Bromodomain Inhibitors

A compound of formula (I) or a pharmaceutically acceptable salt thereof,

• wherein
• R1 is hydrogen, CD2CD3, C1-C6 alkyl, C1-C6 haloalkyl, a C3-C6 cycloalkyl, a phenyl, or a 5-6 membered monocyclic heteroaryl;
• wherein the C3-C6 cycloalkyl, the phenyl, and the 5-6 membered monocyclic heteroaryl are each optionally substituted with 1, 2, 3, or 4 independently selected Rx groups;
• R2 is G2a, C1-C6 haloalkyl, or C1-C6 alkyl wherein the C1-C6 alkyl is optionally substituted with one substituent selected from the group consisting of G2b and —OH;
• G2a is a phenyl or a C3-C6 monocyclic cycloalkyl;
• wherein each G2a is optionally substituted with 1, 2, 3, or 4 independently selected Rx groups;
• G2b is phenyl optionally substituted with 1, 2, 3, or 4 independently selected Rx groups;
• R3 is C1-C6 haloalkyl, C1-C6 alkyl, or a C3-C6 monocyclic cycloalkyl wherein the C3-C6 monocyclic cycloalkyl is optionally substituted with 1, 2, 3, or 4 independently selected Rx groups;
• or
• R2 and R3, together with the carbon atom to which they are attached, form a C3-C6 monocyclic cycloalkyl, a C4-C6 monocyclic cycloalkenyl, or a 4-6 membered monocyclic heterocycle;
• wherein the C3-C6 monocyclic cycloalkyl, the C4-C6 monocyclic cycloalkenyl, and the 4-6 membered monocyclic heterocycle are each optionally substituted with 1, 2, 3, or 4 independently selected Rx groups;
• R4 is phenyl, pyridinyl, a C3-C6 monocyclic cycloalkyl, or a C4-C6 monocyclic cycloalkenyl;
• wherein each R4 is optionally substituted with 1, 2, 3, or 4 independently selected Ry groups;
• or
• R4 is formula (a)
• R4a and R4b are each independently halogen, C4-C6 alkyl, or C1-C6 haloalkyl;
• R4c and R4d are each independently hydrogen, halogen, —CN, C1-C6 alkyl, C1-C6 haloalkyl, —S(C1-C6 alkyl), —S(O)2(C1-C6 alkyl), or —(C1-C6 alkylenyl)-OH;
• Y is C(R4e) or N;
• wherein R4e is hydrogen, halogen, —CN, C1-C6 alkyl, or C1-C6 haloalkyl;
• Rx, at each occurrence, is independently halogen, C1-C6 alkyl, or C1-C6 haloalkyl;
• Ry, at each occurrence, is independently halogen, C1-C6 alkyl, C1-C6 haloalkyl, —O(C1-C6 alkyl), —O(C1-C6 haloalkyl), or —(C1-C6 alkylenyl)-OH;
• X1 and X2 are C(R5);
• or
• one of X1 and X2 is N and the other is C(R5);
• R5, at each occurrence, is independently hydrogen or halogen;
• and
• R6 is hydrogen, halogen, —CN, C1-C6 haloalkyl, or C1-C6 alkyl.