Reactions of [2-(Bromomethyl)phenyl](4-chlorophenyl)methanone: A New Synthesis of [1,3]Thiazolo[3,2-b][2,4]benzodiazepine, Benzimidazo[1,2-b][2,4]benzodiazepine and Benzimidazo[1,2-b][2]benzazepine Derivatives

A new approach to the development of a number of azolo-condensed azepines and diazepines has been proposed. The method for the synthesis of [1,3]thiazolo[3,2-b][2,4]benzodiazepine, benzimidazo[1,2-b][2,4]benzodiazepineandbenzimidazo[1,2-b][2]benzazepinederivatives involves the reaction of [2-(bromomethyl)phenyl](4-chlorophenyl)methanonewith5-methyl-1,3-thiazol-2-amine, 1H-benzimidazol-2-amineand1,2-dimethyl-1H-benzimidazole. The formation of the quaternary salt of the initial diazole has been done under mild conditions in MeCN. The following intramolecular condensation has been realized by heating 2-amino azolium salts in AcOH or in Et3N as in the case of 2-methyl azolium salt. The structures of these cyclic compounds have been confirmed by mass spectrometry measurements, elemental analysis and NMR spectra.