SSAO inhibitor

1. A compound of a formula (IV) or a pharmaceutically acceptable salt thereof,

wherein,

one of R 4 and R 5 is H, and the other is selected from the group consisting of F, Cl, Br and I;

the ring A is 5-9 membered heteroaryl optionally substituted by a R group;

R 1 is selected from the group consisting of H, halogen, OH, NH 2 , CN, COOH, and —C(═O)NH 2 ; or is selected from the group consisting of C 1-6 alkyl, C 1-6 heteroalkyl, C 3-6 cycloalkyl, 5-6 membered heterocycloalkyl, phenyl and 5-6 membered heteroaryl, wherein each is optionally substituted by one, two or three R groups;

L 1 is selected from the group consisting of a single bond, —(CRR) 1-3 —,

 and —NH—;

n is selected from 0, 1, 2 or 3;

R is selected from the group consisting of H, F, Cl, Br, I, OH, NH 2 , and C(═O)NH 2 ; or is selected from the group consisting of C 1-6 alkyl, C 1-6 heteroalkyl, C 3-6 cycloalkyl and C 3-6 cycloalkyl-NH—, wherein each is optionally substituted by one, two or three R′ groups;

R′ is selected from the group consisting of H, F, Cl, Br, I, OH, CN, NH 2 , COOH, Me, Et, CF 3 , CHF 2 , CH 2 F, NHCH 3 and N(CH 3 ) 2 ;

the “hetero” of the 5-9 membered heteroaryl, C 1-6 heteroalkyl, 5-6 membered heterocycloalkyl and 5-6 membered heteroaryl represents a heteroatom or a heteroatom group, and is selected from the group consisting of —C(═O)NH—, —NH—, —C(═NH)—, —S(═O) 2 NH—, —S(═O)NH—, —O—, —S—, N, ═O, ═S, —C(═O)O—, —C(═O)—, —S(═O)— and —S(═O) 2 —; and

in any one of the above cases, the number of the heteroatom or the heteroatom group is independently selected from 1, 2 or 3.

2. The compound or the pharmaceutically acceptable salt thereof according to claim 1 , selected from

wherein,

n is selected from 0, 1, 2 or 3;

m is selected from 0 or 1;

T 1 is selected from N or CH;

T 2 is selected from N or CH;

T 3 is selected from N or CH;

D is selected from 0, S or NH;

R 1 is selected from the group consisting of H, halogen, OH, NH 2 , CN, COOH, and —C(═O)NH 2 ; or is selected from the group consisting of C 1-6 alkyl, C 1-6 heteroalkyl, C 3-6 cycloalkyl, 5-6 membered heterocycloalkyl and phenyl, wherein each is optionally substituted by one, two or three R groups;

L 1 is selected from the group consisting of a single bond, —(CRR) 1-3 —,

 and —NH—;

one of R 4 and R 5 is selected from H, and the other is selected from F, Cl, Br and I;

R is selected from the group consisting of H, F, Cl, Br, I, OH, NH 2 , and C(═O)NH 2 ; or is selected from the group consisting of C 1-6 alkyl, C 1-6 heteroalkyl, C 3-6 cycloalkyl and C 3-6 cycloalkyl-NH—, wherein each is optionally substituted by one, two or three R′ groups;

R′ is selected from the group consisting of H, F, Cl, Br, I, OH, CN, NH 2 , COOH, Me, Et, CF 3 , CHF 2 , CH 2 F, NHCH 3 and N(CH 3 ) 2 ;

the “hetero” of the 5-9 membered heteroaryl, 5-10 membered heterocycloalkyl, C 1-6 heteroalkyl, 5-6 membered heterocycloalkyl and 5-6 membered heteroaryl represents a heteroatom or a heteroatom group, and is selected from the group consisting of —C(═O)NH—, —NH—, —C(═NH)—, —S(═O) 2 NH—, —S(═O)NH—, —O—, —S—, N, ═O, ═S, —C(═O)O—, —C(═O)—, —S(═O)— and —S(═O) 2 —; and

in any one of the above cases, the number of the heteroatom or the heteroatom group is independently selected from 1, 2 or 3.

