The electro-oxidation of 2,3-dimethylhydroquinone (1) has been studied in the presence of 2-hydroxy-1,4-naphthoquinone (4a), 2-mercaptobenzothiazole (3b), 2-mercaptobenzoxazole (3c), and thiazoline-2-thiol (3d) in aqueous solution, using cyclic voltammetry and controlled-potential coulometry. The results indicate that p-benzoquinone, generated by the electrochemical oxidation of 2,3-dimethylhydroquinone, is scavenged by 4a and 3b-3d to give the related products 7a, 5b-5d via various electrochemical mechanisms. (C) 2008 The Electrochemical Society.