Fused heterocyclic compound

1. A compound represented by the formula (I), or a salt thereof:

wherein

R 1 represents a substituent or a hydrogen atom;

R 2 represents an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group;

R 6 and R 7 each independently represent a hydrogen atom, a halogen atom or an optionally substituted hydrocarbon group; and

ring A represents a bicyclic aromatic heterocycle selected from the following formulas (1), (2), (3), (4) and (5):

wherein Xs each independently represent N or C(R 5 ); and

R 3 , R 4 and R 5 each independently represent a hydrogen atom or a substituent.

2. The compound or salt thereof according to claim 1 , wherein

R 2 is

(I) a C 1-6 alkyl group optionally having 1 to 3 five- or six-membered monocyclic aromatic heterocyclic groups optionally having 1 to 3 optionally halogenated C 1-6 alkyl groups; or

(II) an optionally halogenated C 7-16 aralkyl group.

3. The compound or salt thereof according to claim 1 , wherein

ring A is a bicyclic aromatic heterocycle represented by the following formula (1)

4. The compound or salt thereof according to claim 1 , wherein

R 3 is a hydrogen atom;

R 4 is (a) an amino group optionally monosubstituted or disubstituted with a C 1-6 alkyl group, or

(b) a C 1-6 alkoxy group; and

R 5 is (a) a C 1-6 alkoxy group, or

(b) a C 1-6 alkyl group optionally having 1 to 3 hydroxy groups.

5. The compound or salt thereof according to claim 1 , wherein

R 1 is

(I) a C 1-6 alkyl group optionally having 1 to 5 substituents each selected from the group consisting of:

(a) a halogen atom,

(b) a hydroxy group,

(c) a cyano group,

(d) a C 1-6 alkoxy group optionally having 1 to 3 substituents each selected from the group consisting of:

(i) a halogen atom, and

(ii) a hydroxy group, and

(e) a three- to eight-membered nonaromatic heterocyclic group optionally having 1 to 3 halogen atoms;

(II) a three- to eight-membered nonaromatic heterocyclic group optionally having 1 to 5 substituents each selected from the group consisting of:

(a) a C 1-6 alkoxy group,

(b) a halogen atom, and

(c) a hydroxy group;

(III) a five- to fourteen-membered aromatic heterocyclic group optionally having 1 to 3 optionally halogenated C 1-6 alkyl groups;

(IV) a C 1-6 alkoxy group optionally having 1 to 5 substituents each selected from the group consisting of:

(a) a hydroxy group,

(b) a three- to eight-membered nonaromatic heterocyclic group, and

(c) a five- or six-membered monocyclic aromatic heterocyclic group optionally having 1 to 3 optionally halogenated C 1-6 alkyl groups;

(V) an optionally halogenated C 3-10 cycloalkyl group; or

(VI) an amino group optionally monosubstituted or disubstituted with a C 1-6 alkyl group optionally having 1 to 5 substituents each selected from the group consisting of:

(a) a halogen atom,

(b) a hydroxy group, and

(c) a C 1-6 alkoxy group;

R 2 is

(I) a C 1-6 alkyl group optionally having 1 to 3 five- to fourteen-membered aromatic heterocyclic groups optionally having 1 to 3 substituents each selected from the group consisting of:

(a) a halogen atom,

(b) a C 1-6 alkyl group optionally having 1 to 7 substituents each selected from the group consisting of:

(i) a halogen atom,

(ii) a hydroxy group, and

(iii) a C 1-6 alkoxy group,

(c) an optionally halogenated C 3-10 cycloalkyl group,

(d) a C 1-6 alkoxy group,

(e) a C 1-6 alkyl group-C 3-10 cycloalkyl group,

(f) a C 1-6 alkyl group-three- to eight-membered monocyclic nonaromatic heterocyclic group, and

(g) an oxo group; or

(II) a C 7-16 aralkyl group optionally having 1 to 3 substituents each selected from the group consisting of:

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

(i) a halogen atom, and

(ii) a hydroxy group,

(b) a C 1-6 alkoxy-carbonyl group,

(c) a halogen atom,

(d) a C 1-6 alkoxy group optionally having 1 to 3 substituents each selected from the group consisting of:

