Pyrazole compounds useful as protein kinase inhibitors

A compound of formula VIII:

• or a pharmaceutically acceptable salt thereof, wherein:
• Z1 is N or C—R9, Z2 is N or CH, and Z3 is N or C—Rx, provided that one of Z1 and Z3 is nitrogen;
• G is Ring C or Ring D;
• Ring C is selected from a phenyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, or 1,2,4-triazinyl ring, wherein said Ring C has one or two ortho substituents independently selected from —R1, any non-ortho carbon position on Ring C is optionally and independently substituted by —R5, and two adjacent substituents on Ring C are optionally taken together with their intervening atoms to form a fused, unsaturated or partially unsaturated, 5-6 membered ring having 0-3 heteroatoms selected from oxygen, sulfur or nitrogen, said fused ring being optionally substituted by halo, oxo, or —R8;
• Ring D is a 5-7 membered monocyclic ring or 8-10 membered bicyclic ring selected from aryl, heteroaryl, heterocyclyl or carbocyclyl, said heteroaryl or heterocyclyl ring having 1-4 ring heteroatoms selected from nitrogen, oxygen or sulfur, wherein Ring D is substituted at any substitutable ring carbon by halo, oxo, or —R5, and at any substitutable ring nitrogen by —R4, provided that when Ring D is a six-membered aryl or heteroaryl ring, —R5 is hydrogen at each ortho carbon position of Ring D;
• R1 is selected from —halo, —CN, —NO2, T—V—R6, phenyl, 5-6 membered heteroaryl ring, 5-6 membered heterocyclyl ring, or C1-6 aliphatic group, said phenyl, heteroaryl, and heterocyclyl rings each optionally substituted by up to three groups independently selected from halo, oxo, or —R8, said C1-6 aliphatic group optionally substituted with halo, cyano, nitro, or oxygen, or R1 and an adjacent substituent taken together with their intervening atoms form said ring fused to Ring C;
• Rx is T—R3;
• T is a valence bond or a C1-4 alkylidene chain;
• R2 and R2′ are independently selected from —R, —T—W—R6, or R2 and R2′ are taken together with their intervening atoms to form a fused, 5-8 membered, unsaturated or partially unsaturated, ring having 0-3 ring heteroatoms selected from nitrogen, oxygen, or sulfur, wherein each substitutable carbon on said fused ring formed by R2 and R2′ is substituted by halo, oxo, —CN, —NO2, —R7, or —V—R6, and any substitutable nitrogen on said ring formed by R2 and R2′ is substituted by R4;
• R3 is selected from —R, —halo, —OR, —C(═O)R, —CO2R, —COCOR, —COCH2COR, —NO2, —CN, —S(O)R, —S(O)2R, —SR, —N(R4)2, —CON(R7)2, —SO2N(R7)2, —OC(═O)R, —N(R7)COR, —N(R7)CO2(optionally substituted C1-6 aliphatic), —N(R4)N(R4)2, —C═NN(R4)2, —C═N—OR, —N(R7)CON(R7)2, —N(R7)SO2N(R7)2, —N(R4)SO2R, or —OC(═O)N(R7)2;
• each R is independently selected from hydrogen or an optionally substituted group selected from C1-6 aliphatic, C6-10 aryl, a heteroaryl ring having 5-10 ring atoms, or a heterocyclyl ring having 5-10 ring atoms;
• each R4 is independently selected from —R7, —COR7, —CO2(optionally substituted C1-6 aliphatic), —CON(R7)2, or —SO2R7, or two R4 on the same nitrogen are taken together to form a 5-8 membered heterocyclyl or heteroaryl ring;
• each R5 is independently selected from —R, halo, —OR, —C(═O)R, —CO2R, —COCOR, —NO2, —CN, —S(O)R, —SO2R, —SR, —N(R4)2, —CON(R4)2, —SO2N(R4)2, —OC(═O)R, —N(R4)COR, —N(R4)CO2(optionally substituted C1-6 aliphatic), —N(R4)N(R4)2, —C═NN(R4)2, —C═N—OR, —N(R4)CON(R4)2, —N(R4)SO2N(R4)2, —N(R4)SO2R, or —OC(═O)N(R4)2, or R5 and an adjacent substituent taken together with their intervening atoms form said ring fused to Ring C;
• V is —O—, —S—, —SO—, —SO2—, —N(R6)SO2—, —SO2N(R6)—, —N(R6)—, —CO—, —CO2—, —N(R6)CO—, —N(R6)C(O)O—, —N(R6)CON(R6)—, —N(R6)SO2N(R6)—, —N(R6)N(R6)—, —C(O)N(R6)—, —OC(O)N(R6)—, —C(R6)2O—, —C(R6)2S—, —C(R6)2SO—, —C(R6)2SO2—, —C(R6)2SO2N(R6)—, —C(R6)2N(R6)—, —C(R6)2N(R6)C(O)—, —C(R6)2N(R6)C(O)O—, —C(R6)═NN(R6)—, —C(R6)═N—O—, —C(R6)2N(R6)N(R6)—, —C(R6)2N(R6)SO2N(R6)—, or —C(R6)2N(R6)CON(R6)—;
• W is —C(R6)2O—, —C(R6)2S—, —C(R6)2SO—, —C(R6)2SO2—, —C(R6)2SO2N(R6)—, —C(R6)2N(R6)—, —CO—, —CO2—, —C(R6)OC(O)—, —C(R6)OC(O)N(R6)—, —C(R6)2N(R6)CO—, —C(R6)2N(R6)C(O)O—, —C(R6)═NN(R6)—, —C(R6)═N—O—, —C(R6)2N(R6)N(R6)—, —C(R6)2N(R6)SO2N(R6)—, —C(R6)2N(R6)CON(R6)—, or —CON(R6)—;
• each R6 is independently selected from hydrogen, an optionally substituted C1-4 aliphatic group, or two R6 groups on the same nitrogen atom are taken together with the nitrogen atom to form a 5-6 membered heterocyclyl or heteroaryl ring;
• each R7 is independently selected from hydrogen or an optionally substituted C1-6 aliphatic group, or two R7 on the same nitrogen are taken together with the nitrogen to form a 5-8 membered heterocyclyl or heteroaryl ring;
• each R8 is independently selected from an optionally substituted C1-4 aliphatic group, —OR6, —SR6, —COR6, —SO2R6, —N(R6)2, —N(R6)N(R6)2, —CN, —NO2, —CON(R6)2, or —CO2R6;
• and
• R9 is selected from —R, halo, —OR, —C(═O)R, —CO2R, —COCOR, —NO2, —CN, —S(O)R, —SO2R, —SR, —N(R4)2, —CON(R4)2, —SO2N(R4)2, —OC(═O)R, —N(R4)COR, —N(R4)CO2(optionally substituted C1-6 aliphatic), —N(R4)N(R4)2, —C═NN(R4)2, —C═N—OR, —N(R4)CON(R4)2, —N(R4)SO2N(R4)2, —N(R4)SO2R, or —OC(═O)N(R4)2.