Azaindoles useful as inhibitors of Janus kinases

A compound of formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• R3 is Cl or F;
• X1 is CR4;
• R2 is H, F, R′, OH, OR′, COR′, COOH, COOR′, CONH2, CONHR′, CON(R′)2, or CN;
• R4 is H, F, R′, OH, OR′, COR′, COOH, COOR′, CONH2, CONHR′, CON(R′)2, or CN;
• or R2 and R4, taken together, form a 5-7-membered aryl or heteroaryl ring optionally substituted with 1-4 occurrences of R10;
• R′ is a C1-3 aliphatic optionally substituted with 1-4 occurrences of R5;
• each R5 is independently selected from halogen, CF3, OCH3, OH, SH, NO2, NH2, SCH3, NCH3, CN or unsubstituted C1-2 aliphatic, or two R5 groups, together with the carbon to which they are attached, form a cyclopropyl ring or C═O;
• each R10 is independently selected from halogen, OCH3, OH, NO2, NH2, SH, SCH3, NCH3, CN or unsubstituted C1-2aliphatic;
• R1 is
• R″ is H or is a —C1-2 aliphatic optionally substituted with 1-3 occurrences of R11;
• each R11 is independently selected from halogen, OCH3, OH, SH, NO2, NH2, SCH3, NCH3, CN, CON(R15)2 or unsubstituted C1-2 aliphatic, or two R11 groups, together with the carbon to which they are attached, form a cyclopropyl ring or C═O;
• R6 is a C1-4 aliphatic optionally substituted with 1-5 occurrences of R12;
• each R12 is independently selected from halogen, OCH3, OH, NO2, NH2, SH, SCH3, NCH3, CN or unsubstituted C1-2aliphatic, or two R12 groups, together with the carbon to which they are attached, form a cyclopropyl ring;
• Ring A is a 4-8 membered saturated nitrogen-containing ring comprising up to two additional heteroatoms selected from N, O or S and optionally substituted with 1-4 occurrences of R13;
• each R13 is independently selected from halogen, R′, NH2, NHR′, N(R′)2, SH, SR′, OH, OR′, NO2, CN, CF3, COOR′, COOH, COR′, OC(O)R′ or NHC(O)R′;
• or any two R13 groups, on the same substituent or different substituents, together with the atom(s) to which each R13 group is bound, form a 3-7 membered saturated, unsaturated, or partially saturated carbocyclic or heterocyclic ring optionally substituted with 1-3 occurrences of R5;
• R8 is C1-4 aliphatic optionally substituted with 1-5 occurrences of R12;
• R9 is C1-2 alkyl;
• or
• R8 and R9 are taken together to form a 3-7 membered carbocyclic or heterocyclic saturated ring optionally substituted with 1-5 occurrences of R12;
• R14 is H or unsubstituted C1-2 alkyl;
• R15 is H or unsubstituted C1-2 alkyl;
• and
• R7 is a C2-3 aliphatic or cycloaliphatic optionally substituted with up to 6 occurrences of F.