides, which are defined in that at least one nitrogen of the compounds of the present invention is oxidised. The present invention includes all such possible N-oxides.
The present invention also covers useful forms of the compounds of the present invention, such as metabolites, hydrates, solvates, prodrugs, salts, in particular pharmaceutically acceptable salts, and/or co-precipitates.
The compounds of the present invention can exist as a hydrate, or as a solvate, wherein the compounds of the present invention contain polar solvents, in particular water, methanol or ethanol for example, as structural element of the crystal lattice of the compounds. It is possible for the amount of polar solvents, in particular water, to exist in a stoichiometric or non-stoichiometric ratio. In the case of stoichiometric solvates, e.g. a hydrate, hemi-, (semi-), mono-, sesqui-, di-, tri-, tetra-, penta- etc. solvates or hydrates, respectively, are possible. The present invention includes all such hydrates or solvates.
Further, it is possible for the compounds of the present invention to exist in free form, e.g. as a free base, or as a free acid, or as a zwitterion, or to exist in the form of a salt. Said salt may be any salt, either an organic or inorganic addition salt, particularly any pharmaceutically acceptable organic or inorganic addition salt, which is customarily used in pharmacy, or which is used, for example, for isolating or purifying the compounds of the present invention.
The term “pharmaceutically acceptable salt” refers to an inorganic or organic acid addition salt of a compound of the present invention. For example, see S. M. Berge, et al. “Pharmaceutical Salts,” J. Pharm. Sci. 1977, 66, 1-19.
A suitable pharmaceutically acceptable salt of the compounds of the present invention may be, for example, an acid-addition salt of a compound of the present invention bearing a nitrogen atom, in a chain or in a ring, for example, which is sufficiently basic, such as an acid-addition salt with an inorganic acid, or “mineral acid”, such as hydrochloric, hydrobromic, hydroiodic, sulfuric, sulfamic, bisulfuric, phosphoric, or nitric acid, for example, or with an organic acid, such as formic, acetic, acetoacetic, pyruvic, trifluoroacetic, propionic, butyric, hexanoic, heptanoic, undecanoic, lauric, benzoic, salicylic, 2-(4-hydroxybenzoyl)-benzoic, camphoric, cinnamic, cyclopentanepropionic, digluconic, 3-hydroxy-2-naphthoic, nicotinic, pamoic, pectinic, 3-phenylpropionic, pivalic, 2-hydroxyethanesulfonic, itaconic, trifluoromethanesulfonic, dodecylsulfuric, ethanesulfonic, benzenesulfonic, para-toluenesulfonic, methanesulfonic, 2-naphthalenesulfonic, naphthalinedisulfonic, camphorsulfonic acid, citric, tartaric, stearic, lactic, oxalic, malonic, succinic, malic, adipic, alginic, maleic, fumaric, D-gluconic, mandelic, ascorbic, glucoheptanoic, glycerophosphoric, aspartic, sulfosalicylic, or thiocyanic acid, for example.
Further, another suitably pharmaceutically acceptable salt of a compound of the present invention which is sufficiently acidic, is an alkali metal salt, for example a sodium or potassium salt, an alkaline earth metal salt, for example a calcium, magnesium or strontium salt, or an aluminium or a zinc salt, or an ammonium salt derived from ammonia or from an organic primary, secondary or tertiary amine having 1 to 20 carbon atoms, such as ethylamine, diethylamine, triethylamine, ethyldiisopropylamine, monoethanolamine, diethanolamine, triethanolamine, dicyclohexylamine, dimethylaminoethanol, diethylaminoethanol, tris(hydroxymethyl)aminomethane, procaine, dibenzylamine, N-methylmorpholine, arginine, lysine, 1,2-ethylenediamine, N-methylpiperidine, N-methyl-glucamine, N,N-dimethyl-glucamine, N-ethyl-glucamine, 1,6-hexanediamine, glucosamine, sarcosine, serinol, 2-amino-1,3-propanediol, 3-amino-1,2-propanediol, 4-amino-1,2,3-butanetriol, or a salt with a quarternary ammonium ion having 1 to 20 carbon atoms, such as tetramethylammonium, tetraethylammonium, tetra(n-propyl)ammonium, tetra(n-butyl)ammonium, N-benzyl-N,N,N-trimethylammonium, choline or benzalkonium.
Those skilled in the art will further recognise that it is possible for acid addition salts of the claimed compounds to be prepared by reaction of the compounds with the appropriate inorganic or organic acid via any of a number of known methods. Alternatively, alkali and alkaline earth metal salts of acidic compounds of the present invention are prepared by reacting the compounds of the present invention with the appropriate base via a variety of known methods.
The present invention includes all possible salts of the compounds of the present invention as single salts, or as any mixture of said salts, in any ratio.
In the present text, in particular in the Experimental Section, for the synthesis of intermediates and of examples of the present invention, when a compound is mentioned as a salt form with the corresponding base or acid, the exact stoichiometric composition of said salt form, as obtained by the respective preparation and/or purification process, is, in most cases, unknown.
Unless specified otherwise, suffixes to chemical names or structural formulae relating to salts, such as “hydrochloride”, “trifluoroacetate”, “sodium salt”, or “x HCl”, “x CF3COOH”, “x Na+”, for example, mean a salt form, the stoichiometry of which salt form not being specified.
This applies analogously to cases in which synthesis intermediates or example compounds or salts thereof have been obtained, by the preparation and/or purification processes described, as solvates, such as hydrates, with (if defined) unknown stoichiometric composition.
Furthermore, the present invention includes all possible crystalline forms, or polymorphs, of the compounds of the present invention, either as single polymorph, or as a mixture of more than one polymorph, in any ratio.
Moreover, the present invention also includes prodrugs of the compounds according to the invention. The term “prodrugs” here designates compounds which themselves can be biologically active or inactive but are converted (for example metabolically or hydrolytically) into compounds according to the invention during their residence time in the body.
In accordance with a second embodiment of the first aspect, the present invention covers compounds of general formula (I), supra, in which:
In accordance with a third embodiment of the first aspect, the present invention covers compounds of general formula (I), supra, in which:
In accordance with a fourth embodiment of the first aspect, the present invention covers compounds of general formula (I), supra, in which:
Further embodiments of the first aspect of the present invention:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a further embodiment of the first aspect, the present invention covers compounds of formula (I), supra, in which:
In a particular further embodiment of the first aspect, the present invention covers combinations of two or more of the above-mentioned embodiments under the heading “further embodiments of the first aspect of the present invention”.
The present invention covers any sub-combination within any embodiment or aspect of the present invention of compounds of general formula (I), supra.
The present invention covers any sub-combination within any embodiment or aspect of the present invention of intermediate compounds of general formula (II).
The present invention covers the compounds of general formula (I) which are disclosed in the Example Section of this text, infra.
The compounds according to the invention of general formula (I) can be prepared according to the following schemes 1, 2, and 3. The schemes and procedures described below illustrate synthetic routes to the compounds of general formula (I) of the invention and are not intended to be limiting. It is clear to the person skilled in the art that the order of transformations as exemplified in schemes 1, 2, and 3 can be modified in various ways. The order of transformations exemplified in these schemes is therefore not intended to be limiting. In addition, interconversion of any of the substituents R1, R2, R3, R4, R5, R6a or R6b can be achieved before and/or after the exemplified transformations. These modifications can be such as the introduction of protecting groups, cleavage of protecting groups, reduction or oxidation of functional groups, halogenation, metallation, substitution or other reactions known to the person skilled in the art. These transformations include those which introduce a functionality which allows for further interconversion of substituents. Appropriate protecting groups and their introduction and cleavage are well-known to the person skilled in the art. Specific examples are described in the subsequent paragraphs.
Routes for the preparation of compounds of general formula (I) and corresponding intermediates are described in schemes 1, 2, and 3.
Scheme 1: Route for the preparation of compounds of general formula (I) in which X is a leaving group, R is methyl, ethyl, or tert-butyl and R4, R2, R3, R4, R5, R6a and R6b have the meaning as given for general formula (I), supra.
Tetrahydrobenzofuranes of general formula (3) can be obtained via aldol condensation of (1) and (2) followed by intramolecular cyclisation according to the procedures described by Stetter at al. (Chem. Ber. 1960, 93, 603-607) as depicted in Scheme 1. Compounds (1) and (2) are either commercially available or can be prepared according to procedures available from the public domain, as understandable to the person skilled in the art. Depending on the reactivity of the involved centers the regioisomer of (3) can be obtained [i.e. in cases where nucleophilic displacement of the leaving group of (2) by the acidic methylene unit of (1) is taking place prior to intramolecular condensation with the ketone moiety of (2)].
In general, 1,3-diketones of formula (I) can be reacted with alpha-carbonylesters of general formula (2) in the presence of inorganic bases like sodium hydroxide or potassium hydroxide, preferably potassium hydroxide, in protic solvents such as for example methanol, ethanol or water or mixtures thereof, preferably a mixture of the alcohol incorporated in ester (2) and water, at temperatures between 0° C. and the boiling point of the solvent (mixture), preferably between room temperature and 50° C. The reaction times vary between 15 hours and several days. It is usually necessary to isomerize the primary formed cyclisation products to the tetrahydrobenzofuranes of general formula (3) by treatment with acids such as aqueous hydrochloric acid at pH 1-4 at temperatures between 0° C. and the boiling point of the solvent (mixture), preferably at room temperature, for 1-6 hours.
Alternatively, (1) and (2) may be reacted in the presence of organic bases like triethylamine in aprotic solvents like dichloromethane, dichloroethane or tetrahydrofuran, preferably dichloromethane or dichloroethane, at temperatures between room temperature and the boiling point of the solvent, preferably at 40-60° C. (pressure tube), for 12-72 h followed by treatment with acids such as aqueous hydrochloric acid at pH 1-4 at temperatures between 0° C. and the boiling point of the solvent (mixture), preferably at room temperature, for 3-24 hours.
Alternatively, (1) and (2) may be reacted without further additives in toluene at temperatures between room temperature and 120° C., preferably at 80-120° C. for 12-20 hours.
Enamines of general formula (4a) can be synthesized from tetrahydrobenzofuranes of general formula (3) by alpha-methylation with electrophiles like 1-tert-butoxy-N,N,N′,N′-tetramethylmethanediamine (Bredereck's reagent) or 1,1-dimethoxy-N,N-dimethylmethanamine, preferably 1-tert-butoxy-N,N,N′,N′-tetramethylmethanediamine, in aprotic solvents like benzene, toluene or dioxane, preferably toluene, at temperatures between room temperature and the boiling point of the solvent, preferably at 100-110° C., for 15 hours or up to several days.
Alternatively, tetrahydrobenzofuranes of general formula (3) can be transferred to alpha-hydroxymethyleneketones of general formula (4b) by formylation with formic acid derivatives such as ethyl formate or methyl formate in the presence of bases such as sodium methylate, sodium ethylate, potassium tert-butoxide or sodium hydride in solvents such as methanol, ethanol, toluene or tetrahydrofuran or mixtures thereof at temperatures between 0° C. and the boiling point of the solvent (mixture), preferably between room temperature and 50° C., for 1-18 hours.
Furoindazoles of general formula (5) can be obtained starting from either enamines of general formula (4a) or alpha-hydroxymethyleneketones of general formula (4b) by reacting (4a) or (4b) with hydrazine or hydrazine derivatives such as hydrazine hydrates or hydrazine salts, preferably hydrazine hydrate or hydrazine dihydrochloride, in polar protic solvents like ethanol or water or mixtures thereof, preferably ethanol/water mixtures, at temperatures between room temperature and the boiling point of the solvent (mixture), preferably at 70-80° C., for 4-18 hours.
Unsaturated furoindazoles of general formula (6) can be obtained starting from the satured homologues of general formula (5) by oxidation with mild oxidizing agents such as hypochlorites (e.g. sodium hypochlorite), hypervalent iodine compounds (e.g. 2-iodoxy benzoic acid), peroxides (e.g. hydrogen peroxide), further oxidizing agents (e.g. 2,3-dichloro-5,6-dicyano-p-benzoquinone) and oxidizing mixtures (e.g. palladium on charcoal in combination with diethyl fumarate), preferably with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in polar solvents like water or nonpolar solvents like 1,4-dioxane at temperatures between room temperature and 70° C., preferably at 50-60° C., for 2-18 hours.
2-Substituted furoindazole esters of general formula (9) can be synthesized from furoindazoles of general formula (9) either by Mitsunobu reaction with alcohols of general formula (7) in the presence of activating reagents such as diisopropyl azodicarboxylate (DIAD) or N,N,N′,N′-tetramethylazodicarboxamide (TMAD) and a tertiary phosphine such as triphenylphosphine or tri-n-butylphosphine, preferably a combination of TMAD and tri-n-butylphosphine, in aprotic solvents such as tetrahydrofuran or toluene, preferably toluene, at temperatures between room temperature and the boiling point of the solvent, preferably at room temperature, for 12-48 hours. Alternatively, 2-substituted furoindazoles of general formula (9) can be synthesized from furoindazoles of general formula (6) by reaction with electrophiles of general formula (8) such as alkyl halides or alkyl tosylates or alkyl mesylates, preferably alkyl bromides, in the presence of an inorganic base such as potassium carbonate or in the presence of an organic base such as triethylamine or N,N-diisopropylethylamine, preferably potassium carbonate, in a polar, aprotic solvent such as acetonitrile or ethyl acetate, preferably acetonitrile, at temperatures between room temperature and the boiling point of the solvent, preferably at 60-75° C. It can be beneficial to add a catalyst like 4-dimethylaminopyridine (DMAP) to the mixture. Generally, depending on the reactivity of the involved centers the 1-substituted regioisomer of (9) can be obtained in certain cases as well.
Carboxylic acids of general formula (II) may be obtained from carboxylic esters of formula (9) by saponification with inorganic bases such as lithium hydroxide, potassium hydroxide or sodium hydroxide, preferably lithium hydroxide, in a suitable solvent such as methanol, ethanol, tetrahydrofuran, water or mixtures thereof, preferably a mixture of the alcohol incorporated in ester (9), THF and water, at temperatures between 0° C. and the boiling point of the solvent (mixture), typically at 70° C., for 4-48 hours.
Furoindazoles of general formula (I) may be synthesized from suitably functionalized carboxylic acids of general formula (II) by reaction with appropriate amines HN(R4)(R5) (III). For amide formation, however, all processes that are known from peptide chemistry to the person skilled in the art may be applied. The acids of general formula (10) can be reacted with an appropriate amine in aprotic polar solvents, such as for example DMF, acetonitrile or N-methylpyrrolid-2-one via an activated acid derivative, which is obtainable for example with hydroxybenzotriazole and a carbodiimide such as for example diisopropylcarbodiimide, or else with preformed reagents, such as for example O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (see for example Chem. Comm. 1994, 201-203), or else with activating agents such as dicyclohexylcarbodiimide/N,N-dimethylaminopyridine or N-ethyl-N′N′-dimethylaminopropylcarbodiimide/N,N-dimethylaminopyridine. The addition of a suitable base such as for example N-methylmorpholine, triethylamine or DIPEA may be necessary. In certain cases, the activated acid derivative might be isolated prior to reaction with the appropriate amine. Amide formation may also be accomplished via the acid halide (which can be formed from a carboxylic acid by reaction with e.g. oxalyl chloride, thionyl chloride or sulfuryl chloride), mixed acid anhydride (which can be formed from a carboxylic acid by reaction with e.g. isobutylchloroformate), imidazolide (which can be formed from a carboxylic acid by reaction with e.g. carbonyldiimidazole) or azide (which can be formed from a carboxylic acid by reaction with e.g. diphenylphosphorylazide).
