Electrochemical oxidation of clonazepam drug in the presence of arylsulfinic acid in aqueous solutions: A green method for synthesis new sulfonamide derivatives

The electrochemical oxidation of clonazepam (CLNP) has been studied in presence of some aryl sulfinic acids as nucleophiles in aqueous buffered solution by means of cyclic voltammetry, and controlled- potential coulometry. Voltammetric studies of electrochemical behavior of clonazepam have also been investigated in different pH values (pH 1.0 to 10.0) in absence and presence of toluenesulfinic acid (1a) as well as benzenesulfinic acid (1b). The results indicated that peak current and peak potential depends on the level of pH. Finally, the synthetizing new sulfonamide derivatives was conducted through constant current electrolysis of clonazepam in presence of arylsulfinic acids at carbon rod electrodes, employing a green electrochemical protocol. CLNP which has cathodically produced hydroxylamine species is oxidized at the anode to generate nitroso species, participate in reaction with the arylsulfinic acids, converts it to the corresponding new sulfonamide derivatives. The new products have been characterized by IR, MS, 1H NMR and 13C NMR methods.