Synthesis and Characterization of Benzimidazolium Salts Bearing Triazole Groups

Abstract

A propargyl-functionalized salt, 1-(2-methoxyethyl)-3-(prop-2-ynyl)benzimidazolium bromide ( 1 ), was prepared. 1-(2-methoxyethyl)-3-[(1-phenyl-1H-1,2,3-triazol-4-yl)methyl]benzimidazolium hexafluorophos- phate ( 2 ) and 1-(2-methoxyethyl)-3-[(1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)methyl]benzimidazolium hexafluorophosphate ( 3 ) were obtained by Cu(I) catalyzed azide-alkyne cycloaddition reaction of 1 with corresponding azides. Compound 3 was transformed to 1-(2-methoxyethyl)-3-[(1-(4-aminophenyl)-1H-1,2,3-triazol-4-yl)methyl]benzimidazolium hexafluorophosphate ( 4 ) by reduction reaction with hydrazine monohydrate. The structures of these propargyl- and 1,2,3-triazolyl-functionalized benzimidazolium salts were elucidated by FT-IR, 1 H NMR, 13 C NMR and elemental analysis methods.