Substituted pyrazolo[1,5-A]pyridine compounds as RET kinase inhibitors
Provided herein are compounds of the Formula I: and stereoisomers and pharmaceutically acceptable salts or solvates thereof, in which A, B, X 1 , X 2 , X 3 , X 4 , Ring D, and E have the meanings given in the specification, which are inhibitors of RET kinase and are useful in the treatment and prevention of diseases which can be treated with a RET kinase inhibitor, including RET-associated diseases and disorders.
1. A compound of the Formula I:
and pharmaceutically acceptable salts and solvates thereof, wherein:
X 1 , X 2 , X 3 and X 4 are independently CH or N, wherein zero, one or two of X 1 , X 2 , X 3 and X 4 is N;
A is CN;
B is
(b) C1-C6 alkyl optionally substituted with 1-3 fluoros,
(c) hydroxyC2-C6 alkyl-, wherein the alkyl portion is optionally substituted with 1-3 fluoros or a C3-C6 cycloalkylidene ring,
(e) (C1-C6 alkoxy)C1-C6 alkyl- optionally substituted with 1-3 fluoros,
(f) (R 1 R 2 N)C1-C6 alkyl-, wherein said alkyl portion is optionally substituted with OH and wherein R 1 and R 2 are independently H or C1-C6 alkyl (optionally substituted with 1-3 fluoros);
(g) hetAr 1 C1-C3 alkyl-, wherein hetAr 1 is a 5-6 membered heteroaryl ring having 1-3 ring heteroatoms independently selected from N, O and S and is optionally substituted with one or more independently selected C1-C6 alkyl substituents; or
(i) (hetCyc a )C1-C3 alkyl-,
hetCyc a - is a 4-6 membered heterocyclic ring having 1-2 ring heteroatoms independently selected from N and O and optionally substituted with one or more substituents independently selected from OH, C1-C6 alkyl (optionally substituted with 1-3 fluoros), hydroxyC1-C6 alkyl-, C1-C6 alkoxy, (C1-C6 alkyl)C(═O)—, (C1-C6 alkoxy)C1-C6 alkyl- and fluoro, or wherein hetCyc a is substituted with oxo;
Ring D is (i) a saturated 4-7 membered heterocyclic ring having two ring nitrogen atoms, or (ii) a saturated 7-9 membered bridged heterocyclic ring having two ring nitrogen atoms and optionally having a third ring heteroatom which is oxygen, wherein each of said rings is optionally substituted with (a) one to four groups independently selected from halogen, OH, C1-C3 alkyl which is optionally substituted with 1-3 fluoros, or C1-C3 alkoxy which is optionally substituted with 1-3 fluoros, (b) a C3-C6 cycloalkylidene ring, or (c) an oxo group;
E is
(h) Ar 1 C1-C6 alkyl-,
(j) hetAr 2 C1-C6 alkyl-, wherein the alkyl portion is optionally substituted with 1-3 fluoros, or
(l) hetAr 2 C(═O)—,
Ar 1 is phenyl optionally substituted with one or more substituents independently selected from the group consisting of halogen, CN, C1-C6 alkyl (optionally substituted with 1-3 fluoros), C1-C6 alkoxy (optionally substituted with 1-3 fluoros), R e R f N— wherein R e and R f are independently H or C1-C6 alkyl, (R p R q N)C1-C6 alkoxy- wherein R P and R q are independently H or C1-C6 alkyl, and (hetAr a )C1-C6 alkyl- wherein hetAr a is a 5-6 membered heteroaryl ring having 1-2 ring nitrogen atoms, or Ar 1 is a phenyl ring fused to a 5-6 membered heterocyclic ring having 1-2 ring heteroatoms independently selected from N and 0; and
hetAr 2 is a 5-6 membered heteroaryl ring having 1-3 ring heteroatoms independently selected from N, O and S or a 9-10 membered bicyclic heteroaryl ring having 1-3 ring nitrogen atoms, wherein hetAr 2 is optionally substituted with one or more substituents independently selected from the group consisting of halogen, CN, C1-C6 alkyl (optionally substituted with 1-3 fluoros), C1-C6 alkoxy (optionally substituted with 1-3 fluoros), (C1-C6 alkoxy)C1-C6 alkyl-(optionally substituted with 1-3 fluoros), R e R f N— wherein R e and R f are independently H or C1-C6 alkyl, OH, (C1-C6 alkoxy)C1-C6 alkoxy- and C3-C6 cycloalkyl.
2. A compound according to claim 1 , wherein Ring D is
wherein the wavy line indicates the point of attachment to the ring comprising X 1 , X 2 , X 3 and X 4 , and the asterisk indicates the point of attachment to the E group, and wherein said ring is optionally substituted with (a) one to four groups independently selected from halogen, OH, C1-C3 alkyl which is optionally substituted with 1-3 fluoros, or C1-C3 alkoxy which is optionally substituted with 1-3 fluoros, (b) a C3-C6 cycloalkylidene ring, or (c) an oxo group.
