Electro-Organic Synthesis of New Esculetin Derivatives Based on 1,6-Conjugate Addition

Electrochemical oxidation of 4–methylesculetin has been studied in the presence of arylsulfinic acids as nucleophiles in aqueous/ acetonitrile solution mixture, using cyclic voltammetry and controlled-potential coulometry. The results indicate that the o-quinone derived from oxidation of 4–methylesculetin undergoes a 1,6-Michael addition reaction with unique selectivity, converts to the corresponding new sulfone derivative of esculetin. The reaction products were derived with good yields and excellent selectivity based on electrochemical oxidation under controlled potential conditions at a carbon electrode in an undivided cell.