Fused ring compound and use thereof

1. A compound represented by the formula (I):

wherein ring A is a 6-membered ring which is optionally further substituted;

ring B is an optionally substituted 5- to 7-membered non-aromatic nitrogen-containing heterocycle;

W 1 is O, S, SO, SO 2 , an optionally substituted C 1-6 alkylene group or NR 4 wherein R 4 is a hydrogen atom or a C 1-6 alkyl group;

R 1 is an optionally substituted C 6-14 aryl group or an optionally substituted heterocyclic group;

R 3 is a hydrogen atom or a halogen atom;

(1) when W 2 is O, S, SO or SO 2 , R 2 is an optionally substituted heterocyclic group; and

(2) when W 2 is a bond, R 2 is a hydrogen atom, a halogen atom, an optionally substituted C 1-6 alkyl group, an optionally substituted C 3-10 cycloalkyl group or an optionally substituted heterocyclic group,

or a salt thereof.

2. The compound or salt according to claim 1 , wherein W 2 is O, S, SO or SO 2 .

3. The compound or salt according to claim 1 , wherein ring A is a benzene ring.

4. The compound or salt according to claim 1 , wherein R 3 is a hydrogen atom.

5. The compound or salt according to claim 1 , wherein ring B is a thiazoline ring optionally substituted by a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from the group consisting of:

(1) a hydroxy group,

(2) a carbamoyl group optionally mono- or di-substituted by C 1-6 alkyl group(s) optionally substituted by 1 to 3 substituents selected from the group consisting of:

(i) a hydroxy group,

(ii) a halogen atom,

(iii) a C 1-6 alkoxy group,

(iv) a C 1-6 alkylsulfonyl group, and

(v) a cyano group,

(3) a carboxy group, and

(4) a C 1-6 alkoxy-carbonyl group.

6. The compound or salt according to claim 1 , wherein W 1 is O.

7. The compound or salt according to claim 1 , wherein R 1 is a phenyl group or a pyridyl group each optionally substituted by 1 to 3 substituents selected from the group consisting of:

(1) a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from the group consisting of:

(i) a C 1-6 alkoxy group optionally substituted by a C 1-6 alkoxy group, and

(ii) a C 1-6 alkylsulfonyl group, and

(2) a C 1-6 alkylsulfonyl group.

8. The compound or salt according to claim 1 , wherein W 2 is O, and R 2 is a tetrahydropyranyl group.

9. The compound or salt according to claim 1 , wherein W 2 is a bond, and R 2 is a hydrogen atom or a C 1-6 alkyl group.

10. The compound or salt according to claim 1 , wherein

ring A is a benzene ring;

ring B is a thiazoline ring optionally substituted by a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from the group consisting of:

(1) a hydroxy group,

(2) a carbamoyl group optionally mono- or di-substituted by C 1-6 alkyl group(s) optionally substituted by 1 to 3 substituents selected from the group consisting of:

(i) a hydroxy group,

(ii) a halogen atom,

(iii) a C 1-6 alkoxy group,

(iv) a C 1-6 alkylsulfonyl group, and

(v) a cyano group,

(3) a carboxy group, and

(4) a C 1-6 alkoxy-carbonyl group;

W 1 is O;

R 1 is a phenyl group or a pyridyl group each optionally substituted by 1 to 3 substituents selected from the group consisting of:

(1) a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from the group consisting of:

(i) a C 1-6 alkoxy group optionally substituted by a C 1-6 alkoxy group, and

(ii) a C 1-6 alkylsulfonyl group, and

(2) a C 1-6 alkylsulfonyl group;

R 3 is a hydrogen atom;

W 2 is O; and

R 2 is a tetrahydropyranyl group.

11. The compound or salt according to claim 1 , wherein

ring A is a benzene ring;

ring B is a thiazoline ring optionally substituted by a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from the group consisting of:

(1) a hydroxy group,

(2) a carbamoyl group optionally mono- or di-substituted by C 1-6 alkyl group(s) optionally substituted by 1 to 3 substituents selected from the group consisting of:

(i) a hydroxy group,

(ii) a halogen atom,

(iii) a C 1-6 alkoxy group,

(iv) a C 1-6 alkylsulfonyl group, and

(v) a cyano group,

(3) a carboxy group, and

(4) a C 1-6 alkoxy-carbonyl group;

W 1 is O;

R 1 is a phenyl group or a pyridyl group each optionally substituted by 1 to 3 substituents selected from the group consisting of:

(1) a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from the group consisting of:

(i) a C 1-6 alkoxy group optionally substituted by a C 1-6 alkoxy group, and

(ii) a C 1-6 alkylsulfonyl group, and

(2) a C 1-6 alkylsulfonyl group;

R 3 is a hydrogen atom;

W 2 is a bond; and

R 2 is a hydrogen atom or a C 1-6 alkyl group.

12. N-M ethyl-2-{2-[5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-7-(tetrahydro-2H-pyran-4-yloxy)-1H-indol-2-yl]-4,5-dihydro-1,3-thiazol-5-yl}acetamide or a salt thereof.

13. N-Methyl-2-[2-(5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-1H-indol-2-yl)-4,5-dihydro-1,3-thiazol-5-yl]acetamide or a salt thereof.

14. N,N-Dimethyl-2-[2-(5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-1H-indol-2-yl)-4,5-dihydro-1,3-thiazol-5-yl]acetamide or a salt thereof.

15. N-(2-Methoxyethyl)-2-[2-(5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-1H-indol-2-yl)-4,5-dihydro-1,3-thiazol-5-yl]acetamide or a salt thereof.

16. 2-[2-(7-Ethyl-5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-1H-indol-2-yl)-4,5-dihydro-1,3-thiazol-5-yl]-N-methylacetamide or a salt thereof.

17. A prodrug of the compound or salt according to claim 1 .

18. A pharmaceutical composition comprising the compound or salt according to claim 1 or a prodrug thereof and a pharmaceutically acceptable carrier.

19. The pharmaceutical composition according to claim 18 , which is a glucokinase activator.

20. The pharmaceutical composition according to claim 18 , which is an agent for the treatment of diabetes or obesity.

21. A method for the treatment of diabetes or obesity in a mammal, comprising administering an effective amount of the compound or salt according to claim 1 or a prodrug thereof to the mammal.