[Formula 1] The present invention provides new compounds having histone deacetylase inhibiting enzymatic activity of the formula (I) [wherein, Y and 5, X R 1, R 2 R 3, R 4, R has the meaning as defined] of , their preparation, I would include the use of them as well as pharmaceutical compositions containing them.【化1】本発明は、ヒストンデアセチラーゼ阻害酵素活性をもつ、式(I)[式中、R1、R2R3、R4、R5、X及びYは定義された意味をもつ]の新化合物、それらの調製、それらを含有する組成物並びに医薬としてのそれらの使用を含んでなる。