Mercaptotriazole as a nucleophile in addition to o-quinone electrochemically derived from catechol: application to electrosynthesis of a new group of triazole compounds

Electrochemical oxidation of catechol in the presence of 3-mercapto-1,2,4-triazole (MTA) as a nucleophile in aqueous buffered solutions was studied by cyclic voltammetry and controlled-potential coulometry. The mechanism of electrochemical reaction is confirmed by spectrophotometric tracing in various times of controlled-potential coulometry. The voltammetric and spectrophotometric foundations indicate that a 1,4 Michael addition of MTA from its thiol moiety to the electrochemically derived o-quinone is occurred. The electrochemical synthesis of Michael addition product has been successfully accomplished by controlled-potential coulometry in a divided H-type cell and the reaction product was characterized by spectrophotometric, 1H and 13C NMR, elemental analysis and mass spectrometric methods.