Verfahren zur Herstellung von 1-Alkyl-pyrazol-5-carbonsäureestern

摘要

The present invention relates to a method for preparing 1-alkyl-pyrazol-5-carboxylic acid esters, wherein said method involves reacting the enolate of a 2,4-diketocarboxylic acid ester with a salt of N-alkylhydrazinium in the presence of water and a solvent. This method can be used for readily preparing 1-alkyl-pyrazol-5-carboxylic acid esters at a low cost, while minimising the formation of unwanted isomers.