A METHOD OF PREPARING PYRIDAZINONE DERIVATIVES

摘要

A method for the preparation of a pyridazinone derivative having general formula (I), where: R<1> is a phenyl group, optionally substituted, R<2> is H, alkyl or carboxy, R<3> is H, alkyl or alkoxy and R<4> is alkyl; said method comprising reacting a hydrazone of glyoxylic acid halide having formula (VII) in which X is halogen, with an ester of formula (VIII) in the presence of an alkaline earth base.