Patent ID: 6566535
Filing Date: 2003-05-20
Classification: C07D

Abstract:
A process for preparing a compound represented by the following formula: wherein each symbol is as defined below, or a salt thereof, characterized by subjecting a compound represented by the following formula: wherein R1 is an electron-attracting group; R2, R3, R4, R5, R6 and R7 are each a hydrogen atom, a halogen atom, an optionally substituted amino group, an optionally substituted hydroxyl group, an optionally substituted thiol group, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group, provided that R6 and R7 may be united to form a ring; and R8 is a hydrogen atom or an optionally substituted hydrocarbon group, or a salt thereof, to a ring-closing reaction.