Transforming Growth Factor Modulators

A compound of formula I

• wherein:
• R1 is aryl or heteroaryl, and is optionally substituted with 1 to 3 Ra;
• R2 is aryl or heteroaryl, and is optionally substituted with 1 to 3 Rb;
• Ring A is a 5- to 8-membered cycloaliphatic, or a 5- to 8-membered heterocycloaliphatic containing one to three heteroatoms;
• Ring B is a 5- to 8-membered heterocycloaliphatic containing one to three heteroatoms;
• each of Ra and Rb is independently an aliphatic, alkoxy, acyl, halo, hydroxy, amino, amido, nitro, cyano, guanadino, amidino, carboxy, sulfo, sulfinyl, sulfonyl, sunfanyl, alkoxycarbonyl, alkylcarbonyloxy, urea, thiourea, sulfamoyl, sulfamide, carbamoyl, cycloalkyl, cycloalkyloxy, heterocycloalkyl, heterocycloalkyloxy, aryl, aryloxy, aroyl, heteroaryl, heteroaryloxy, heteroaroyl, oxo, thioxo, ═N—ORf, —N3, or ═N—N(Rf)2;
• or
• any two of Ra or any two of Rb on adjacent atoms, together with the atoms to which they are attached, may form a 3- to 8-membered cycloaliphatic or a 3- to 8-membered heterocycloaliphatic;
• each of R3 and R4, if present, is independently an aliphatic, acyl, alkoxy, cycloalkyloxy, heterocycloalkyloxy, aryloxy, heteroaryloxy, aralkyloxy, heteroarylalkoxy, amino, amido, nitro, carboxy, cyano, halo, hydroxyl, sulfanyl, sulfinyl, sulfonyl, urea, thiourea, sulfamoyl, sulfamide, oxo, thioxo, —N3, ═N—ORf, or ═N—N(Rf)2;
• or
• any two of R3 or any two of R4 on the same atom, together with the atom to which they are attached, may form a 3- to 8-membered cycloaliphatic or heterocycloaliphatic ring, or
• any two of R3 or any two of R4 on adjacent atoms, together with the atoms to which they are attached, may form a 3- to 8-membered cycloaliphatic or a 3- to 8-membered heterocycloaliphatic ring;
• each of the optional heteroatoms of Rings A and B is independently O, S, or N, and the S and N atoms in Rings A and B may be part of the groups —S(O)m— and —N(Rf)—;
• each Rf is independently H, alkyl, heteroaryl, aryl, acyl, aroyl, heteroaroyl, amido, sulfamoyl, sulfamide, or carboxy;
• X1 is C and X2 is N, or X1 is N and X2 is C;
• each i is independently an integer from 0 to 3;
• each j is independently an integer from 0 to 3;
• and
• each m is independently an integer from 0 to 2.