The electrochemical synthesis of new benzofuran derivatives

Abstract

Electrochemical oxidation of naphthazarin (5,8-dihydroxy-1,4-naphthoquinone, 1), 2,5-dihydroxy- benzoic acid (2), 2,3-dihydroxybenzoic acids (3) and hydroquinone (4) have been studied in the presence of dimedone (5) as a nucleophile using cyclic voltammetry (CV). The results indicate that the quinones derived from 1, 2, 3 and 4 participate separately with 5 in the 1,4-Michael addition reactions to form the corresponding new benzofuran derivatives. The electrochemical synthesis was carried out in the H2O/CH3CN solution mixture using constant current technique to give the pure benzofuran derivatives in high yield.