PYRAZOLOTRIAZINES

BACKGROUND

The present invention provides compounds of general formula (I) which impair the activity of CDK12. In particular, the present invention provides compositions and methods for the treatment of cancer and other CDK12-dependant diseases. More particularly, the present invention provides compounds which induce the proteolytic degradation of CDK12 and/or Cyclin K in the cell. Thus, the present invention provides compounds capable of degrading CDK12 and/or Cyclin K for the treatment of breast cancer, liver cancer, lung cancer, ovarian cancer, endometrial cancer, cervical cancer, colorectal cancer, gastric cancer, esophageal cancer, bladder cancer, prostate cancer, Ewing sarcoma, glioblastoma and acute myeloid leukemia. Even more particularly, the present invention provides compounds capable of degrading CDK12 and/or Cyclin K for the treatment of lung cancer, breast cancer, liver cancer, colorectal cancer, gastric cancer, prostate cancer and leukemia.

Cyclin-dependent kinase (CDK) 12 (CDK12, gene id 51755) is a member of the subset of the CDK serine/threonine kinase family that phosphorylates the C-terminal domain (CTD) of RNA polymerase 11. CDK12 in complex with Cyclin K (CCNK, gene id 8812) regulates transcriptional, co- and posttranscriptional processes by phosphorylation of Ser2 and Ser5 of the CTD of RNA polymerase II complexes which are important in the elongation phase of pre-mRNA synthesis. CDK12/Cyclin K has been reported to regulate transcriptional elongation and mRNA processing, in particular co- and post-transcriptional pre-mRNA splicing, alternative splicing, 3′end processing, and suppression of intronic polyadenlyation. CDK13 (CDK13, gene id 8621), a kinase which is closely related to CDK12, also forms a complex with Cyclin K and regulates the transcription of a different set of genes (Bartkowiak et al. Genes Dev. 2010; 24:2303-16. Dubbury et al. Nature. 2018; 564:141-5. Greenleaf, Transcription. 2018; 10:91-110. Greifenberg et al. Cell Rep. 2016; 14:320-31. Liang et al. Mol. Cell. Biol. 2015; 35:928-38. Lui et al. J. Clin. Pathol. 2018; 71:957-62. Tien et al. Nuc. Acids Res. 2017; 45:6698-716). The transcription of genes encoding components of DNA damage signaling and repair pathways, such as the homologous recombination and replication stress response genes BRCA1, FANCD2, FANCI, and ATR, as well as encoding components of other stress response pathways, such as NF-κB and oxidative stress response, has been reported to be specifically regulated by CDK12/Cyclin K as demonstrated by gene knock-down and chemoproteomics studies (Blazek et al. Genes Dev. 2011; 25:2158-72. Henry et al. Sci. Signal. 2018; 11:eaam8216. Li et al. Sci. Rep. 2016; 6:21455.). In addition, CDK12/Cyclin K has been reported to control the translation of a subset of mRNAs, including the CHK1 mRNA, by directly phosphorylating the mRNA 5′ cap-binding translational repressor 4E-BP1 leading to its release from the mRNA cap (Choi et al. Genes Dev. 2019; 33:418-35). The recent discovery of rare bi-allelic CDK12 inactivating mutations in high-grade serous ovarian cancer and in primary and castration-resistant prostate cancer leading to a special type of genomic instability which is characterized by the occurance of numerous tandem duplications, indicating gross defects in DNA repair, underscores the role of CDK12 in DNA damage response and the maintenance of the genome (Ekumi et al. Nucl. Acids Res. 2015; 43:2575-89. Grasso et al. Nature. 2012; 487:239-43. Joshi et al. J. Biol. Chem. 2014; 289:9247-53. Menghi et al. Cancer Cell. 2018; 34:197-210.e5. Popova et al. Cancer Res. 2016; 76:1882-91. Quigley et al. Cell. 2018; 174:758-69.e9. Robinson et al. 2015; 162:454. Viswanathan et al. Cell. 2018; 174:433-47.e19. Wu et al. Cell. 2018; 173:1770-82.e14). The CDK12 gene is located on chromosome 17 about 200 kb proximal to the ERBB2 gene and is often coamplified in breast cancer. Furthermore, CDK12 gene amplification has been observed in other cancer types such as stomach cancer, esophageal cancer, pancreatic cancer, uterine cancer, endometrial cancer, prostate cancer, and bladder cancer (Lui et al. J Clin Pathol. 2018; 71:957-62. Gupta et al. Clin. Cancer Res. 2017; 23:1346-57). CDK12 amplification and high expression levels suggest a tumor promoting role of CDK12 which is, at least partially, based on alterantively spliced mRNAs, increased DNA repair capabilities and increased stress tolerance (Lui et al. J Clin Pathol. 2018; 71:957-62. Tien et al. Nucl. Acids Res. 2017; 45:6698-716). Taken together these data validated CDK12 as a potential target to develop drugs for the treatment of cancer and other diseases such as myotonic dystrophy type 1.

Some inhibitors of CDK12 kinase activity are known:

Flavopiridol, a micromolar non-selective inhibitor of CDK12 which inhibits other kinases such as CDK9, CDK1, CDK4 etc. (Bösken et al. Nat. Comm. 2014; 5:3505). Dinaciclib, a pan CDK inhibitor (Johnson et al. Cell Rep. 2016; 17:2367-81). THZ531, a dual inhibitor of CDK12 and CDK13 (Zhang et al. Nat. Chem. Biol. 2016; 12:876-84). SR-3029 and related purine compounds (Johannes et al. Chem. Med. Chem. 2018; 13:231-5). SR-4835, a dual inhibitor of CDK12 and CDK13 (Quereda et al. Cancer Cell 2019; 36:1-14). Compound 919278, a micromolar CDK12 inhibitor (Henry et al. Science Signal. 2018; 11:eaam8216). Arylurea derivatives (Ito et al. J. Med. Chem. 2018; 61:7710-28).

There is a need for development of compounds selectively impairing the function of CDK12/Cycdin K for the treatment of cancer and other diseases, e.g. by inducing the proteolytic degradation of CDK12 and/or Cyclin K protein in the cell. Restricted selectivity of inhibitors targeting the ATP pocket is an issue which may lead to undesired side effects and limited clinical utility (Sawa. Mini-Rev. Med. Chem 2008; 8:1291-7). Surprisingly, the compounds described in the present invention induce the proteolytic degradation of CDK12 and/or Cyclin K protein in the cell. CDK12 inhibitors with low kinase inhibition potential at physiological ATP concentrations but strong CDK12 degrading potency are selective against other kinases. In addition, by degradation of CDK12 and/or Cyclin K functions of the CDK12/CyclinK protein complex which are independent from the sole kinase activity, such as scaffolding functions for other proteins e.g. in the RNA polymerase II complex or the pre-mRNA splicing complex will be impaired as well. Thus, there is a need to provide compounds which impair the activity of CDK12/Cyclin K in the cell and which exhibit a good degree of selectivity towards the targeting of other CDKs and other kinases, such as, for example, casein kinases.

