PROBLEM TO BE SOLVED: To provide an agent for preventing, inhibiting, or treating cancer.SOLUTION: The present invention provides a compound represented by formula (I) or pharmaceutically acceptable salt thereof (a monocycle on the left side is a pyridazine, a pyrimidine or a pyrazine group R is H, a halogen atom or the like R is H, a halogen atom, a COOR1 group, a NO2 group, a NR1R2 group, a morpholinyl group or the like n is an integer of 1-3 n is 1 or 2 Z, Y, X, U are N or C).SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】ガンを予防し、抑制し、又は治療する為の剤の提供。【解決手段】式(I)で表される化合物又はその医薬的に許容される塩。(左側単環はピリダジン、ピリミジン又はピラジン基;RはH、ハロゲン原子等;R’はH、ハロゲン原子、COOR1基、NO2基、NR1R2基、モルホリニル基等;nは1~3の整数;n’は、1又は2;Z、Y、X、UはN又はC)【選択図】なし