| abstract |
To provide a compound useful as a medicinal agent having a P2Y12-inhibiting activity, particularly as a platelet aggregation inhibitor. Disclosed is a P2Y12 inhibitor. Specifically disclosed is a bicyclic heterocyclic compound having an amino group substituted by a lower alkyl, a cycloalkyl or a lower alkylene-cycloalkyl at a specific position (e.g., quinazolidione, isoquinolone), which has an excellent platelet aggregation-inhibiting activity. The compound has an excellent P2Y12-inhibiting activity and an excellent platelet aggregation-inhibiting activity, and is therefore useful as a platelet aggregation inhibitor. |