Electoreduction of 4-(nitrophenyl) substituted 1,4-dihydropyridines on the mercury electrode in aprotic medium

Electrochemical studies on 4-(nitrophenyl) substituted 1,4-dihydropyridines of pharmacological importance have allowed us to generate the one-electron reduction product, the nitro radical anion, ArNO2.-, in aprotic media. Cyclic voltammetric technique have been employed to study the tendency of ArNO2.- to undergo further chemical reaction. Second order kinetics for the decay of ArNO2.- were established for all the 1,4-dihydropyridines examined. The 1,4-dihydropyridine derivatives that have the nitro group in the orto position in the ring shows a trend to give less stable radicals when comparing with meta substitution. The cyclic voltammograms of the couple ArNO2/ArNO2.- has also been examined in the presence and absence of glutathione concluding that it does not exist interaction among glutathione and the nitro radical anions in aprotic media. (C) 1997 Elsevier Science Ltd.