The present invention provides a compound represented by general formula (1) below or a pharmaceutically acceptable salt thereof: wherein: X is selected from heteroaryl etc., Y 1 and Y 2 are selected from -N= etc., Y 3 and Y 4 are selected from -CH= etc., A is selected from sulfamide etc., R 1 is selected from hydrogen etc., and R 2 is selected from C 1-6 alkyl etc. The compound or salt has sufficiently high antitumor activity, and is useful in the treatment of cell proliferative disorders, particularly cancers. The present invention also provides a pharmaceutical composition containing the compound or salt as an active ingredient.