3. The compound or the pharmaceutically acceptable salt thereof according to claim 1 , wherein R is selected from the group consisting of H, F, Cl, Br, I, OH, NH 2 , and C(═O)NH 2 ; or is selected from the group consisting of Me, Et,

wherein each is optionally substituted by one, two or three R′ groups.

4. The compound or the pharmaceutically acceptable salt thereof according to claim 3 , wherein R is selected from the group consisting of H, F, Cl, Br, I, OH, NH 2 , Me, Et, CF 3 , C(═O)NH 2 ,

5. The compound or the pharmaceutically acceptable salt thereof according to any one of claim 1 , wherein the ring A is selected from the group consisting of 1,3,4-oxadiazolyl, 1,2,4-oxadiazolyl, 1H-1,2,4-triazolyl, thiazolyl, isothiazolyl, 1,2,4-thiadiazolyl, oxazolyl, isoxazolyl, 1H-tetrazyl, pyridyl, pyrimidinyl, pyridazinyl, indolyl, benzoxazolyl, benzisoxazolyl, 4,5,6,7-tetrahydro-1H-benzimidazolyl, 2H-1,2,3-triazolyl, benzo[d]thiazolyl, 2H-benzo[d]imidazolyl, indoline-2,3-diketo, 4,5-dihydro-1H-imidazolyl and 1,3-dihydro-1H-pyrrole, wherein each is optionally substituted by a R group.

6. The compound or the pharmaceutically acceptable salt thereof according to claim 5 , wherein the ring A is selected from the group consisting of

wherein each is optionally substituted by a R group.

7. The compound or the pharmaceutically acceptable salt thereof according to claim 6 , wherein the ring A is selected from the group consisting of

8. The compound or the pharmaceutically acceptable salt thereof according to claim 2 , wherein the structural unit

is selected from

9. The compound or the pharmaceutically acceptable salt thereof according to claim 8 , wherein the structural unit

is selected from

10. The compound or the pharmaceutically acceptable salt thereof according to claim 1 , wherein R 1 is selected from the group consisting of H, halogen, OH, NH 2 , CN, COOH, and —C(═O)NH 2 ; or is selected from the group consisting of C 1-3 alkyl, C 1-3 heteroalkyl, phenyl, cyclopropyl, cyclopentyl, cyclohexyl, morpholinyl, cyclobutyl and tetrahydro-2H-pyranyl, wherein each is optionally substituted by one, two or three R groups.

11. The compound or the pharmaceutically acceptable salt thereof according to claim 10 , wherein R 1 is selected from the group consisting of H, F, Cl, Br, I, OH, NH 2 , CN, COOH, —C(═O)NH 2 , Me, CF 3 , Et,

12. The compound or the pharmaceutically acceptable salt thereof according to claim 1 , wherein L 1 is selected from the group consisting of a single bond, —CH 2 —, —CH 2 CH 2 —,

and —NH—.

13. The compound or the pharmaceutically acceptable salt thereof according to claim 11 , wherein the structural unit

is selected from the group consisting of H, NH 2 , COOH, —C(═O)NH 2 , Me, CF 3 , Et,

14. The compound or the pharmaceutically acceptable salt thereof according to claim 13 , wherein the structural unit

is selected from the group consisting of

15. The compound or the pharmaceutically acceptable salt thereof according to claim 9 , wherein the structural unit

is selected from the group consisting of

16. The compound or the pharmaceutically acceptable salt thereof according to claim 1 , selected from

wherein,

R 1 , L 1 and R are defined as in claim 1 .

17. The compound of the following formula or a pharmaceutically acceptable salt thereof according to claim 1 , selected from

18. The compound or the pharmaceutically acceptable salt thereof according to claim 17 , selected from

19. The compound or the pharmaceutically acceptable salt thereof according to claim 13 , wherein the structural unit

is selected from the group consisting of