The present invention provides a compound represented by the following formula (I) or a physiologically acceptable salt thereof, and use thereof for the prophylaxis or treatment of TGF-β-related diseases:whereinY is a hydrogen atom and the like;R2 isand the like;R3 is —NR8—R9— and the like;R4, R5, R6 and R7 are the same or different and each is a hydrogen atom and the like; andX isand the like.