SUMMARY

The present invention provides compounds of general formula (I):

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in which X, R¹, R²and R³are as described and defined herein, methods of preparing said compounds, intermediate compounds useful for preparing said compounds, pharmaceutical compositions and combinations comprising said compounds, and the use of said compounds for manufacturing pharmaceutical compositions for the treatment and/or prophylaxis of diseases, in particular of hyperproliferative disorders such as cancer disorders, as a sole agent or in combination with other active ingredients.

DESCRIPTION OF THE INVENTION

It has now been found that the compounds of the present invention effectively impair the activity of CDK12/Cyclin K for which data are given in the biological experimental section and may therefore be used for the treatment and/or prophylaxis of hyperproliferative disorders, such as cancer disorders. In particular, the compounds of the present invention are CDK12 inhibitors with low kinase inhibition potential at physiological ATP concentrations but strong proteolytic CDK12 and/or Cyclin K degrading potency in cells and are therefore selective against other kinases while maintaining an impairing effect towards CDK12/Cyclin K.

In accordance with a first aspect, the present invention provides compounds of general formula (I):

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wherein

R¹is selected from a halogen atom, a C₁-C₆-alkyl group, a C₁-C₆-haloalkyl group, a C₃-C₆-cycloalkyl group, a (C₃-C₆-cycloalkyl)-(C₁-C₆-alkyl)- group, a cyano group, a phenyl group, a heterocycloalkyl group and a heteroaryl group,
- wherein said C₁-C₆-alkyl, C₃-C₆-cycloalkyl, phenyl, heterocycloalkyl or heteroaryl group is each optionally substituted with one or more substituents independently selected from a halogen atom, a cyano group, a C₁-C₆-alkyl group, a C₁-C₆-alkoxy group, a C₁-C₆-haloalkyl group, a C₁-C₆-haloalkoxy group, a C₃-C₆-cycloalkyl group, a C₃-C₆-cycloalkoxy group and a R⁵R⁶N— group;

R²is selected from a C₁-C₆-alkyl group, a C₁-C₆-alkoxy group, a C₁-C₆-haloalkyl group, a C₁-C₆-haloalkoxy group, a C₃-C₆-cycloalkyl group, a C₃-C₈-cycloalkoxy group, a (C₃-C₆-cycloalkyl)-(C₁-C₂-alkyl)-O— group, a (C₃-C₆-hydroxyalkyl)-(C₁-C₂-alkyl)-O— group, a (C₃-C₆-alkoxyalkyl)-(C₁-C₂-alkyl)-O— group, a ((CH₃)₂N)—(C₁-C₂-alkyl)-O— group, a heterocycloalkyl group, a (heterocycloalkyl)-O— group and a —NR^aR^bgroup,
- wherein said heterocycloalkyl group is connected to the rest of the molecule via a carbon atom of said heterocycloalkyl group,
- wherein R^aand R^bare each independently selected from a hydrogen atom, a C₁-C₆-alkyl group, a C₃-C₈-cycloalkyl group, a C₁-C₆-haloalkyl group, a (C₃-C₆-cycloalkyl)-(C₁-C₆-alkyl)- group, a C₁-C₆-hydroxyalkyl group, a (C₁-C₆-alkoxy)-(C₁-C₆-alkyl)- group, a heterocycloalkyl group, a heteroaryl group and a phenyl group,
  - wherein said C₃-C₈-cycloalkyl, phenyl, heteroaryl or heterocycloalkyl group is each optionally substituted with one or more substituents independently selected from a halogen atom, a cyano group, a hydroxy group, a C₁-C₆-alkyl group, a C₁-C₆-hydroxyalkyl group, a C₁-C₆-haloalkyl group, a C₁-C₆-alkoxy group, a C₁-C₆-haloalkoxy group and a R⁵R⁶N— group,
  - wherein at least one of R^eor R^bis not a hydrogen atom;
- or R^aand R^btogether with the nitrogen atom to which they are attached form a 4- to 9-membered nitrogen-containing monocyclic or 5- to 11-membered nitrogen-containing bicyclic heterocycloalkyl group, a 7- to 9-membered nitrogen-containing bridged compound or a 7- to 12-membered nitrogen-containing spiro compound,
  - said 4- to 9-membered nitrogen-containing monocyclic or 5- to 11-membered nitrogen-containing bicyclic heterocycloalkyl group, 7- to 9-membered nitrogen-containing bridged compound or 7- to 12-membered nitrogen-containing spiro compound each optionally containing one, two or three further heteroatoms independently selected from nitrogen, oxygen and sulfur or one group selected from —NR⁸—, —S(═O)—, —S(═O)₂— and —S(═O)(═NH)—,
  - and/or optionally being substituted one, two or three times, each substituent independently selected from a halogen atom or a group selected from cyano, hydroxy, a C₁-C₆alkyl group, a C₁-hydroxyalkyl group, a C₁-C₂haloalkyl group, a C₁-C₂-alkoxy group, a C₃-C₄-cycloalkyl group, a (C₁-C₂alkyl)OOC— group, a R⁵R⁶N— group and oxo;

X is selected from a nitrogen atom and a CR⁴group;

R³is selected from a C₃-C₈-cycloalkyl group, a heterocycloalkyl group, a phenyl group and a heteroaryl group,
- wherein said heterocycloalkyl, phenyl or heteroaryl group is each optionally substituted with one or more substituents independently selected from a halogen atom, a cyano group, a hydroxy group, a C₁—C— alkyl group, a C₁-C₆-hydroxyalkyl group, a C₁-C₆-haloalkyl group, a C₁-C₆-alkoxy group, a C₁-C₆-haloalkoxy group, a C₃-C₈-cycloalkyl group, a R⁵R⁶N— group, and a R⁷OOC— group;

R⁴is selected from a hydrogen atom, a C₁-C₃-alkyl group and a C₁-C₃-haloalkyl group;

or, where X is a CR⁴group, R³and R⁴, together with the carbon atoms to which they are attached form a 5- to 7-membered cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, phenyl or heteroaryl group,
- wherein said heterocycloalkyl, heterocycloalkenyl or heteroaryl group contains one or two heteroatoms independently selected from nitrogen, oxygen and sulfur,
- and wherein said cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, phenyl or heteroaryl group is each optionally substituted one, two or three times, each substituent independently selected from a halogen atom, a cyano group, a C₁-C₆-alkyl group, a C₁-C₆-hydroxyalkyl group, a C₁-C₆-haloalkyl group, a C₁-C₆-alkoxy group, a C₁-C₆-haloalkoxy group, a C₃-C₆-cycloalkyl group, a C₃-C₆-cycloalkoxy group, a R⁵R⁶N— group, a (R⁵R⁶N)—(C₁-C₆-alkyl)- group, and a R⁷OOC— group;

