One-Pot Telescopic Approach to Synthesize Disubstituted Benz­imidazoles in Deep Eutectic Solvent

An ongoing challenge in the pharmaceutical sector is the need to find and implement novel synthetic approaches because traditional methods sometimes violate the principles of green chemistry. While benzimidazoles are of great importance as building blocks for the creation of molecules having pharmacological activity, the development of methods for their sustainable synthesis has been a challenge for organic synthesis. Herein, we have carried out a one-pot telescopic approach to the synthesis of disubstituted benzimidazole derivatives in a deep eutectic solvent (DES) medium to investigate an alternate synthetic technique. Starting with methyl 4-fluoro-3-nitrobenzoate, SNAr reaction, reduction, and cyclization were performed with choline chloride/glycerol/H2O as DES medium, which gave the best performance out of the five DESs examined. We report the synthesis of disubstituted benzimidazoles via one-pot telescopic approach.