Heterocyclic compound

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

wherein

m and n are each independently 0 or 1,

Ring A is an optionally further substituted cyclic group,

Ring B is an azetidine ring, a pyrrolidine ring or a piperidine ring, each of which is an optionally further substituted,

Ring D is an optionally further substituted 6-membered aromatic ring,

L is —CH 2 —O—CH 2 —, —O—CR 1 R 2 —, —CH(R 1 )—O—, —CF 2 —CH 2 —, —CH 2 —CF 2 — or —CF 2 —,

R 1 and R 2 is each independently a hydrogen atom, or an optionally substituted C 1-6 alkyl group,

X and Y are each independently a carbon atom or a nitrogen atom,

Z is —O—CH 2 —, —NR—CH 2 —, —CH 2 —CH 2 —, —CH═CH—, —CH 2 —, —O—, —S— or —NR—, and

R is a substituent,

provided that

7-((4-(phenoxymethyl)piperidin-1-yl)carbonyl)-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one,

7-((4-((3-methoxyphenoxy)methyl)piperidin-1-yl)carbonyl)-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one, and

7-((4-((2-methoxyphenoxy)methyl)piperidin-1-yl)carbonyl)-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one

are excluded,

or a salt thereof.

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

wherein

m and n are each independently 0 or 1,

Ring A is an optionally further substituted cyclic group,

Ring B is an azetidine ring, a pyrrolidine ring or a piperidine ring, each of which is an optionally further substituted,

Ring D is an optionally further substituted 6-membered aromatic ring,

L is —CH 2 —O—CH 2 — or —O—CH 2 —,

X and Y are each independently a carbon atom or a nitrogen atom,

Z is —O—CH 2 —, —NR—CH 2 —, —CH 2 —CH 2 —, —CH═CH—, —CH 2 —, —O—, —S— or —NR—, and

R is a substituent,

provided that

7((4-(phenoxymethyl)piperidin-1-yl)carbonyl)-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one,

7-((4-((3-methoxyphenoxy)methyl)piperidin-1-yl)carbonyl)-1H-pyrido [2,3-b][1,4]oxazin-2(3H)-one, and

7((44(2-methoxyphenoxy)methyl)piperidin-1-yl)carbonyl)-1H-pyrido [2,3-b][1,4]oxazin-2(3H)-one

are excluded,

or a salt thereof.

3. The compound or salt according to claim 1 , wherein Ring B is an optionally further substituted azetidine ring, or an optionally further substituted piperidine ring.

4. The compound or salt according to claim 1 , wherein Ring B is an optionally further substituted azetidine ring.

5. The compound or salt according to claim 1 , wherein X and Y are both carbon atoms.

6. The compound or salt according to claim 1 , wherein Z is —O—CH 2 — or —O—.

7. The compound or salt according to claim 1 , wherein L is —O—CH 2 — or —CH 2 —O—.

8. The compound or salt according to claim 1 , wherein Ring A is

(1) a C 6-14 aryl group which is optionally further substituted and optionally fused with a C 3-10 cycloalkane,

(2) an optionally further substituted pyridyl group,

(3) an optionally further substituted pyrimidinyl group,

(4) an optionally further substituted imidazopyridyl group,

(5) an optionally further substituted benzothiazolyl group,

(6) an optionally further substituted indazolyl group,

(7) an optionally further substituted pyrazolyl group,

(8) an optionally further substituted benzoxazolyl group,

(9) an optionally further substituted benzisoxazolyl group,

(10) an optionally further substituted quinoxalinyl group,

(11) an optionally further substituted quinolyl group,

(12) an optionally further substituted isoquinolyl group,

(13) an optionally further substituted pyrazolopyridyl group,

(14) an optionally further substituted C 3-10 cycloalkyl group,

(15) an optionally further substituted tetrahydropyranyl group,

(16) an optionally further substituted dihydrobenzofuryl group, or

(17) an optionally further substituted dihydropyranopyridyl group.

