A compound represented by formula (I) or a pharmacologically acceptable salt thereof, which can inhibit a fibroblast growth factor receptor (FGFR) family kinase in cancer tissues. (In the formula, A represents a 5- to 10-membered heteroaryl group, or a C6-10 aryl group; R1 and R2 independently represent H, OH, X, CN, NO2, a C1-4 haloalkyl group, a C1-6 alkyl group, or the like ; R3 represents H, a C1-5 alkyl group, a C6-10 aryl group, a C1-5 alkyl group, or a C1-4 haloalkyl group; and R4 represents H, X, a C1-3 alkyl group, a C1-4 haloalkyl group, OH, CN, NO2, or the like.)