Substituted pyrrolopyridines as inhibitors of activin receptor-like kinase

A compound of Formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• ring A is chosen from monocyclic aryl, monocyclic heteroaryl, quinolinyl, and bicyclic heterocyclyl, wherein only one ring of said bicyclic heterocyclyl is aromatic;
• each R1 is independently chosen from halo, cyano, oxo, C1-C4 alkyl, —O—(C1-C4 alkyl), —C(O)—(C1-C4 alkyl), —C(O)—O—(C1-C4 alkyl), —C(O)—N(R8)—(C1-C4 alkyl), —N(R8)2, —N(R8)—C(O)—(C1-C4 alkyl), —S(O)p—(C1-C4 alkyl), —O—(C1-C4 alkylene)-C(O)—O—(C1-C4 alkyl), —O—(C1-C4 alkylene)-N(R8)2, —O—(C1-C4 alkylene)-C(O)—N(R8)2, —Si(R9)(C1-C4 alkyl)2, C3-C8 carbocyclyl, —C(O)—(C3-C5 carbocyclyl), —O—(C0-C4 alkylene)-(C3-C8 carbocyclyl), —O—(C0-C4 alkylene)-C(O)—(C3-C5 carbocyclyl), —(C0-C4 alkylene)-aryl, —O—(C0-C4 alkylene)-aryl, heterocyclyl, —C(O)-heterocyclyl, —O—(C0-C4 alkylene)-heterocyclyl, and —O—(C0-C4 alkylene)-C(O)-heterocyclyl, wherein:
• any said alkyl or said alkylene portion of R1 is optionally substituted with one to five substituents independently chosen from halo, cyano, hydroxyl, and O—(C1-C4 alkyl);
• and
• any said carbocyclyl, said aryl, or said heterocyclyl portion of R1 is optionally substituted with one to five substituents independently chosen from halo, C1-C4 alkyl, C1-C4 haloalkyl, cyano, hydroxyl, —O—(C1-C4 alkyl), heterocyclyl, —N(R8)2, and —N(R8)—C(O)—O—(C1-C4 alkyl);
• R2 is a bond or —O—;
• R3 is chosen from C1-C6 alkyl, —(C0-C6 alkylene)-(C3-C8 carbocyclyl), and —(C0-C6 alkylene)-(monocyclic —O— or S-containing heterocyclyl), wherein:
• a carbon atom of said monocylic heterocyclyl is the attachment point for said monocylic heterocyclyl;
• any said alkyl or said alkylene portion of R3 is optionally substituted with one to five substituents independently chosen from halo, cyano, hydroxyl, C1-C4 alkyl, —O—(C1-C4 alkyl), —O—(C3-C8 cycloalkyl), and —S(O)p—(C1-C4 alkyl);
• and
• any said carbocyclyl or said heterocyclyl portion of R3 is optionally substituted with one to five substituents independently chosen from halo, cyano, oxo, hydroxyl, C1-C4 alkyl, C1-C4 haloalkyl, —O—(C1-C4—O—(C1-C4 haloalkyl), —C(O)—(C1-C4 alkyl), —C(O)—O—(C1-C4—S(O)p—(C1-C4 alkyl), —O-phenyl, —(C1-C4 alkyl)-phenyl, and morpholin-4-yl;
• R4 is chosen from hydrogen, C1-C4 alkyl, C2-C4 alkenyl, C2-C4 alkynyl, C3-C6 cycloalkyl, —C(O)—(C1-C4 alkyl), halo, and cyano, wherein:
• any said alkyl portion of R4 is optionally substituted with hydroxyl;
• each R8 is independently chosen from hydrogen and C1-C4 alkyl, or two R8 together with the nitrogen atom to which they are joined form a heterocyclyl;
• each R9 is independently chosen from hydrogen, C1-C4 alkyl, and hydroxyl;
• n is 0, 1, 2, 3, 4, 5, or 6;
• and
• p is 0, 1, or 2.