Photoreactions of Nitroso Compounds in Solution. XXIII. A Novel Oxidative Photoreaction of Nitrosamines and Nitrosamides

Abstract

Novel oxidations attending the photorearrangement of a nitrosamide and the photoaddition of nitrosamine are described and compared with the corresponding non-oxidative photoreactions. With proper filters, disproportionation during photorearrangement of N-nitrosohexylacetamide and tautomerization during nitrosopiperidine photoaddition to cyclohexene can be minimized to give improved yields of the anti-dimers of C-nitroso compounds. These side reactions are shown to be exclusively derived from secondary photoreactions of the C-nitroso compounds. In the presence of oxygen, the courses of the photoreactions are diverted cleanly to form nitrate esters. Oxygen reacts with nitric oxide, both in the free state and when paired with the C-radical thus diverting the course of the reaction. The rate constant of radical combination between a C-radical and nitric oxide is estimated to be in the range of 2 × 107 s−1.