Substituted pyrazolo[1,5-A]pyridine compounds as RET kinase inhibitors
Provided herein are compounds of the Formula I: or pharmaceutically acceptable salt or solvate thereof, wherein A, B, X 1 , X 2 , X 3 , X 4 , Ring D, E, R a , R b , n and m 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 a C3-C6 cycloalkylidene ring, 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 0 and optionally substituted with one or more substituents independently selected from OH, C1-C6 alkyl (optionally substituted with 1-3 fluoros), hydroxyC1-C6 alkyl, halogen, (C1-C6 alkyl)C(═O)—, C1-C6 alkoxy, oxo, and (C1-C6 alkoxy)C(═O)—;
Ring D is
a saturated monocyclic 4-7 membered heterocyclic ring having one ring heteroatom which is nitrogen;
each R a is independently C1-C6 alkyl (optionally substituted with 1-3 fluoros);
R b is (a) hydroxy;
n is 0 or 1;
m is 0 or 1;
E is:
(e) hetAr 2 C1-C6 alkyl-,
(h) hetAr 2 —O—,
(k) R 3 C(═O)NR g — where R g is H or C1-C6 alkyl,
(l) Ar i C(═O)NR g — where R g is H or C1-C6 alkyl, or
(m) hetAr 2 C(═O)NR g (CH 2 ) p — where p is 0 or 1 and R g is H or C1-C6 alkyl;
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), (C1-C6 alkoxy)C1-C6 alkyl- (optionally substituted with 1-3 fluoros), C3-C6 cycloalkyl, hydroxyC1-C6 alkyl, (C1-C6 alkyl)SO 2 —, R e R f N— and (R e R f N)C1-C6 alkyl- where each R e and R f is independently H or C1-C6 alkyl;
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 having 1-2 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) and hydroxyC1-C6 alkoxy-;
R 3 is C1-C6 alkyl (optionally substituted with 1-3 fluoros), hydroxyC1-C6 alkyl-, C1-C6 alkoxy, C3-C6 cycloalkyl, (C3-C6 cycloalkyl)CH 2 —, (C3-C6 cycloalkyl)O—, (C3-C6 cycloalkyl)CH 2 O—, hetCyc 7 O—, Ph-O—, or (C1-C6 alkoxy)C1-C6 alkyl-; wherein each of said C3-C6 cycloalkyl moieties is optionally substituted with C1-C6 alkyl (optionally substituted with 1-3 fluoros), C1-C6 alkoxy, OH, or R′R″N— where R′ and R″ are independently hydrogen or C1-C6 alkyl; and
hetCyc 7 is a 5-7 membered heterocyclic ring having 1-3 ring heteroatoms independently selected from N, O and S.
2. A compound according to claim 1 , wherein Ring D is
wherein the wavy line indicates the point of attachment of Ring D to the ring comprising X 1 , X 2 , X 3 and X 4 , and the asterisk indicates the point of attachment of Ring D to the E group.
3. A compound according to claim 2 , wherein D is
wherein the wavy line indicates the point of attachment of Ring D to the ring comprising X 1 , X 2 , X 3 and X 4 , and the asterisk indicates the point of attachment of Ring D to the E group.
4. A compound according to claim 3 , wherein D is
wherein the wavy line indicates the point of attachment of Ring D to the ring comprising X 1 , X 2 , X 3 and X 4 , and the asterisk indicates the point of attachment of Ring D to the E group.
5. A compound according to claim 3 , wherein D is
wherein the wavy line indicates the point of attachment of Ring D 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.
6. A compound according to claim 3 , wherein E is:
(e) hetAr 2 C1-C6 alkyl-,
(h) hetAr 2 —O—,
(l) Ar 1 C(═O)NR g — where R g is H or C1-C6 alkyl, or
(m) hetAr 2 C(═O)NR g (CH 2 ) p — where p is 0 or 1 and R g is H or C1-C6 alkyl.
7. A compound according to claim 3 , wherein B is C1-C6 alkyl optionally substituted with 1-3 fluoros, or hydroxyC2-C6 alkyl wherein the alkyl portion is optionally substituted with a C3-C6 cycloalkylidene ring.
