A compound of formula (I) ** Formula ** or a pharmaceutically acceptable salt thereof, wherein X is NH2； R1, R2, R3 are independently selected from the group consisting of H； halogen； CN； C (O) OR4； OR4； C (O) R4； C (O) N (R4R4a)； S (O) 2N (R4R4a)； S (O) N (RaR4a)； S (O) 2R4； S (O) R4； N (R4) S (O) 2N (R4aR4b)； N (R4) S (O) N (R4aR4b)； SR4； N (R4R4a)； OC (O) R4； N (R4) C (O) R4a； N (R4) S (O) 2R4a； N (R4) S (O) R4a； N (R4) C (O) N (R4aR4b)； N (R4) C (O) OR4a； OC (O) N (R4R4a) and C1-6 alkyl, wherein C1-6 alkyl is optionally substituted with one or more halogens, which are the same or different； R4, R4a, R4b are independently selected from the group consisting of H and C1-6 alkyl, in which C1-6 alkyl is optionally substituted with one or more halogens, which are the same or different； T1 is 4-7 membered heterocyclyl； 9-11 member heterobicyclyl； phenyl； naphthyl； indenyl or indanyl； wherein T1 is optionally substituted with one or more R5 and / or one or more R6； R5 is halogen； CN； C (O) OR7； OR7； oxo (>； = O), in which the ring is at least partially saturated； C (O) R7； C (O) N (R7R7a)； S (O) 2N (R7R7a)； S (O) N (R7R7a)； S (O) 2R7； S (O) R7； N (R7) S (O) 2N (R7aR7b)； N (R7) S (O) N (R7aR7b)； SR7； N (R7R7a)； OC (O) R7； N (R7) C (O) R7； N (R7) S (O) 2R7a； N (R7) S (O) R7a； N (R7) C (O) N (R7aR7b)； N (R7) C (O) OR7a； OC (O) N (R7R7a)； or C1-6 alkyl, wherein C1-6 alkyl is optionally substituted with one or more R8； R6 is T2； C (O) OR9； OR9； C (O) R9； C (O) N (R9R9a)； S (O) 2N (R9R9a)； S (O) N (R9R9a)； S (O) 2R9； S (O) R9； N (R9) S (O) 2N (R9aR9b)； N (R9) S (O) N (R9aR9b)； SR9； N (R9R9a)； OC (O) R9； N (R9) C (O) R9a； N (R9) S (O) 2R9a； N (R9) S (O) R9a； N (R9) C (O) N (R9aR9b)； N (R9) C (O) OR9a； OC (O) N (R9R9a) or C1-6 alkyl substituted with one or more T2 and optionally substituted with one or more R8； R9, R9a, R9b are independently selected from the group consisting of R9c and R9d, with the proviso that at least one of R9, R9a, R9b is R9c； R9c is T2 or C1-6 alkyl, w