Scheme 2: Alternative route for the preparation of compounds of general formula (I) in which Hal is Cl, Br, or I and R1, R2, R3, R4, R5, R6a and R6b have the meaning as given for general formula (I), supra.
An alternative route for the preparation of furoindazoles of general formula (I) is depicted in Scheme 2. 3-substituted tetrahydrobenzofuranes of general formula (12) can be synthesized from 1,3-dicarbonyls of general formula (1) and α-haloketones or α-haloaldehydes of general formula (11) in the presence of inorganic bases like sodium hydroxide or potassium hydroxide, preferably potassium hydroxide, in protic solvents such as for example methanol, ethanol or water or mixtures thereof, preferably aqueous methanol, at temperatures between room temperature and the boiling point of the solvent (mixture), preferably between room temperature and 50° C. It is usually necessary to isomerize the primary formed cyclisation products to the tetrahydrobenzofuranes of general formula (12) by treatment with acids such as aqueous hydrochloric acid at pH 1-4 at temperatures between 0° C. and the boiling point of the solvent (mixture), preferably at room temperature, for 1-6 h. The next two steps to the furoindazoles of general formula (15) via (13a) or (13b) and (14) can be done according to the corresponding procedures described in Scheme 1.
The subsequent formylation to aldehydes of general formula (16) can be performed by any formylation processes that is known to the person skilled in the art, preferably by the well-known Vilsmeier-Haack reaction using a mixture of trichlorophosphate in N,N-dimethylformamide (DMF) with or without additional inert solvent such as dichloromethane, 1,2-dichloroethane or others at temperatures between 0° C. and room temperature for 1-18 hours.
Carboxamides of general formula (IV) can be directly obtained from aldehydes of general formula (16) similar to the procedures described in Synthesis 2003, 7, 1055-1064. Aldehydes of general formula (16) can be reacted with an appropriate amine (III) in the presence of cyanide salts like sodium cyanide or potassium cyanide and in the presence of oxidizing agents like manganese (IV) dioxide in solvents like tetrahydrofuran, dichloromethane or dimethylsulfoxide, preferably tetrahydrofuran, at temperatures between 0° C. and the boiling point of the solvent, preferably at room temperature for 24-96 hours.
Carboxamides of general formula (I) may by synthesized from their saturated homologues of general formula (IV) using any mild oxidizing agent already described in Scheme 1, preferably by the employment of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in nonpolar solvents like 1,4-dioxane at temperatures between room temperature and 70° C., preferably at 50-60° C., for 2-18 hours.
Scheme 3: Alternative route for the preparation of compounds of general formula (Ia) in which R1═CH3—CH2—, R2═CH3, and R3, R4, R5, R6a and R6b have the meaning as given for general formula (I), supra.
An alternative route for the preparation of 8-methyl-furoindazoles of general formula (Ia) is depicted in Scheme 3. 3-Methyl-5H-spiro[[1]benzofuran-6,1′-cyclopropan]-4(7H)-one (formula (20)) can be synthesized from spiro[2.5]octane-5,7-dione formula (18) by a two-step procedure involving reaction of the enolate of (1) with allenic sulfonium salt (19) [prepared in situ by reaction of propargyl bromide with dimethyl sulfide] and subsequent acid catalysed isomerization to (20) according to the procedures described by Kanematsu et al. (J. Org. Chem. 1993, 58, 3960-3968 and Heterocycles 1990, 31, 6, 1003-1006).
Brominated furane of formula (21) may be obtained from furane of general formula (20) by any aromatic bromination reaction known to the person skilled in the art. For example, compounds of formula (20) may be reacted with bromo electrophiles such as N-bromo-succinimide (NBS) in polar solvents such as pyridine or N,N-dimethylformamide, preferably pyridine, at temperatures between 0° C. and the boiling point of the solvent, preferably at room temperature. The reaction times vary between 2 hours and several days.
Enamine of general formula (22a) and alpha-hydroxymethyleneketone of general formula (22b) can be synthesized starting from (20) according to the procedures described for (4a) and (4b) in Scheme 1.
8-Methyl-furoindazole of general formula (23) can be obtained from either (22a) or (22b) by reaction with hydrazine derivatives as described for the synthesis of (5) in Scheme 1.
2-Substituted furoindazoles of general formula (24) can be synthesized from compound of general formula (23) and alcohols (7) or electrophiles (8) as described for the synthesis of (9) from (6) in Scheme 1.
Carboxylic acids of general formula (25) may be obtained from bromo-furoindazoles (24) by carbonylation reactions. Bromides of general formula (24) can be reacted in the presence of a carbon monoxide source such as for example molybdenum hexacarbonyl or under a carbon monoxide atmosphere at pressures between 1 and 20 bar (autoclave), preferably under a carbon monoxide atmosphere at 15 bar (autoclave), and in the presence of a suitable palladium catalyst such as palladium acetate or bis(triphenylphosphine) palladium(II) dichloride, preferably palladium acetate, and in the presence of a ligand such as 1,1′-bis(diphenylphosphino)ferrocene and a suitable base such as potassium acetate in a polar solvent such as dimethylsulfoxide at temperatures between room temperature and 180° C., preferably at 100° C., for 12-24 h. The carbonylation reaction conditions also lead to partial the rearrangement of the spiro-cyclopropyl ring to the en-ethyl moiety as shown for compounds of general formula (25a) that can be isolated as well.
Carboxamides of general formula (Ia) can be directly obtained from carboxylic acids of general formula (25a) in amidation reactions with amines of general formula (III). In presence of coupling reagent such as for example O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate and a base such as DIPEA in aprotic polar solvents, such as for example DMF, as described in Scheme 1 for the synthesis of compounds of general formula (I) takes place as shown for compounds of general formula (Ia) in Scheme 3.
Specific examples are described in the Experimental Section.
In accordance with a second aspect, the present invention covers methods of preparing compounds of general formula (I) as defined supra, said methods comprising the step of allowing an intermediate compound of general formula (II):
In accordance with a third aspect, the present invention covers methods of preparing compounds of general formula (I) as defined supra, said methods comprising the step of allowing an intermediate compound of general formula (II):
The present invention covers methods of preparing compounds of the present invention of general formula (I), said methods comprising the steps as described in the Experimental Section herein.
In accordance with a fourth aspect, the present invention covers intermediate compounds which are useful for the preparation of the compounds of general formula (I), supra.
Particularly, the invention covers the intermediate compounds of general formula (II):
In accordance with a fifth aspect, the present invention covers the use of said intermediate compounds for the preparation of a compound of general formula (I) as defined supra.
Particularly, the invention covers the use of intermediate compounds of general formula (II):
In accordance with a sixth aspect, the present invention covers methods of preparing compounds of general formula (I) as defined supra, said methods comprising the step of allowing an intermediate compound of general formula (IV):
In accordance with a seventh aspect, the present invention covers methods of preparing compounds of general formula (I) as defined supra, said methods comprising the step of allowing an intermediate compound of general formula (IV):
The present invention covers methods of preparing compounds of the present invention of general formula (I), said methods comprising the steps as described in the Experimental Section herein.
In accordance with an eighth aspect, the present invention covers intermediate compounds which are useful for the preparation of the compounds of general formula (I), supra.
Particularly, the invention covers the intermediate compounds of general formula (IV):
In accordance with a ninth aspect, the present invention covers the use of said intermediate compounds for the preparation of a compound of general formula (I) as defined supra.
Particularly, the invention covers the use of intermediate compounds of general formula (IV):
The present invention covers the intermediate compounds which are disclosed in the Example Section of this text, infra.
The present invention covers any sub-combination within any embodiment or aspect of the present invention of intermediate compounds of general formulae (II) or (IV), supra.
The compounds of general formula (I) of the present invention can be converted to any salt, preferably pharmaceutically acceptable salts, as described herein, by any method which is known to the person skilled in the art. Similarly, any salt of a compound of general formula (I) of the present invention can be converted into the free compound, by any method which is known to the person skilled in the art.
Compounds of general formula (I) of the present invention demonstrate a valuable pharmacological spectrum of action which could not have been predicted. Compounds of the present invention have surprisingly been found to be effective antagonists of GPR84 and it is possible therefore that said compounds be used for the treatment or prophylaxis of diseases, in particular of autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
Compounds of the present invention can be utilized to inhibit, antagonize, block, reduce, decrease GPR84 signal transduction, activity and cellular function. This method comprises administering to a mammal in need thereof, including a human, an amount of a compound of this invention, or a pharmaceutically acceptable salt, isomer, polymorph, metabolite, hydrate, solvate or ester thereof; which is effective to treat the disorder.
In particular of autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
The present invention also provides methods of treating PCOS and symptoms
These disorders have been well characterized in humans, but also exist with a similar aetiology in other mammals and can be treated by administering pharmaceutical compositions of the present invention.
The term “treating”, or “treatment” as used in the present text is used conventionally, e.g., the management or care of a subject for the purpose of combating, alleviating, reducing, relieving, improving the condition of a disease or disorder, such as PCOS or IPF.
The compounds of the present invention can be used in particular in therapy and prevention, i.e. prophylaxis and treatment of autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
In accordance with a further aspect, the present invention covers compounds of general formula (I), as described supra, or stereoisomers, tautomers, N-oxides, hydrates, solvates, and salts thereof, particularly pharmaceutically acceptable salts thereof, or mixtures of same, for use in the treatment or prophylaxis of diseases, in particular autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
The pharmaceutical activity of the compounds according to the invention can be explained by their activity as GPR84 antagonists.
In accordance with a further aspect, the present invention covers the use of compounds of general formula (I), as described supra, or stereoisomers, tautomers, N-oxides, hydrates, solvates, and salts thereof, particularly pharmaceutically acceptable salts thereof, or mixtures of same, for the treatment or prophylaxis of diseases, in particular autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
In accordance with a further aspect, the present invention covers the use of a compound of formula (I), described supra, or a stereoisomer, a tautomer, an N-oxide, a hydrate, a solvate, or a salt thereof, particularly a pharmaceutically acceptable salt thereof, or a mixture of same, for the prophylaxis or treatment of diseases, in particular autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
In accordance with a further aspect, the present invention covers the use of compounds of general formula (I), as described supra, or stereoisomers, tautomers, N-oxides, hydrates, solvates, and salts thereof, particularly pharmaceutically acceptable salts thereof, or mixtures of same, in a method of treatment or prophylaxis of diseases, in particular autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
In accordance with a further aspect, the present invention covers use of a compound of general formula (I), as described supra, or stereoisomers, tautomers, N-oxides, hydrates, solvates, and salts thereof, particularly pharmaceutically acceptable salts thereof, or mixtures of same, for the preparation of a pharmaceutical composition, preferably a medicament, for the prophylaxis or treatment of diseases, in particular autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals.
In accordance with a further aspect, the present invention covers a method of treatment or prophylaxis of diseases, in particular autoimmune diseases such as multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, primary and secondary autoimmune uveitis, inflammatory disorders like endometriosis, inflammatory eye diseases, inflammatory kidney diseases, inflammatory liver diseases like non-alcoholic, alcoholic- and toxic fatty liver diseases, lung diseases like asthma, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and metabolic and metabolic-endocrine disorders like metabolic syndrome, insulin resistance, diabetes mellitus type I and type II, and polycystic ovary syndrome (PCOS) disorders, neuropathic and inflammatory pain disorders in humans and animals, using an effective amount of a compound of general formula (I), as described supra, or stereoisomers, tautomers, N-oxides, hydrates, solvates, and salts thereof, particularly pharmaceutically acceptable salts thereof, or mixtures of same.
In accordance with a further aspect, the present invention covers pharmaceutical compositions, in particular a medicament, comprising a compound of general formula (I), as described supra, or a stereoisomer, a tautomer, an N-oxide, a hydrate, a solvate, a salt thereof, particularly a pharmaceutically acceptable salt, or a mixture of same, and one or more excipients), in particular one or more pharmaceutically acceptable excipient(s). Conventional procedures for preparing such pharmaceutical compositions in appropriate dosage forms can be utilized.
The present invention furthermore covers pharmaceutical compositions, in particular medicaments, which comprise at least one compound according to the invention, conventionally together with one or more pharmaceutically suitable excipients, and to their use for the above-mentioned purposes.
It is possible for the compounds according to the invention to have systemic and/or local activity. For this purpose, they can be administered in a suitable manner, such as, for example, via the oral, parenteral, pulmonary, nasal, sublingual, lingual, buccal, rectal, vaginal, dermal, transdermal, conjunctival, otic route or as an implant or stent.
For these administration routes, it is possible for the compounds according to the invention to be administered in suitable administration forms.
For oral administration, it is possible to formulate the compounds according to the invention to dosage forms known in the art that deliver the compounds of the invention rapidly and/or in a modified manner, such as, for example, tablets (uncoated or coated tablets, for example with enteric or controlled release coatings that dissolve with a delay or are insoluble), orally-disintegrating tablets, films/wafers, films/lyophilizates, capsules (for example hard or soft gelatine capsules), sugar-coated tablets, granules, pellets, powders, emulsions, suspensions, aerosols or solutions. It is possible to incorporate the compounds according to the invention in crystalline and/or amorphized and/or dissolved form into said dosage forms.
Parenteral administration can be effected with avoidance of an absorption step (for example intravenous, intraarterial, intracardial, intraspinal or intralumbal) or with inclusion of absorption (for example intramuscular, subcutaneous, intracutaneous, percutaneous or intraperitoneal). Administration forms which are suitable for parenteral administration are, inter alia, preparations for injection and infusion in the form of solutions, suspensions, emulsions, lyophilizates or sterile powders.
Examples which are suitable for other administration routes are pharmaceutical forms for inhalation [inter alia powder inhalers, nebulizers], nasal drops, nasal solutions, nasal sprays; tablets/films/wafers/capsules for lingual, sublingual or buccal administration; suppositories; eye drops, eye ointments, eye baths, ocular inserts, ear drops, ear sprays, ear powders, ear-rinses, ear tampons; vaginal capsules, aqueous suspensions (lotions, mixture agitandae), lipophilic suspensions, emulsions, ointments, creams, transdermal therapeutic systems (such as, for example, patches), milk, pastes, foams, dusting powders, implants or stents.
The compounds according to the invention can be incorporated into the stated administration forms. This can be effected in a manner known per se by mixing with pharmaceutically suitable excipients. Pharmaceutically suitable excipients include, inter alia,
The present invention furthermore relates to a pharmaceutical composition which comprise at least one compound according to the invention, conventionally together with one or more pharmaceutically suitable excipient(s), and to their use according to the present invention.
NMR peak forms are stated as they appear in the spectra, possible higher order effects have not been considered.
The 1H-NMR data of selected compounds are listed in the form of 1H-NMR peaklists. Therein, for each signal peak the δ value in ppm is given, followed by the signal intensity, reported in round brackets. The δ value-signal intensity pairs from different peaks are separated by commas. Therefore, a peaklist is described by the general form: δ1 (intensity1), δ2 (intensity2), . . . , δi (intensityi), . . . , δn (intensityn).
