Mechanism of the polarographic reduction of a new 5-nitrofuran derivative with antibacterial activity

The reduction at mercury electrodes of a new 5-nitrofuran derivative with antibacterial activity, N2-(5-nitrofurfurylidene)formohydrazide-4-(3,5-dicyanophenyl)-6-ethoxy-2- pyridyl)imide, was studied by conventional, normal pulse, reverse normal pulse and differential pulse polarography in water-dimethylformamide (30%) buffered media. The waves observed, whose number depended on pH, are attributed to the reduction of the nitro group (6 electrons) and the azomethinic unit (4 electrons). The basic mechanisms of the electrode reactions have been deduced from the characteristics of the waves. Conditions for determining the formal potential of the nitroderivative/radical-anion system, a parameter related to pharmacological activity, are also reported.