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

m and n are each independently 0 or 1;

Ring A is

(1) a C 6-14 aryl group which is optionally fused with a C 3-10 cycloalkane wherein the C 6-14 aryl group is optionally further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

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

(iii) a cyano group,

(iv) a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from

(a) a halogen atom, and

(b) a hydroxy group,

(v) a C 3-10 cycloalkyl group,

(vi) a C 2-6 alkenyl group,

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

(viii) a C 1-6 alkylsulfonyl group,

(ix) a C 6-14 aryl group optionally substituted by 1 to 3 C 1-6 alkoxy groups,

(x) a C 6-14 aryloxy group,

(xi) a 5- to 14-membered aromatic heterocyclic group optionally substituted by 1 to 3 substituents selected from

(a) a halogen atom,

(b) a C 1-6 alkyl group optionally substituted by 1 to 3 halogen atoms, and

(c) a C 3-10 cycloalkyl group, and

(xii) a 3- to 14-membered non-aromatic heterocyclic group optionally substituted by 1 to 3 substituents selected from

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

(b) a halogen atom,

(2) a 5- to 14-membered aromatic heterocyclic group optionally further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

(ii) a C 1-6 alkyl group,

(iii) an amino group,

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

(v) a C 6-14 aryl group optionally substituted by 1 to 3 halogen atoms, and

(vi) a 5- to 14-membered aromatic heterocyclic group optionally substituted by 1 to 3 C 1-6 alkyl groups,

(3) a C 3-10 cycloalkyl group optionally further substituted by 1 to 3 halogen atoms, or

(4) a 3- to 14-membered non-aromatic heterocyclic group optionally further substituted by 1 to 3 C 1-6 alkyl groups;

Ring B is

(1) an azetidine ring optionally further substituted by 1 to 3 substituents selected from

(i) a halogen atom, and

(ii) a C 1-6 alkyl group,

(2) a pyrrolidine ring, or

(3) a piperidine ring optionally further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

(ii) a hydroxy group, and

(iii) a cyano group;

Ring D is

(1) a benzene ring optionally further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

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

(iii) a C 1-6 alkoxy group, or

(2) a pyridine ring optionally further substituted by 1 to 3 C 1-6 alkyl groups;

L is

(1) —CH 2 —O—CH 2 —,

(2) —O—CR 1 R 2 — wherein R 1 and R 2 is each independently

(1) a hydrogen atom, or

(2) a C 1-6 alkyl group optionally substituted by one substituent selected from a hydroxy group and a C 1-6 alkoxy group,

(3) —CH(R 1 )—O— wherein R 1 is a hydrogen atom or a C 1-6 alkyl group,

(4) —CF 2 —CH 2 —, or

(5) —CF 2 —;

X is a carbon atom or a nitrogen atom;

Y is a carbon atom or a nitrogen atom; and

Z is —O—CH 2 —, —CH 2 —CH 2 —, —CH═CH—, —CH 2 — or —O—.

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

m and n are both 0 or both 1;

Ring A is

(1) a phenyl group further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

(ii) a cyano group,

(iii) an optionally halogenated C 1-6 alkyl group,

(iv) a C 2-6 alkenyl group,

(v) a pyridyl group optionally substituted by 1 to 3 substituents selected from

(a) a halogen atom, and

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

(vi) an azetidinyl group optionally substituted by 1 to 3 halogen atoms,

(2) an indanyl group,

(3) a tetrahydronaphthyl group, or

(4) a pyridyl group optionally further substituted by 1 to 3 halogen atoms;

Ring B is

(1) an azetidine ring, or

(2) a piperidine ring optionally further substituted by 1 to 3 hydroxy groups;

Ring D is

(1) a benzene ring optionally further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

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

(iii) a C 1-6 alkoxy group, or

(2) a pyridine ring;

L is —O—CH 2 — or —CH 2 —O—;

X is a carbon atom;

Y is a carbon atom or a nitrogen atom; and

Z is —O—CH 2 — or —O—.

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

m and n are both 0 or both 1;

Ring A is

(1) a phenyl group further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

(ii) a cyano group,

(iii) an optionally halogenated C 1-6 alkyl group,

(iv) a pyridyl group optionally substituted by 1 to 3 substituents selected from

(a) a halogen atom, and

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

(v) an azetidinyl group optionally substituted by 1 to 3 halogen atoms,

(2) a tetrahydronaphthyl group, or

(3) a pyridyl group optionally further substituted by 1 to 3 halogen atoms;

Ring B is an azetidine ring or a piperidine ring;

Ring D is

(1) a benzene ring optionally further substituted by 1 to 3 halogen atoms, or

(2) a pyridine ring;

L is —O—CH 2 — or —CH 2 —O—;

X is a carbon atom;

Y is a carbon atom or a nitrogen atom; and

Z is —O—CH 2 —.

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

m and n are both 0;

Ring A is

(1) a phenyl group further substituted by 1 to 3 substituents selected from

(i) a pyridyl group optionally substituted by 1 to 3 substituents selected from

(a) a halogen atom, and

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

(ii) an azetidinyl group optionally substituted by 1 to 3 halogen atoms;

Ring B is an azetidine ring;

Ring D is a benzene ring further substituted by 1 to 3 halogen atoms;

L is —O—CH 2 — or —CH 2 —O—;

X is a carbon atom;

Y is a carbon atom; and

Z is —O—CH 2 —.

