3-alkyl-4-amido-bicyclic [4,5,0] hydroxamic acids as HDAC inhibitors

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

X 1 is O;

X 2 and X 4 are each independently CR 1 R 2 , C═O, S(O) or SO 2 ;

X 3 is CR 1′ R 2′ ;

Y 1 and Y 4 are not bound to —C(O)NHOH and are each independently N or CR 1 ;

Y 2 and Y 3 are each independently N or CR 1 when not bonded to —C(O)NHOH and Y 2 and Y 3 are C when bonded to —C(O)NHOH;

L is selected from the group consisting of —C(O)—, —C(O)(CR 1 R 2 ) m —, and —C(O)(CR 1 R 2 ) m O—, wherein L is bound to the ring nitrogen through the carbonyl group;

R is selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 4 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, —C 5 -C 12 spirocycle, heterocyclyl, spiroheterocyclyl, aryl, and heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O, wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, spirocyclyl, heterocyclyl, spiroheterocyclyl, aryl, or heteroaryl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, oxo, —NO 2 , —CN, —R 1 , —R 2 , —OR 3 , —NHR 3 , —NR 3 R 4 , —S(O) 2 NR 3 R 4 , —S(O) 2 R 1 , —C(O)R 1 , —CO 2 R 1 , —NR 3 S(O) 2 R 1 , —S(O)R 1 , —S(O)NR 3 R 4 , —NR 3 S(O)R 1 , heterocyclyl, aryl, and heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O, with the proviso that R is not bound to L via a nitrogen atom;

R 1 and R 2 are independently, at each occurrence, selected from the group consisting of —H, —R 3 , —R 4 , —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 3 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O, —OH, halogen, —NO 2 , —CN, —NHC 1 -C 6 alkyl, —N(C 1 -C 6 alkyl) 2 , —S(O) 2 N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O) 2 R 5 , —S(O) 2 (C 1 -C 6 alkyl), —(C 1 -C 6 alkyl)S(O) 2 R 5 , —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)S(O) 2 C 1 -C 6 alkyl, and —(CHR 5 ) n NR 3 R 4 , wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, —NO 2 , oxo, —CN, —R 5 , —OR 3 , —NHR 3 , —NR 3 R 4 , —S(O) 2 N(R 3 ) 2 , —S(O) 2 R 5 , —C(O)R 5 , —CO 2 R 5 , —NR 3 S(O) 2 R 5 , —S(O)R 5 , —S(O)NR 3 R 4 , —NR 3 S(O)R 5 , heterocyclyl, aryl, or heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O;

or R 1 and R 2 can combine with the carbon atom to which they are both attached to form a spirocycle, spiroheterocycle, or a spirocycloalkenyl;

or R 1 and R 2 , when on non-adjacent atoms, can combine to form a bridging cycloalkyl or heterocycloalkyl;

R 1″ and R 2′ are independently, at each occurrence, selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 3 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, heterocyclyl, —OH, halogen, —NO 2 , —CN, —NHC 1 -C 6 alkyl, —N(C 1 -C 6 alkyl) 2 , —S(O) 2 N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O) 2 R 5 , —S(O) 2 (C 1 -C 6 alkyl), —(C 1 -C 6 alkyl)S(O) 2 R 5 , —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)S(O) 2 C 1 -C 6 alkyl, and —(CHR 5 ) n NR 3 R 4 , wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, or heterocyclyl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, —NO 2 , oxo, —CN, —R 5 , —OR 3 , —NHR 3 , NR 3 R 4 , —S(O) 2 N(R 3 ) 2 , —S(O) 2 R 5 , —C(O)R 5 , —CO 2 R 5 , —NR 3 S(O) 2 R 5 , —S(O)R 5 , —S(O)NR 3 R 4 , —NR 3 S(O)R 5 , heterocyclyl, aryl, and heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O;

or R 1′ and R 2′ can combine with the carbon atom to which they are both attached to form a spirocycle, spiroheterocycle, or a spirocycloalkenyl;

or R 1′ and R 2′ can combine with R 1 or R 2 on adjacent atoms to form a heterocycle, cycloalkyl, aryl, heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O, or cycloalkenyl;

or R 1″ and R 2′ can combine with R 1 or R 2 on non-adjacent atoms, to form a bridging cycloalkyl or heterocycloalkyl;

R 3 and R 4 are independently, at each occurrence, selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 3 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O, —S(O) 2 N(C 1 -C 6 alkyl) 2 , —S(O) 2 (C 1 -C 6 alkyl), —(C 1 -C 6 alkyl)S(O) 2 R 5 , —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, and —(CHR 5 ) n N(C 1 -C 6 alkyl) 2 , wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl is optionally substituted with one or more substituents selected from the group consisting of —OH, halogen, —NO 2 , oxo, —CN, —R 5 , —O(C 1 -C 6 alkyl), —NH(C 1 -C 6 alkyl), N(C 1 -C 6 alkyl) 2 , —S(O) 2 N(C 1 -C 6 alkyl) 2 , —S(O) 2 NHC 1 -C 6 alkyl, —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)S(O) 2 C 1 -C 6 alkyl, —S(O)R 5 , —S(O)N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O)R 5 , heterocyclyl, aryl, and heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O;

