Photochemical Rearrangement of N-Substituted 2-Metyl-5-nitro-1H-imidazoles in the Presence of Water

Article abstract of DOI:10.1002/hlca.19870700121

The photochemical behaviour of 2-methyl-5-nitro-1H-imidazoles 1 in water-containing solutions has been studied.In a first reaction step, the photorearrangement of 1 yields 2-methyl-2-imidazoline-4,5-dione-4-oximes 2.Hydrolysis of 2 and subsequent elimination of water from a supposed intermediate 5 leads to 5-methyl-1,2,4-oxadiazole-3-carboxamides 4.The basic structure of 4 was determined by X-ray analysis of the derivative 4e.Further irradiation destroys the products 4 in part by light-induced hydrolysis.