R⁵and R⁶are each independently selected from a hydrogen atom, a C₁-C₆-alkyl group, a C₃-C₈-cycloalkyl group, a C₁-C₆-haloalkyl group, a (C₃-C₈-cycloalkyl)-(C₁-C₆-alkyl)- group, a C₁-C₆-hydroxyalkyl group, a (C₁-C₆-alkoxy)-(C₁-C₆-alkyl)- group, a formyl (HCO—) group, an acetyl (H₃CCO—) group, a heterocycloalkyl group, a heteroaryl group and a phenyl group;

R⁷is selected from a hydrogen atom and a C₁-C₃-alkyl group;

R^ais selected from a hydrogen atom, a C₁-C₆-alkyl group, a C₃-C₆-cycloalkyl group and a C₁-C₆-haloalkyl group;

or a tautomer, or an N-oxide, or a salt thereof, or a salt of a tautomer, or a salt of an N-oxide, or a mixture of same.

DETAILED DESCRIPTION
Definitions

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, more particularly 1 or 2, and even more particularly 1.

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”.

When groups in the compounds according to the invention are substituted, it is possible for said groups to be mono-substituted or poly-substituted with substituent(s), unless otherwise specified. Within the scope of the present invention, the meanings of all groups which occur repeatedly are independent from one another. It is possible that groups in the compounds according to the invention are substituted with one, two or three identical or different substituents, particularly with one, two or three substituents, more particularly with one substituent.

The terms “oxo”, “an oxo group” or “an oxo substituent” mean a doubly bonded oxygen atom ═O. Oxo may be attached to atoms of suitable valency, for example to a saturated carbon atom or to a sulfur atom. For example, but without limitation, one oxo group can be attached to a carbon atom, resulting in the formation of a carbonyl group C(═O), or two oxo groups can be attached to one sulfur atom, resulting in the formation of a sulfonyl group —S(═O)₂.

The term “ring substituent” means a substituent attached to an aromatic or nonaromatic ring which replaces an available hydrogen atom on the ring.

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 sulfur 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.

If within the present text any item is referred to as “supra” within the description it indicates any of the respective disclosures made within the specification in any of the preceding pages, or above on the same page.

If within the present text any item is referred to as “infra” within the description it indicates any of the respective disclosures made within the specification in any of the subsequent pages, or below on the same page.

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, more particularly a fluorine atom.

The term “C₁-C₆-alkyl” means a linear or branched, saturated, monovalent hydrocarbon group having 1, 2, 3, 4, 5 or 6 carbon atoms, e.g. a methyl-, ethyl-, propyl-, isopropyl-, butyl-, sec-butyl-, isobutyl-, tert-butyl-, pentyl-, isopentyl-, 2-methylbutyl-, 1-methylbutyl-, 1-ethylpropyl-, 1,2-dimethylpropyl-, neo-pentyl-, 1,1-dimethylpropyl-, hexyl-, 1-methylpentyl-, 2-methylpentyl-, 3-methylpentyl-, 4-methylpentyl-, 1-ethylbutyl-, 2-ethylbutyl-, 1,1-dimethylbutyl-, 2,2-dimethylbutyl-, 3,3-dimethylbutyl-, 2,3-dimethylbutyl-, 1,2-dimethylbutyl- or a 1,3-dimethylbutyl- group, or an isomer thereof. Particularly, said group has 1, 2, 3 or 4 carbon atoms (“C₁-C₄-alkyl”), e.g. a methyl-, ethyl-, propyl-, isopropyl-, butyl-, sec-butyl-, isobutyl- or a tert-butyl group, more particularly 1, 2 or 3 carbon atoms (“C₁-C₃-alkyl”), e.g. a methyl-, ethyl-, n-propyl- or an isopropyl group.

The term “C₁-C₆-hydroxyalkyl” means a linear or branched, saturated, monovalent hydrocarbon group in which the term “C₁-C₆-alkyl” is defined supra, and in which one or more hydrogen atoms are replaced with a hydroxy group, e.g. a hydroxymethyl-, 1-hydroxyethyl-, 2-hydroxyethyl-, 1,2-dihydroxyethyl-, 3-hydroxypropyl-, 2-hydroxypropyl-, 1-hydroxypropyl-, 1-hydroxypropan-2-yl-, 2-hydroxypropan-2-yl-, 2,3-dihydroxypropyl-, 1,3-dihydroxypropan-2-yl-, 3-hydroxy-2-methyl-propyl-, 2-hydroxy-2-methyl-propyl- or a 1-hydroxy-2-methyl-propyl- group.

The term “C₁-C₆-alkylsulfanyl” means a linear or branched, saturated, monovalent group of formula (C₁-C₆-alkyl)-S—, in which the term “C₁-C₆-alkyl” is as defined supra, e.g. a methylsulfanyl-, ethylsulfanyl-, propylsulfanyl-, isopropylsulfanyl-, butylsulfanyl-, sec-butylsulfanyl-, isobutylsulfanyl-, tert-butylsulfanyl-, pentylsulfanyl-, isopentylsulfanyl- or a hexylsulfanyl- group.

The term “C₁-C₆-haloalkyl” means a linear or branched, saturated, monovalent hydrocarbon group in which the term “C₁-C₆-alkyl” is as defined supra and in which one or more of the hydrogen atoms are replaced, identically or differently, with a halogen atom. Preferably, said halogen atom is a fluorine atom. Said C₁-C₆-haloalkyl, particularly a C₁-C₃-haloalkyl group is, for example, fluoromethyl-, difluoromethyl-, trifluoromethyl-, 2-fluoroethyl-, 2,2-difluoroethyl-, 2,2,2-trifluoroethyl-, pentafluoroethyl-, 3,3,3-trifluoropropyl- or a 1,3-difluoropropan-2-yl group.

The term “C₁-C₆-alkoxy” means a linear or branched, saturated, monovalent group of formula (C₁-C₆-alkyl)-O—, in which the term “C₁-C₆-alkyl” group is as defined supra, e.g. methoxy-, ethoxy-, n-propoxy-, isopropoxy-, n-butoxy-, sec-butoxy-, isobutoxy-, tert-butoxy-, pentyloxy-, isopentyloxy- or a n-hexyloxy group, or an isomer thereof.

