Electrochemical oxidation of catechol (1a), 3-methylcatechol (lb) and 3-methoxycatechol (1c) in the presence of 1,3-diethyl-2thiobarbituric acid (3) as a nucleophile in aqueous solution has been studied using cyclic voltammetry and controlled-potential coulometry. The results indicate that (1a-1e) participating in a 1,4 (Michael) addition reaction converts to dispirothiopyrimidine derivatives (6a-6c). The electrochemical synthesis of 6a-6c has been successfully performed in an undivided cell in good yield and purity.