In the present work, the electrooxidation of hydroquinones 1a and 1b, and catechols 1c and 1d was studied in the presence of rhodanine (3) as nucleophile in a mixture of EtOH and phosphate buffer solution as green media using cyclic voltammetry and controlled-potential coulometry. The results indicated that the corresponding p- and o-quinones formed from the hydroquinones and catechols, respectively, participate in Michael addition reaction to yield new thiazole derivatives. The electrochemical syntheses of these new thiazole derivatives were performed successfully at three graphite rod electrodes in undivided cells in good-to-excellent yields at room temperature without any catalyst.