Investigation of the electrochemical behavior of catechol and 4-methylcatechol in the presence of methyl mercapto thiadiazol as a nucleophile: application to electrochemical synthesis

摘要

The present study concerns the electrochemical behavior of catechol and 4-methylcatechol in the presence of 2-mercapto-5-methyl-1,3,4-thiadiazole (MMT) in aqueous medium on the surface of the glassy carbon electrode by means of cyclic voltammetry and controlled-potential coulometry. The oxidation mechanism was deduced from voltammetric and spectrophotometric data. The electro-generation of quinoid intermediates and their subsequent Michael-type reaction with MMT has been investigated as a clean and convenient strategy for the synthesis of corresponding reaction products. In addition, electro-synthesis of Michael addition products has been successfully accomplished by controlled-potential coulometry in a divided H-type cell in mild conditions that can be considered as a green procedure. The reaction products were characterized by spectrophotometric, 1H and 13C NMR, and mass spectrometric methods. Keywords Mercapto thiadiazole - Catechols - Electro-synthesis - Michael addition - Cyclic voltammetry - Controlled-potential coulometry