Oxidation of hydroxylamine derivatives. Part 5. Anodic oxidation of N-hydroxy- and N-alkoxy-ureas

Abstract

The anodic oxidation of the ureas EtNH·CO·NR¹OR²(1)–(5) has been studied by cyclic voltammetry and controlled potential electrolysis in acetonitrile at a glassy carbon electrode. The products of oxidation suggest that (1)–(3) result in cleavage between the carbon of the ethylaminocarbonyl group and the nitrogen of the hydroxyamino-group. Part of the intermediate radical of (3) undergoes disproportionation rather than cleavage of the carbon–nitrogen bond. In the case of (4) and (5), the cleavage of the carbon–nitrogen bond as observed in (1)–(3) is the main reaction route, but the possibility of N–N coupling of the intermediate followed by intramolecular rearrangement cannot be neglected. Oxidations were carried out in both divided and undivided cells.