An efficient electrochemical method for a unique synthesis of new derivatives of 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one

The electrochemical oxidation of catechols (1a–c) has been studied in the presence of 6-methyl-1,2,4-triazine-3-thion-5-one 3 in aqueous sodium acetate, using cyclic voltammetry and controlled-potential coulometry. A plausible mechanism for the oxidation of catechols and their reaction with 3 is presented. All the catechol derivatives (1a–c) were converted into 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives (6a–c) through a Michael-type addition reaction of 3 to anodically generated o-quinones. The electrochemical syntheses of 6a–c were successfully performed in one pot in an undivided cell using an environmentally friendly method with high atomic economy.