It was discovered that a compound represented by the general formula (I) shows strong c-Kit kinase inhibitory activity, and it inhibits proliferation of c-Kit kinase activated-cancer cells in vitro and in vivo. A novel anticancer agent showing c-Kit kinase inhibitory activity was discovered.The general formula (I): (wherein R1 represents methyl etc., R2 represents cyano etc., R3 represents hydrogen etc., R4 represents hydrogen etc.).