The intensity of a sharp signal correlates with the height (in cm) of the signal in a printed NMR spectrum. When compared with other signals, this data can be correlated to the real ratios of the signal intensities. In the case of broad signals, more than one peak, or the center of the signal along with their relative intensity, compared to the most intense signal displayed in the spectrum, are shown. A 1H-NMR peaklist is similar to a classical 1H-NMR readout, and thus usually contains all the peaks listed in a classical NMR interpretation. Moreover, similar to classical 1H-NMR printouts, peaklists can show solvent signals, signals derived from stereoisomers of the particular target compound, peaks of impurities, 13C satellite peaks, and/or spinning sidebands. The peaks of stereoisomers, and/or peaks of impurities are typically displayed with a lower intensity compared to the peaks of the target compound (e.g., with a purity of >90%). Such stereoisomers and/or impurities may be typical for the particular manufacturing process, and therefore their peaks may help to identify a reproduction of the manufacturing process on the basis of “by-product fingerprints”. An expert who calculates the peaks of the target compound by known methods (MestReC, ACD simulation, or by use of empirically evaluated expectation values), can isolate the peaks of the target compound as required, optionally using additional intensity filters. Such an operation would be similar to peak-picking in classical 1H-NMR interpretation. A detailed description of the reporting of NMR data in the form of peaklists can be found in the publication “Citation of NMR Peaklist Data within Patent Applications” (cf. http://www.researchdisclosure.com/searching-disclosures, Research Disclosure Database Number 605005, 2014, 1 Aug. 2014). In the peak picking routine, as described in the Research Disclosure Database Number 605005, the parameter “MinimumHeight” can be adjusted between 1% and 4%. However, depending on the chemical structure and/or depending on the concentration of the measured compound it may be reasonable to set the parameter “MinimumHeight”<1%.
Chemical names were generated using the ACD/Name software from ACD/Labs. In some cases, generally accepted names of commercially available reagents were used in place of ACD/Name generated names.
The following Table 1 lists the abbreviations used in this paragraph and in the Examples section as far as they are not explained within the text body. Other abbreviations have their meanings customary per se to the skilled person.
The following table lists the abbreviations used herein.
The various aspects of the invention described in this application are illustrated by the following examples which are not meant to limit the invention in any way.
The example testing experiments described herein serve to illustrate the present invention and the invention is not limited to the examples given.
All reagents, for which the synthesis is not described in the experimental part, are either commercially available, or are known compounds or may be formed from known compounds by known methods by a person skilled in the art.
The compounds and intermediates produced according to the methods of the invention may require purification. Purification of organic compounds is well known to the person skilled in the art and there may be several ways of purifying the same compound. In some cases, no purification may be necessary. In some cases, the compounds may be purified by crystallization. In some cases, impurities may be stirred out using a suitable solvent. In some cases, the compounds may be purified by chromatography, particularly flash column chromatography, using for example prepacked silica gel cartridges, e.g. Biotage SNAP cartidges KP-Sil® or KP-NH® in combination with a Biotage autopurifier system (SP4® or Isolera Four®) and eluents such as gradients of hexane/ethyl acetate or DCM/methanol. In some cases, the compounds may be purified by preparative HPLC using for example a Waters autopurifier equipped with a diode array detector and/or on-line electrospray ionization mass spectrometer in combination with a suitable prepacked reverse phase column and eluents such as gradients of water and acetonitrile which may contain additives such as trifluoroacetic acid, formic acid or aqueous ammonia.
In some cases, purification methods as described above can provide those compounds of the present invention which possess a sufficiently basic or acidic functionality in the form of a salt, such as, in the case of a compound of the present invention which is sufficiently basic, a trifluoroacetate or formate salt for example, or, in the case of a compound of the present invention which is sufficiently acidic, an ammonium salt for example. A salt of this type can either be transformed into its free base or free acid form, respectively, by various methods known to the person skilled in the art or be used as salts in subsequent biological assays. It is to be understood that the specific form (e.g. salt, free base etc.) of a compound of the present invention as isolated and as described herein is not necessarily the only form in which said compound can be applied to a biological assay in order to quantify the specific biological activity.
Analytical UPLC-MS was performed as described below. The masses (m/z) are reported from the positive mode electrospray ionisation unless the negative mode is indicated (ESI−). In most of the cases method 1 is used. If not, it is indicated.
Analytical characterization of enantiomers was performed by analytical chiral HPLC. In the description of the individual examples is referred to the applied HPLC procedure.
Biotage Isolera™ chromatography system (http://www.biotage.com/product-area/flash-purification) using pre-packed silica and pre-packed modified silica cartridges.
Preparative HPLC, Method A: Instrument: pump: Labomatic HD-5000 or HD-3000, head HDK 280, low pressure gradient module ND-B1000; manual injection valve: Rheodyne 3725i038; detector: Knauer Azura UVD 2.15; collector: Labomatic Labocol Vario-4000; column: Chromatorex RP C-18 10 μm, 125×30 mm; eluent A: water+0.2 vol-% ammonia (32%), eluent B: acetonitrile;
To cyclohexane-1,3-dione (3.50 g, 31.2 mmol) was added ethyl 2-chloro-4,4,4-trifluoro-3-oxobutanoate (5.9 ml, 37 mmol) at 20° C. and the reaction mixture subsequently stirred at 100° C. for 24 h. The mixture was purified by Biotage Isolera™ chromatography (SNAP KP-Sil—340 g, eluting with dichloromethane-ethanol, 4:1) to afford 717 mg (8% yield, 95% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.30 (t, 3H), 2.08-2.17 (m, 2H), 2.52-2.54 (m, 2H), 3.00 (t, 2H), 4.36 (q, 2H).
LC-MS (Method 1): Rt=1.13 min; MS (ESIpos): m/z=277 [M+H]+
A solution of ethyl formate (5.8 ml, 72 mmol; CAS-RN:[109-94-4]) in toluene (29 mL) was treated with sodium hydride (1.74 g, 60% purity, 43.4 mmol; CAS-RN:[7646-69-7]) at 0° C. After stirring for 0.5 hours, a solution of ethyl 4-oxo-3-(trifluoromethyl)-4,5,6,7-tetrahydro-1-benzofuran-2-carboxylate (4.0 g, 14.5 mmol; intermediate 1) in toluene (5 mL) was added to the above mixture. The reaction mixture was stirred at room temperature over night and diluted with ethyl acetate (100 ml) After quenching with aqueous 4 N HCl (pH˜4). The phases were separated, and the aqueous phase extracted with ethyl acetate. The combined organic phases were washed with brine, dried over anhydrous sodium sulfate, filtrated and concentrated in vacuo to afford 5.15 g (84% yield, 72% purity) of the title compound as a brown oil.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.30 (t, 3H), 2.71-2.81 (m, 2H), 2.96 (t, 2H), 4.35 (q, 2H), 7.66 (d, 1H), 11.15 (d, 1H).
LC-MS (Method 2): Rt=1.15 min; MS (ESIpos): m/z=305 [M+H]+
A solution of crude (5E/Z)-ethyl 5-(hydroxymethylene)-4-oxo-3-(trifluoromethyl)-4,5,6,7-tetrahydro-1-benzofuran-2-carboxylate (5.15 g, 12.2 mmol; intermediate 2) in ethanol (44 mL) was treated with a solution of hydrazine dihydrochloride (2.56 g, 24.4 mmol; CAS-RN:[5341-61-7]) in water (5 mL) at room temperature. The reaction mixture was stirred at 60° C. for 1 h and quenched with saturated aqueous sodium carbonate (pH˜9). The formed precipitate obtained was collected by filtration, washed with ethyl acetate and dried to afford 3.01 g (72% yield, 87% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.31 (t, 3H), 2.85-2.92 (m, 2H), 2.96-3.02 (m, 2H), 4.34 (q, 2H), 7.59 (s, 1H), 12.65 (br s, 1H).
LC-MS (Method 2): Rt=1.06 min; MS (ESIpos): m/z=301 [M+H]+
To a solution of ethyl 8-(trifluoromethyl)-4,5-dihydro-1H-furo[2,3-g]indazole-7-carboxylate (1.00 g, 3.33 mmol; intermediate 3) in 1,4-dioxane (40 ml) was added 4,5-dichloro-3,6-dioxocyclohexa-1,4-diene-1,2-dicarbonitrile (1.51 g, 6.66 mmol). The solution was stirred for 2 h at 60° C. and quenched with aqueous saturated sodium bicarbonate solution. After phase separation the organic layer was washed with brine, filtered over an water-free filter and concentrated in vacuo to afford 300 mg (27% yield, 88% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.37 (t, 3H), 4.44 (q, 2H), 7.64 (d, 1H), 8.06 (d, 1H), 8.33 (s, 1H), 13.26 (s, 1H).
LC-MS (Method 1): Rt=1.14 min; MS (ESIpos): m/z=299 [M+H]+
A solution of ethyl 8-(trifluoromethyl)-1H-furo[2,3-g]indazole-7-carboxylate (intermediate 4, 1.0 eq, 1.00 g, 3.35 mmol) and [(2R)-1,4-dioxan-2-yl]methyl trifluoromethanesulfonate (1.8 eq, 1.68 g, 90% purity, 6.04 mmol) in acetonitrile (20.0 ml) at rt was treated with caesium carbonate (3 eq., 3.28 g, 10 mmol) and the resulting reaction mixture was stirred at room temperature overnight. To the reaction mixture, additional [(2R)-1,4-dioxan-2-yl]methyl trifluoromethanesulfonate (1 eq, 0.8 g, 90% purity, 3.67 mmol), caesium carbonate (1.45 eq., 1.6 g, 4.9 mmol) and acetonitrile (10 mL) were added and further stirred at 80° C. for 5 h. After cooling to rt, the reaction mixture was diluted with ethyl acetate (100 mL), water (10 mL) and sat. aq. NH4Cl solution (20 mL) and the resulting mixture was stirred for 10 min at rt. The phases were separated and the organic phase was evaporated to give the crude material, which was subjected to column chromatography (SiO2, EtOAc/Hexane) to give the title compound (980 mg, 73%) as a white solid.
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: 1.172 (0.75), 1.346 (7.07), 1.363 (16.00), 1.381 (7.47), 1.987 (1.34), 2.518 (1.73), 2.523 (1.08), 3.357 (2.22), 3.362 (2.17), 3.386 (2.04), 3.426 (0.53), 3.431 (0.63), 3.452 (1.49), 3.458 (1.61), 3.480 (1.50), 3.485 (1.50), 3.505 (1.36), 3.509 (1.41), 3.532 (1.67), 3.538 (1.62), 3.559 (0.68), 3.564 (0.91), 3.623 (1.87), 3.649 (1.40), 3.718 (1.74), 3.746 (1.48), 3.846 (1.55), 3.852 (1.70), 3.875 (1.45), 3.881 (1.49), 4.002 (0.44), 4.009 (0.50), 4.013 (0.65), 4.016 (0.68), 4.020 (0.97), 4.027 (1.00), 4.034 (1.03), 4.038 (1.10), 4.044 (0.90), 4.052 (0.61), 4.056 (0.54), 4.063 (0.42), 4.401 (2.10), 4.419 (6.81), 4.436 (6.66), 4.454 (2.02), 4.484 (0.88), 4.502 (0.68), 4.519 (2.55), 4.537 (2.60), 4.546 (2.61), 4.557 (2.55), 4.581 (0.84), 4.592 (0.69), 7.518 (5.72), 7.542 (5.82), 7.960 (6.06), 7.983 (5.40), 8.591 (8.49).
LC-MS (Method 1): Rt=1.23 min; MS (ESIpos): m/z=399 [M+H]+
Ethyl 8-(trifluoromethyl)-4,5-dihydro-1H-furo[2,3-g]indazole-7-carboxylate (1.30 g, 4.36 mmol; intermediate 4) was reacted with [(2S)-1,4-dioxan-2-yl]methanol (618 mg, 5.23 mmol), tri-n-butylphosphine (1.7 ml, 7.0 mmol; CAS-RN:[998-40-3]) and TMAD ((1.20 g, 6.97 mmol; CAS-RN:[10465-78-8]) in toluene (13 mL) at rt overnight. The reaction mixture was diluted water while stirring was continued for 30 min. After phase separation, the aqueous layer was extracted with toluene. The combined organic phases were dried with a hydrophobic filter paper and concentrated in vacuo. The residue was diluted with 2 ml acetonitrile and purified by preparative HPLC (Method A, gradient D). The product fractions were pooled and concentrated in vacuo to afford 1.36 g (76% yield, 97% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.36 (t, 3H), 3.35-3.39 (m, 1H), 3.42-3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.61-3.66 (m, 1H), 3.73 (br d, 1H), 3.86 (dd, 1H), 3.99-4.06 (m, 1H), 4.43 (q, 2H), 4.47-4.60 (m, 2H), 7.53 (d, 1H), 7.97 (d, 1H), 8.59 (s, 1H).
LC-MS (Method 1): Rt=1.28 min; MS (ESIpos): m/z=399 [M+H]+
ethyl 2-[(6-methylpyridin-3- yl)methyl]-8- (trifluoromethyl)-2H-furo[2,3- g]indazole-7-carboxylate
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: 0.867 (0.85), 0.883 (0.81), 1.338 (5.46), 1.356 (11.91), 1.375 (5.54), 2.436 (16.00), 2.518 (2.78), 2.523 (1.80), 4.395 (1.60), 4.413 (5.18), 4.430 (5.11), 4.448 (1.52), 5.711 (7.37), 7.238 (2.28), 7.258 (2.51), 7.521 (4.35), 7.544 (4.53), 7.648 (1.67), 7.653 (1.68), 7.668 (1.53), 7.674 (1.53), 7.960 (4.64), 7.983 (3.95), 8.527 (2.38), 8.532 (2.37), 8.708 (6.61). LC-MS (Method 1): Rt = 1.27 min; MS (ESIpos): m/z = 404 [M + H]+
ethyl 4-methyl-2-[(pyridin-2- yl)methyl]-8- (trifluoromethyl)-2H-furo[2,3- g]indazole-7-carboxylate
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.35 (t, 3H), 2.61 (d, 3H), 4.41 (q, 2H), 5.80 (s, 2H), 7.22 (d, 1H), 7.35 (br d, 2H), 7.80 (td, 1H), 8.52-8.56 (m, 1H), 8.81 (s, 1H). LC-MS (Method 1): Rt = 1.31 min; MS (ESIpos): m/z = 404 [M + H]+
ethyl 4-methyl-2-[(pyridin-4- yl)methyl]-8- (trifluoromethyl)-2H-furo[2,3- g]indazole-7-carboxylate
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.35 (t, 3H), 2.61 (d, 3H), 4.41 (q, 2H), 5.78 (s, 2H), 7.19- 7.23 (m, 2H), 7.37 (d, 1H), 8.53- 8.56 (m, 2H), 8.83 (s, 1H). LC-MS (Method 1): Rt = 1.25 min; MS (ESIpos): m/z = 404 [M + H]+
ethyl 4-methyl-2-[(5- methylpyridin-2-yl)methyl]- 8-(trifluoromethyl)-2H- furo[2,3-g]indazole-7- carboxylate
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.35 (t, 3H), 2.27 (s, 3H), 2.61 (d, 3H), 4.41 (q, 2H), 5.74 (s, 2H), 7.16 (d, 1H), 7.34 (d, 1H), 7.59-7.63 (m, 1H), 8.36-8.38 (m, 1H), 8.77 (s, 1H). LC-MS (Method 1): Rt = 1.37 min; MS (ESIpos): m/z = 418 [M + H]+
ethyl 2-{[(2S)-1,4-dioxan-2- yl]methyl}-4-methyl-8- (trifluoromethyl)-2H-furo[2,3- g]indazole-7-carboxylate
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.36 (t, 3H), 2.60 (d, 3H), 3.36-3.41 (m, 1H), 3.45-3.52 (m, 1H), 3.53-3.58 (m, 1H), 3.64 (br d, 1H), 3.73 (d, 1H), 3.86 (dd, 1H), 4.01-4.09 (m, 1H), 4.34-4.57 (m, 4H), 7.33 (d, 1H), 8.64 (s, 1H). LC-MS (Method 1): Rt = 1.29 min; MS (ESIpos): m/z = 413 [M + H]+
Ethyl 2-[(6-methylpyridin-3-yl)methyl]-8-(trifluoromethyl)-2H-furo[2,3-g]indazole-7-carboxylate (1.0 eq, 220 mg, 545 μmol; intermediate 6-1) was reacted with aqueous lithium hydroxide (2 M; 5 eq., 1.4 mL, 2.7 mmol) in 1:1 mixture of ethanol (4.2 ml) and THF (4.2 mL) at 70° C. overnight. The reaction mixture was cooled to rt and acidified with aqueous 6 N HCl (to pH 2) and the resulting mixture was stirred for 30 min at rt. The mixture was then evaporated under reduced pressure. To the residue were added DCM (50 mL) and isopropanol (1 mL) and stirred at rt overnight. The solids were filtered off and washed with DCM, and the combined filtrate was evaporated to afford 220 mg of the title compound as a crude material, which was used in the next step without further purification.