(i) a halogen atom, and

(ii) a hydroxy group,

(e) a mono- or di-C 1-6 alkyl-carbamoyl group,

(f) a cyano group,

(g) an amino group optionally monosubstituted or disubstituted with a substituent selected from the group consisting of:

(i) a C 1-6 alkyl group, and

(ii) a C 1-6 alkoxy-carbonyl group,

(h) a nitro group, and

(i) a carboxy group;

each of R 6 and R 7 is a hydrogen atom;

ring A is a bicyclic aromatic heterocycle selected from the formulae (1), (2), (3) and (4);

Xs each independently represent C(R 5 ) or N;

R 3 is a hydrogen atom;

R 4 is

(I) a hydrogen atom,

(II) a halogen atom,

(III) an optionally halogenated C 1-6 alkoxy group, or

(IV) an amino group optionally monosubstituted or disubstituted with a C 1-6 alkyl group; and

R 5 is

(I) a hydrogen atom,

(II) a halogen atom,

(III) a cyano group,

(IV) a C 1-6 alkyl group optionally having 1 to 5 substituents each selected from the group consisting of:

(a) a halogen atom,

(b) a C 1-6 alkoxy group,

(c) a C 1-6 alkoxy-C 1-6 alkoxy group,

(d) a hydroxy group, and

(e) a C 1-6 alkyl-carbonyloxy group,

(V) a C 1-6 alkoxy group,

(VI) a C 2-6 alkenyl group optionally having 1 to 3 C 1-6 alkoxy groups,

(VII) a C 2-6 alkynyl group,

(VIII) a cyano-C 6-14 aryl group,

(IX) a five- to fourteen-membered aromatic heterocyclic group optionally having 1 or 2 C 1-6 alkyl groups optionally having 1 to 3 substituents each selected from the group consisting of:

(a) a halogen atom,

(b) a five- or six-membered monocyclic aromatic heterocyclic group, and

(c) a three- to eight-membered monocyclic nonaromatic heterocyclic group,

(X) a C 1-6 alkyl-carbonyl group,

(XI) a hydroxy group,

(XII) a C 1-6 alkyl-five- to fourteen-membered aromatic heterocyclic oxy group,

(XIII) a three- to eight-membered monocyclic nonaromatic heterocyclic group optionally having 1 to 3 substituents each selected from the group consisting of:

(a) a halogen atom,

(b) a C 1-6 alkoxy group, and

(c) an oxo group, or

(XIV) an amino group optionally monosubstituted or disubstituted with an optionally halogenated C 1-6 alkyl.

6. 6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1-((3-methyl-1,2,4-thiadiazol-5-yl)methyl)-1H-imidazo[4,5-b]pyridine, or a salt thereof.

7. 1-((5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)methyl)-6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1H-imidazo[4,5-b]pyridine, or a salt thereof.

8. 1-((5-(1,1-difluoroethyl)-1,3,4-oxadiazol-2-yl)methyl)-6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1H-imidazo[4,5-b]pyridine, or a salt thereof.

9. 1-((5-((1R)-1-fluoroethyl)-1,3,4-oxadiazol-2-yl)methyl)-6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1H-imidazo[4,5-b]pyridine, or a salt thereof.

10. A medicament comprising the compound or salt thereof according to claim 1 and a pharmacologically acceptable carrier.

11. A medicament comprising a pharmacologically acceptable carrier and at least one compound or salt selected from the group consisting of:

6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1-((3-methyl-1,2,4-thiadiazol-5-yl)methyl)-1H-imidazo[4,5-b]pyridine or a salt thereof,

1-((5-(difluoromethyl)-1,3,4-oxadiazol-2-yl)methyl)-6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1H-imidazo[4,5-b]pyridine or a salt thereof,

1-((5-(1,1-difluoroethyl)-1,3,4-oxadiazol-2-yl)methyl)-6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1H-imidazo[4,5-b]pyridine or a salt thereof, and

1-((5-((1R)-1-fluoroethyl)-1,3,4-oxadiazol-2-yl)methyl)-6-(4-methoxypyrrolo[2,1-f][1,2,4]triazin-5-yl)-2-methyl-1H-imidazo[4,5-b]pyridine or a salt thereof.