Oxidation of pyrazoles containing the 2-hydroxyethyl group on a NiO(OH) electrode in aqueous alkali

Abstract

The electrooxidation of pyrazoles containing hydroxyethyl group bound with the pyrazole ring at its N and C atoms (1-(2-hydroxyethyl)pyrazole and (4-(2-hydroxyethyl)pyrazole, respectively) in an undivided cell on a NiO(OH) electrode in aqueous alkali is studied. The oxidation of 1-(2-hydroxyethyl)pyrazole is shown to result in the formation of pyrazole-1-acetic acid with a yield of 80.0%. In the case of 4-(2-hydroxyethyl)pyrazole the process proceeds more exhaustively, leading to the formation of pyrazole-4-carboxylic acid as the major product with a yield of 57.0%. The regularities of these processes are discussed.