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

m and n are both 0;

Ring A is

(1) a phenyl group further substituted by 1 to 3 substituents selected from

(i) a halogen atom,

(ii) an optionally halogenated C 1-6 alkyl group, and

(iii) an azetidinyl group optionally substituted by 1 to 3 halogen atoms, or

(2) a tetrahydronaphthyl group;

Ring B is an azetidine ring;

Ring D is a benzene ring further substituted by 1 to 3 halogen atoms;

L is —O—CH 2 — or —CH 2 —O—;

X is a carbon atom;

Y is a carbon atom; and

Z is —O—CH 2 —.

14. 7-Fluoro-6-((3-((5,6,7,8-tetrahydronaphthalen-2-yloxy)methyl)azetidin-1-yl)carbonyl)-2H-1,4-benzoxazin-3(4H)-one, or a salt thereof.

15. 7-Fluoro-6-((3-((2-fluoro-4-(trifluoromethyl)phenoxy)methyl)azetidin-1-yl)carbonyl)-2H-1,4-benzoxazin-3(4H)-one, or a salt thereof.

16. 6-((3-((2-Chloro-4-(3-fluoroazetidin-1-yl)phenoxy)methyl)azetidin-1-yl)carbonyl)-7-fluoro-2H-1,4-benzoxazin-3(4H)-one, or a salt thereof.

17. 6-((3-((2-Chloro-4-fluorobenzyl)oxy)azetidin-1-yl)carbonyl)-7-fluoro-2H-1,4-benzoxazin-3(4H)-one, or a salt thereof.

18. A medicament comprising a compound represented by the formula (I):

wherein

m and n are each independently 0 or 1,

Ring A is an optionally further substituted cyclic group,

Ring B is an azetidine ring, a pyrrolidine ring or a piperidine ring, each of which is an optionally further substituted,

Ring D is an optionally further substituted 6-membered aromatic ring,

L is —CH 2 —O—CH 2 —, —O—CR′R 2 —, —CH(R 1 )—O—, —CF 2 —CH 2 —, —CH 2 —CF 2 — or —CF 2 —,

R 1 and R 2 is each independently a hydrogen atom, or an optionally substituted C 1-6 alkyl group,

X and Y are each independently a carbon atom or a nitrogen atom,

Z is —O—CH 2 —, —NR—CH 2 —, —CH 2 —CH 2 —, —CH═CH—, —CH 2 —, —O—, —S— or —NR—, and

R is a substituent,

or a salt thereof.

19. A method of inhibiting monoacylglycerol lipase in a mammal, which comprises administering an effective amount of a compound represented by the formula (I):

wherein

m and n are each independently 0 or 1,

Ring A is an optionally further substituted cyclic group,

Ring B is an azetidine ring, a pyrrolidine ring or a piperidine ring, each of which is an optionally further substituted,

Ring D is an optionally further substituted 6-membered aromatic ring,

L is —CH 2 —O—CH 2 —, —O—CR′R 2 —, —CH(R 1 )—O—, —CF 2 —CH 2 —, —CH 2 —CF 2 — or —CF 2 —,

R 1 and R 2 is each independently a hydrogen atom, or an optionally substituted C 1-6 alkyl group,

X and Y are each independently a carbon atom or a nitrogen atom,

Z is —O—CH 2 —, —NR—CH 2 —, —CH 2 —CH 2 —, —CH═CH—, —CH 2 —, —O—, —S— or —NR—, and

R is a substituent,

or a salt thereof, to the mammal.

20. A method for the prophylaxis or treatment of Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, anxiety disorder, pain, epilepsy or depression in a mammal, which comprises administering an effective amount of a compound represented by the formula (I):

wherein

m and n are each independently 0 or 1,

Ring A is an optionally further substituted cyclic group,

Ring B is an azetidine ring, a pyrrolidine ring or a piperidine ring, each of which is an

optionally further substituted,

Ring D is an optionally further substituted 6-membered aromatic ring,

L is —CH 2 —O—CH 2 —, —O—CR 1 R 2 —, —CH(R 1 )—O—, —CF 2 —CH 2 —, —CH 2 —CF 2 — or —CF 2 —,

R 1 and R 2 is each independently a hydrogen atom, or an optionally substituted C 1-6 alkyl group,

X and Y are each independently a carbon atom or a nitrogen atom,

Z is —O—CH 2 —, —NR—CH 2 —, —CH 2 —CH 2 —, —CH═CH—, —CH 2 —, —O—, —S— or —NR—, and

R is a substituent,

or a salt thereof, to the mammal.