Dimethylsulfoximine derivative

A compound represented by formula (II) or a pharmaceutically acceptable salt thereof,

• wherein, X is selected from O and NRb;
• R1 and R4 are each independently selected from H, C1-3 alkyl, phenyl and 5- to 6-membered heteroaryl, and the C1-3 alkyl, phenyl and 5- to 6-membered heteroaryl are optionally substituted with 1, 2 or 3 Ra;
• R2 and R3 are each independently selected from H, NH2, halogen and C1-3 alkyl;
• or R1 and R2 together with the carbon atoms to which they are attached form C4-5 cycloalkyl or C4-5 cycloalkenyl;
• or R3 and R4 together with the carbon atoms to which they are attached form C4-5 cycloalkyl or C4-5 cycloalkenyl;
• R5 is selected from H, F, Cl, D and CN;
• Ra is each independently selected from H, C1-3 alkoxy and CN;
• Rb is selected from H, CN and C1-3 alkyl;
• ring A is selected from 5-membered heteroaryl;
• the 5- to 6-membered heteroaryl and 5-membered heteroaryl contain 1, 2, 3 or 4 heteroatoms or heteroatom groups independently selected from —NH—, —O—, —S— and N.