A compound of the general formula (I): [wherein, R 1 represents a halogen atom, or the like, R 2 represents a hydrogen atom, or the like, R 3 and R 4 , each independently, represent a hydrogen atom, a C 1-4 alkyl group, or the like, R 5 represents a hydrogen atom, a halogen atom, or the like, R 6 represents a hydrogen atom, a halogen atom, or the like, R 7 and R 8 , each independently, represent a hydrogen atom, a halogen atom, or the like, R 9 and R 10 , each independently, represent a hydrogen atom, a C 1-4 alkyl group, R 11 and R 12 , each independently, represent a hydrogen atom, a C 1-4 alkyl group, or the like, X represents an oxygen atom, a group -CH 2 -, or the like, Y represents a nitrogen atom, a group =CH-, or the like, and Z represents a nitrogen atom, or the like] or a pharmacologically acceptable salt thereof, which has an excellent suppressive action on platelet aggregation, and is useful for prevention and/or treatment of thromboembolism.