LC-MS (Method 1): Rt=0.61 min; MS (ESIpos): m/z=376 [M+H]+
Ethyl 2-{[(2S)-1,4-dioxan-2-yl]methyl}-8-(trifluoromethyl)-2H-furo[2,3-g]indazole-7-carboxylate (1.36 g, 3.41 mmol; intermediate 6) was reacted with aqueous lithium hydroxide (17 ml, 2.0 M, 34 mmol) in THF (5 mL) at rt overnight. After stirring for further 1 h at 70° C., the reaction mixture was acidified with aqueous 4 N HCl (pH 2) and concentrated in vacuo and resulting precipitate was filtered off to afford 1.15 g (86% yield, 95% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.42-3.49 (m, 2H), 3.50-3.57 (m, 1H), 3.61-3.66 (m, 1H), 3.73 (br d, 1H), 3.86 (dd, 1H), 3.99-4.07 (m, 1H), 4.45-4.60 (m, 2H), 7.50 (d, 1H), 7.94 (d, 1H), 8.58 (s, 1H), 13.36-14.93 (m, 1H).
LC-MS (Method 2): Rt=0.88 min; MS (ESIpos): m/z=371 [M+H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.61 (d, 3H), 5.82 (s, 2H), 7.24 (d, 1H), 7.32 (d, 1H), 7.38 (ddd, 1H), 7.84 (td, 1H), 8.54-8.59 (m, 1H), 8.80 (s, 1H), 14.22 (br s, 1H). LC-MS (Method 2): Rt = 0.93 min; MS (ESIpos): m/z = 376 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.62 (d, 3H), 5.94 (s, 2H), 7.36 (d, 1H), 7.48 (d, 2H), 8.71 (d, 2H), 8.86 (s, 1H), 14.26 (br s, 1H). LC-MS (Method 2): Rt = 0.68 min; MS (ESIpos): m/z = 376 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.28 (s, 3H), 2.60 (d, 3H), 5.75 (s, 2H), 7.17 (d, 1H), 7.31 (d, 1H), 7.64 (dd, 1H), 8.38-8.41 (m, 1H), 8.76 (s, 1H). LC-MS (Method 2): Rt = 0.98 min; MS (ESIpos): m/z = 390 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.59 (d, 3H), 3.42-3.61 (m, 3H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.86 (dd, 1H), 4.00-4.10 (m, 1H), 4.43-4.59 (m, 2H), 7.30 (d, 1H), 8.62 (s, 1H), 14.20 (br s, 1H). LC-MS (Method 2): Rt = 0.94 min; MS (ESIpos): m/z = 385 [M + H]+
Ethyl 8-methyl-4,5-dihydro-1H-furo[2,3-g]indazole-7-carboxylate (commercially available, CAS-RN:[903163-04-2]; 1.0 eq., 3.0 g, 12 mmol) was reacted with 2-(bromomethyl)pyridine (1.6 eq., 3.4 g, 20 mmol), potassium carbonate (15.0 eq., 25.3 g, 183 mmol) and DMAP (2.5 mol %, 37 mg, 300 μmol) in EtOAc (200 mL) at 75° C. for 44 h. Another amount of 2-(bromomethyl)pyridine (1.3 eq., 2.7 g, 16 mmol) and DMAP (2.5 mol %, 37 mg, 300 μmol) was added and stirring at 75° C. continued for another 3 days to give upon column chromatography (SiO2, hexane/DCM) the title compound (3.7 g, 71%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.29 (t, 3H), 2.46 (s, 3H), 2.85-2.95 (m, 4H), 4.26 (q, 2H), 5.39 (s, 2H), 7.07 (d, 1H), 7.31 (ddd, 1H), 7.65 (s, 1H), 7.77 (dt, 1H), 8.53-8.55 (m, 1H).
UPLC-MS (Method 1): Rt=1.15 min; MS (ESIpos): m/z=338 [M+H]+.
Ethyl 8-methyl-2-[(pyridin-2-yl)methyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxylate (3.68 g, 10.9 mmol; intermediate 9) was reacted with aqueous lithium hydroxide (2 M; 15 eq., 82 mL, 160 mmol) in a 1:1 mixture of ethanol and THF (40 mL) at 70° C. overnight. Upon acidification (pH 2-3) with 6 N aqueous hydrochloric acid and dilution with EtOAc a precipitate was formed which was isolated by filtration. The precipitate was taken up with EtOAc, dried with Na2SO2, filtrated and concentrated under reduced pressure to give the desired carboxylic acid (1.9 g, 54%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.44 (s, 3H), 2.84-2.93 (m, 4H), 5.39 (s, 2H), 7.07 (d, 1H), 7.32 (dd, 1H), 7.65 (s, 1H), 7.78 (dt, 1H), 8.53-8.55 (m, 1H), 12.80 (br. s., 1H).
UPLC-MS (Method 1): Rt=0.50 min; MS (ESIpos): m/z=310 [M+H]+.
8-Methyl-2-[(pyridin-2-yl)methyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxylic acid (intermediate 10; 1.00 eq., 300 mg, 970 μmol) was reacted with 1-[(2S)-tetrahydrofuran-2-yl]methanamine (CAS No. [7175-81-7]; 1.2 eq., 120 μL, 1.2 mmol), HATU (CAS No. [148893-10-1]; 1.50 eq., 553 mg, 1.46 mmol) and N,N-diisopropylethylamine (CAS No. [7087-68-5]; 3.0 eq., 500 μL, 52 mmol) in DMF (4 mL) at rt overnight to give upon Biotage Isolera™ chromatography (SNAP Si-NH—28 g, eluting with dichloromethane-methanol, 1:0 to 95:5) followed by trituration with acetonitrile the title compound (87 mg, 23%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.53-1.61 (m, 1H), 1.74-1.90 (m, 3H), 2.44 (s, 3H), 2.86-2.93 (m, 4H), 3.18-3.26 (m, 2H), 3.58-3.64 (m, 1H), 3.73-3.78 (m, 1H), 3.91-3.97 (m, 1H), 5.38 (s, 2H), 7.07 (d, 1H), 7.31 (ddd, 1H), 7.63 (s, 1H), 7.77 (dt, 1H), 7.98 (t, 1H), 8.53-8.54 (m, 1H).
UPLC-MS (Method 1): Rt=0.99 min; MS (ESIpos): m/z=393 [M+H]+.
6,7-Dihydro-1-benzofuran-4(5H)-one (commercially available, CAS No. [16806-93-2]; 5.00 g, 36.7 mmol) was reacted with 1-tert-butoxy-N,N,N′,N′-tetramethylmethanediamine (Bredereck's reagent, CAS No. [5815-08-7]; 1.20 eq., 7.68 g, 44.1 mmol) in toluene (100 mL) at 100° C. for 2 h. Another amount of 1-tert-butoxy-N,N,N′,N′-tetramethylmethanediamine (1.20 eq., 7.68 g, 44.1 mmol) was added and stirring at 100° C. continued for another 6 h. The reaction mixture was concentrated under reduced pressure and the obtained crude title compound used in the subsequent reaction without further purification steps.
UPLC-MS (Method 1): Rt=0.83 min; MS (ESIpos): m/z=192 [M+H]+.
Crude (5E/Z)-5-[(dimethylamino)methylidene]-6,7-dihydro-1-benzofuran-4(5H)-one (1.0 eq., 7.0 g, 37 mmol; intermediate 12) was reacted with hydrazine hydrate 1:1 (5.0 eq., 8.9 mL, 180 mmol) in ethanol (100 mL) at 70° C. for 3 h to give upon column chromatography (SiO2, DCM/MeOH) the title compound (5.6 g, 35% over two steps).
UPLC-MS (Method 1): Rt=0.80 min; MS (ESIpos): m/z=161 [M+H]+.
4,5-Dihydro-1H-furo[2,3-g]indazole (1.0 eq., 5.6 g, 35 mmol; intermediate 13) was reacted with 2-(bromomethyl)pyridine (1.2 eq., 7.2 g, 42 mmol), potassium carbonate (15 eq., 73 g, 530 mmol) and DMAP (2.5 mol %, 110 mg, 880 μmol) in EtOAc (150 mL) at 75° C. for 3 days to give upon column chromatography (SiO2, DCM/MeOH) the title compound (6.0 g, 52%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.86 (s, 4H), 5.34 (s, 2H), 6.62 (d, 1H), 7.03-7.05 (m, 1H), 7.27-7.31 (m, 1H), 7.57-7.60 (m, 2H), 7.76 (dt, 1H), 8.52-8.53 (m, 1H).
UPLC-MS (Method 1): Rt=0.96 min; MS (ESIpos): m/z=252 [M+H]+.
2-[(Pyridin-2-yl)methyl]-4,5-dihydro-2H-furo[2,3-g]indazole (1.00 eq., 1.00 g, 3.98 mmol; intermediate 14) was reacted with phosphoric trichloride (CAS No. [10025-87-3]; 5.0 eq., 1.9 mL, 20 mmol) and DMF (5.0 eq., 1.5 mL, 20 mmol) at rt for 1 h to give upon column chromatography (SiO2, DCM/MeOH) and subsequent preparative HPLC the title compound (63 mg, 5%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.91-2.95 (m, 2H), 3.00-3.04 (m, 2H), 5.39 (s, 2H), 7.09 (d, 1H), 7.31 (ddd, 1H), 7.67 (s, 1H), 7.70 (s, 1H), 7.77 (dt, 1H), 8.52-8.54 (m, 1H), 9.52 (s, 1H).
UPLC-MS (Method 1): Rt=0.83 min; MS (ESIpos): m/z=280 [M+H]+.
2-[(Pyridin-2-yl)methyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carbaldehyde (intermediate 15; 1.00 eq., 50.0 mg, 179 μmol) was reacted with 1-[(2S)-tetrahydrofuran-2-yl]methanamine (CAS No. [7175-81-7]; 5.0 eq., 90.5 mg, 895 μmol), sodium cyanide (1.0 eq., 8.8 mg, 180 μmol) and manganese (IV) dioxide (15.0 eq., 233 mg, 2.69 mmol) in THF (2 mL) at rt for 30 minutes. Another amount of manganese (IV) dioxide (15.0 eq., 233 mg, 2.69 mmol) was added and stirring at rt continued for 20 h. The reaction mixture was filtered over Celite, the filtrate diluted with dichloromethane and washed with water and brine. The organic phase was dried with Na2SO4, filtrated and concentrated under reduced pressure. The obtained crude product was purified by preparative HPLC to give the title compound (33 mg, 47%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.52-1.60 (m, 1H), 1.74-1.91 (m, 3H), 2.87-2.97 (m, 4H), 3.20-3.29 (m, 2H), 3.58-3.64 (m, 1H), 3.73-3.78 (m, 1H), 3.90-3.97 (m, 1H), 5.37 (s, 2H), 7.07 (d, 1H), 7.21 (s, 1H), 7.31 (ddd, 1H), 7.64 (s, 1H), 7.77 (dt, 1H), 8.31 (t, 1H), 8.54 (ddd, 1H).
LC-MS (Method A): Rt=0.87 min; MS (ESIpos): m/z=379 [M+H]+.
5-methylcyclohexane-1,3-dione (500 mg, 3.96 mmol; CAS-RN:[4341-24-6]) was suspended in toluene (5.4 ml) together with 4 Å mol sieves (1.36 g) and triethylamine (830 μl, 5.9 mmol; CAS-RN:[121-44-8]), and then ethyl 2-chloro-4,4,4-trifluoro-3-oxobutanoate (750 μl, 4.8 mmol, CAS No [363-58-6]) was added and the resulting mixture was stirred for 18 h at 100° C. under nitrogen. The reaction mixture was concentrated in vacuo and purified by Biotage Isolera™ chromatography (SNAP KP-Sil—25 g, eluting with dichloromethane-ethanol, 1:0 to 2.5:1) to afford 187 mg (15% yield, 91% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.09 (d, 3H), 1.30 (t, 3H), 2.34-2.44 (m, 2H), 2.53 (br s, 1H), 2.73 (dd, 1H), 3.05-3.14 (m, 1H), 4.36 (q, 2H).
LC-MS (Method 1): Rt=1.24 min; MS (ESIpos): m/z=291 [M+H]+
To a solution of ethyl (±)-6-methyl-4-oxo-3-(trifluoromethyl)-4,5,6,7-tetrahydro-1-benzofuran-2-carboxylate (200 mg, 689 μmol; intermediate 17) in toluene (15 ml) was added sodium hydride (82.7 mg, 60% purity, 2.07 mmol; CAS-RN:[7646-69-7]) at 0° C. After stirring for 0.5 hours, a solution of ethyl formate (330 μl, 4.1 mmol; CAS-RN:[109-94-4]) in toluene (3 mL) was added to the above mixture. The reaction mixture was stirred at room temperature over night and diluted with ethyl acetate (150 ml). After acidification with aqueous 4 N HCl (pH˜4), the phases were separated, and the aqueous phase extracted with ethyl acetate. The combined organic phases were washed with brine, filtered over an water-free filter and concentrated in vacuo to afford 250 mg (crude) of the title compound.
1H NMR (400 MHz, CDCl3) 5 [ppm]: 1.41 (t, 3H), 2.70 (t, 2H), 2.97 (t, 2H), 4.44 (q, 2H), 4.48 (s, 1H), 7.37-7.40 (m, 1H), 13.48-13.50 (m, 1H).
LC-MS (Method 2): Rt=0.84 min; MS (ESIneg): m/z=317 [M−H]−.
To a mixture of ethyl (±)-5-(hydroxymethylidene)-6-methyl-4-oxo-3-(trifluoromethyl)-4,5,6,7-tetrahydro-1-benzofuran-2-carboxylate (250 mg, 786 μmol; intermediate 18) in ethanol (2.4 ml) was added hydrazine dihydrochloride (165 mg, 1.57 mmol; CAS-RN:[5341-61-7]) in water (960 μl). After stirring for 2 h at 25° C., the reaction mixture was diluted with dichloromethane and aqueous saturated sodium bicarbonate solution. The layers were separated and the organic layer was washed with brine, filtered over an water-free filter and concentrated in vacuo to afford 240 mg (92% yield, 95% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.31 (t, 3H), 2.86-2.90 (m, 2H), 2.97-3.01 (m, 2H), 4.34 (q, 2H), 7.58 (s, 1H), 12.64 (br s, 1H).