8. A compound according to claim 3 , 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:
N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)benzamide;
6-ethoxy-4-(6-(4-hydroxy-4-(pyridin-2-ylmethyl)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(pyridin-2-yloxy)azetidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-((6-methoxypyridazin-3-yl)oxy)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
(S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(pyridin-2-yloxy)pyrrolidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile;
N-(1-(5-(3-cyano-6-((3-fluoro-1-methylazetidin-3-yl)methoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-5-fluoro-2-methylbenzamide;
3-chloro-N-(1-(5-(3-cyano-6-((3-fluoro-1-methylazetidin-3-yl)methoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)picolinamide;
N-((3 S,4 S)-1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-3-hydroxypiperidin-4-yl)-3-methylbutanamide;
6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-hydroxy-4-(pyridin-2-ylmethyl)piperidin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; and
3-chloro-N-((3 S,4 S)-1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyrazin-2-yl)-3-hydroxypiperidin-4-yl)picolinamide;
or a pharmaceutically acceptable salt thereof.
10. A compound according to claim 1 , wherein the compound of Formula I is
N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)benzamide, or a pharmaceutically acceptable salt thereof.
11. A compound according to claim 1 , wherein the compound of Formula I is
6-ethoxy-4-(6-(4-hydroxy-4-(pyridin-2-ylmethyl)piperidin-1-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
6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(pyridin-2-yloxy)azetidin-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-(4-((6-methoxypyridazin-3-yl)oxy)piperidin-1-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
(S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(pyridin-2-yloxy)pyrrolidin-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
N-(1-(5-(3-cyano-6-((3-fluoro-1-methylazetidin-3-yl)methoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-5-fluoro-2-methylbenzamide, or a pharmaceutically acceptable salt thereof.
16. A compound according to claim 1 , wherein the compound of Formula I is
3-chloro-N-(1-(5-(3-cyano-6-((3-fluoro-1-methylazetidin-3-yl)methoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)picolinamide, or a pharmaceutically acceptable salt thereof.
17. A compound according to claim 1 , wherein the compound of Formula I is
N-((3 S,4S)-1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-3-hydroxypiperidin-4-yl)-3-methylbutanamide, or a pharmaceutically acceptable salt thereof.
18. A compound according to claim 1 , wherein the compound of Formula I is
6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-hydroxy-4-(pyridin-2-ylmethyl)piperidin-1-yl)pyridin-3-yl)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
3-chloro-N-((3 S,4 S)-1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyrazin-2-yl)-3-hydroxypiperidin-4-yl)picolinamide, 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
N-(1-(5-(3-cyano-6-(2-hydroxy-2-methylpropoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)benzamide, or a pharmaceutically acceptable salt thereof.
22. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-ethoxy-4-(6-(4-hydroxy-4-(pyridin-2-ylmethyl)piperidin-1-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
6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(pyridin-2-yloxy)azetidin-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-(4-((6-methoxypyridazin-3-yl)oxy)piperidin-1-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
(S)-6-(2-hydroxy-2-methylpropoxy)-4-(6-(3-(pyridin-2-yloxy)pyrrolidin-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
N-(1-(5-(3-cyano-6-((3-fluoro-1-methylazetidin-3-yl)methoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)-5-fluoro-2-methylbenzamide, or a pharmaceutically acceptable salt thereof.
27. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
3-chloro-N-(1-(5-(3-cyano-6-((3-fluoro-1-methylazetidin-3-yl)methoxy)pyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-4-methylpiperidin-4-yl)picolinamide, or a pharmaceutically acceptable salt thereof.
28. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
N-((3S,4S)-1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyridin-2-yl)-3-hydroxypiperidin-4-yl)-3-methylbutanamide, or a pharmaceutically acceptable salt thereof.
29. A pharmaceutical composition according to claim 20 , wherein the compound of Formula I is
6-(2-hydroxy-2-methylpropoxy)-4-(6-(4-hydroxy-4-(pyridin-2-ylmethyl)piperidin-1-yl)pyridin-3-yl)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
3-chloro-N-((3 S,4 S)-1-(5-(3-cyano-6-ethoxypyrazolo[1,5-a]pyridin-4-yl)pyrazin-2-yl)-3-hydroxypiperidin-4-yl)picolinamide, or a pharmaceutically acceptable salt thereof.