摘要 |
A method for the preparation of a pyridazinone derivative having general formula (I), where: R1 is a phenyl group, optionally substituted, R2 is H, alkyl or carboxy, R3 is H, alkyl or alkoxy and R4 is alkyl; said method comprising reacting a hydrazone of glyoxylic acid halide having formula (VII) in which X is haloge n, with an ester of formula (VIII) in the presence of an alkaline earth base.
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