Intramolecular specific C-H... N interactions with participation of the pyridine ring nitrogen atom and amino and imino groups in 2-substituted 1-vinylbenzimidazoles, according to1H and13C NMR data

Abstract

In 1-viny1–2,2′-pyridylbenzimidazole, a double intramolecular specific C-H...N interaction is accomplished between the α-H of the vinyl group with the pyridine ring nitrogen and between the H3′ atom of the pyridine ring and the benzimidazole ring nitrogen. In 1-viny1–2-aminobenzimidazole, there are no intramolecular interactions between the hydrogen atoms of the vinyl group and the nitrogen of the amino group. In 1,3-divinyl-2-iminobenzimidazole, the specific interaction of the imino group nitrogen with the β-cis-hydrogen of the vinyl group is greatly weakened by a degenerate tautomeric equilibrium.