Tyk2 inhibitor compound containing bicyclic ring

A compound of formula I or a pharmaceutically acceptable salt thereof:

• wherein,
• X is selected from the group consisting of N and CH;
• each R1 is independently selected from halogen;
• q is selected from the group consisting of 0, 1, and 2;
• each R2 is independently selected from the group consisting of halogen, hydroxy, amino, cyano, and nitro;
• n is selected from the group consisting of 0, 1, and 2;
• T1, T2, T3, T4, and T5 are each independently selected from the group consisting of CH and N, at least one of which is selected from CH;
• ring A is selected from C3-10 cycloalkyl, 3- to 10-membered heterocyclyl, C6-10 aryl, and 5- to 10-membered heteroaryl;
• each R3 is independently selected from the group consisting of ═O, halogen, hydroxy, amino, cyano, nitro, C1-8 alkyl, C3-10 cycloalkyl, 3- to 10-membered heterocycloalkyl, 5- to 10-membered heteroaryl, C6-10 aryl, and C1-8 alkoxy, wherein the C1-8 alkyl, C3-10 cycloalkyl, 3- to 10-membered heterocycloalkyl, 5- to 10-membered heteroaryl, C6-10 aryl, or C1-8 alkoxy is optionally substituted with one or more Ra;
• m is selected from the group consisting of 0, 1, 2, 3, and 4;
• each Ra is independently selected from the group consisting of halogen, hydroxy, amino, and cyano.