LC-MS (Method 2): Rt=1.14 min; MS (ESIpos): m/z=315 [M+H]+
To a solution of ethyl (±)-4-methyl-8-(trifluoromethyl)-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxylate (240 mg, 764 μmol; intermediate 19) in 1,4-dioxane (3 ml) was added 4,5-dichloro-3,6-dioxocyclohexa-1,4-diene-1,2-dicarbonitrile (347 mg, 1.53 mmol; CAS-RN:[84-58-2]). The solution was stirred for 2 h at 60° C., diluted with ethyl acetate and quenched with aqueous saturated sodium bicarbonate solution. After phase separation the organic layer was washed with brine, filtered over an water-free filter and concentrated in vacuo. The residue was diluted with 2 ml acetonitrile/water (7:3) and purified by preparative HPLC (Method A, gradient D). The product fractions were pooled and concentrated in vacuo to afford 32.4 mg (7% yield, 54% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.30 (t, 3H), 2.70 (s, 3H), 4.43 (q, 2H), 7.45 (s, 1H), 8.38 (s, 1H), 13.24 (br s, 1H).
LC-MS (Method 1): Rt=1.22 min; MS (ESIpos): m/z=313 [M+H]+
In analogy to K. Kanematsu et al., Heterocycles 1990, 31, 6, 1003-1006 and J. Org. Chem. 1993, 58, 3960-3968:
To a solution of 3-bromoprop-1-yne (CAS No. [106-96-7]; 2.00 eq., 12 mL, 145 mmol) in anhydrous acetonitrile (10 mL) was added dimethyl sulfide (CAS No.:[75-18-3]; 0.57 eq., 3.0 mL, 41 mmol) and the reaction mixture stirred in a light-protected flask at rt overnight. A solution of sodium ethoxide (1.1 eq., 19 mL of a 21% solution in ethanol, 81 mmol) and spiro[2.5]octane-5,7-dione (CAS No. [893411-52-4]; 1.00 eq., 10.0 g, 72.4 mmol) in ethanol (190 mL) was added and the mixture heated to reflux for 1.5 hours. The reaction mixture was diluted with water, concentrated under reduced pressure and the obtained residue extracted with dichloromethane. The combined organic layers were concentrated under reduced pressure, the residue taken up with toluene (75 mL) and treated with 4-methylbenzenesulfonic acid (CAS No. [104-15-4]; 4 mol %, 0.50 g, 2.9 mmol) at room temperature overnight. The reaction mixture was quenched with saturated aqueous NaHCO3, the layers separated, and the aqueous layer extracted with dichloromethane. The combined organic layers were filtered with a hydrophobic filter, concentrated under reduced pressure and the obtained crude product subjected to column chromatography (SiO2, hexane/EtOAc) to give the title compound (3.8 g, 29%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 0.42-0.44 (m, 2H), 0.47-0.50 (m, 2H), 2.11 (d, 3H), 2.28 (s, 2H), 2.75 (s, 2H), 7.44 (m, 1H).
UPLC-MS (Method 1): Rt=1.07 min; MS (ESIpos): m/z=177 [M+H]+.
A solution of 3-methyl-5H-spiro[[1]benzofuran-6,1′-cyclopropan]-4(7H)-one (1.00 eq., 3.80 g, 21.6 mmol; intermediate 21) in pyridine (30 mL) was treated with 1-bromopyrrolidine-2,5-dione (NBS, CAS No. [128-08-5]; 1.01 eq., 3.88 g, 21.8 mmol) and stirred at rt overnight. Another amount of 1-bromopyrrolidine-2,5-dione (1.00 eq., 3.84 g, 21.6 mmol) was added and stirring at rt continued overnight. The reaction mixture acidified with aqueous 2 N HCl (pH 4) and extracted with dichloromethane. The combined organic layers were dried with Na2SO4, filtered, concentrated under reduced pressure and the crude product subjected to column chromatography (SiO2, hexane/EtOAc) to give the title compound (2.68 g, 46%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 0.42-0.46 (m, 2H), 0.48-0.52 (m, 2H), 2.07 (s, 3H), 2.31 (s, 2H), 2.78 (s, 2H).
UPLC-MS (Method 1): Rt=1.28 min; MS (ESIpos): m/z=255/257 [M+H]+ (Br isotope pattern).
2-Bromo-3-methyl-5H-spiro[[1]benzofuran-6,1′-cyclopropan]-4(7H)-one (1.00 eq., 2.00 g, 7.84 mmol; intermediate 22) was reacted with 1-tert-butoxy-N,N,N′,N′-tetramethylmethanediamine (Bredereck's reagent, CAS No. [5815-08-7]; 1.2 eq., 1.9 mL, 9.4 mmol) in toluene (20 mL) at 100° C. overnight. The reaction mixture was concentrated under reduced pressure and the obtained crude title compound used in the subsequent reaction without further purification steps.
UPLC-MS (Method 1): Rt=1.33 min; MS (ESIpos): m/z=310/312 [M+H]+ (Br isotope pattern).
Crude (5E/Z)-2-bromo-5-[(dimethylamino)methylidene]-3-methyl-5H-spiro[[1]benzofuran-6,1′-cyclopropan]-4(7H)-one (1.0 eq., 2.5 g, 8.1 mmol; intermediate 23) was reacted with hydrazine hydrate 1:1 (5.0 eq., 2.0 mL, 40 mmol) in ethanol (35 mL) at 70° C. for 5 hours to give upon column chromatography (SiO2, hexane/EtOAc) the title compound (1.3 g, 59% over two steps).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 0.78-0.80 (m, 2H), 0.82-0.85 (m, 2H), 2.14 (s, 3H), 2.78 (s, 2H), 7.29 (s, 1H), 12.33 (s, 1H).
UPLC-MS (Method 1): Rt=1.20 min; MS (ESIpos): m/z=279/281 [M+H]+ (Br isotope pattern).
7′-Bromo-8′-methyl-1′,5′-dihydrospiro[cyclopropane-1,4′-furo[2,3-g]indazole] (1.00 eq., 700 mg, 2.51 mmol; intermediate 24) was reacted with [(2S)-1,4-dioxan-2-yl]methanol (CAS No. [406913-93-7]; 1.10 eq., 326 mg, 2.76 mol), tri-n-butylphosphine (CAS No. [998-40-3]; 1.6 eq., 1.0 mL, 4.0 mmol) and TMAD (CAS No. [10465-78-8]; 1.60 eq., 691 mg, 4.01 mmol) in toluene (32 mL) at rt for two days to give upon column chromatography (SiO2, hexane/EtOAc) the title compound (595 mg, 65% purity, 41%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 0.76-0.80 (m, 2H), 0.82-0.85 (m, 2H), 2.12 (s, 3H), 2.77-2.78 (m, 2H), 3.24 (dd, 1H), 3.43 (dt, 1H), 3.53 (dt, 1H), 3.61-3.64 (m, 1H), 3.69-3.73 (m, 2H), 3.78-3.84 (m, 1H), 3.97-4.07 (m, 2H), 7.25 (s, 1H).
UPLC-MS (Method 1): Rt=1.31 min; MS (ESIpos): m/z=379/381 [M+H]+ (Br isotope pattern).
7′-Bromo-2′-{[(2S)-1,4-dioxan-2-yl]methyl}-8′-methyl-2′,5′-dihydrospiro[cyclopropane-1,4′-furo[2,3-g]indazole] (1.00 eq., 989 mg, 2.61 mmol; intermediate 25) was carbonylated in a steel autoclave (90 mL) in the presence of bis(diphenylphosphino)ferrocene (CAS No. [12150-46-8]; 0.201 eq., 300 mg, 524 μmol), palladium(II) acetate (5.0 mol %, 29 mg, 130 μmol) and potassium acetate (4.00 eq., 1.02 g, 10.4 mmol) in DMSO (40 mL) under a carbon monoxide pressure of ca. 16 bar at 100° C. for 23 hours to give upon work-up the crude title compound (0.67 g, 60% purity, 45% yield; containing a minor amount of 2-[(2S)-1,4-dioxan-2-ylmethyl]-4-ethyl-8-methyl-2H-furo[2,3-g]indazole-7-carboxylic acid) which was used in the subsequent reactions without further purification steps.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 0.78-0.87 (m, 4H), 2.85-2.86 (m, 2H), 3.25 (dd, 1H), 3.44 (dt, 1H), 3.54 (dt, 1H), 3.61-3.64 (m, 1H), 3.70-3.74 (m, 2H), 3.80-3.86 (m, 1H), 4.00-4.06 (m, 2H), 7.29 (s, 1H), 12.86 (br. s., 1H).
UPLC-MS (Method 1): Rt=0.51 min; MS (ESIpos): m/z=345 [M+H]+.
2-{[(2S)-1,4-dioxan-2-yl]methyl}-8-(trifluoromethyl)-2H-furo[2,3-g]indazole-7-carboxylic acid (Intermediate 8, 1.00 eq, 500 mg, 1.35 mmol) was dissolved in tetrahydrofuran (15 mL) under nitrogen atmosphere, and HATU (1.5 eq., 770 g, 2.03 mmol) and DIPEA (3.0 eq., 0.71 mL, 4.05 mmol) were added and the resulting mixture was stirred for few minutes at room temperature. To this mixture, (R)-(1,4-dioxan-2-yl)methanamine hydrochloride (1.5 eq., 311 mg, 2.03 mmol) was added followed by DMF (1 mL) and the resulting mixture was stirred further for 18 h at room temperature. The reaction mixture was diluted with ethyl acetate and saturated aqueous sodium bicarbonate solution and the corresponding layers were separated. The organic layer was washed with saturated aqueous sodium chloride solution and the resulting organic phase was dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was stirred with 2 ml ethanol and the solids were collected by filtration and further washed with cold ethanol. The collected solids were purified by column chromatography (SiO2, 100% EtOAc to DCM/MeOH 7:3) to give the title compound (260 mg, 41% yield) after recrystallization with acetonitrile (at 70° C. to room temperature).
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: 2.074 (2.48), 2.518 (4.34), 2.523 (2.71), 3.241 (3.04), 3.265 (4.17), 3.269 (3.95), 3.281 (1.50), 3.294 (4.49), 3.300 (2.74), 3.315 (5.40), 3.321 (5.02), 3.352 (3.97), 3.357 (4.65), 3.361 (3.95), 3.371 (1.51), 3.386 (4.09), 3.425 (0.97), 3.431 (1.17), 3.445 (1.35), 3.452 (3.56), 3.458 (2.96), 3.472 (2.99), 3.479 (4.87), 3.485 (2.76), 3.499 (2.67), 3.506 (4.08), 3.512 (2.63), 3.535 (2.96), 3.540 (2.78), 3.552 (2.22), 3.558 (2.68), 3.567 (1.72), 3.580 (2.92), 3.587 (3.02), 3.606 (1.11), 3.613 (2.64), 3.628 (4.65), 3.659 (3.44), 3.674 (1.73), 3.681 (2.14), 3.690 (1.62), 3.698 (1.71), 3.705 (1.70), 3.720 (3.85), 3.749 (7.63), 3.771 (4.43), 3.777 (4.93), 3.846 (2.77), 3.852 (3.02), 3.875 (2.55), 3.881 (2.58), 4.002 (0.74), 4.013 (1.09), 4.020 (1.65), 4.027 (1.75), 4.032 (1.53), 4.037 (1.90), 4.044 (1.56), 4.055 (0.95), 4.061 (0.73), 4.481 (1.50), 4.499 (1.18), 4.515 (4.15), 4.534 (4.26), 4.543 (4.29), 4.554 (4.10), 4.579 (1.48), 4.590 (1.20), 7.447 (9.99), 7.469 (10.51), 7.887 (10.64), 7.910 (9.22), 8.568 (16.00), 9.071 (1.83), 9.086 (3.80), 9.100 (1.75).