The term “C₁-C₆-haloalkoxy” means a linear or branched, saturated, monovalent C₁-C₆-alkoxy group, as defined supra, in which one or more of the hydrogen atoms is replaced, identically or differently, with a halogen atom. Preferably, said halogen atom in “C₁-C₆-haloalkoxy-” is fluorine, resulting in a group referred herein as “C₁-C₆-fluoroalkoxy-”. Representative C₁-C₆-fluoroalkoxy- groups include, for example, —OCF₃, —OCHF₂, —OCH₂F, —OCF₂CF₃and —OCH₂CF₃.

The term “C₂-C₆-alkenyl-” means a linear or branched, monovalent hydrocarbon group, which contains one or more double bonds and which has 2, 3, 4, 5 or 6 carbon atoms, preferably 2, 3 or 4 carbon atoms (“C₂-C₄-alkenyl-”) or 2 or 3 carbon atoms (“C₂-C₃-alkenyl-”), it being understood that in the case in which said alkenyl- group contains more than one double bond, then said double bonds may be isolated from, or conjugated with, each other. Representative alkenyl groups include, for example, an ethenyl-, prop-2-enyl-, (E)-prop-1-enyl-, (Z)-prop-1-enyl-, iso-propenyl-, but-3-enyl-, (E)-but-2-enyl-, (Z)-but-2-enyl-, (E)-but-1-enyl-, (Z)-but-1-enyl-, 2-methylprop-2-enyl-, 1-methylprop-2-enyl-, 2-methylprop-1-enyl-, (E)-1-methylprop-1-enyl-, (Z)-1-methylprop-1-enyl-, buta-1,3-dienyl-, pent-4-enyl-, (E)-pent-3-enyl-, (Z)-pent-3-enyl-, (E)-pent-2-enyl-, (Z)-pent-2-enyl-, (E)-pent-1-enyl-, (Z)-pent-1-enyl-, 3-methylbut-3-enyl-, 2-methylbut-3-enyl-, 1-methylbut-3-enyl-, 3-methylbut-2-enyl-, (E)-2-methylbut-2-enyl-, (Z)-2-methylbut-2-enyl-, (E)-1-methylbut-2-enyl-, (Z)-1-methylbut-2-enyl-, (E)-3-methylbut-1-enyl-, (Z)-3-methylbut-1-enyl-, (E)-2-methylbut-1-enyl-, (Z)-2-methylbut-1-enyl-, (E)-1-methylbut-1-enyl-, (Z)-1-methylbut-1-enyl-, 1,1-dimethylprop-2-enyl-, 1-ethylprop-1-enyl-, 1-propylvinyl-, 1-isopropylvinyl-, (E)-3,3-dimethylprop-1-enyl-, (Z)-3,3-dimethylprop-1-enyl-, penta-1,4-dienyl-, hex-5-enyl-, (E)-hex-4-enyl-, (Z)-hex-4-enyl-, (E)-hex-3-enyl-, (Z)-hex-3-enyl-, (E)-hex-2-enyl-, (Z)-hex-2-enyl-, (E)-hex-1-enyl-, (Z)-hex-1-enyl-, 4-methylpent-4-enyl-, 3-methylpent-4-enyl-, 2-methylpent-4-enyl-, 1-methylpent-4-enyl-, 4-methylpent-3-enyl-, (E)-3-methylpent-3-enyl-, (Z)-3-methylpent-3-enyl-, (E)-2-methylpent-3-enyl-, (Z)-2-methylpent-3-enyl-, (E)-1-methylpent-3-enyl-, (Z)-1-methylpent-3-enyl-, (E)-4-methylpent-2-enyl-, (Z)-4-methylpent-2-enyl-, (E)-3-methylpent-2-enyl-, (Z)-3-methylpent-2-enyl-, (E)-2-methylpent-2-enyl-, (Z)-2-methylpent-2-enyl-, (E)-1-methylpent-2-enyl-, (Z)-1-methylpent-2-enyl-, (E)-4-methylpent-1-enyl-, (Z)-4-methylpent-1-enyl-, (E)-3-methylpent-1-enyl-, (Z)-3-methylpent-1-enyl-, (E)-2-methylpent-1-enyl-, (Z)-2-methylpent-1-enyl-, (E)-1-methylpent-1-enyl-, (Z)-1-methylpent-1-enyl-, 3-ethylbut-3-enyl-, 2-ethylbut-3-enyl-, 1-ethylbut-3-enyl-, (E)-3-ethylbut-2-enyl-, (Z)-3-ethylbut-2-enyl-, (E)-2-ethylbut-2-enyl-, (Z)-2-ethylbut-2-enyl-, (E)-1-ethylbut-2-enyl-, (Z)-1-ethylbut-2-enyl-, (E)-3-ethylbut-1-enyl-, (Z)-3-ethylbut-1-enyl-, 2-ethylbut-1-enyl-, (E)-1-ethylbut-1-enyl-, (Z)-1-ethylbut-1-enyl-, 2-propylprop-2-enyl-, 1-propylprop-2-enyl-, 2-isopropylprop-2-enyl-, 1-isopropylprop-2-enyl-, (E)-2-propylprop-1-enyl-, (Z)-2-propylprop-1-enyl-, (E)-1-propylprop-1-enyl-, (Z)-1-propylprop-1-enyl-, (E)-2-isopropylprop-1-enyl-, (Z)-2-isopropylprop-1-enyl-, (E)-1-isopropylprop-1-enyl-, (Z)-1-isopropylprop-1-enyl-, hexa-1,5-dienyl- and a 1-(1,1-dimethylethyl-)ethenyl group. Particularly, said group is an ethenyl- or a prop-2-enyl group.

The same definitions can be applied should the alkenyl group be placed within a chain as a bivalent “C₂-C₆-alkenylene” moiety. All names as mentioned above then will bear a “ene” added to their end, thus e.g., a “pentenyl” becomes a bivalent “pentenylene” group.

The term “C₂-C₆-haloalkenyl-” means a linear or branched hydrocarbon group in which one or more of the hydrogen atoms of a “C₂-C₆-alkenyl-” as defined supra are each replaced, identically or differently, by a halogen atom. Preferably, said halogen atom is fluorine, resulting in a group referred herein as “C₂-C₆-fluoroalkenyl-”. Representative C₂-C₆-fluoroalkenyl- groups include, for example, —CH═CF₂, —CF═CH₂, —CF═CF₂, —C(CH₃)═CF₂, —CH═C(F)—CH₃, —CH₂—CF═CF₂and —CF₂—CH═CH₂.

