Provided is a compound represented by formula (I) and having an HER2 inhibitory action or a pharmacologically acceptable salt of the compound.[In formula (I), T is phenyl, indazolyl, or benzofuryl, n is an integer of 0-3, R is a hydrogen atom, a halogen atom, a C alkyl, a C alkenyl, a C alkynyl, or a C alkoxy, m is an integer of 0-3, R is hydroxy or a C alkyl optionally substituted by one or two C alkoxy groups, and R is a hydrogen atom, a C alkyl, or a C alkynyl.].