Aqueous 1 M Glucose Solution as a Novel and Fully Green Reaction Medium and Catalyst for the Oxidant-Free Synthesis of 2-Arylbenzimidazoles

Abstract

The reaction of various o-phenylenediamines and substituted benzaldehydes was carried out in 1 M glucose solution as reaction medium and catalyst under one-pot oxidant-free conditions. The desired products were obtained at 60 °C with good to excellent yields, and the reaction was performed chemoselectively without formation of 1,2-disubstituted benzimidazoles. No need for any extra oxidant, simple workup, and use of carbohydrates as fully green promoters are some advantages of the present work.

Keywords:

• 2-Arylbenzimidazoles
• 1 M glucose solution
• o-phenylenediamine
• Schiff bases
• oxidant-free conditions

ACKNOWLEDGMENT

The authors gratefully acknowledge the Research Council of K. N. Toosi University of Technology for partial financial support of this work.

Notes

^a Reaction conditions: o-phenylenediamine (1 mmol), benzaldehyde (1 mmol), and different volumes of aqueous 1 M glucose solution.

^b Isolated yield.

^a Isolated yield.