Molecular Rearrangements. XXIX. Thermolysis of Aromatic Ketoximes

Abstract

Abstract Thermolysis of benzophenone O-benzoyloxime leads to the formation of NH3, CO2, benzene, biphenyl, benzophenone, benzanilide, benzonitrile, benzoic acid, 2-phenylbenzoxazole, salicylaldehyde and its p-isomer. Analogous results were also obtained on thermolysis of acetophenone O-benzoyloxime. Similarly, benzophenone and/or acetophenone O-benzyloximes give pyrolysis products of the same nature in addition to others corresponding to the benzyl moiety. Thermolysis of deoxybenzoin oxime gives NH3, toluene, benzonitrile, bibenzyl, benzil, benzyl alcohol, and 2-phenylindole. Moreover, its O-benzoyl ether affords in addition to these products, benzoic acid and benzyl benzoate. The main feature of these pyrolyses is the homolysis of the N–O bond together with either O-benzyl or O-benzoyl bonds providing free radicals that undergo different reactions involving H-abstraction, dimerization, fragmentation, rearrangement and cyclization to form the identified products.