LC-MS (Method 1): Rt=0.95 min; MS (ESIpos): m/z=470 [M+H]+
2-{[(2S)-1,4-dioxan-2-yl]methyl}-N-{[(2S)- tetrahydrofuran-2-yl]methyl}-8- (trifluoromethyl)-2H-furo[2,3- glindazole-7-carboxamide
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: 1.565 (0.45), 1.580 (1.38), 1.596 (1.07), 1.601 (1.68), 1.609 (1.60), 1.617 (1.22), 1.625 (1.06), 1.631 (1.76), 1.647 (0.98), 1.796 (0.78), 1.817 (1.40), 1.820 (1.33), 1.836 (2.69), 1.851 (3.23), 1.869 (1.65), 1.889 (1.01), 1.902 (1.76), 1.919 (1.73), 1.924 (0.96), 1.931 (1.64), 1.940 (1.10), 1.945 (1.22), 1.948 (1.20), 1.952 (1.21), 1.963 (0.89), 1.969 (0.84), 1.983 (0.56), 2.337 (0.83), 2.518 (9.64), 2.523 (6.31), 2.674 (1.84), 2.679 (0.81), 3.346 (12.68), 3.356 (5.44), 3.361 (9.06), 3.385 (3.45), 3.425 (0.90), 3.431 (1.08), 3.452 (2.45), 3.458 (2.74), 3.480 (2.51), 3.485 (2.35), 3.507 (2.14), 3.512 (2.34), 3.535 (2.78), 3.541 (2.65), 3.561 (1.14), 3.568 (1.48), 3.622 (3.64), 3.642 (3.09), 3.657 (3.97), 3.676 (1.96), 3.722 (2.87),
N-{[(2R)-1,4-dioxan-2-yl]methyl}-2-[(6- methylpyridin-3-yl)methyl]- 8-(trifluoromethyl)-2H- furo[2,3-g]indazole-7-carboxamide
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: 2.437 (16.00), 3.235 (1.42), 3.259 (1.91), 3.263 (1.86), 3.274 (0.89), 3.288 (2.36), 3.294 (1.69), 3.308 (3.04), 3.446 (0.68), 3.467 (1.38), 3.473 (1.42), 3.494 (1.19), 3.501 (1.11), 3.546 (0.91), 3.552 (1.04), 3.575 (1.35), 3.581 (1.40), 3.607 (1.03), 3.627 (1.47), 3.657 (1.44), 3.668 (0.88), 3.674 (1.05), 3.683 (0.77), 3.691 (0.82), 3.698 (0.78), 3.712 (0.44), 3.742 (2.63), 3.771 (2.34), 5.709 (7.29), 7.240 (2.37), 7.259 (2.60), 7.447 (3.91), 7.470 (4.05), 7.650 (1.72), 7.655 (1.75), 7.670 (1.62), 7.676 (1.58),
2-[(6-methylpyridin-3- yl)methyl]-N-{[(2S)- tetrahydrofuran-2-yl]methyl}-8- (trifluoromethyl)-2H-furo[2,3- glindazole-7-carboxamide
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: 1.558 (0.48), 1.572 (0.58), 1.574 (0.83), 1.588 (0.62), 1.593 (0.74), 1.595 (0.74), 1.602 (0.94), 1.612 (0.51), 1.624 (0.86), 1.798 (0.50), 1.814 (0.85), 1.816 (0.83), 1.830 (1.62), 1.847 (1.68), 1.854 (0.89), 1.863 (0.96), 1.867 (0.96), 1.879 (0.52), 1.883 (0.61), 1.896 (0.88), 1.907 (0.54), 1.912 (0.89), 1.919 (0.55), 1.926 (0.76), 1.942 (0.72), 1.947 (0.70), 1.956 (0.60), 1.961 (0.50), 2.436 (16.00), 3.195 (0.74), 3.223 (0.77), 3.249 (0.76), 3.252 (0.85), 3.257 (1.00), 3.262 (1.22), 3.616 (0.76), 3.635 (1.32), 3.653 (1.65), 3.671 (1.00), 3.761
N-{[(2RS)-4,4-dimethyltetrahydrofuran-2- yl]methyl}-2-{[(2S)-1,4-dioxan-2-yl]methyl}-8- (trifluoromethyl)-2H-furo[2,3-glindazole-7-carboxamide
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.16 (s, 3H), 1.22 (s, 3H), 1.68-1.78 (m, 3H), 1.97-2.08 (m, 1H), 3.32-3.39 (m, 3H), 3.41-3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.86 (dd, 1H), 4.00-4.11 (m, 2H), 4.47- 4.61 (m, 2H), 7.45 (d, 1H), 7.89 (d, 1H), 8.57 (s, 1H), 9.00 (t, 1H). LC-MS (Method 1): Rt = 1.18 min; MS (ESIpos): m/z = 482 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.18-2.31 (m, 1H), 2.54- 2.65 (m, 1H), 3.36-3.40 (m, 1H), 3.42-3.58 (m, 4H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.81-3.92 (m, 2H), 4.00-4.13 (m, 2H), 4.34 (dt, 1H), 4.47-4.61 (m, 2H), 7.45 (d, 1H), 7.90 (d, 1H), 8.57 (s, 1H), 9.18 (t, 1H). LC-MS (Method 1): Rt = 1.09 min; MS (ESIpos): m/z = 490 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.18 (d, 3H), 1.37-1.49 (m, 1H), 1.63-1.72 (m, 1H), 1.89-2.00 (m, 2H), 2.84-2.98 (m, 2H), 3.26- 3.30 (m, 1H), 3.35-3.40 (m, 1H), 3.43-3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.60-3.66 (m, 1H), 3.70-3.76 (m, 1H), 3.84-4.13 (m, 3H), 4.46- 4.62 (m, 2H), 7.45 (d, 1H), 7.89 (d, 1H), 8.57 (s, 1H), 9.04 (t, 1H). LC-MS (Method 1): Rt = 1.08 min; MS (ESIneg): m/z = 466 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 0.05-0.11 (m, 2H), 0.39- 0.46 (m, 2H), 0.70-0.79 (m, 1H), 1.45 (q, 2H), 3.35-3.40 (m, 3H), 3.41-3.57 (m, 2H), 3.64 (d, 1H), 3.73 (d, 1H), 3.86 (dd, 1H), 3.99- 4.07 (m, 1H), 4.46-4.61 (m, 2H), 7.45 (d, 1H), 7.89 (d, 1H), 8.56 (s, 1H), 9.03 (t, 1H). LC-MS (Method 1): Rt = 1.16 min; MS (ESIpos): m/z = 438 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.07 (s, 3H), 3.35-3.40 (m, 1H), 3.40-3.49 (m, 3H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.68-3.76 (m, 3H), 3.86 (dd, 1H), 3.99-4.08 (m, 1H), 4.46-4.62 (m, 2H), 7.45 (d, 1H), 7.92 (d, 1H), 8.58 (s, 1H), 9.24 (t, 1H). LC-MS (Method 1): Rt = 0.86 min; MS (ESIneg): m/z = 474 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.42- 3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.73 (br d, 1H), 3.86 (dd, 1H), 3.99-4.08 (m, 1H), 4.41 (d, 2H), 4.46-4.62 (m, 2H), 7.44 (d, 1H), 7.90 (d, 1H), 8.02 (d, 1H), 8.36 (d, 1H), 8.57 (s, 1H), 9.46 (t, 1H). LC-MS (Method 1): Rt = 0.83 min; MS (ESIpos): m/z = 451 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.39 (m, 1H), 3.42- 3.58 (m, 2H), 3.62 (s, 4H), 3.73 (br d, 1H), 3.86 (dd, 1H), 3.99-4.07 (m, 1H), 4.34 (d, 2H), 4.46-4.60 (m, 2H), 7.01 (d, 1H), 7.43 (d, 1H), 7.52 (d, 1H), 7.89 (d, 1H), 8.56 (s, 1H), 9.27 (t, 1H). LC-MS (Method 1): Rt = 0.88 min; MS (ESIpos): m/z = 464 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.39 (m, 1H), 3.42- 3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.64 (d, 1H), 3.74 (br d, 1H), 3.87 (dd, 1H), 4.00-4.07 (m, 1H), 4.47- 4.60 (m, 2H), 4.80 (d, 2H), 7.46 (d, 1H), 7.68 (d, 1H), 7.77 (d, 1H), 7.93 (d, 1H), 8.58 (s, 1H), 9.90 (t, 1H). LC-MS (Method 1): Rt = 0.95 min; MS (ESIpos): m/z = 467 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.39 (m, 1H), 3.41- 3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.64 (d, 1H), 3.73 (d, 1H), 3.86 (dd, 1H), 4.00-4.06 (m, 1H), 4.47-4.60 (m, 2H), 4.72 (d, 2H), 7.44 (d, 1H), 7.86 (d, 1H), 7.91 (d, 1H), 8.57 (s, 1H), 9.01 (d, 1H), 9.71 (t, 1H). LC-MS (Method 1): Rt = 0.91 min; MS (ESIpos): m/z = 467 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.43- 3.50 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.74 (d, 1H), 3.87 (dd, 1H), 4.01-4.07 (m, 1H), 4.48-4.54 (m, 1H), 4.55-4.60 (m, 1H), 4.70 (d, 2H), 7.43 (t, 1H), 7.48 (d, 1H), 7.93 (d, 1H), 8.58 (s, 1H), 8.81 (d, 2H), 9.51 (t, 1H). LC-MS (Method 1): Rt = 0.91 min; MS (ESIneg): m/z = 460 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.42- 3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.74 (d, 1H), 3.86 (dd, 1H), 3.99-4.07 (m, 1H), 4.48-4.54 (m, 1H), 4.54-4.60 (m, 1H), 4.67 (d, 2H), 7.46 (d, 1H), 7.92 (d, 1H), 8.56-8.59 (m, 2H), 8.63 (dd, 1H), 8.70 (d, 1H), 9.67 (t, 1H). LC-MS (Method 1): Rt = 0.83 min; MS (ESIpos): m/z = 462 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.42- 3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.87 (dd, 1H), 4.00-4.08 (m, 1H), 4.48-4.54 (m, 1H), 4.55-4.59 (m, 1H), 4.60 (d, 2H), 7.48 (d, 1H), 7.49-7.52 (m, 1H), 7.93 (d, 1H), 8.59 (s, 1H), 8.78 (d, 1H), 9.15 (d, 1H), 9.68 (t, 1H). LC-MS (Method 1): Rt = 0.89 min; MS (ESIneg): m/z = 460 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.39 (m, 1H), 3.42- 3.49 (m, 1H), 3.51-3.58 (m, 1H), 3.61-3.66 (m, 1H), 3.74 (br d, 1H), 3.87 (dd, 1H), 4.00-4.07 (m, 1H), 4.48-4.54 (m, 1H), 4.54-4.60 (m, 1H), 4.81 (d, 2H), 7.46 (d, 1H), 7.67-7.70 (m, 1H), 7.70-7.74 (m, 1H), 7.92 (d, 1H), 8.58 (s, 1H), 9.17 (dd, 1H), 9.74 (t, 1H). LC-MS (Method 1): Rt = 0.86 min; MS (ESIpos): m/z = 462 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.29 (s, 3H), 3.35-3.39 (m, 1H), 3.42-3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.74 (d, 1H), 3.87 (dd, 1H), 4.00-4.07 (m, 1H), 4.47-4.54 (m, 1H), 4.54-4.60 (m, 3H), 7.28 (d, 1H), 7.46 (d, 1H), 7.59-7.63 (m, 1H), 7.91 (d, 1H), 8.36-8.39 (m, 1H), 8.58 (s, 1H), 9.56 (t, 1H). LC-MS (Method 1): Rt = 1.07 min; MS (ESIpos): m/z = 475 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.32 (s, 3H), 3.36-3.40 (m, 1H), 3.42-3.50 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.87 (dd, 1H), 3.99-4.08 (m, 1H), 4.48-4.60 (m, 4H), 7.12-7.15 (m, 1H), 7.21 (s, 1H), 7.47 (d, 1H), 7.91 (d, 1H), 8.39 (d, 1H), 8.58 (s, 1H), 9.55 (t, 1H). LC-MS (Method 1): Rt = 1.06 min; MS (ESIpos): m/z = 475 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.42- 3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.86 (dd, 1H), 3.99-4.07 (m, 1H), 4.48-4.60 (m, 2H), 4.61 (d, 2H), 7.46 (d, 1H), 7.91 (d, 1H), 8.51 (d, 1H), 8.55 (d, 1H), 8.57 (s, 1H), 9.64 (t, 1H). LC-MS (Method 1): Rt = 0.90 min; MS (ESIpos): m/z = 476 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.61 (s, 3H), 3.35-3.39 (m, 1H), 3.42-3.49 (m, 1H), 3.50-3.57 (m, 1H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.86 (dd, 1H), 4.00-4.07 (m, 1H), 4.48-4.54 (m, 1H), 4.54-4.60 (m, 1H), 4.76 (d, 2H), 7.46 (d, 1H), 7.57 (s, 2H), 7.92 (d, 1H), 8.58 (s, 1H), 9.71 (t, 1H). LC-MS (Method 1): Rt = 0.90 min; MS (ESIneg): m/z = 474 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.36-3.39 (m, 1H), 3.42- 3.49 (m, 1H), 3.51-3.58 (m, 1H), 3.64 (br d, 1H), 3.74 (br d, 1H), 3.87 (dd, 1H), 4.00-4.07 (m, 1H), 4.47-4.54 (m, 1H), 4.55-4.61 (m, 1H), 4.69 (d, 2H), 7.47 (d, 1H), 7.58-7.62 (m, 1H), 7.93 (d, 1H), 8.32 (dd, 1H), 8.58 (s, 1H), 9.01 (dd, 1H), 9.70 (t, 1H). LC-MS (Method 1): Rt = 1.01 min; MS (ESIneg): m/z = 484 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.42- 3.50 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.74 (br d, 1H), 3.86 (dd, 1H), 4.00-4.07 (m, 1H), 4.48- 4.54 (m, 1H), 4.55-4.59 (m, 1H), 4.61 (d, 2H), 7.47 (d, 1H), 7.69- 7.72 (m, 1H), 7.93 (d, 1H), 8.03 (dd, 1H), 8.58 (s, 1H), 8.73 (dd, 1H), 9.69 (t, 1H). LC-MS (Method 1): Rt = 1.01 min; MS (ESIneg): m/z = 484 [M − H]−
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.40 (m, 1H), 3.42- 3.50 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (d, 1H), 3.71-3.77 (m, 1H), 3.86 (s, 3H), 3.85-3.88 (m, 1H), 3.99-4.08 (m, 1H), 4.49-4.60 (m, 4H), 6.71 (d, 1H), 6.95 (d, 1H), 7.47 (d, 1H), 7.70 (dd, 1H), 7.92 (d, 1H), 8.58 (s, 1H), 9.56 (t, 1H). LC-MS (Method 2): Rt = 1.19 min; MS (ESIpos): m/z = 491 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.35-3.39 (m, 1H), 3.42- 3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.59-3.67 (m, 3H), 3.70-3.77 (m, 1H), 3.86 (dd, 1H), 3.99-4.06 (m, 1H), 4.20 (t, 2H), 4.47-4.62 (m, 2H), 6.89 (t, 1H), 7.20 (t, 1H), 7.44 (d, 1H), 7.63 (t, 1H), 7.91 (d, 1H), 8.57 (s, 1H), 9.16 (t, 1H). LC-MS (Method 1): Rt = 0.83 min; MS (ESIpos): m/z = 464 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.22 (d, 3H), 3.35-3.39 (m, 1H), 3.42-3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.64 (br d, 1H), 3.71-3.76 (m, 3H), 3.86 (dd, 1H), 3.99-4.07 (m, 1H), 4.48-4.59 (m, 4H), 7.43 (d, 1H), 7.85 (d, 1H), 7.91 (d, 1H), 8.57 (s, 1H), 9.18 (t, 1H). LC-MS (Method 1): Rt = 0.89 min; MS (ESIpos): m/z = 479 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 3.03 (t, 2H), 3.35-3.39 (m, 1H), 3.41-3.49 (m, 1H), 3.50-3.58 (m, 1H), 3.61-3.70 (m, 3H), 3.73 (d, 1H), 3.86 (dd, 1H), 3.99-4.07 (m, 1H), 4.46-4.60 (m, 2H), 7.24 (ddd, 1H), 7.32 (d, 1H), 7.44 (d, 1H), 7.73 (td, 1H), 7.89 (d, 1H), 8.51-8.54 (m, 1H), 8.57 (s, 1H), 9.14 (t, 1H). LC-MS (Method 1): Rt = 0.97 min; MS (ESIpos): m/z = 475 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.90 (t, 2H), 3.35-3.39 (m, 1H), 3.42-3.59 (m, 4H), 3.64 (d, 1H), 3.73 (br d, 1H), 3.86 (dd, 1H), 3.99-4.06 (m, 1H), 4.46-4.60 (m, 2H), 7.34 (ddd, 1H), 7.44 (d, 1H), 7.70 (dt, 1H), 7.90 (d, 1H), 8.43 (dd, 1H), 8.48-8.49 (m, 1H), 8.57 (s, 1H), 9.14 (t, 1H). LC-MS (Method 1): Rt = 0.91 min; MS (ESIpos): m/z = 475 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.56-1.65 (m, 1H), 1.79- 1.97 (m, 3H), 2.61 (d, 3H), 3.30- 3.35 (m, 2H), 3.60-3.68 (m, 1H), 3.79 (ddd, 1H), 3.99 (quin, 1H), 5.80 (s, 2H), 7.21 (d, 1H), 7.26 (d, 1H), 7.34 (ddd, 1H), 7.80 (td, 1H), 8.55 (ddd, 1H), 8.77 (s, 1H), 8.98 (t, 1H). LC-MS (Method 1): Rt = 1.13 min; MS (ESIpos): m/z = 459 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.61 (d, 3H), 3.22-3.31 (m, 3H), 3.43-3.51 (m, 1H), 3.53-3.61 (m, 1H), 3.62-3.72 (m, 2H), 3.75 (dd, 2H), 5.80 (s, 2H), 7.21 (d, 1H), 7.26 (d, 1H), 7.34 (ddd, 1H), 7.80 (td, 1H), 8.51-8.57 (m, 1H), 8.77 (s, 1H), 9.01 (t, 1H). LC-MS (Method 1): Rt = 1.04 min; MS (ESIpos): m/z = 475 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.57-1.65 (m, 1H), 1.78- 1.98 (m, 3H), 2.61 (d, 3H), 3.32- 3.35 (m, 2H), 3.62-3.69 (m, 1H), 3.79 (td, 1H), 4.00 (quin, 1H), 5.78 (s, 2H), 7.18-7.23 (m, 2H), 7.27 (d, 1H), 8.51-8.57 (m, 2H), 8.80 (s, 1H), 8.98 (t, 1H). LC-MS (Method 1): Rt = 1.07 min; MS (ESIpos): m/z = 459 