Electrochemical reduction of 2-acetyl benzofuran and its derivatives at glassy carbon electrode

Abstract

Electrochemical reduction of 2-acetylbenzo[b]furan and its derivatives namely 2-acetylbromobenzo[-b]furan, 2-acetylbromo-5-bromobenzo[b]furan and 2-acetyl naphtha[2,1-b] furan has been carried out in four different aqueous solvents namely DMSO, DMF, acetonitrile, ethanol using Britton Robinson buffer as supporting electrolyte at glassy carbon electrode employing cyclic voltametric techinque. Single irreversible wave was observed due to the reduction of >C=O moiety to secondary alcohol derivatives of benzofuran. Formation of pinacol due to dimerization of the intermediate radical was ruled out on steric consideration. The other data viz. the effect of sweep rate, concentration of the electroactive species, effect of temperature, effect of surfactant, effect of dielectric constant on cathodic peak potential (Epc), and cathodic peak current (ipc) has been found out. Diffusion coefficent (Dℴ) and heterogeneous rate constant (kℴ) have been evaluated. The electrode process was shown to be diffusion controlled and irreversible. The electrolytic products are characterised/identified by controlled potential electrolysis. The results of the electroreduction are compared with that of the chemical reduction method.