PROCESS FOR THE PREPARATION OF 1-ALKYL-PYRAZOLE-5-CARBOXYLIC ACID ESTERS

摘要

1-alkyl-pyrazole-5-carboxylic acid esters are prepared by reacting the enolate o f a 2,4-diketocarboxylic acid ester with an N-alkylhydrazinium salt in the presence of a solvent. This process allows a particularly economic preparation of 1-alkyl-pyrazole-5-carboxylic acid esters in a simple manner and with only littl e formation of undesirable isomers.