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Abstract: Electrochemical oxidation of catechol (1a) and 3-methyl-catechol (1b) has been studied in the presence of chloranilic acid (3) as a nucleophile in aqueous solution using cyclic voltammetry and controlled-potential coulometry. In this work, we proposed a novel mechanism for the electrode process and derived variety of products with good yield and purity using controlled-potential electrochemical oxidation at a graphite electrode in a two compartment cell. [Copyright &y& Elsevier]

Abstract: Electrochemical oxidation of 2,3-dimethylhydroquinone 1 has been studied in the presence of o-phenylenediamines 3a–c as nucleophiles in aqueous solution, using cyclic voltammetry and controlled potential coulometry. The results indicate that the quinone 2 derived from 2,3-dimethylhydroquinone participates in Michael addition and imine condensation reactions with o-phenylenediamine via an ECECC mechanism, and is converted to the corresponding phenazine derivatives 7a–c and 7′b. The electrochemical synthesis of compounds 7a–c and 7′b has been performed successfully at a carbon rod electrode in an undivided cell with good yields and high purities. [Copyright &y& Elsevier]

Abstract: Electrochemical oxidation of 3,4-dihydroxybenzoic acid (1a) has been studied in the presence of 4-hydroxy-1-methyl-2(1H)-quinolone (3) as a nucleophile in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results indicate that 1a via a 1,4-(Michael) addition reaction under electro-decarboxylation reaction converts to benzofuran (or isochromeno[4,3-c]quinoline) derivative (6a). The electrochemical synthesis of 6a has been successfully performed in an undivided cell in good yield and purity. The oxidation mechanism was deduced from voltammetric data and by coulometry at controlled-potential. The product has been characterized after purification by IR, 1H NMR, 13C NMR and MS. [Copyright &y& Elsevier]