The term “C₂-C₆-alkynyl-” means a linear or branched, monovalent hydrocarbon group which contains one or more triple bonds, and which contains 2, 3, 4, 5 or 6 carbon atoms, preferably 2, 3 or 4 carbon atoms (“C₂-C₄-alkynyl-”) or 2 or 3 carbon atoms (“C₂-C₃-alkynyl-”). Representative C₂-C₆-alkynyl- groups include, for example, an ethynyl-, prop-1-ynyl-, prop-2-ynyl-, but-1-ynyl-, but-2-ynyl-, but-3-ynyl-, pent-1-ynyl-, pent-2-ynyl, pent-3-ynyl-, pent-4-ynyl-, hex-1-ynyl-, hex-2-ynyl-, hex-3-ynyl-, hex-4-ynyl-, hex-5-ynyl-, 1-methylprop-2-ynyl-, 2-methylbut-3-ynyl-, 1-methylbut-3-ynyl-, 1-methylbut-2-ynyl-, 3-methylbut-1-ynyl-, 1-ethylprop-2-ynyl-, 3-methylpent-4-ynyl-, 2-methylpent-4-ynyl-, 1-methylpent-4-ynyl-, 2-methylpent-3-ynyl-, 1-methylpent-3-ynyl-, 4-methylpent-2-ynyl-, 1-methylpent-2-ynyl-, 4-methylpent-1-ynyl-, 3-methylpent-1-ynyl-, 2-ethylbut-3-ynyl-, 1-ethylbut-3-ynyl-, 1-ethylbut-2-ynyl-, 1-propylprop-2-ynyl-, 1-isopropylprop-2-ynyl-, 2,2-dimethylbut-3-ynyl-, 1,1-dimethylbut-3-ynyl-, 1,1-dimethylbut-2-ynyl- and a 3,3-dimethylbut-1-ynyl- group. Particularly, said alkynyl- group is an ethynyl-, a prop-1-ynyl- or a prop-2-ynyl group.

The term “C₃-C₈-cycloalkyl” means a saturated, monovalent, mono- or bicyclic hydrocarbon ring which contains 3, 4, 5, 6, 7 or 8 carbon atoms (“C₃-C₈-cycloalkyl”). Analogously, the term “C₃-C₆-cycloalkyl” means a saturated, monovalent, mono- or bicyclic hydrocarbon ring which contains 3, 4, 5 or 6 carbon atoms (“C₃-C₆-cycloalkyl”). Said C₃-C₈-cycloalkyl or C₃-C₆-cycloalkyl group is for example, a monocyclic hydrocarbon ring, e.g. a cyclopropyl-, cyclobutyl-, cyclopentyl-, cyclohexyl-, cycloheptyl- or cyclooctyl- group, or a bicyclic hydrocarbon ring, e.g. a bicyclo[4.2.0]octyl- or a octahydropentalenyl- group.

The term “C₃-C₆-halocycloalkyl” means a saturated, monovalent hydrocarbon ring which contains 3, 4, 5 or 6 carbon atoms in which the term “C₃-C₆-cycloalkyl” is as defined supra and in which one or more of the hydrogen atoms of the hydrocarbon ring are replaced, identically or differently, with a halogen atom. Preferably, said halogen atom is a fluorine atom. The “C₃-C₆-cycloalkyl” group as defined supra in which one or more of the hydrogen atoms are replaced, identically or differently, with a halogen atom, preferably a fluorine atom, is for example and preferably, a monocyclic hydrocarbon ring, e.g. a cyclopropyl-, cyclobutyl-, cyclopentyl-, cyclohexyl- group.

The term “C₄-C₃-cycloalkenyl” means a monovalent, mono- or bicyclic hydrocarbon ring which contains 4, 5, 6, 7 or 8 carbon atoms and one double bond. Particularly, said ring contains 4, 5 or 6 carbon atoms (“C₄-C₆-cycloalkenyl”). Said C₄-C₃-cycloalkenyl group is for example, a monocyclic hydrocarbon ring, e.g., a cyclobutenyl-, cyclopentenyl-, cyclohexenyl-, cycloheptenyl- or a cyclooctenyl group, or a bicyclic hydrocarbon ring, e.g., a bicyclo[2.2.1]hept-2-enyl- or a bicyclo[2.2.2]oct-2-enyl group.

The term “C₃-C₈-cycloalkoxy” means a saturated, monovalent, mono- or bicyclic group of formula (C₃-C₈-cycloalkyl)-O—, which contains 3, 4, 5, 6, 7 or 8 carbon atoms, in which the term “C₃-C₈-cycloalkyl” is defined supra, e.g. a cyclopropyloxy-, cyclobutyloxy-, cyclopentyloxy-, cyclohexyloxy-, cycloheptyloxy- or a cyclooctyloxy- group.

If the term “heterocycloalkyl” is used without specifying a number of atoms it is meant to be a “4- to 10-membered heterocycloalkyl-” group, more particularly a 5- to 6-membered heterocycloalkyl group. The terms “4- to 7-membered heterocycloalkyl”, “4- to 6-membered heterocycloalkyl” and “5- to 7-membered heterocycloalkyl” mean a monocyclic, saturated heterocycle with “4, 5, 6 or 7” or, respectively, “4, 5 or 6” or “5, 6 or 7” ring atoms in total, which are saturated or partially unsaturated monocycles, bicycles or polycycles that contain one or two identical or different ring heteroatoms selected from nitrogen, oxygen and sulfur or one group selected from —S(═O)—, —S(═O)₂— and —S(═O)(═NH)—. It is 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.

Exemplarily, without being limited thereto, said “4- to 7-membered heterocycloalkyl”, can be a 4-membered ring, a “4-membered heterocycloalkyl-” group, such as an azetidinyl- or an oxetanyl group; or a 5-membered ring, a “5-membered heterocycloalkyl-” group, such as a tetrahydrofuranyl-, dioxolinyl-, pyrrolidinyl-, imidazolidinyl-, pyrazolidinyl- or a pyrrolinyl group; or a 6-membered ring, a “6-membered heterocycloalkyl-” group, such as a tetrahydropyranyl-, piperidinyl-, morpholinyl-, 3-oxomorpholin-4-yl, dithianyl-, thiomorpholinyl- or a piperazinyl group; or a 7-membered ring, a “7-membered heterocycloalkyl-” group, such as an azepanyl-, diazepanyl- or an oxazepanyl group, for example. The heterocycloalkyl groups may be substituted one or more times independently with C₁-C₃-alkyl, C₁-C₃-alkoxy, hydroxy, halogen or a carbonyl group.

Particularly, “4- to 6-membered heterocycloalkyl” means a 4- to 6-membered heterocycloalkyl as defined supra containing one ring nitrogen atom and optionally one further ring heteroatom selected from nitrogen, oxygen and sulfur. Particularly, “5- to 7-membered heterocycloalkyl” means a 5- to 7-membered heterocycloalkyl as defined supra containing one ring nitrogen atom and optionally one further ring heteroatom selected from nitrogen, oxygen and sulfur. More particularly, “5- or 6-membered heterocycloalkyl” means a monocyclic, saturated heterocycle with 5 or 6 ring atoms in total, containing one ring nitrogen atom and optionally one further ring heteroatom selected from nitrogen and oxygen.

