Direct Electrophilic Acylation of N-Substituted Pyrazoles by Anhydrides of Carboxylic Acids

Abstract

A simple, convenient and scalable approach to 1-substituted 4-acylpyrazoles through direct acylation of pyrazoles by anhydrides of aliphatic, aromatic and fluorinated carboxylic acids in the presence of concentrated sulfuric acid as a catalyst is described. Target ketones were obtained in 41–86% isolated yields in high purity without laborious purification. The scope and limitations of the method are discussed.

Key words

electrophilic aromatic acylation - heterocycles - ketones - catalysis

• References



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