An object is to provide a novel compound which has a glycogen synthase activation ability, but activates a receptor PPAR to a low degree and is highly safe. Provided is a compound represented by the following general formula (I) or a pharmaceutically acceptable salt thereof: wherein Ar1 represents any one of the following rings (II) and (III): wherein R2 represents an alkyl group, and R3 represents a hydrogen atom or an alkyl group, and R1 represents any one of the following substituents (IV) and (V):