Diversity in electrochemical oxidation of dihydroxybenzoic acids in the presence of acetylacetone. A green method for synthesis of new benzofuran derivatives

Abstract

Electrochemical oxidation of diol derivatives of benzoic acid (1–3) have been studied in the presence of acetylacetone (4) as the nucleophile in aqueous solutions, using cyclic voltammetry and controlled-potential coulometry. The results indicate that the quinones derived from dihydroxybenzoic acids (1a–3a) participate in Michael addition reactions with acetylacetone (4) and via various mechanisms convert to the corresponding benzofurans (1d–3d). In this work, we derive various products with good yields based on electrochemical oxidation under controlled potential conditions in aqueous solutions, without toxic reagents and solvents at a carbon electrode in an undivided cell, using an environmentally friendly method.