The reaction of simple aromatic nitro-compounds with transition-metal oxalates: the question of nitrene intermediates

Azo- and azoxy-benzenes and phenazines were obtained by heating nitrobenzene derivatives with transition-metal oxalates, but not in their absence. Traces of primary amines were isolated occasionally. The formation of the azo- and azoxy-benzenes was shown to be an intermolecular process. It is suggested that the results are best explained in terms of a nitrene intermediate bound to the surface of the metal derivative. The reaction of some nitrosobenzene derivatives with ferrous oxalate was also examined with similar results.