3. A compound according to claim 2 , wherein E is:
(h) Ar 1 C1-C6 alkyl-, or
(j) hetAr 2 C1-C6 alkyl- wherein said alkyl portion is optionally substituted with 1-3 fluoros.
4. A compound according to claim 1 , wherein Ring D is
wherein the wavy line indicates the point of attachment to the ring comprising X 1 , X 2 , X 3 and X 4 , and the asterisk indicates the point of attachment to the E group, and wherein said ring is optionally substituted with (a) one to four groups independently selected from halogen, OH, C1-C3 alkyl which is optionally substituted with 1-3 fluoros, or C1-C3 alkoxy which is optionally substituted with 1-3 fluoros, (b) a C3-C6 cycloalkylidene ring, or (c) an oxo group.
5. A compound according to claim 4 , wherein E is
(j) hetAr 2 C1-C6 alkyl- wherein said alkyl portion is optionally substituted with 1-3 fluoros, or
(l) hetAr 2 C(═O)—.
6. A compound according to claim 3 , wherein B is
(c) hydroxyC2-C6 alkyl- wherein the alkyl portion is optionally substituted with a C3-C6 cycloalkylidene ring,
(e) (C1-C6 alkoxy)C1-C6 alkyl- optionally substituted with 1-3 fluoros, or
(i) (hetCyc a )C1-C3 alkyl-.
7. A compound according to claim 5 , wherein B is
(b) C1-C6 alkyl optionally substituted with 1-3 fluoros, or
(c) hydroxyC2-C6 alkyl- wherein the alkyl portion is optionally substituted with a C3-C6 cycloalkylidene ring,
(f) (R 1 R 2 N)C1-C6 alkyl-, wherein said alkyl portion is optionally substituted with OH and wherein R 1 and R 2 are independently H or C1-C6 alkyl (optionally substituted with 1-3 fluoros);
(g) hetAr 1 C1-C3 alkyl-, wherein hetAr 1 is a 5-6 membered heteroaryl ring having 1-3 ring heteroatoms independently selected from N, O and S and is optionally substituted with one or more independently selected C1-C6 alkyl substituents; or
(i) (hetCyc a )C1-C3 alkyl-.
8. A compound according to claim 1 , wherein X 1 is N, and X 2 , X 3 and X 4 are CH.
9. A compound according to claim 1 , wherein the compound of Formula I is selected from the group consisting of:
4-(6-(4-benzylpiperazin-1-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-hydroxyethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
(R)-6-(2-hydroxypropoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-methoxyethoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(6-methoxynicotinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-(dimethylamino)ethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile;
4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-((l-methyl-1H-imidazol-4-yl)methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile; and
6-ethoxy-4-(5-(6-((5-fluoro-6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyrazin-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
or a pharmaceutically acceptable salt thereof.
10. A compound according to claim 1 , wherein the compound of Formula I is
4-(6-(4-benzylpiperazin-1-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
11. A compound according to claim 1 , wherein the compound of Formula I is
6-(2-hydroxyethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
12. A compound according to claim 1 , wherein the compound of Formula I is
(R)-6-(2-hydroxypropoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
13. A compound according to claim 1 , wherein the compound of Formula I is
6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
14. A compound according to claim 1 , wherein the compound of Formula I is
6-(2-methoxyethoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
15. A compound according to claim 1 , wherein the compound of Formula I is
6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(6-methoxynicotinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
16. A compound according to claim 1 , wherein the compound of Formula I is
6-(2-(dimethylamino)ethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
17. A compound according to claim 1 , wherein the compound of Formula I is
4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
18. A compound according to claim 1 , wherein the compound of Formula I is
4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-((1-methyl-1H-imidazol-4-yl)methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
19. A compound according to claim 1 , wherein the compound of Formula I is
6-ethoxy-4-(5-(6-((5-fluoro-6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyrazin-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
20. A pharmaceutical composition, comprising a compound according to claim 1 , or a pharmaceutically acceptable salt or solvate thereof, in admixture with a pharmaceutically acceptable diluent or carrier.
21. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
4-(6-(4-benzylpiperazin-1-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
22. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-(2-hydroxyethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
23. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
(R)-6-(2-hydroxypropoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
24. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
25. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-(2-methoxyethoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
26. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(6-methoxynicotinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
27. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-(2-(dimethylamino)ethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
28. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
29. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-((1-methyl-1H-imidazol-4-yl)methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.
30. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-ethoxy-4-(5-(6-((5-fluoro-6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyrazin-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.