[Reaction of ortho-ortho-dimethylphenacyl-halides with formamide. Formation of 4(5)-(ortho-ortho-dimethylbenzoyl)imidazoles].

Reaction of 2,3,5,6-tetramethylphenacyl halides with formamide did not produce the expected 4(5)-(2,3,5,6-tetramethylphenyl)imidazole, but 4(5)-(2,3,5,6-tetramethylbenzoyl)imidazole (VII) was isolated as the major product together with 5-(2,3,5,6-tetramethylphenyl)oxazole (III), alpha-formylamino-2,3,5,6-tetramethylacetophenone (IV) and alpha-chloro-beta-amino-vinyl 2,3,5,6-tetramethylphenyl ketone (IX) as by-products. The corresponding mesitylene derivatives gave analogous results, whereas 4(5)-(2-methylphenyl)imidazole was obtained from 2-methylphenacyl bromide as expected according to the Bredereck's reaction. The structure of the isolated compounds were elucidated by element analysis, mass, I.R., U.V. and N.M.R. spectra, and by chemical reactivity.