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.61 (d, 3H), 3.23-3.31 (m, 3H), 3.43-3.51 (m, 1H), 3.54-3.61 (m, 1H), 3.62-3.72 (m, 2H), 3.73- 3.79 (m, 2H), 5.78 (s, 2H), 7.19- 7.23 (m, 2H), 7.28 (d, 1H), 8.52- 8.56 (m, 2H), 8.80 (s, 1H), 9.02 (t, 1H). LC-MS (Method 1): Rt = 0.99 min; MS (ESIpos): m/z = 475 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.62 (d, 3H), 4.61 (d, 2H), 5.80 (s, 2H), 7.19 (d, 1H), 7.22 (d, 1H), 7.26 (d, 1H), 7.34 (ddd, 1H), 7.80 (td, 1H), 8.09 (d, 1H), 8.51- 8.57 (m, 1H), 8.78 (s, 1H), 9.61 (t, 1H). LC-MS (Method 1): Rt = 1.03 min; MS (ESIpos): m/z = 456 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.61 (d, 3H), 3.79 (s, 3H), 4.41 (d, 2H), 5.80 (s, 2H), 6.16 (d, 1H), 7.21 (d, 1H), 7.24 (d, 1H), 7.34 (ddd, 1H), 7.61 (d, 1H), 7.80 (td, 1H), 8.50-8.57 (m, 1H), 8.76 (s, 1H), 9.33 (t, 1H). LC-MS (Method 1): Rt = 1.04 min; MS (ESIpos): m/z = 469 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.56-1.65 (m, 1H), 1.76- 1.97 (m, 3H), 2.27 (s, 3H), 2.60 (d, 3H), 3.32 (br s, 1H), 3.34 (s, 1H), 3.59-3.69 (m, 1H), 3.79 (ddd, 1H), 3.99 (quin, 1H), 5.74 (s, 2H), 7.15 (d, 1H), 7.25 (d, 1H), 7.57-7.64 (m, 1H), 8.35-8.41 (m, 1H), 8.73 (s, 1H), 8.97 (t, 1H). LC-MS (Method 1): Rt = 1.20 min; MS (ESIpos): m/z = 473 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.27 (s, 3H), 2.60 (d, 3H), 3.22-3.32 (m, 3H), 3.42-3.51 (m, 1H), 3.54-3.61 (m, 1H), 3.62-3.72 (m, 2H), 3.72-3.78 (m, 2H), 5.74 (s, 2H), 7.15 (d, 1H), 7.25 (d, 1H), 7.61 (dt, 1H), 8.37-8.39 (m, 1H), 8.73 (s, 1H), 8.98-9.04 (m, 1H). LC-MS (Method 1): Rt = 1.12 min; MS (ESIpos): m/z = 489 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.27 (s, 3H), 2.61 (d, 3H), 4.61 (d, 2H), 5.74 (s, 2H), 7.16 (d, 1H), 7.19 (d, 1H), 7.25 (d, 1H), 7.57-7.64 (m, 1H), 8.09 (d, 1H), 8.36-8.40 (m, 1H), 8.75 (s, 1H), 9.61 (t, 1H). LC-MS (Method 1): Rt = 1.10 min; MS (ESIpos): m/z = 470 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.55-1.66 (m, 1H), 1.77- 1.97 (m, 3H), 2.59 (d, 3H), 3.34- 3.42 (m, 2H), 3.44-3.58 (m, 2H), 3.60-3.67 (m, 2H), 3.71-3.90 (m, 3H), 3.95-4.10 (m, 2H), 4.44-4.58 (m, 3H), 7.24 (d, 1H), 8.61 (s, 1H), 8.98 (t, 1H). LC-MS (Method 1): Rt = 1.11 min; MS (ESIpos): m/z = 468 [M + H]+
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 2.60 (d, 3H), 3.21-3.31 (m, 2H), 3.36-3.41 (m, 1H), 3.41-3.53 (m, 3H), 3.53-3.71 (m, 5H), 3.71- 3.79 (m, 3H), 3.86 (dd, 1H), 3.98- 4.13 (m, 1H), 4.47-4.58 (m, 2H), 7.24 (d, 1H), 8.61 (s, 1H), 9.01 (t, 1H). LC-MS (Method 1): Rt = 1.02 min; MS (ESIpos): m/z = 484 [M + H]+
A mixture of 8-methyl-2-(pyridin-2-ylmethyl)-N-[(2S)-tetrahydrofuran-2-ylmethyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxamide (intermediate 11; 1.00 eq., 550 mg, 1.40 mmol) in ethane-1,2-diol (5 mL) was treated with diethyl fumarate (CAS No. [623-91-6]; 1.0 eq., 230 μL, 1.4 mmol) and palladium (0.20 eq., 600 mg, 0.28 mmol, 5% on charcoal) and heated to 190° C. for 16 h. Another amount of diethyl fumarate (1.0 eq., 230 μL, 1.4 mmol) was added and stirring at 190° C. continued for 8 h. The reaction mixture was cooled to rt, filtered over a polytetrafluoroethylene (PTFE) filter and the filter residue washed with dichloromethane and water. The filtrate was collected and the layers separated. The aqueous layer was extracted twice with dichloromethane, the combined organic layers filtered with a hydrophobic filter, concentrated under reduced pressure and the obtained crude product subjected to preparative HPLC to give the title compound (71 mg, 12%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.57-1.65 (m, 1H), 1.78-1.95 (m, 3H), 2.74 (s, 3H), 3.28-3.32 (m, 2H), 3.60-3.65 (m, 1H), 3.75-3.81 (m, 1H), 3.97-4.03 (m, 1H), 5.80 (s, 2H), 7.19 (d, 1H), 7.31-7.35 (m, 2H), 7.77 (d, 1H), 7.79 (dt, 1H), 8.35 (t, 1H), 8.55 (ddd, 1H), 8.63 (s, 1H).
LC-MS (Method B): Rt=0.93 min; MS (ESIpos): m/z=391 [M+H]+.
An ice-cooled mixture of 8-methyl-2-(pyridin-2-ylmethyl)-N-[(2S)-tetrahydrofuran-2-ylmethyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxamide (intermediate 11; 1.00 eq., 800 mg, 2.04 mmol) in DMF (10 mL) was treated with N-bromosuccinimide (CAS No. [128-08-5]; 1.50 eq., 544 mg, 3.06 mmol), warmed to rt and stirred at rt for 6 h. Another amount of N-bromosuccinimide (0.50 eq., 180 mg, 1.0 mmol) was added and stirring at rt continued overnight. This procedure of adding and stirring overnight was repeated once more. The reaction mixture was concentrated under reduced pressure and the obtained residue purified by Biotage Isolera™ chromatography (SNAP KP-Sil, eluting with dichloromethane-ethanol, 9:1 to 0:1), followed by RP C18 HPLC afforded 5.5 mg (1% yield, 95% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.57-1.64 (m, 1H), 1.77-1.96 (m, 3H), 3.34-3.40 (m, 2H), 3.62-3.66 (m, 1H), 3.77-3.81 (m, 1H), 4.01 (quint, 1H), 5.13 (d, 2H), 5.73 (t, 1H), 5.81 (s, 2H), 7.22 (d, 1H), 7.33 (ddd, 1H), 7.37 (d, 1H), 7.79 (dt, 1H), 7.81 (d, 1H), 8.54 (ddd, 1H), 8.67 (s, 1H), 8.84 (t, 1H).
LC-MS (Method 2): Rt=0.91 min; MS (ESIpos): m/z=407 [M+H]+.
A mixture of 2-(pyridin-2-ylmethyl)-N-[(2S)-tetrahydrofuran-2-ylmethyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxamide (intermediate 16; 1.00 eq., 100 mg, 264 μmol) in pyridine (2 mL) was treated with N-bromosuccinimide (CAS No. [128-08-5]; 1.0 eq., 48 mg, 270 μmol) and stirred at rt overnight. Another amount of N-bromosuccinimide (1.0 eq., 48 mg, 270 μmol) was added and stirring at rt continued for 3 days. The reaction mixture was adjusted to pH 4 by addition of aqueous hydrochloric acid (2 M) and diluted with dichloromethane. The layers were separated, the organic layer dried with anhydrous sodium sulfate and concentrated under reduced pressure. The obtained material was subjected to preparative HPLC to give the title compound (0.5 mg, 1%).
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.56-1.64 (m, 1H), 1.78-1.94 (m, 3H), 3.57-3.66 (m, 2H), 3.71-3.81 (m, 2H), 3.98-4.05 (m, 1H), 5.80 (s, 2H), 7.20 (d, 1H), 7.34-7.37 (m, 1H), 7.40 (d, 1H), 7.75-7.80 (m, 2H), 8.54-8.55 (m, 1H), 8.66 (s, 1H).
LC-MS (Method A): Rt=0.86 min; MS (ESIpos): m/z=377 [M+H]+.
An ice-cooled solution of 2-(pyridin-2-ylmethyl)-N-[(2S)-tetrahydrofuran-2-ylmethyl]-4,5-dihydro-2H-furo[2,3-g]indazole-7-carboxamide (intermediate 16; 1.0 eq., 73 mg, 190 μmol) in DMF (1 mL) was treated with a solution of bromine (0.50 eq., 5.0 μL, 96 μmol) in DMF (0.2 mL), warmed to rt and stirred at rt for 2 h. Additional amounts of bromine (0.50 eq., 5.0 μL, 96 μmol) were added twice and stirring at rt continued for 4 h. Trifluoroacetic acid (CAS No. [76-05-1]; 3.0 eq., 45 μL, 580 μmol) and bromine (0.50 eq., 5.0 μL, 96 μmol) were added to the mixture and stirring at rt continued overnight. Again, trifluoroacetic acid (10 eq., 150 μL, 1.9 mmol) and bromine (2.0 eq., 20 μL, 390 μmol) were added and the mixture stirred at rt for 1 h. The reaction mixture was diluted with ethyl acetate and the organic layer washed twice with an aqueous mixture of saturated NaHCO3 and saturated Na2S2O3 (1:2) and subsequently with brine. The organic layer was filtered with a hydrophobic filter, concentrated in vacuo and the residue purified by preparative HPLC to give 1.9 mg (2% yield, 95% purity) of the title compound.
1H NMR (400 MHz, DMSO-d6) δ [ppm]: 1.56-1.65 (m, 1H), 1.78-1.97 (m, 3H), 3.35-3.36 (m, 2H), 3.61-3.67 (m, 1H), 3.76-3.82 (m, 1H), 3.97-4.05 (m, 1H), 5.80 (s, 2H), 7.21 (d, 1H), 7.34 (ddd, 1H), 7.79 (dt, 1H), 7.91 (s, 1H), 8.12 (s, 1H), 8.54 (ddd, 1H), 8.66 (s, 1H), 8.67 (t, 1H).
LC-MS (Method C): Rt=0.95 min; MS (ESIpos): m/z=455/457 [M+H]+ (Br isotope pattern).
The crude mixture of 2′-{[(2S)-1,4-dioxan-2-yl]methyl}-8′-methyl-2′,5′-dihydrospiro[cyclo-propane-1,4′-furo[2,3-g]indazole]-7′-carboxylic acid and 2-[(2S)-1,4-dioxan-2-ylmethyl]-4-ethyl-8-methyl-2H-furo[2,3-g]indazole-7-carboxylic acid (intermediate 26; 1.0 eq., 150 mg, 440 μmol) was reacted with 1-[(2R)-1,4-dioxan-2-yl]methanamine hydrochloride (1:1) (CAS No. [1523541-84-5]; 1.5 eq., 100 mg, 650 μmol), HATU (CAS No. [148893-10-1]; 1.5 eq., 250 mg, 650 μmol) and N,N-diisopropylethylamine (CAS No. [7087-68-5]; 3.0 eq., 230 μL, 1.3 mmol) in DMF (3 mL) at rt overnight to give upon preparative HPLC the title compound (4.6 mg, 2%).
1H-NMR (400 MHz, DMSO-d6) δ [ppm]: −0.149 (0.77), 0.146 (0.75), 0.935 (1.55), 0.951 (1.51), 1.298 (3.88), 1.317 (8.51), 1.335 (3.92), 1.958 (0.43), 2.053 (0.65), 2.334 (3.26), 2.338 (1.48), 2.520 (16.00), 2.524 (10.34), 2.542 (0.93), 2.676 (3.35), 2.680 (1.45), 2.735 (0.49), 2.759 (14.48), 2.778 (0.92), 2.904 (0.74), 2.923 (2.14), 2.942 (2.11), 2.961 (0.77), 3.076 (0.42), 3.089 (0.41), 3.223 (1.21), 3.236 (0.68), 3.248 (1.50), 3.252 (1.84), 3.270 (1.55), 3.276 (1.71), 3.286 (1.25), 3.308 (2.60), 3.367 (1.79), 3.395 (1.27), 3.442 (0.79), 3.469 (1.81), 3.496 (1.53), 3.518 (0.91), 3.522 (0.96), 3.538 (0.93), 3.544 (1.52), 3.551 (1.17), 3.566 (1.16), 3.572 (1.47), 3.599 (0.82), 3.628 (1.40), 3.635 (1.44), 3.660 (1.36), 3.676 (0.91), 3.693 (0.72), 3.700 (0.72), 3.728 (2.60), 3.734 (2.62), 3.757 (2.10), 3.763 (2.03), 3.828 (0.94), 3.834 (1.07), 3.856 (0.86), 3.862 (0.85), 4.061 (0.57), 4.078 (0.68), 4.085 (0.56), 4.437 (0.49), 4.455 (0.46), 4.472 (1.39), 4.490 (1.36), 4.501 (1.35), 4.512 (1.36), 4.536 (0.58), 4.547 (0.46), 7.090 (4.14), 8.305 (0.67), 8.320 (1.38), 8.335 (0.64), 8.547 (5.84).
The in vitro activity of the compounds of the present invention can be demonstrated in the following assay:
cAMP HTRF® Assay for Identification of Cellular GPR84 Antagonists
By using a Homogenous Time-Resolved Fluorescence (HTRF®) based assay (#62AM5PEJ, Cisbio, Condolet, France) the inhibition of the Gi-coupled GPR84 receptor can be detected. CHO-K1 cells stably expressing human GPR84 receptor (purchased from DiscoveRx, now Eurofins) were used and treated with Forskolin (F6886, Sigma, Germany) to stimulate membrane adenylyl cyclases and thereby unspecific cAMP formation. Activation of the Gi-coupled GPR84 by a natural or small molecule agonist (e.g. 6-n-octyl aminouracile, inhouse) results in inhibition of cellular cAMP formation which can be released again by antagonists to this receptor. Detection and quantification of cellular cAMP levels in this HTRF assay is achieved by interaction between a fluorescent cAMP tracer (cAMP-d2) and an Eu-cryptate labelled anti-cAMP antibody. Following excitation at 337 nm this pairing allows for the generation of a fluorescence resonance energy transfer (FRET) between the partners and results in FRET induced emissions at 665 nm and 620 nm, the latter representing background signal by Eu-cryptate labelled anti-cAMP antibody. Maximal signal is obtained in the absence of any cellular cAMP (no competition for the binding of the tracer to the antibody). Given the combination of the Gi coupling properties of GPR84 and the competitive nature of the detection system agonist treatment should result in an increase in the HTRF signal due to lowered cAMP levels. Any signal decrease in the presence of Forskolin, agonist and compound is indicative of antagonist mediated abrogation of GPR84 signalling.
For the assay, frozen aliquots of CHO-K1 cells expressing hGPR84 (prepared by acCELLerate, Hamburg, Germany) were thawed and a cell suspension (1.67E+06 cells/mL) in assay media (Ham's F12 Nutrient Mix, Thermo Fisher Scientific, Waltham, USA; 5% fetal calf serum, Biomol, Hamburg, Germany) containing cAMP-d2 (dilution 1:20, supplied with the kit #62AM5PEJ, Cisbio, Condolet, France) was prepared. After recovery of cells for 20 minutes at 37° C., 3 μL/well cell suspension including cAMP-d2 were added to a pre-dispensed assay plate (Greiner Bio-One, Kremsmuenster, Austria) containing 50 nl/well test compound in 100% DMSO or 100% DMSO as control. This was followed by a 30 minutes incubation step at room temperature. The stimulation time was started by addition of 2 μL/well assay media containing 2.5×EC80 agonist 6-OAU and 2.5×EC90 Forskolin (negative control: 2.5×EC90 Forskolin in assay media) and was continued for 30 minutes at room temperature. The reaction was stopped by addition of 3 μL/well lysis buffer containing cAMP Eu-Cryptate antibody (dilution 1:20) (both supplied with the kit #62AM5PEJ, Cisbio, Condolet, France). To enable complete lysis, plates were incubated for 60 minutes at room temperature before measurement in an HTRF reader, e.g. a PHERAstar (BMG Labtech, Ortenberg, Germany).
