Pyridazinone derivatives, processes for production thereof and use thereof

摘要

Pyridazinone derivatives of formula (I): <IMAGE> (I) wherein R1 represents a hydrogen atom or a methyl group which may be substituted with an aliphatic cyclic amino group optionally containing a hetero atom in the ring thereof; each of X1 and X2 independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a nitro group or a group shown by -CO-NR2R3 (wherein each of R2 and R3 independently represents an alkyl group having 1 to 6 carbon atoms); Y represents a halogen atom; Z represents an alkoxy group having 1 to 6 carbon atoms; l represents 0 or an integer of 1 to 3; A represents CH or N; m represents 0 or an integer of 1 or 2; and n represents an integer of 1 to 8, exhibit a platelet aggregation inhibiting activity and are useful for the treatment of circulatory disorders such as cerebral infarction.