Heterocycle-substituted tetracyclic compounds and methods of use thereof for the treatment of viral diseases

1. A compound having the formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

A is:

A′ is:

each occurrence of R 1 is independently selected from H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 1 -C 6 haloalkyl, —O—C 1 -C 6 alkyl, —N(R 9 ) 2 , —O—(C 1 -C 6 haloalkyl), and halo;

each occurrence of R 1A is independently selected from H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 1 -C 6 haloalkyl, —O—C 1 -C 6 alkyl, —N(R 9 ) 2 , —O—(C 1 -C 6 haloalkyl), and halo, or one R 1A group and an R 1 group that are attached to same ring, together with the ring carbon atoms to which they are attached, can combine to form a fused C 3 -C 7 cycloalkyl group, or two R 1A groups that are attached to the same carbon atom, and the common carbon atom to which they are attached, can combine to form a spirocyclic C 3 -C 7 cycloalkyl group;

each occurrence of R 1B is independently H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 1 -C 6 haloalkyl, —O—C 1 -C 6 alkyl, —N(R 9 ) 2 , —O—(C 1 -C 6 haloalkyl), or halo, or an R 1B group and an R 1A group that are attached to the same ring, together with the carbon atoms to which they are attached, can combine to form a fused C 3 -C 7 cycloalkyl group, or an R 1B group and an R 1 group that are attached to the same ring, can combine to form a bridging group having the formula —CH 2 — or —CH 2 CH 2 —;

R 2 is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, phenyl or halo, wherein said phenyl group and said C 3 -C 7 cycloalkyl can be optionally substituted with up to 4 groups, which can be the same or different and are selected from C 1 -C 6 alkyl, halo, —O—C 1 -C 6 alkyl and —N(R 9 ) 2 ;

R 3 is selected from furanyl, oxazolyl, oxadiazolyl, isoxazolyl, imidazolyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, pyrazolo[1,5-a]pyridinyl, imidazo[1,2-a]pyridinyl, and 6,7-dihydro-5H-pyrrolo[1,2-a]imidazolyl, wherein said furanyl, oxazolyl, oxadiazolyl, isoxazolyl, imidazolyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, pyrazolo[1,5-a]pyridinyl, imidazo[1,2-a]pyridinyl, and 6,7-dihydro-5H-pyrrolo[1,2-a]imidazolyl, groups can be optionally substituted on one or more ring carbon atoms with R 6 , and optionally substituted on a ring nitrogen atom with C 1 -C 6 alkyl;

each occurrence of R 4 is independently selected from —C(O)—C(R 7 ) 2 NHC(O)O—R 8 ;

R 5 represents up to 3 substituents, each independently selected from halo, —CN, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 3 -C 7 cycloalkyl, 4 to 6-membered monocyclic heterocycloalkyl, 5 or 6-membered monocyclic heteroaryl, C 6 -C 10 aryl, benzyl and —O—(C 1 -C 6 alkyl), wherein said C 3 -C 7 cycloalkyl group, said 4 to 6-membered monocyclic heterocycloalkyl group, said 5 or 6-membered monocyclic heteroaryl group, said C 6 -C 10 aryl group, or the phenyl moiety of said benzyl group can be optionally substituted with up to 3 groups, which can be the same or different, and are selected from halo, —CN, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, —O—C 1 -C 6 alkyl, —(C 1 -C 6 alkylene)-O—C 1 -C 6 alkyl and —O—(C 1 -C 6 haloalkyl);

R 6 represents up to 3 optional substituents, each independently selected from halo, —CN, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 3 -C 7 cycloalkyl, C 6 -C 10 aryl, benzyl, —O—(C 1 -C 6 alkyl), C 2 -C 6 alkenyl, C 1 -C 6 hydroxyalkyl, —N(R 9 ) 2 , —(C 1 -C 6 alkylene) m -(C 6 -C 10 aryl), —(C 1 -C 6 alkylene) m -(C 3 -C 7 cycloalkyl), 5 or 6-membered monocyclic heteroaryl, and 9 or 10-membered bicyclic heteroaryl, wherein said 5 or 6-membered monocyclic heteroaryl group can be optionally substituted on a ring carbon atom with C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or phenyl, and optionally substituted on a ring nitrogen atom with C 1 -C 6 alkyl; said C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or phenyl can be optionally substituted a ring carbon atom with halo, C 1 -C 6 alkyl or C 3 -C 7 cycloalkyl;