From the fluorescence emissions at 665 nm (FRET) and at 620 nm (background signal of Eu-cryptate) the ratio (emission at 665 nm divided by emission at 620 nm×10000) was calculated and the data were normalized (reaction without test compound, only 100% DMSO=0% inhibition; all other assay components except agonist=100% inhibition). For dose response testing on the same microtiter plate, compounds were tested at 11 different concentrations in the range of 20 μM to 0.07 nM (20 μM, 5.7 μM, 1.6 μM, 0.47 μM, 0.13 μM, 38 nM, 11 nM, 3.1 nM, 0.89 nM, 0.25 and 0.07 nM; dilution series prepared before the assay at the level of the 100-fold conc. stock solutions by serial 1:3.5 dilutions in 100% DMSO) in duplicate values for each concentration. IC50 values were calculated by 4-parameter fitting using a commercial software package (Genedata Screener, Basel, Switzerland).
Examples were tested in selected biological assays one or more times. When tested more than once, data are reported as either average values or as median values, wherein
Examples were synthesized one or more times. When synthesized more than once, data from biological assays represent average values or median values calculated utilizing data sets obtained from testing of one or more synthetic batch.
The suitability of the compounds of the present invention for the treatment of PCOS and associated symptoms and pain disorders can be demonstrated in the following animal models:
The efficacy of Example 3-2 in vivo on the treatment of POCS was measured in the DHT driven rat PCOS model. At 3 weeks of age, Han-Wistar rats were randomly divided into three experimental groups [control (n=10), DHT (n=10), and DHT plus Example 3-2 (n=10)] and implanted s.c. with 60-d continuous-DHT-release pellets (80 μg/d, Bayer AG, Germany). The dose of DHT was chosen to mimic the hyperandrogenic state in women with PCOS. Controls received identical pellets lacking the bioactive DHT molecule. Animal received a standard chow, only for the last week standard show was replaced by a high fat diet. Rats were weighted bi-weekly from 21 d of age. The study was concluded after 26 days of drug administration. Example 3-2 treated animal gained less weight compared to the untreated control. Statistical analysis was performed with one-way analysis of variance, followed by Bonferroni's multiple comparison test against vehicle control groups using the GraphPad PRISM software, *p<0.05.
The efficacy of Example 3-2 in vivo on inflammatory pain was measured in inflamed paws after administration of complete Freund's adjuvant (CFA) (24 h) in the dynamic weight-bearing (DWB) model. The effects of repeated preventive treatment with Example 3-2 on pain following repeated oral administration (3×) in the mouse CFA model of inflammation were investigated using a preventive setting. The GPR84 antagonist Example 3-2 (20 or 60 mg/kg, 3× doses) was administered 2 h before injection of CFA and 6-8 h later at day 0. At 24 h after CFA application, the third dose of Example 3-2 was given 2 h before DWB testing. Statistical analysis was performed with one-way analysis of variance, followed by Bonferroni's multiple comparison test against vehicle control groups using the GraphPad PRISM software, *p<0.05.
The in vivo activity of the compounds of the present invention can be demonstrated in the following assays:
The anti-fibrotic effect of examples is evaluated in the kidney fibrosis model. The study is performed on male Sprague Dawley rats (age: 7-8 weeks) that can be obtained from Charles River. Rats are anesthetized with continuous inhaled isoflurane, and the left ureter is exposed via a mid-abdominal incision. The mid-ureter is obstructed by two-point ligation with silk sutures. The SHAM-operated rats (n=6) undergo the same procedure except for the obstruction of the left ureter.
Rats are randomized into three groups (n=12 each group) and are dosed bidaily with vehicle and example compound starting directly after UUO. At nine days after surgery, blood samples as well as kidneys are collected under terminal anesthesia. After centrifugation of the blood samples, serum is isolated. Serum osteopontin levels are assessed via Ella Automated Immunoassay System according to the manufacturers protocol. Kidneys are divided in two parts. One part is snap-frozen in liquid nitrogen for RNA analysis. The other part is stored in Davidson's fixative for the preparation of histological sections. Total RNA is isolated from parts of the harvested kidneys. Kidney tissue is homogenized, and RNA is obtained and transcribed to cDNA. Using TaqMan real time PCR renal mRNA expression of inflammatory and fibrotic markers is analyzed in kidney tissues. For the assessment of fibrosis on the protein level paraffin tissue sections are stained with alpha-smooth muscle actin (αSMA) and Sirius Red/Fast Green Collagen Stainings using standard procedures.
Quantitative measurements of alpha-smooth muscle actin (αSMA)-positive as well as Sirius Red (collagen) positive areas within the kidneys are obtained by computer image analysis using the Axio Scan Z1 (Zeiss) microscope and the Zen software.
All data are expressed as means±S.D. Differences between groups are analyzed by one-way ANOVA with Dunnett's corrections for multiple comparisons. Statistical significance is defined as p<0.05.
Anti-fibrotic and anti-inflammatory effects of examples are evaluated in the silica mouse model of pulmonary fibrosis in a therapeutic treatment setting.
Adult C57BL/6JR male mice (18-20 g; 9 weeks old) are purchased from (Janvier Labs, Germany). Mice are anesthetized in a chamber with isoflurane (3% v/v) and 2.5 mg of the fine crystalline silica DQ12 dissolved in 70 μl of sterile phosphate buffered saline is applied intratracheally. Control animals receive the same volume of phosphate buffered saline. From day 10 after silica instillation, the animals receive either the GPR84 antagonist examples (p.o. bid) or the ethanesulfonate salt of nintedanib (60 mg/kg p.o bid) for the following 20 days. 30 days after silica instillation, mice are anesthetized with an intraperitoneal injection of ketamine/medetomidine (50 mg/kg and 0.33 mg/kg i.p.) combined with a subcutaneous injection of temgesic (0.06 mg/kg s.c.) and EDTA plasma samples are taken for pharmacokinetic determination of examples plasma levels and determination of biomarkers. After exsanguination, the trachea is cannulated and the lungs of the animals are lavaged (broncho-alveolar lavage fluid, BALF) three times, each time with 0.5 ml ice-cold PBS. Then the lungs of the animals are excised, weighed and snap-frozen on dry ice for biomarker analysis. Cytokines are determined with the Bio-Plex cytokine array system (BIORAD), procollagen Iα1 with an ELISA (R&D Systems) and hydroxyproline with HPLC (Waters). 13,14-dihydro-15keto-PGF2α is measured with an ELISA (Cayman).
Data are presented as means±SEM from 12 animals per group. Statistical analyses are performed using unpaired Student's t-test. P values of <0.05 are considered significant.
Example compounds are evaluated in another preclinical model of pulmonary fibrosis. The study is performed on male C57BL/6N mice (age 8 weeks at arrival) that are obtained from Charles River, Germany. At least one day prior to the start of the experiment, all animals are allocated randomly into 11 groups (n=7-12 per group). The rats are dosed bidaily (p.o.) with vehicle, Nintedanib and example compounds starting on day 7 till day 20 (group 1-6) or starting on day 20 till day 34 (group 7-11).
Bleomycin is administered intranasally at a dose of 1 mg/kg to all animals in groups 2-11 on D0. Prior to i.n. administration, mice are anaesthetized i.p. with a combination of ketamine and xylazine.
Animals are examined clinically twice daily. Animals are weighted on D0, D1, from D4 they are weighted every day until D34. On day 21 and 34, after anesthesia, blood is sampled (except group 1) from groups 2-6 and 7-11 respectively. On day 21 and 34, lungs are sampled from groups 1-6 and 7-11, respectively. The lungs are excised by gently opening the thorax and by cutting down either side of the sternum and ribs and trimming back. The lungs are weighted individually using precise analytical balance and weights are recorded. Lungs are placed into marked bottles containing 10% buffered formalin for further histopathological valuation (Ashcroft/Matsuse score, collagen I quantification).
Data for assessment of body weight and lung weight are processed by using MS Excel. Statistical analysis and graphical presentation are performed using Graphpad Prism software (version 8.1.1.). One-way ANOVA or Mann-Whitney test is employed. Mixed effects analysis for body weight changes is employed. Differences between groups are considered statistically significant when p<0.05.
For histopathological evaluation, whole lungs are embedded in paraffin and stained according to Crossman's Trichrome (Gray P. The Microtomist's Formulary and Guide. Published by Robert E. Krieger Publishing Co.). Pulmonary histological changes are assessed using Matsuse modification of Ashcroft score (Ashcroft H et al. J Clin Pathol (1988) 41:467-70; Matsuse T et al. Eur Respir J (1999) 13:71-77).
Immunohistochemistry for collagen are performed using the anti-collagen 1A1 (COL1A1) antibody. Antigen retrieval is performed using Bloxall pH 9 (PT Link modul, DAKO). Slides are incubated with primary rabbit polyclonal anti-COL1A1 antibody for 1 hour (1:2000) followed by ImmPRESS Detection Kit (Vector) (Autostainer Link48, DAKO). Level of de novo collagen 1A1 (COL1A1) deposition are evaluated using digital image analysis software (Calopix software, TRIBVN, France).
Statistical analysis and graphical presentation are performed using GraphPad Prism software (version 8.1.1). Mann-Whitney test is employed. Differences between groups are considered statistically significant when p<0.05.
Kidney protective effects of example compounds are evaluated in ZSF1 rats, a model of renal disease.
A total of 45 male obese ZSF1 rats and 30 lean littermates (Charles River) are used in the study. At 14 weeks of age, animals are assigned to one of the 5 experimental groups: lean control animals receiving no drug treatment for 12 weeks (Ln-ZSF1 group); obese control animals receiving vehicle treatment for 12 weeks (Ln-vehicle group); obese animals receiving vehicle treatment for 12 weeks (Ob-vehicle group); obese animals receiving enalapril in drinking water (per day) for 12 weeks (Ob-enalapril group); or obese animals receiving example compounds for 12 weeks (Ob-GPR84).
Metabolic cage studies are performed at 0, 4, 8, 12 weeks of treatment. Urine from the measurement period is collected and stored at −80° C. for measurement of creatinine, urinary total protein, albumin and glucose. Plasma samples are analyzed for triglycerides and cholesterol and non-esterified fatty acids.
Kidneys are divided in two parts. One part is snap-frozen in liquid nitrogen for RNA analysis. The other part is stored in Davidson's fixative for the preparation of histological sections. Total RNA is isolated from parts of harvested kidneys. Kidney tissue is homogenized, and RNA is obtained and transcribed to cDNA. Using TaqMan real time PCR renal mRNA expression of inflammatory and fibrotic markers is analyzed in kidney tissues. For the assessment of fibrosis on the protein level paraffin tissue sections are stained with alpha-smooth muscle actin (αSMA) and Sirius Red/Fast Green Collagen Stainings using standard procedures.
Quantitative measurements of alpha-smooth muscle actin (αSMA)-positive as well as Sirius Red (collagen) positive areas within the kidneys are obtained by computer image analysis using the Axio Scan Z1 (Zeiss) microscope and the Zen software.
The efficacy of example compounds in vivo on the treatment of POCS is measured in the DHT driven rat PCOS model with high fat diet. At 15 weeks of age, Han-Wistar rats are randomly divided into experimental groups [DHT (n=10), and DHT plus example compounds (n=10)] and 60-d continuous-DHT-release pellets are implanted (80 μg/d, Bayer AG, Germany). The dose of DHT is chosen to mimic the hyperandrogenic state in women with PCOS. Controls receive identical pellets lacking the bioactive DHT molecule. Animal receive a high fat diet (RD12492). Rats are weighted bi-weekly. The study is concluded after 28 days of drug administration. The metabolic, fibrotic and inflammatory profile is analyzed including insulin levels and adiponectin/leptin ratio compared to the untreated control. Plasma insulin, adiponectin and leptin is measured with MSD (mesoscale). Statistical analysis is performed with an unpaired t test and the Grubbs test to identify outliers using the GraphPad PRISM software, *p<0.05.
The efficacy of example compounds in vivo on inflammatory pain is measured in inflamed paws after administration of complete Freunds' adjuvans (CFA, 50 μl) with von Frey measurement after 48 h. The effects of repeated preventive treatment with example compounds on pain following repeated administration in the rat (Han Wistar female, 8 weeks) CFA model of inflammation is investigated using a preventive setting. The GPR84 antagonist example compounds are administered with the first application 2 h before injection of CFA at day 0. At 48 h after CFA application, example compounds are given 2 h before von Frey testing (5 repeated measurements). Statistical analysis is performed with an unpaired t test and the Grubbs test to identify outliers using the GraphPad PRISM software, *p<0.05.
The efficacy of example compounds in vivo on chemotherapy (Oxaliplatin; OPNP)) induced pain is measured in a rat Oxaliplatin-induced 6 weeks neuropathic pain model. Sprague Dawley male rats at the age of about 9 weeks are used for the experiment. Rats are randomly divided into experimental groups (e.g. n=10). Pain is induced by oxaliplatin application (2 mg/kg) once per day for 5 days. The GPR84 antagonist example compounds are administered with the first application at d1. Rats are habituated to the circumstances for 30 min before starting with behavioral test. Prior to treatment, von Frey test is conducted on all animals for baseline measurement. To assess mechanical allodynia, paw withdrawal thresholds is measured by applying the von Frey filaments (with ascending weights; 0.4, 0.6, 1.4, 2, 4, 6, 8, 15 g) on the center of the right hind paw. Von Frey tests are conducted prior to test article administration (baseline) and once per week, 1 hr, 2 hr and 4 hr post dosing until the end of the experiment. Statistical analysis is performed with one-way analysis of variance, followed by Dunnett multiple comparison test against vehicle control group using the GraphPad PRISM software, *p<0.05.
The study assesses the analgesic effect of example compounds to reverse diabetic neuropathy, in the Streptozotocin (STZ)-induced neuropathic pain model. Diabetes is induced in Sprague Dawley male rats by dosing of Streptozotocin (STZ, 60 mg/kg) on study day 0. The development of diabetes is confirmed by the measurement of blood glucose levels on study day 3. On study day 10 the sensitivity of all animals to von Frey filaments is tested and diabetic animals (>300 mg/dL) that show a decrease in the withdrawal force threshold (average pain threshold of ≤15 g for both hind paws) are included in the study. Animals are treated with the example compounds or the vehicle from study day 5 (or alternatively day 10) until day 25. Mechanical pain sensitivity is tested using the von Frey test, which measures the withdrawal force threshold of the animals. Statistical analysis is performed with one-way analysis of variance, followed by Dunnett multiple comparison test against vehicle control group using the GraphPad PRISM software, *p<0.05.
The study assesses the effect of 8 weeks treatment with example compounds on NAFLD activity score including fibrosis stage in male CDAA-HFD rats. About 14 weeks old male Sprague Dawley rats receive the CDAA-HFD diet (Gubra, A16092003) 4 weeks for liver fibrosis induction and for the duration of the study. Rats are randomly divided into experimental groups (e.g. n=12) (Vehicle and example compounds). Animals are treated with the example compounds or the vehicle alone from study day 28 until end of week 14.
After autopsy, liver samples stained with Hematoxylin and Eosin (H&E) are used to score for NAS and fibrosis stage respectively using the clinical criteria outlined by Kleiner et al. 2005. Total NAS represents the sum of scores for steatosis, inflammation, and ballooning, and ranges from 0-8.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21158585.6 | Feb 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/054042 | 2/18/2022 | WO |
