Electrochemical study of catechols in the presence of 4,6-dihydroxy-2-methylpyrimidine

Electrochemical oxidation of catechol (1a), 3-methylcatechol (1b), and 3-methoxycatechol (1c) has been studied in the presence of 4,6-dihydroxy-2-methylpyrimidine (3) as a nucleophile in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results indicate that the quinones derived from catechols (1a-1c) participate in Michael addition reactions with 3 to form the corresponding benzofuro[2,3-d]pyrimidine derivatives (6a-6c). The electrochemical synthesis of (6a-6c) has been successfully performed in an undivided cell in good yield and purity. The mechanism of oxidation was deduced from voltammetric data and by coulometry at controlled-potential. The products have been characterized after purification by IR, 1H NMR, 13C NMR and MS.