The term “heteroaryl-” means a monocyclic, bicyclic or tricyclic aromatic ring system having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms (a “5- to 14-membered heteroaryl-” group), preferably 5, 6, 9 or 10 ring atoms and which contains 1, 2, 3 or 4 heteroatoms which may be identical or different, said heteroatoms being selected from oxygen, nitrogen and sulfur. Said heteroaryl- group can be a 5-membered heteroaryl group, such as, for example, a thienyl-, furanyl-, pyrrolyl-, oxazolyl-, thiazolyl-, imidazolyl-, pyrazolyl-, isoxazolyl-, isothiazolyl-, oxadiazolyl-, triazolyl-, thiadiazolyl- or a tetrazolyl group; or a 6-membered heteroaryl group, such as, for example, a pyridyl-, pyridazinyl-, pyrimidyl-, pyrazinyl- or a triazinyl group; or a benzo-fused 5-membered heteroaryl- group, such as, for example, a benzofuranyl-, benzothienyl-, benzoxazolyl-, benzisoxazolyl-, benzimidazolyl-, benzothiazolyl-, benzotriazolyl-, indazolyl-, indolyl- or a isoindolyl group; or a benzo-fused 6-membered heteroaryl group, such as, for example, a quinolinyl-, quinazolinyl-, isoquinolinyl-, cinnolinyl-, phthalazinyl- or quinoxalinyl-; or another bicyclic group, such as, for example, indolizinyl-, purinyl- or a pteridinyl group.

Preferably, “heteroaryl-” is a monocyclic aromatic ring system having 5 or 6 ring atoms and which contains at least one heteroatom, if more than one, they may be identical or different, said heteroatom being selected from oxygen, nitrogen and sulfur, a (“5- to 6-membered monocyclic heteroaryl-”) group, such as, for example, a thienyl-, furanyl-, pyrrolyl-, oxazolyl-, thiazolyl-, imidazolyl-, pyrazolyl-, isoxazolyl-, isothiazolyl-, oxadiazolyl-, triazolyl-, thiadiazolyl-, tetrazolyl-, pyridyl-, pyridazinyl-, pyrimidyl-, pyrazinyl- or a triazinyl group.

In particular, in the context of the present invention, when applied to any of the substituents of the compounds of general formula (I), the term “heteroaryl” is to be understood as meaning preferably a monocyclic aromatic ring system having 5 or 6 ring atoms and which contains one, two or three heteroatoms, preferably one or two heteroatoms, which may be identical or different, said heteroatom(s) being independently selected from oxygen, sulphur and nitrogen, preferably from oxygen and nitrogen, i.e. a (“5- to 6-membered monocyclic heteroaryl-”) group.

In general, and unless otherwise mentioned, said heteroaryl- groups include all the possible isomeric forms thereof, e.g., the positional isomers thereof. Thus, for some illustrative non-restricting example, the term pyridyl-includes pyridin-2-yl-, pyridin-3-yl- and pyridin-4-yl-; the term thienyl-includes thien-2-yl- and thien-3-yl-, and a heteroarylene group may be inserted into a chain also in the inverse way such as e.g. a 2,3-pyridinylene includes pyridine-2,3-yl as well as pyridine-3,2-yl. Furthermore, said heteroaryl- groups can be attached to the rest of the molecule via any one of the carbon atoms, or, if applicable, a nitrogen atom, e.g., a pyrrol-1-yl-, a pyrazol-1-yl- or an imidazol-1-yl- group.

Particularly, the heteroaryl group is a pyridyl- or pyrimidyl group or a imidazolyl group, including a hydroxy substitution of the pyridyl group leading, e.g., to a 2-hydroxy-pyridine which is the tautomeric form to a 2-oxo-2(1H)-pyridine. In some embodiments, the heteroaryl group is an oxazolyl group.

Further, as used herein, the term “C₃-C₈”, as used throughout this text, e.g., in the context of the definition of “C₃-C₈-cycloalkyl-”, is to be understood as meaning e.g. a cycloalkyl- group having a whole number of carbon atoms of 3 to 8, i.e., 3, 4, 5, 6, 7 or 8 carbon atoms. It is to be understood further that said term “C₃-C₈” is to be interpreted as disclosing any sub-range comprised therein, e.g., C₃-C₆, C₄-C₅, C₃-C₆, C₃-C₄, C₄-C₆, C₅-C₇, preferably C₃-C₆.

Similarly, as used herein, the term “C₂-C₆”, as used throughout this text, e.g., in the context of the definitions of “C₂-C₆-alkenyl-” and “C₂-C₆-alkynyl-”, is to be understood as meaning an alkenyl- group or an alkynyl- group having a whole number of carbon atoms from 2 to 6, i.e., 2, 3, 4, 5 or 6 carbon atoms. It is to be understood further that said term “C₂-C₆” is to be interpreted as disclosing any sub-range comprised therein, e.g., C₂-C₆, C₃-C₆, C₃-C₄, C₂-C₃, C₂-C₄, C₂-C₅preferably C₂-C₃.

The term “C₁-C₆”, as used throughout this text, e.g., in the context of the definition of “C₁-C₆-alkyl-”, “C₁-C₆-haloalkyl-”, “C₁-C₆-alkoxy-” or “C₁-C₆-haloalkoxy-” is to be understood as meaning an alkyl group having a whole number of carbon atoms from 1 to 6, i.e., 1, 2, 3, 4, 5 or 6 carbon atoms. It is to be understood further that said term “C₁-C₆” is to be interpreted as disclosing any sub-range comprised therein, e.g. C₁-C₆, C₂-C₅, C₃-C₄, C₁-C₂, C₁-C₃, C₁-C₄, C₁-C₅, C₁-C₆preferably C₁-C₂, C₁-C₃, C₁-C₄, C₁-C₅, C₁-C₆more preferably C₁-C₄, in the case of “C₁-C₆-haloalkyl-” or “C₁-C₆-haloalkoxy-” even more preferably C₁-C₂.

When a range of values is given, said range encompasses each value and sub-range within said range.

