Five-membered heterocyclic alkanoic acid derivative

1. A compound represented by the formula:

wherein

R 1 is an optionally substituted oxazolyl group;

X is a bond, an oxygen atom, a sulfur atom, —CO—, —CS—, —CR 3 (OR 4 )— or —NR 5 — (R 3 is a hydrogen atom or an optionally substituted hydrocarbon group, R 4 is a hydrogen atom or a hydroxy-protecting group and R 5 is a hydrogen atom, an optionally substituted hydrocarbon group or an amino-protecting group);

Q is a divalent hydrocarbon group having 1 to 20 carbon atoms;

Y is a bond, an oxygen atom, a sulfur atom, —SO—, —SO 2 —, —NR 6 —, —CONR 6 — or —NR 6 CO— (R 6 is a hydrogen atom or an optionally substituted hydrocarbon group);

ring A

is an aromatic ring optionally further having 1 to 3 substituents;

Z is —(CH 2 ) n —Z 1 — or —Z 1 —(CH 2 ) n — (n is an integer of 0 to 8, Z 1 is a bond, an oxygen atom, a sulfur atom, —SO—, —SO 2 —, —NR 7 —, —CONR 7 — or —NR CO— (R 7 is a hydrogen atom or an optionally substituted hydrocarbon group));

ring B

is a pyrazole ring optionally further having 1 to 3 substituents;

W is a divalent saturated hydrocarbon group having 1 to 20 carbon atoms; and

R 2 is —OR 8 (R 8 is a hydrogen atom or an optionally substituted hydrocarbon group) provided that ring B does not have, on the ring-constituting N atom, a substituent represented by the formula:

wherein

R 1a is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group;

Xa is a bond, an oxygen atom, a sulfur atom, —CO—, —CS—, —CR 2a (OR 3a )— or —NR 4a — (R 2a and R 4a are each a hydrogen atom or an optionally substituted hydrocarbon group and R 3a is a hydrogen atom or a hydroxy-protecting group);

ma is an integer of 0 to 3;

Ya is an oxygen atom, a sulfur atom, —SO—, —SO 2 —, —NR 5a —, —CONR 5a — or —NR 5a CO— (R 5a is a hydrogen atom or an optionally substituted hydrocarbon group);

ring Aa

is an aromatic ring optionally further having 1 to 3 substituents; and

na is an integer of 1 to 8,

or a salt thereof,

or a prodrug thereof.

2. The compound of claim 1 , wherein X is a bond or —NR 5 — (R 5 is a hydrogen atom, an optionally substituted hydrocarbon group or an amino-protecting group).

3. The compound of claim 1 , wherein Q is C 1-6 alkylene or C 2-6 alkenylene.

4. The compound of claim 1 , wherein Y is an oxygen atom or —NR 6 — (R 6 is a hydrogen atom or an optionally substituted hydrocarbon group).

5. The compound of claim 1 , wherein n is an integer of 0 to 3, Z 1 is a bond, an oxygen atom, a sulfur atom, —NR 7 —, —CONR 7 — or —NR 7 CO— (R 7 is a hydrogen atom or an optionally substituted hydrocarbon group).

6. The compound of claim 1 , wherein W is a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.

7. The compound of claim 1 , wherein the substituent that the ring B optionally further has is a hydrocarbon group.

8. The compound of claim 1 , which is [1-methyl-3-[4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzyloxy]-1H-pyrazol-4-yl]acetic acid,

[3-[4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzyloxy]-1-phenyl-1H-pyrazol-4-yl]acetic acid,

3-[3-[3-methoxy-4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzyloxy]-1-phenyl-1H-pyrazol-5-yl]propionic acid,

3-[3-[4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzyloxy]-1-phenyl-1H-pyrazol-5-yl]propionic acid, or

3-[3-[3-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzyloxy]-1-phenyl-1H-pyrazol-5-yl]propionic acid.

9. A pharmaceutical composition comprising the compound of claim 1 or a salt thereof or a prodrug thereof and a phamaceutically acceptable carrier, excipient or diluent.

10. The pharmaceutical composition of claim 9 , which is a therapeutic agent of diabetes mellitus.

11. The pharmaceutical composition of claim 9 , which is a therapeutic agent of hyperlipidemia.

12. The pharmaceutical composition of claim 9 , which is a therapeutic agent of impaired glucose tolerance.