R 5 is independently, at each occurrence, selected from the group consisting of —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 3 -C 8 cycloalkenyl, —C 2 -C 6 alkynyl, —C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P, and O, —OH, halogen, —NO 2 , —CN, —NH(C 1 -C 6 alkyl), —N(C 1 -C 6 alkyl) 2 , —S(O) 2 NH(C 1 -C 6 alkyl), —S(O) 2 N(C 1 -C 6 alkyl) 2 , —S(O) 2 C 1 -C 6 alkyl, —C(O)C 1 -C 6 alkyl, —CO 2 C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)SO 2 C 1 -C 6 alkyl, —S(O)(C 1 -C 6 alkyl), —S(O)N(C 1 -C 6 alkyl) 2 , —N(C 1 -C 6 alkyl)S(O)(C 1 -C 6 alkyl) and —(CH 2 ) n N(C 1 -C 6 alkyl) 2 ;

n is independently and at each occurrence an integer from 0 to 6; and

m is independently and at each occurrence an integer from 1 to 6.

2. The compound of claim 1 , wherein: X 4 is CR 1 R 2 .

3. The compound of claim 1 , wherein the compound is of the Formula IA:

or a pharmaceutically acceptable salt thereof.

4. The compound of claim 3 , wherein X 4 is CR 1 R 2 .

5. The compound of claim 1 , wherein the compound is of the Formula IB

or a pharmaceutically acceptable salt thereof.

6. The compound of claim 5 , wherein X 4 is CR 1 R 2 .

7. A pharmaceutical composition comprising a compound of claim 1 and a pharmaceutically acceptable carrier.

8. The compound of claim 4 , wherein X 2 is CR 1 R 2 , wherein R 1 is —H, or —C 1 -C 6 alkyl; and R 2 is —H, —R 3 , aryl, or —C 1 -C 6 alkyl optionally substituted with one or more substituents selected from oxo, —OR 3 , and —NR 3 R 4 .

9. The compound of claim 8 , wherein X 3 is CR 1′ R 2′ , wherein R 1′ is —H, or —C 1 -C 6 alkyl; and R 2′ is —H, heterocyclyl, or —C 1 -C 6 alkyl optionally substituted with one or more substituents selected from halogen, aryl, and —OR 3 .

10. The compound of claim 9 , wherein Y 1 is CR 1 , Y 3 is CR 1 , and Y 4 is CR 1 .

11. The compound of claim 10 , wherein L is —C(O)—.

12. The compound of claim 6 , wherein X 2 is CR 1 R 2 ; R 1 is —H, or —C 1 -C 6 alkyl; and R 2 is —H, —R 3 , aryl, or —C 1 -C 6 alkyl optionally substituted with one or more substituents selected from oxo, —OR 3 , and —NR 3 R 4 .

13. The compound of claim 12 , wherein X 3 is CR 1′ R 2′ , wherein R 1′ is —H, or —C 1 -C 6 alkyl; and R 2′ is —H, heterocyclyl, or —C 1 -C 6 alkyl optionally substituted with one or more substituents selected from halogen, aryl, and —OR 3 .

14. The compound of claim 13 , wherein Y 1 is CR 1 , Y 2 is CR 1 , and Y 4 is CR 1 .

15. The compound of claim 14 , wherein L is —C(O)—.

16. The compound of claim 1 , wherein the compound is N-hydroxy-4-(3-methoxy-2,2-dimethylpropanoyl)-2,3,4,5-tetrahydrobenzo[f][1,4]oxazepine-8-carboxamide, or a pharmaceutically acceptable salt thereof.

17. The compound of claim 1 , wherein the compound is (S)-4-(1-acetylpiperidine-4-carbonyl)-N-hydroxy-3-methyl-2,3,4,5-tetrahydrobenzo[f][1,4]oxazepine-8-carboxamide, or a pharmaceutically acceptable salt thereof.

18. The compound of claim 1 , wherein the compound is (S)—N-hydroxy-5-methyl-4-((S)-3-methyltetrahydro-2H-pyran-3-carbonyl)-2,3,4,5-tetrahydrobenzo[f][1,4]oxazepine-8-carboxamide, or a pharmaceutically acceptable salt thereof.

19. The compound of claim 1 , wherein the compound (S)-6-fluoro-N-hydroxy-3-methyl-4-(4-methyltetrahydro-2H-pyran-4-carbonyl)-2,3,4,5-tetrahydrobenzo[f][1,4]oxazepine-8-carboxamide, or a pharmaceutically acceptable salt thereof.

20. A pharmaceutical composition comprising a compound of claim 16 and a pharmaceutically acceptable carrier.

21. A pharmaceutical composition comprising a compound of claim 17 and a pharmaceutically acceptable carrier.

22. A pharmaceutical composition comprising a compound of claim 18 and a pharmaceutically acceptable carrier.

23. A pharmaceutical composition comprising a compound of claim 19 and a pharmaceutically acceptable carrier.