| abstract |
The invention relates to a thrombin receptor antagonist comprising a compound represented by the formula (I): (I) (wherein R1a, R1b and R2 independently represent a hydrogen atom, a hydrocarbon group which may be substituted, a heterocyclic group which may be substituted or alkoxy which may be substituted, R3 represents a group represented by any of the formulae, -NHCOR4, -NHSO2R5, -NHCON(R6a)(R6b), -NHCOOR7 and -CONHR8 (wherein R4, R5, R6a, R6b, R7 and R8 independently represent a hydrogen atom, a hydrocarbon group which may be substituted, a heterocyclic group which may be substituted or the like), the ring A represents a monocyclic aromatic ring which may further have a substituent, R1a and R1b may be bound to each other to form a nitrogen-containing nonaromatic heterocyclic ring which may be substituted), or a salt thereof or a prodrug thereof. The thrombin receptor antagonist of the invention has a thrombin receptor (particularly PAR-1) antagonism and is useful for preventing or treating PAR-1 associated pathologic conditions or diseases. |