Synthesis and crystal structures of N-H, N-phenyl and N-benzyl-2-(4-hexyl-oxyphen-yl)benzimidazoles

Abstract

The title compounds, 2-(4-hexyl-oxyphen-yl)-1H-benzimidazole (C₁₉H₂₂N₂O; 1), 2-(4-hexyl-oxyphen-yl)-1-phenyl-1H-benzimidazole (C₂₅H₂₆N₂O; 2) and 1-benzyl-2-(4-hexyl-oxyphen-yl)-1H-benzimidazole (C₂₆H₂₈N₂O; 3) were synthesized and their structures were determined by single-crystal X-ray analysis. The N-substituent at the imidazole moiety slightly affects the inter-planar angle between the 4-hexyl-oxyphenyl ring and the benzimidazole system. The unsubstituted benzimidazole (1) forms inter-molecular N-H⋯N bonds while in the crystal structures of 2 and 3, the mol-ecules are assembled only through π-π and C-H⋯π inter-actions.

Keywords: H-bonding; NMR study; benzimidazole; crystal structure; synthesis.