A compound having a hypoglycemic effect is provided. The compound and a pharmaceutically acceptable salt thereof are useful for the treatment or prevention of diabetes, obesity, and the like. The compound is represented by the general formula (1): (wherein R1 and R2 are each independently a hydrogen atom, a halogen atom, an amino group, a hydroxyl group, a hydroxyamino group, a nitro group, a cyano group, a sulfamoyl group, a C1 to C6 alkyl group, a C1 to C6 alkoxy group, a C1 to C6 alkylsulfanyl group, a C1 to C6 alkylsulfinyl group, a C1 to C6 alkylsulfonyl group, or a C1 to C6 alkoxy-C1 to C6 alkylsulfonyl group, and A is a substituted or unsubstituted heteroaryl group).