Reactions of lead tetra-acetate. Part XVI. The oxidation of monoacylhydrazines

Abstract

Five aroylhydrazines have been oxidised by lead tetra-acetate, usually at room temperature, to give, after hydrolysis, high yields of the corresponding aroic acids. A study of the reaction of benzhydrazide under various conditions has provided evidence that reaction occurs by way of the aroyldi-imide, and this can be diverted in Part to give benzaldehyde and thence, by further reactions, 2,5-diphenyloxadiazole. When the hydrazide is in considerable excess, it can trap an intermediate in the oxidation to give NN′-dibenzoylhydrazine. The oxidation of benzhydrazide by mercuric acetate occurs in a similar manner, although not under such mild conditions.