Research on imidazo[1,2-a]benzimidazole derivatives.

3-Alkoxycarbonyl-2-arylimidazo1,2-a]benzimidazoles were synthesized by alkaline cleavage of 3-trichloromethyl ketones of the imidazo1,2-a]benzimidazole series, which are formed by acylation of this three-ring system with trichloroacetyl chloride. The same compounds were also obtained by esterification of the corresponding 3-carboxylic acid. The haloform reaction with 3-acetyl-2-phenylimidazo1,2-a]benzimidazole proceeds anomalously and leads to bis(9-methy1-2-phenylimidazo1,2-a]benzimidazo1-3-yl)-2-buten-1,4-dione, the structure of which was confirmed by independent synthesis.See 1] for communication XV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 522–525, April, 1978.