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

A compound having the formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• A is:
• A′ is:
• each occurrence of R1 is independently selected from H, C1-C6 alkyl, C3-C7 cycloalkyl, C1-C6 haloalkyl, —O—C1-C6 alkyl, —N(R9)2, —O—(C1-C6 haloalkyl), and halo;
• each occurrence of R1A is independently selected from H, C1-C6 alkyl, C3-C7 cycloalkyl, C1-C6 haloalkyl, —O—C1-C6 alkyl, —N(R9)2, —O—(C1-C6 haloalkyl), and halo, or one R1A group and an R1 group that are attached to same ring, together with the ring carbon atoms to which they are attached, can combine to form a fused C3-C7 cycloalkyl group, or two R1A 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 C3-C7 cycloalkyl group;
• each occurrence of R1B is independently H, C1-C6 alkyl, C3-C7 cycloalkyl, C1-C6 haloalkyl, —O—C1-C6 alkyl, —N(R9)2, —O—(C1-C6 haloalkyl), or halo, or an R1B group and an R1A group that are attached to the same ring, together with the carbon atoms to which they are attached, can combine to form a fused C3-C7 cycloalkyl group, or an R1B group and an R1 group that are attached to the same ring, can combine to form a bridging group having the formula —CH2— or —CH2CH2—;
• R2 is H, C1-C6 alkyl, C3-C7 cycloalkyl, phenyl or halo, wherein said phenyl group and said C3-C7 cycloalkyl can be optionally substituted with up to 4 groups, which can be the same or different and are selected from C1-C6 alkyl, halo, —O—C1-C6 alkyl and —N(R9)2;
• R3 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 R6, and optionally substituted on a ring nitrogen atom with C1-C6 alkyl;
• each occurrence of R4 is independently selected from —C(O)—C(R7)2NHC(O)O—R8;
• R5 represents up to 3 substituents, each independently selected from halo, —CN, C1-C6 alkyl, C1-C6 haloalkyl, C3-C7 cycloalkyl, 4 to 6-membered monocyclic heterocycloalkyl, 5 or 6-membered monocyclic heteroaryl, C6-C10 aryl, benzyl and —O—(C1-C6 alkyl), wherein said C3-C7 cycloalkyl group, said 4 to 6-membered monocyclic heterocycloalkyl group, said 5 or 6-membered monocyclic heteroaryl group, said C6-C10 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, C1-C6 alkyl, C1-C6 haloalkyl, —O—C1-C6 alkyl, —(C1-C6 alkylene)-O—C1-C6 alkyl and —O—(C1-C6 haloalkyl);
• R6 represents up to 3 optional substituents, each independently selected from halo, —CN, C1-C6 alkyl, C1-C6 haloalkyl, C3-C7 cycloalkyl, C6-C10 aryl, benzyl, —O—(C1-C6 alkyl), C2-C6 alkenyl, C1-C6 hydroxyalkyl, —N(R9)2, —(C1-C6 alkylene)m-(C6-C10 aryl), —(C1-C6 alkylene)m-(C3-C7 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 C1-C6 alkyl, C3-C7 cycloalkyl or phenyl, and optionally substituted on a ring nitrogen atom with C1-C6 alkyl;
• said C1-C6 alkyl, C3-C7 cycloalkyl or phenyl can be optionally substituted a ring carbon atom with halo, C1-C6 alkyl or C3-C7 cycloalkyl;
• each occurrence of R7 is independently selected from H, C1-C6 alkyl, C1-C6 haloalkyl, phenyl, 4 to 8-membered monocyclic heterocycloalkyl, 6 to 10-membered bicyclic heterocycloalkyl and C3-C7 cycloalkyl, wherein said 4 to 8-membered monocyclic heterocycloalkyl group, said 6 to 10-membered bicyclic heterocycloalkyl group and said C3-C7 cycloalkyl group can be optionally substituted with up to 5 groups, each independently selected from halo, —CN, C1-C6 alkyl, C1-C6 haloalkyl, C3-C7 cycloalkyl, —O—C1-C6 alkyl, —N(R9)2 and —O—(C1-C6 haloalkyl), and wherein said C3-C7 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 C3-C7 cycloalkyl group can be substituted on a ring carbon atom with a spirocyclic C3-C6 cycloalkyl group;
• and wherein said C3-C7 cycloalkyl group can be substituted on a ring carbon atom with a spirocyclic 3 to 6-membered monocyclic heterocycloalkyl group, and wherein two R7 groups, that are attached to a common carbon atom, together with the common carbon atom to which they are attached, join to form a C3-C7 cycloalkyl group;
• each occurrence of R8 is independently C1-C6 alkyl, C3-C7 cycloalkyl and C6-C10 aryl;
• each occurrence of R9 is independently selected from H, C1-C6 alkyl, C3-C7 cycloalkyl and C6-C10 aryl;
• and
• each occurrence of m is independently 0 or 1.