A compound of the formula: wherein A is C 6 -C 10 aryl or C 5 -C 6 heteroaryl; each R 1 is independently hydrogen, halogen, C 1 -C 6 alkyl, C 1 -C 6 heteroalkyl, -(C 1 -C 4 alkyl)(C 5 -C 6 heteroalkyl), -(C 0 -C 4 alkyl)(C 3 -C 7 cycloalkyl), -(C 0 -C 4 heteroalkyl)(C 3 -C 7 cycloalkyl), -(C 0 -C 4 alkyl)(C 3 -C 7 cycloheteroalkyl), -(C 0 -C 4 heteroalkyl)(C 3 -C 7 cycloheteroalkyl), -(C 0 -C 4 alkyl)(C 4 -C 10 bicyclyl), -(C 0 -C 4 alkyl)(C 5 -C 6 aryl), -(C 0 -C 4 alkyl)(C 5 -C 6 heteroaryl), -(C 0 -C 4 alkyl)(C 4 -C 10 heterobicyclyl), C 5 -C 12 spiranyl, C 5 -C 12 heterospiranyl, dimethylphosphoryl, adamantyl, C 1 -C 6 alkoxy, -(C 1 -C 4 alkyl)-SO 2 -(C 1 -C 4 alkyl), difluoromethylsulfanyl, or pentafluorosulfanyl, wherein each R 1 is unsubstituted or when it is capable of being substituted, it is substituted with one or more substituents that are independently selected from the group consisting of halogen, cyano, hydroxyl, oxo, methyl, methoxy, hydroxymethyl, ethyl, ethoxy, hydroxyethyl, methylamine, N,N-dimethylmethylamine, mono-, di, or trihalomethoxy, mono-, di-, or tri-halomethyl, and C 0 -C 3 alkyl-pyrrolidinyl, where the pyrrolidinyl group is unsubstituted or substituted with one, two or 3 independently selected halogen atoms, and wherein two R 1 groups can fuse to form a ring structure that includes a portion of A and is optionally aromatic, and n is 1, 2, 3, 4, 5, or 6; X 1, X 2, X 3, and X 4 are each independently N, CH, C-CH 3, C-CH 2 -OH, C-OCH 3, C-CH 2 -OCH 3, or C-halogen; and R 2 is C 1 -C 6 alkyl, -(C 0 -C 4 alkyl)(C 3 -C 7 cycloalkyl), -(C 0 -C 4 alkyl)(C 4 -C 7 heterocycloalkyl), -(C 0 -C 4 alkyl)(C 4 -C 10 bicyclic) each optionally substituted with one or more of halogen, cyano, hydroxyl, oxo, methyl, methoxy, hydroxymethyl, ethyl, ethoxy, hydroxyethyl, cyclopropyl, or mono-, di-, or tri-halomethyl; or a pharmaceutically acceptable salt thereof. A is C 6 -C 10 aryl or C 5 -C 6 heteroaryl; each R 1 is independently hydrogen, halogen, C 1 -C 6 alkyl, C 1 -C 6 heteroalkyl, -(C 1 -C 4 alkyl)(C 5 -C 6 heteroalkyl), -(C 0 -C 4 alkyl)(C 3 -C 7 cycloalkyl), -(C 0 -C 4 heteroalkyl)(C 3 -C 7 cycloalkyl), -(C 0 -C 4 alkyl)(C 3 -C 7 cycloheteroalkyl), -(C 0 -C 4 heteroalkyl)(C 3 -C 7 cycloheteroalkyl), -(C 0 -C 4 alkyl)(C 4 -C 10 bicyclyl), -(C 0 -C 4 alkyl)(C 5 -C 6 aryl), -(C 0 -C 4 alkyl)(C 5 -C 6 heteroaryl), -(C 0 -C 4 alkyl)(C 4 -C 10 heterobicyclyl), C 5 -C 12 spiranyl, C 5 -C 12 heterospiranyl, dimethylphosphoryl, adamantyl, C 1 -C 6 alkoxy, -(C 1 -C 4 alkyl)-SO 2 -(C 1 -C 4 alkyl), difluoromethylsulfanyl, or pentafluorosulfanyl, wherein each R 1 is unsubstituted or when it is capable of being substituted, it is substituted with one or more substituents that are independently selected from the group consisting of halogen, cyano, hydroxyl, oxo, methyl, methoxy, hydroxymethyl, ethyl, ethoxy, hydroxyethyl, methylamine, N,N-dimethylmethylamine, mono-, di, or trihalomethoxy, mono-, di-, or tri-halomethyl, and C 0 -C 3 alkyl-pyrrolidinyl, where the pyrrolidinyl group is unsubstituted or substituted with one, two or 3 independently selected halogen atoms, and wherein two R 1 groups can fuse to form a ring structure that includes a portion of A and is optionally aromatic, and n is 1, 2, 3, 4, 5, or 6; X 1, X 2, X 3, and X 4 are each independently N, CH, C-CH 3, C-CH 2 -OH, C-OCH 3, C-CH 2 -OCH 3, or C-halogen; and R 2 is C 1 -C 6 alkyl, -(C 0 -C 4 alkyl)(C 3 -C 7 cycloalkyl), -(C 0 -C 4 alkyl)(C 4 -C 7 heterocycloalkyl), -(C 0 -C 4 alkyl)(C 4 -C 10 bicyclic) each optionally substituted with one or more of halogen, cyano, hydroxyl, oxo, methyl, methoxy, hydroxymethyl, ethyl, ethoxy, hydroxyethyl, cyclopropyl, or mono-, di-, or tri-halomethyl; or a pharmaceutically acceptable salt thereof.