Electrochemical study of catechol and some of 3-substituted catechols in the presence of 1,3-diethyl-2-thio-barbituric acid. Application to the electro-organic synthesis of new dispirothiopyrimidine derivatives

Abstract

Electrochemical oxidation of catechol ( 1a), 3-methylcatechol ( 1b) and 3-methoxycatechol ( 1c) in the presence of 1,3-diethyl-2-thiobarbituric acid ( 3) as a nucleophile in aqueous solution has been studied using cyclic voltammetry and controlled-potential coulometry. The results indicate that ( 1a– 1c) 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.