SOME OBSERVATIONS CONCERNING BROMINATION OF IMIDAZOLE DERIVATIVES IN CHLOROFORM

The bromination of imidazole. N-methylimidazole, benzimidazole and N-methyl- benzimidazole in chloroform has been studied. Imidazole gives with half mole of bromine a C-polybromoderivative together with imidazole hydrobromide which by treatment with additional bromine gives a red dicoordinate complex of unipositive bromine, N-methylimidazole gives a similar result. Benzimidazole also gives a dicoordinate complex but, probably, the intermediate is the N-bromobenzimidazole hydrobromide: no C-bromination is detected in this case. Under similar conditions N-methylbenzimidazole gives a 1:1 complex of the n-donor type. The reasons for these differences are discussed. © 1969.