Inhibitors of activin receptor-like kinase

A method of treating or ameliorating diffuse intrinsic pontine glioma in a subject in need thereof, comprising administering to the subject a pharmaceutically effective amount of a compound of formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• ring A is phenyl or heteroaryl, wherein ring A is optionally substituted with 1, 2, or 3 independently selected substituents selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl in addition to R2;
• R1 is selected from NH(C1-C6 alkyl), N(C1-C6 alkyl)2, C1-C6 alkyl, —O—C1-C6 alkyl, —C(O)—C1-C4 alkyl, carbocyclyl, heterocyclyl, —O—(C0-C4 alkylene)-carbocyclyl, —O—(C0-C4 alkylene)-heterocyclyl, —NH—(C0-C4 alkylene)-carbocyclyl, —NH-phenyl, —NH—O—(C1-C4 alkyl), —S-heterocyclyl, —S—(C0-C3 alkylene)-(O-containing heterocyclyl), and —NH—(C0-C4 alkylene)-heterocyclyl,
• wherein each alkyl, alkylene, carbocyclyl, and heterocyclyl portion of R1 is optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• wherein any phenyl portion of R1 is optionally substituted with 1, 2, or 3 substituents, wherein each optional substituent is independently selected from deuterium, halo, cyano, acetyl, C1-C4 alkyl, C1-C4 haloalkyl, —O—C1-C4 alkyl, —C1-C4 alkylene-O—C1-C4 alkyl, heteroaryl, phenyl, cycloalkyl, —COOH, and —OH, wherein each of said heteroaryl, phenyl, and cycloalkyl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• or
• R1 is taken together with one R3 to form a saturated ring fused to the piperazine ring in formula (I), and wherein the ring formed by R1 and R3 is optionally substituted with 1, 2, or 3 substituents independently selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• if ring A is phenyl, then R2 is selected from halo, C1-C6 alkyl, heterocyclyl, cycloalkyl, —NH—(C0-C4 alkylene)-heterocyclyl, —(C1-C4 alkylene)-heterocyclyl, —(C1-C4 alkylene)—NH-heterocyclyl, and —O—(C0-C4 alkylene)-heterocyclyl, wherein any heterocyclyl, cycloalkyl, alkyl, or alkylene portion of R2 is optionally substituted with 1, 2, 3, or substituents independently selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• or R2 is taken together with any ring atom in ring A to form a cycloalkyl or saturated heterocyclyl ring that is fused to ring A, and wherein the ring formed by R2 and the ring atom in ring A is optionally substituted with 1, 2, or 3 substituents independently selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• if ring A is heteroaryl, then R2 is selected from halo, C1-C6 alkyl, heterocyclyl, cycloalkyl, —NH—(C0-C4 alkylene)-heterocyclyl, —(C1-C4 alkylene)-heterocyclyl, —(C1-C4 alkylene)-NH-heterocyclyl, and —O—(C0-C4 alkylene)-heterocyclyl, wherein any heterocyclyl, cycloalkyl, alkyl, or alkylene portion of R2 is optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• or R2 is taken together with any saturated ring atom in ring A to form a cycloalkyl or saturated heterocyclyl ring that is fused, spirofused, or bridged to ring A, and wherein the ring formed by R2 and the ring atom in ring A is optionally substituted with 1, 2, or 3 substituents independently selected from halo, ═O, cyano, —ORc, —NRdRe, —S(O)kRc, —NRcS(O)2Rc, —S(O)2NRdRe, —C(═O)ORc, —OC(═O)ORc, —OC(═O)Rc, —OC(═S)ORc, —C(═S)ORc, —O(C═S)Rc, —C(═O)NRdRe, —NRcC(═O)Rc, —C(═S)NRdRe, —NRcC(═S)Rc, —NRc(C═O)ORc, —O(C═O)NRdRe, —NRc(C═S)ORc, —O(C═S)NRdRe, —NRc(C═O)NRdRe, —NRc(C═S)NRdRe, —C(═S)Rc, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, and (C1-C6-heteroalkylene)-heteroaryl, wherein each of said alkyl, alkylene, heteroalkyl, heteroalkylene, carbocyclyl, heterocyclyl, aryl, and heteroaryl are optionally substituted with one or more of halo, ORc, —NO2, cyano, —NRcC(═O)Rc, —NRdRe, —S(O)kRc, —C(═O)ORc, —C(═O)NRdRe, —C(═O)Rc, C1-C6 alkyl, C1-C6 haloalkyl, or C1-C6 heteroalkyl;
• each R3 is independently selected from C1-C4 alkyl and C1-C4 haloalkyl;
• each Rc is selected from hydrogen, hydroxy, C1-C6 alkyl, C1-C6 heteroalkyl, carbocyclyl, (C1-C6-alkylene)-carbocyclyl, (C1-C6-heteroalkylene)-carbocyclyl, heterocyclyl, (C1-C6-alkylene)-heterocyclyl, (C1-C6-heteroalkylene)-heterocyclyl, aryl, (C1-C6-alkylene)-aryl, (C1-C6-heteroalkylene)-aryl, heteroaryl, (C1-C6-alkylene)-heteroaryl, or (C1-C6-heteroalkylene)-heteroaryl, each of which is optionally substituted with one or more of halo, hydroxy, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 heteroalkyl, carbocyclyl, heterocyclyl, aryl, or heteroaryl;
• each Rd and Re are independently selected from hydrogen, C1-C6 alkyl, or C1-C6 heteroalkyl;
• each k is independently 0, 1, or 2;
• and
• n is 0, 1, 2, or 3.