Nitro and aminobenzimidazoles

Abstract

Abstract A summary of the preparation methods of 2 tautomeric and 4 N-methylated benzimidazoles with a nitro group on the benzene ring (1–6) and with an amino group in the same positions (7–12) were summarized. Annular tautomerism of the title compounds 1–12 has been studied using 1H, 13C and 15N NMR spectra in liquid and solid state (CPMAS), UV spectra and quantum chemical calculations.