For example:

“C₁-C₆” encompasses C₁, C₂, C₃, C₄, C₅, C₆, C₁-C₆, C₁-C₆, C₁-C₄, C₁-C₃, C₁-C₂, C₂- C₆, C₂-C₅, C₂-C₄, C₂-C₃, C₃-C₆, C₃-C₆, C₃-C₄, C₄-C₆, C₄-C₅, and C₅-C₆;

“C₂-C₆” encompasses C₂, C₃, C₄, C₅, C₆, C₂-C₆, C₂-C₅, C₂-C₄, C₂-C₃, C₃-C₆, C₃-C₆, C₃-C₄, C₄-C₆, C₄-C₅, and C₅-C₆;

“C₃-C₁₀” encompasses C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₃-C₁₀, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, C₄-C₅, C₅-C₁, C₅-C₉, C₅-C₈, C₅-C₇, C₅-C₆, C₆-C₁₀, C₆-C₉, C₆-C₈, C₆-C₇, C₇-C₁₀, C₇-C₉, C₇-C₈, C₈-C₁₀, C₈-C₉and C₉-C₁₀;

“C₃-C₈” encompasses C₃, C₄, C₅, C₆, C₇, C₈, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₈, C₃-C₄, C₄- C₈, C₄-C₇, C₄-C₆, C₄-C₅, C₅-C₈, C₅-C₇, C₅-C₆, C₆-C₈, C₆-C₇and C₇-C₈;

“C₃-C₆” encompasses C₃, C₄, C₅, C₆, C₃-C₆, C₃-C₆, C₃-C₄, C₄-C₆, C₄-C₅, and C₅-C₆;

“C₄-C₈” encompasses C₄, C₅, C₆, C₇, C₈, C₄-C₈, C₄-C₇, C₄-C₆, C₄-C₅, C₅-C₈, C₅-C₇, C₅-C₆, C₆-C₈, C₆-C₇and C₇-C₈;

“C₄-C₇” encompasses C₄, C₅, C₆, C₇, C₄-C₇, C₄-C₆, C₄-C₅, C₅-C₇, C₅-C₆and C₆-C₇;

“C₄-C₆” encompasses C₄, C₅, C₆, C₄-C₆, C₄-C₅and C₅-C₆;

“C₅-C₁₀” encompasses C₅, C₆, C₇, C₈, C₉, C₁₀, C₅-C₁₀, C₅-C₉, C₅-C₈, C₅-C₇, C₅-C₆, C₆-C₁₀, C₆-C₉, C₆-C₈, C₆-C₇, C₇-C₁₀, C₇-C₉, C₇-C₈, C₈-C₁₀, C₈-C₉and C₉-C₁₀;

“C₆-C₁₀” encompasses C₆, C₇, C₈, C₉, C₁₀, C₆-C₁₀, C₆-C₉, C₆-C₈, C₆-C₇, C₇-C₁₀, C₇-C₉, C₇-C₈, C₈-C₁₀, C₈-C₉and C₉-C₁₀.

In particular embodiments for the compounds of formula (I) of the present invention, reference is made to the fact that, when substituted, a particular phenyl group is preferably substituted in one or more of the ortho- and/or meta-positions with respect to the point of attachment of said phenyl group to the rest of the molecule. This is shown below, where the ortho- and meta-positions in which the phenyl group is preferably substituted with respect to the point of attachment to the rest of the molecule are marked (*):

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In particular, preferred embodiments of the compounds of formula (I) of the present invention may comprise a phenyl group as substituent R³which is, when substituted, preferably substituted in one or more of the ortho- and/or meta-positions (marked with * below) with respect to the point of attachment of said phenyl group to the rest of the molecule:

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As used herein, the term “leaving group” refers to an atom or a group of atoms that is displaced in a chemical reaction as stable species taking with it the bonding electrons, e.g., typically forming an anion. Preferably, a leaving group is selected from the group comprising: halo, in particular a chloro, bromo or iodo, (methylsulfonyl)oxy-, [(4-methylphenyl)sulfonyl]oxy-, [(trifluoromethyl)sulfonyl]oxy-, [(nonafluorobutyl)sulfonyl]oxy-[(4-bromophenyl)sulfonyl]oxy-, [(4-nitrophenyl)sulfonyl]oxy-, [(2-nitro-phenyl)sulfonyl]oxy-, [(4-isopropylphenyl)sulfonyl]oxy-, [(2,4,6-triisopropylphenyl)sulfonyl]oxy-, [(2,4,6-trimethylphenyl)sulfonyl]oxy-, [(4-tert-butylphenyl)sulfonyl]oxy-, (phenylsulfonyl)oxy-, and a [(4-methoxyphenyl)sulfonyl]oxy group.

As used herein, the term “protective group” is a protective group attached to an oxygen or nitrogen atom in intermediates used for the preparation of compounds of the general formula (I). Such groups are introduced e.g., by chemical modification of the respective hydroxy or amino group in order to obtain chemoselectivity in a subsequent chemical reaction. Protective groups for hydroxy and amino groups are described for example in T. W. Greene and P. G. M. Wuts in Protective Groups in Organic Synthesis, 4^thedition, Wiley 2006; more specifically, protective groups for amino groups can be selected from substituted sulfonyl groups, such as a mesyl-, tosyl- or a phenylsulfonyl group, acyl groups such as a benzoyl-, acetyl- or a tetrahydropyranoyl group, or carbamate based groups, such as a tert-butoxycarbonyl group (Boc). Protective groups for hydroxy groups can be selected from acyl groups such as a benzoyl-, acetyl-, pivaloyl- or a tetrahydropyranoyl group, or can include silicon, as in e.g., a tert-butyldimethylsilyl-, tert-butyldiphenylsilyl-, triethylsilyl- or a triisopropylsilyl group.

The term “substituent” refers to a group “substituted” on, e.g., an alkyl-, haloalkyl-, cycloalkyl-, heterocyclyl-, heterocycloalkenyl-, cycloalkenyl-, aryl-, or a heteroaryl group at any atom of that group, replacing one or more hydrogen atoms therein. In one aspect, the substituent(s) on a group are independently any one single, or any combination of two or more of the permissible atoms or groups of atoms delineated for that substituent. In another aspect, a substituent may itself be substituted with any one of the above substituents. Further, as used herein, the phrase “optionally substituted” means unsubstituted (e.g., substituted with an H) or substituted.

It will be understood that the description of compounds herein is limited by principles of chemical bonding known to those skilled in the art. Accordingly, where a group may be substituted by one or more of a number of substituents, such substitutions are selected so as to comply with principles of chemical bonding with regard to valencies, etc., and to give compounds which are not inherently unstable. For example, any carbon atom will be bonded to two, three, or four other atoms, consistent with the four valence electrons of carbon.

By “subject” is meant a mammal, including, but not limited to, a human or non-human mammal, such as a bovine, equine, canine, ovine, rodent, or feline.

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 invention also includes all suitable isotopic variations of a compound of the invention.

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 expression “unnatural proportion” in relation to an isotope 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.

