The reaction of some diazoamino-compounds with lead tetra-acetate

Abstract

The dehydrogenation of some diazoamino-compounds with lead tetra-acetate in aromatic solvents has been shown to give rise to mixtures of biaryls and azo-compounds. The reaction of diazoaminobenzene, in monosubstituted benzene derivatives as solvents, gives azobenzene and mixtures of isomeric biphenyls as products. The isomer ratio for the biphenyls suggests that they are formed by substitution of intermediate phenyl radicals in the aromatic solvent. The dehydrogenation of 1,1-di-2-naphthyltriazen in benzene led to 2-phenylnaphthalene and dibenzo[a,h]phenazine as products. The latter product is also obtained from the thermal decomposition of 2-naphthyl azide. These latter results indicate the intervention of nitrenes as intermediates. The electron paramagnetic resonance spectrum of the reaction mixture of 1,3-diphenyltriazen with lead tetra-acetate exhibited a triplet with a coupling constant of about 10 gauss, which may be indicative of an intermediate triazenyl radical, which would break down to afford a phenyl radical, phenylnitrene, and nitrogen.