CDK inhibitors and their use as pharmaceuticals

A compound of

• or a pharmaceutically acceptable salt or solvate thereof,
• wherein:
• X1, X2, and X3 are each independently N or CR3;
• A1 is N or C—R4,
• B1 is C—R6R7, N—R5;
• A2 is N—R8, S, or O;
• B2 is C—R9;
• R1 is C3-10cycloalkyl or 4-10 membered heterocycloalkyl optionally substituted with 1, 2, 3, 4, 5, 6, 7 or 8 independently selected Rb substituents;
• R2 is C1-6 alkyl;
• R3 is H, D, OH, halogen, CN, C1-6 alkyl, C3-10 cycloalkyl, C1-6 alkoxyl, C1-6 haloalkyl, or 4-14 membered heterocycloalkyl;
• R4 is H, D, C1-6 alkyl, C1-6 alkoxy, C3-6 cycloalkyl, or 4-6 membered heterocycloalkyl;
• R5 is C1-6 alkyl, C1-6 alkoxy, —CF3(CH)CH3, C3-6 cycloalkyl, —CH2-(C3-6 cycloalkyl), or 4-6 membered heterocycloalkyl;
• or R4 and R5, together with the atoms to which they are attached, form a 5-, 6-, or 7-membered heterocycloalkyl ring optionally substituted with 1, 2, 3, 4 or 5 independently selected Rb substituents;
• R6 is C1-6 alkyl, C1-6 alkoxy, C3-6 cycloalkyl, or 4-6 membered heterocycloalkyl;
• R7 is C1-6 alkyl, C1-6 alkoxy, C3-6 cycloalkyl, or 4-6 membered heterocycloalkyl;
• or R6 and R7 together with the carbon atom to which they are both attached, form a C4-7 spirocyclic ring;
• R8 is C1-6 alkyl, C1-6 alkoxy, C3-6 cycloalkyl, or 4-6 membered heterocycloalkyl;
• and
• R9 is C1-6 alkyl, C1-6 alkoxy, C3-6 cycloalkyl, or 4-6 membered heterocycloalkyl;
• or R8 and R9, together with the atoms to which they are attached, form an 5- or 6-membered heterocycloalkyl ring optionally substituted with 1, 2, 3, 4 or 5 independently selected Rb substituents;
• Rb is CN, C1-4 alkyl, 5-10 membered heteroaryl, 4-14 membered heterocycloalkyl, NRcC(═NRc)NRcRc, NRcC(═NOH)NRcRc, NRcC(═NCN)NRcRc, NRcC(O)Rc, NRcC(O)ORc, NRcC(O)NRcRc, NRcS(O)Rc, or NRcS(O)2Rc, NRcS(O)2NRcRc;
• each Rc is independently H, OH, C1-6 alkyl, C1-6 alkoxy, C2-6 alkenyl, C2-6 alkynyl, C6-10 aryl, C3-10 cycloalkyl, 4-10 membered heterocycloalkyl, 5-10 membered heteroaryl, C6-10 aryl-C1-4 alkyl, C3-10 cycloalkyl-C1-4 alkyl, or (4-10 membered heterocycloalkyl)-C1-4 alkyl, or (5-10 membered heteroaryl)-C1-4 alkyl;
• wherein when Rc is C1-6 alkyl, C1-6 alkoxy, C3-10 cycloalkyl, 4-10 membered heterocycloalkyl, or (5-10 membered heteroaryl)-C1-4 alkyl, then Rc is optionally substituted with 1, 2, 3, 4, or 5 independently selected Rf substituents;
• each Rf is independently halogen, CN, C1-4 alkyl, or ORg;
• and
• each Rg is independently H or C1-6 alkyl.