PROBLEM TO BE SOLVED: To provide a compound useful for treatment of central diseases such as schizophrenia and Alzheimers disease.SOLUTION: This invention provides a compound represented by formula (I) or its pharmacologically acceptable salt. In the formula (I), R1 represents a C1-3 alkyl group, X represents an oxygen atom, NH or the like, m and n represent each independently 1, 2 or 3, R2 represents a C1-6 alkyl group, a C3-7 cycloalkyl group or the like, R3, R4 and R5 represent each independently a hydrogen atom, a halogen atom or the like, and R6 represents a hydrogen atom, a C1-3 alkyl group or the like.COPYRIGHT: (C)2014,JPO&INPIT【課題】統合失調症、アルツハイマー病等の中枢疾患の治療に有用な化合物の提供。【解決手段】式(I):[式中、R1はC1-3アルキル基を表し、Xは酸素原子、NH等を表し、mおよびnは、互いに独立して1、2または3を表し、R2はC1-6アルキル基、C3-7シクロアルキル基等を表し、R3、R4およびR5は互いに独立して、水素原子、ハロゲン原子等を表し、R6は水素原子、C1-3アルキル基等を表す]で表される化合物またはその薬学的に許容される塩を提供する。【選択図】なし