each occurrence of R 7 is independently selected from H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, phenyl, 4 to 8-membered monocyclic heterocycloalkyl, 6 to 10-membered bicyclic heterocycloalkyl and C 3 -C 7 cycloalkyl, wherein said 4 to 8-membered monocyclic heterocycloalkyl group, said 6 to 10-membered bicyclic heterocycloalkyl group and said C 3 -C 7 cycloalkyl group can be optionally substituted with up to 5 groups, each independently selected from halo, —CN, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 3 -C 7 cycloalkyl, —O—C 1 -C 6 alkyl, —N(R 9 ) 2 and —O—(C 1 -C 6 haloalkyl), and wherein said C 3 -C 7 cycloalkyl group can be optionally fused to a 4 to 6-membered monocyclic heterocycloalkyl group, and wherein said 4 to 8-membered monocyclic heterocycloalkyl group and said C 3 -C 7 cycloalkyl group can be substituted on a ring carbon atom with a spirocyclic C 3 -C 6 cycloalkyl group; and wherein said C 3 -C 7 cycloalkyl group can be substituted on a ring carbon atom with a spirocyclic 3 to 6-membered monocyclic heterocycloalkyl group, and wherein two R 7 groups, that are attached to a common carbon atom, together with the common carbon atom to which they are attached, join to form a C 3 -C 7 cycloalkyl group;

each occurrence of R 8 is independently C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl and C 6 -C 10 aryl;

each occurrence of R 9 is independently selected from H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl and C 6 -C 10 aryl; and

each occurrence of m is independently 0 or 1.

2. The compound of claim 1 , wherein each occurrence of R 4 is independently —C(O)CH(R 7 )NHC(O)OCH 3 , or a pharmaceutically acceptable salt thereof.

3. The compound of claim 1 , wherein each occurrence of R 4 is independently —C(O)CH(R 7 )—NHC(O)OCH 3 and R 7 is C 1 -C 6 alkyl, C 1 -C 6 haloalkyl or 4 to 6-membered monocyclic heterocycloalkyl, wherein said 4 to 6-membered monocyclic heterocycloalkyl group can be optionally substituted with up to five C 1 -C 6 alkyl groups or said 4 to 6-membered monocyclic heterocycloalkyl group can be optionally substituted on a ring carbon atom with a spirocyclic C 3 -C 6 cycloalkyl group, or a pharmaceutically acceptable salt thereof.

4. The compound of claim 1 having the formula:

or a pharmaceutically acceptable salt thereof,

wherein:

each R 1 is H;

each R 1A is independently H or F, or an R 1A group and an R 1 group that are attached to same ring, together with the ring carbon atoms to which they are attached, can combine to form a fused cyclopropyl group;

R 3 is selected from furanyl, oxazolyl, oxadiazolyl, isoxazolyl, imidazolyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, pyrazolo[1,5-a]pyridinyl, imidazo[1,2-a]pyridinyl, and 6,7-dihydro-5H-pyrrolo[1,2-a]imidazolyl, wherein said furanyl, oxazolyl, oxadiazolyl, isoxazolyl, imidazolyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, pyrazolo[1,5-a]pyridinyl, imidazo[1,2-a]pyridinyl, and 6,7-dihydro-5H-pyrrolo[1,2-a]imidazolyl, groups can be optionally substituted on a ring carbon atom with C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or phenyl, and optionally substituted on a ring nitrogen atom with C 1 -C 6 alkyl; said C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or phenyl can be optionally substituted a ring carbon atom with halo, C 1 -C 6 alkyl or C 3 -C 7 cycloalkyl;

R 5 is H or F; and

each occurrence of R 7 is independently selected from C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, and 4 to 6-membered monocyclic heterocycloalkyl, wherein said 4 to 6-membered monocyclic heterocycloalkyl group can be optionally substituted with up to 5 groups, each independently selected from halo, C 1 -C 6 alkyl and C 3 -C 7 cycloalkyl.

5. The compound of claim 1 , wherein A and A′ are each independently selected from:

or a pharmaceutically acceptable salt thereof.

6. The compound of claim 1 , wherein R 3 is:

or a pharmaceutically acceptable salt thereof.

7. The compound of claim 1 , wherein each occurrence of R 7 is independently selected from isopropyl,

or a pharmaceutically acceptable salt thereof.

8. The compound of claim 1 , wherein, R is F and each occurrence of R 7 is independently selected from isopropyl or:

or a pharmaceutically acceptable salt thereof.

9. A compound selected from:

or a pharmaceutically acceptable salt thereof.

10. A pharmaceutical composition comprising an effective amount of the compound of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

11. The pharmaceutical composition of claim 10 , further comprising a second therapeutic agent selected from the group consisting of HCV antiviral agents, immunomodulators, and anti-infective agents.

12. The pharmaceutical composition of claim 11 , further comprising a third therapeutic agent selected from the group consisting of HCV protease inhibitors, HCV NS5A inhibitors and HCV NS5B polymerase inhibitors.

13. A method of treating a patient infected with HCV comprising the step of administering an amount of the compound according to claim 1 , or a pharmaceutically acceptable salt thereof, effective to treat infection by HCV in said patient.

14. The method of claim 13 , further comprising administering a second additional therapeutic agent to said patient, wherein said second additional therapeutic agent is independently selected from HCV protease inhibitors, HCV NS5A inhibitors and HCV NS5B polymerase inhibitors.

15. The method of claim 14 , further comprising administering a third additional therapeutic agent to said patient, wherein said third additional therapeutic agent is independently selected from HCV protease inhibitors, HCV NS5A inhibitors and HCV NS5B polymerase inhibitors.

16. The method of claim 14 , wherein said second additional therapeutic agent is grazoprevir.