Synthesis of fluorine-containing benzimidazole derivatives

Various fluorine-containing benzimidazoles were obtained by the reaction of o-phenylene-diamine, 3,4-diaminotoluene, and 1,2-diamino-4-chlorobenzene with hexafluoropropene or perfluoro(methyl vinyl ether) in DMF. A new efficient method of synthesis of 2-(1,2,2,2-tet-rafluoroethyl)benzimidazole by the reaction of o-phenylenediamine with hexafluoropropene in the presence of diethylamine or dimethylamine in ethyl acetate is developed.