Heteroarylcarboxylic acid ester derivative

1. A method for the prophylaxis or treatment of obesity, comprising administering an effective amount of a compound represented by formula (I):

wherein

R1, R2, R3, and R4 may be the same or different and are each independently a hydrogen atom, a nitro group, a halogeno group, a cyano group, a hydroxyl group, a thiol group, an amino group, a guanidino group, a formyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower acyl group, a carboxyl group, a sulfo group, a phosphono group, a lower alkoxyl group, a lower alkylthio group, a lower alkylamino group, a lower acyloxy group, a lower acylamino group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a lower alkylsulfonylamino group, or a sulfamoyl group;

HetAr is a furan ring optionally having substituent(s);

X is a lower alkylene group optionally having substituent(s), a lower alkenylene group optionally having substituent(s), a lower alkynylene group optionally having substituent(s), or a thiophenylene group;

Y is a carbonyl group, a thiocarbonyl group, or a sulfonyl group; and

A is a group of formula (II):

wherein R6 and R7 may be the same or different and are each independently a hydrogen atom, a hydroxyl group, a lower alkyl group optionally having substituent(s), a lower alkenyl group optionally having substituent(s), a lower alkynyl group optionally having substituent(s), or a lower alkoxyl group optionally having substituent(s), or R6 and R7 may be bonded to form a cyclic amino group optionally having substituent(s),

or a pharmaceutically acceptable salt thereof,

to a subject in need thereof, wherein said obesity is caused by diabetes.

2. A method for the prophylaxis or treatment of obesity, comprising administering an effective amount of a compound represented by formula (I):

wherein

R1, R2, R3, and R4 may be the same or different and are each independently a hydrogen atom, a nitro group, a halogeno group, a cyano group, a hydroxyl group, a thiol group, an amino group, a guanidino group, a formyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower acyl group, a carboxyl group, a sulfo group, a phosphono group, a lower alkoxyl group, a lower alkylthio group, a lower alkylamino group, a lower acyloxy group, a lower acylamino group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a lower alkylsulfonylamino group, or a sulfamoyl group;

HetAr is a furan ring optionally having substituent(s);

X is a lower alkylene group optionally having substituent(s), a lower alkenylene group optionally having substituent(s), or a lower alkynylene group optionally having substituent(s);

Y is a carbonyl group, a thiocarbonyl group, or a sulfonyl group; and

A is a group of formula (II):

wherein R6 and R7 may be the same or different and are each independently a hydrogen atom, a hydroxyl group, a lower alkyl group optionally having substituent(s), a lower alkenyl group optionally having substituent(s), a lower alkynyl group optionally having substituent(s), or a lower alkoxyl group optionally having substituent(s), or R6 and R7 may be bonded to form a cyclic amino group optionally having substituent(s),

or a pharmaceutically acceptable salt thereof,

to a subject in need thereof, wherein said obesity is caused by diabetes.

3. A method according to claim 1 , wherein R1, R2, R3, and R4 are each independently a hydrogen atom, a nitro group, or a halogeno group.

4. A method according to claim 1 , wherein —HetAr—is a heteroaromatic ring group represented by formula (III-1) or (III-2):

wherein Z1 and Z2 are each independently CRa, and Z3 is an oxygen atom, wherein each Ra may be the same or different and is independently a hydrogen atom, a nitro group, a halogeno group, a cyano group, a hydroxyl group, a thiol group, an amino group, a guanidino group, a formyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower acyl group, a carboxyl group, a sulfo group, a phosphono group, a lower alkoxyl group, a lower alkylthio group, a lower alkylamino group, a lower acyloxy group, a lower acylamino group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a lower alkylsulfonylamino group, or a sulfamoyl group.

5. A method according to claim 1 , wherein X is a lower alkylene group optionally having substituent(s) or a lower alkenylene group optionally having substituent(s), wherein said substituent(s) is selected from the group consisting of a halogeno group, a hydroxyl group, an amino group, a lower alkyl group, a lower alkoxyl group, and a lower acyl group.

6. A method according to claim 1 , wherein Y is a carbonyl group or a sulfonyl group.

7. A method according to claim 1 , wherein A is a group of formula (IV):

wherein R60 is a carboxyl group, a sulfo group, a phosphono group, a lower alkoxycarbonyl group, or a hydroxyl group,

D is a lower alkylene group optionally having substituent(s), a lower alkenylene group optionally having substituent(s), or a lower alkynylene group optionally having substituent(s), wherein said substituent(s) is selected from the group consisting of a nitro group, a halogeno group, a cyano group, a hydroxyl group, a thiol group, an amino group, a guanidino group, a formyl group, a lower acyl group, a carboxyl group, a sulfo group, a phosphono group, a lower alkoxyl group, a lower alkylthio group, a lower alkylamino group, a lower acyloxy group, a lower acylamino group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a lower alkylsulfonylamino group, an arylsulfonylamino group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s), an aryloxy group optionally having substituent(s), an arylthio group optionally having substituent(s), an aralkyl group optionally having substituent(s), an aralkyloxy group optionally having substituent(s), an aralkylthio group optionally having substituent(s), a heterocyclic group optionally having substituent(s), a heterocyclic oxy group optionally having substituent(s), a heterocyclic thio group optionally having substituent(s), and an oxo group, and

R70 is a hydrogen atom, a hydroxyl group, a lower alkyl group optionally having substituent(s), or a lower alkoxyl group optionally having substituent(s),

or R70 and D may be bonded to form a cyclic amino group optionally having substituent(s).

8. A method according to claim 7 , wherein R60 is a carboxyl group, a sulfo group, a lower alkoxycarbonyl group, or a hydroxyl group,

D is a lower alkylene group optionally having substituent(s), wherein said substituent(s) is selected from the group consisting of a halogeno group, a hydroxyl group, a thiol group, an amino group, a guanidino group, a carboxyl group, a sulfo group, a lower alkoxyl group, a lower alkylthio group, a lower alkylamino group, a lower acylamino group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a lower alkylsulfonylamino group, an arylsulfonylamino group optionally having substituent(s), an aryl group optionally having substituent(s), a heterocyclic group optionally having substituent(s), and an oxo group, and

R70 is a hydrogen atom, a hydroxyl group, a lower alkyl group optionally having substituent(s), or a lower alkoxyl group optionally having substituent(s),

or R70 and D may be bonded to form a cyclic amino group optionally having substituent(s).

9. A method according to claim 1 , wherein R1, R2, R3, and R4 are each independently a hydrogen atom, a nitro group, or a fluorine atom, and

HetAr is furan optionally having substituent(s).