NaI-Mediated Electrochemical Cyclization-Desulfurization for the Synthesis of N -Substituted 2-Aminobenzimidazoles.

An electrochemical method for the synthesis of N -substituted 2-aminobenzimidazoles through a NaI-mediated desulfurization-cyclization process is reported. This electrosynthesis method utilizes cost-effective NaI as both a mediator and an electrolyte in a catalytic amount (0.2 equiv), replacing traditional oxidizing reagents. N -Substituted o -phenylenediamines and isothiocyanates undergo a thiourea formation/cyclization/desulfurization process to provide N -substituted 2-aminobenzimidazoles (55 examples, up to 98% yield) in a single reaction vessel. Importantly, this electrochemical methodology is applicable to gram-scale synthesis, maintaining reaction efficiency.