Invention provides a compound of formula, (I): [Formula 1] [Formula, X, [2] of shows a group represented by the formula, Y is [3] of shows a group represented by the formula, Ar 1 is, [Omitted] on a pharmaceutically acceptable salt thereof or a compound represented by the] indicates a group represented by the formula. None [Selection Figure]本発明は、式(I):【化1】[式中、Xは、【化2】で表される基等を示し、Yは、【化3】で表される基等を示し、Ar1は、【化4】で表される基等を示す]で表される化合物又はその薬学的に許容される塩に関する。【選択図】なし