An isotopic variation of a compound of the invention is defined as one in which at least one atom is replaced by an atom having the same atomic number but an atomic mass different from the atomic mass usually or predominantly found in nature. Examples of isotopes that can be incorporated into a compound of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulphur, fluorine, chlorine, bromine and iodine, such as ²H (deuterium), ³H (tritium), ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁷O, ⁸O, ³²P, ³³P, ³³S, ³⁴S, ³⁵S, ³⁶S, ¹⁸F, ³⁶Cl, ⁸²Br, ¹²³I, ¹²⁴I, ¹²⁹I and ¹³¹I, respectively. Accordingly, recitation of “hydrogen” or “H” should be understood to encompass ¹H (protium), ²H (deuterium), and ³H (tritium) unless otherwise specified. Certain isotopic variations of a compound of the invention, for example, those in which one or more radioactive isotopes such as ³H or ¹⁴C are incorporated, are useful in drug and/or substrate tissue distribution studies. Tritiated and carbon-14, i.e., ¹⁴C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with isotopes such as deuterium may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements and hence may be preferred in some circumstances. Isotopic variations of a compound of the invention can generally be prepared by conventional procedures known by a person skilled in the art such as by the illustrative methods or by the preparations described in the examples hereafter using appropriate isotopic variations of suitable reagents.

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, Mass., USA; and CombiPhos Catalysts, Inc., Princeton, N.J., 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 may be possible for the compounds of the present invention to exist as tautomers. For example, any compound of the present invention which contains an imidazopyridine moiety as a heteroaryl group for example can exist as a 1H tautomer, or a 3H tautomer, or even a mixture in any amount of the two tautomers, namely:

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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, in the context of the present invention, it may be possible for the compounds of formula (I) to exist as tautomers. For example, as depicted below, the compounds of formula (I) according to the present invention can exist as a 1H tautomer, or a 3H tautomer, or even a mixture in any amount of two or more of the possible tautomers:

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The present invention includes all possible tautomers of the compounds of formula (I) of the present invention as single tautomers, or as any mixture of any two or more of any possible tautomers, in any ratio.

Further, in the context of the present invention, it may be possible for the compounds of formula (I) where X is a nitrogen atom to exist as tautomers. For example, as depicted below, the compounds of formula (I) according to the present invention where X is a nitrogen atom can exist as a 1H tautomer, or a 4H tautomer, or even a mixture in any amount of two or more of the possible tautomers:

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The present invention includes all possible tautomers of the compounds of formula (I) of the present invention where X is a nitrogen atom as single tautomers, or as any mixture of any two or more possible tautomers, in any ratio.

Further, in the context of the present invention, it may be possible for the compounds of formula (I) where X is a CR⁴group to exist as tautomers. For example, as depicted below, the compounds of formula (I) according to the present invention where X is a CR₄group can exist as two different 1H tautomers, or even a mixture in any amount of two or more of the possible tautomers:

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The present invention includes all possible tautomers of the compounds of formula (I) of the present invention where X is a CR⁴group as single tautomers, or as any mixture of any two or more possible tautomers, in any ratio.

Further, in the context of the present invention, it may be possible for the triazine core of the compounds of formula (I) to exhibit tautomerism and for said compounds to exist as single tautomers or even as a mixture in any amount of two or more of the possible tautomers:

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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 provides 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.

Physiologically acceptable salts of the compounds according to the invention encompass acid addition salts of mineral acids, carboxylic acids and sulfonic acids, for example salts of hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, bisulfuric acid, phosphoric acid, nitric acid 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, persulfuric, 3-phenylpropionic, picric, pivalic, 2-hydroxyethanesulfonate, itaconic, sulfamic, trifluoromethanesulfonic, dodecylsulfuric, ethansulfonic, benzenesulfonic, para-toluenesulfonic, methansulfonic, 2-naphthalenesulfonic, naphthalenedisulfonic, camphorsulfonic acid, citric, tartaric, stearic, lactic, oxalic, malonic, succinic, malic, adipic, alginic, maleic, fumaric, D-gluconic, mandelic, ascorbic, glucoheptanoic, glycerophosphoric, aspartic, sulfosalicylic, hemisulfuric, or thiocyanic acid, for example.

A “pharmaceutically acceptable anion” refers to the deprotonated form of a conventional acid, such as, for example, a hydroxide, a carboxylate, a sulfate, a halide, a phosphate, or a nitrate.

Physiologically acceptable salts of the compounds according to the invention also comprise salts of conventional bases, such as, by way of example and by preference, alkali metal salts (for example lithium, sodium and potassium salts), alkaline earth metal salts (for example calcium, strontium and magnesium salts) and ammonium salts derived from ammonia or organic amines with 1 to 16 C atoms, such as, by way of example and by preference, ethylamine, diethylamine, triethylamine, ethyldiisopropylamine, monoethanolamine, diethanolamine, triethanolamine, dicyclohexylamine, dimethylaminoethanol, procaine, dibenzylamine, N-methylmorpholine, arginine, lysine, ethylenediamine, N-methylpiperidine, N-methylglucamine, dimethylglucamine, ethylglucamine, 1,6-hexadiamine, glucosamine, sarcosine, serinol, tris(hydroxymethyl)aminomethane, aminopropanediol, Sovak base, and 1-amino-2,3,4-butanetriol.

Additionally, the compounds according to the invention may form salts with a quaternary ammonium ion obtainable, e.g., by quaternisation of a basic nitrogen-containing group with agents such as lower alkylhalides such as methyl-, ethyl-, propyl-, and butylchlorides, -bromides and -iodides; dialkylsulfates such as dimethyl-, diethyl-, dibutyl- and diamylsulfates, long chain halides such as decyl-, lauryl-, myristyl- and stearylchlorides, -bromides and -iodides, aralkylhalides such as benzyl- and phenethylbromides and others. Examples of suitable quaternary ammonium ions are tetramethylammonium, tetraethylammonium, tetra(n-propyl)ammonium, tetra (n-butyl)ammonium, or N-benzyl-N,N,N-trimethylammonium.

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.

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.

Solvates and hydrates of disclosed intermediates or example compounds, or salts thereof, which have been obtained, by the preparation and/or purification processes described herein, may be formed in any ratio.

Furthermore, the present invention includes all possible crystalline forms, or polymorphs, of the compounds of the present invention, either as a 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” 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. For example, a prodrug may be in the form of an in vivo hydrolysable ester of the specified compound. Derivatives of the compounds of formula (I) and the salts thereof which are converted into a compound of formula (I) or a salt thereof in a biological system (bioprecursors or pro-drugs) are covered by the invention. Said biological system may be, for example, a mammalian organism, particularly a human subject. The bioprecursor is, for example, converted into the compound of formula (I) or a salt thereof by metabolic processes.

Further, in the context of the present invention, when the inhibitory and/or degradatory activity of the compounds of formula (I) according to the present invention is referred to, the following terms are defined as follows:

As used herein and in the context of the present invention, the term “IC50 CDK12 hATP” refers to the IC₅₀values obtained according to the assay described in section 2.2 of the Experimental Section herein below, i.e. the IC₅₀values for the inhibition of CDK12 at high ATP.

DESCRIPTION
Further Embodiments of the First Aspect of the Present Invention