Transmission of the substituent effects in 2‐substituted benzimidazoles studied by ¹H and ¹³C nuclear magnetic resonance

Abstract

Abstract The substituent influence on the 1 H and 13 C NMR chemical shifts in 2‐substituted benzimidazoles and their anions and cations has been investigated. The transmission of the electronic effects of substituents from C‐2 to C‐5 (6) is approximately 20% less effective than that in the opposite direction. The solvent influence on the chemical shifts of protons and transmission effects in the charged forms of 2‐substituted benzimidazoles has been studied.