It is intended to provide a compound represented by the following general formula(1) or a pharmaceutically acceptable salt thereof. Because of having a sufficientlyhigh antitumor activity, this compound or its salt is useful as a remedy for cellproliferative diseases, in particular, cancer. It is also intended to providea medicinal composition which contains the above-described compound or itssalt as the active ingredient. [Chemical formula 1] (1) wherein X is selectedfrom heteroaryl, etc.； Y and Y are selected from -N=, etc.；Y and Y are selected from -CH=, etc.； A is selected fromsulfamide, etc.； R is selected from hydrogen, etc.； and Ris selected from C alkyl, etc.
