Efficient preparation of acidic ionic liquid-functionalized reduced graphene oxide and its catalytic performance in synthesis of benzimidazole derivatives

摘要

This article reports an efficient method with a simple workup for the facile synthesis of benzimidazole derivatives using an acidic ionic liquid covalently supported on graphene sheets. The catalyst was efficiently synthesized and characterized using FTIR, scanning electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction techniques. The catalytic organic reaction was performed in different conditions. Among the various catalysts, A-FGO is an excellent catalyst in the reaction. A wide variety of aldehydes were used under optimal reaction conditions to synthesis benzimidazole derivatives. The reaction conditions are mild and the workup method is simple as well as giving high yields. All synthesised products were characterised using melting point, FTIR, H-1 NMR, C-13 NMR and CHN techniques. At the end of the reaction, the catalyst was recovered by a simple filtration, washed with dichloromethane, dried and then reused in successive reactions. Products were obtained at the same purity as in the initial runs. Shorter reaction times, high yields, safer reaction condition, the eco-friendly nature and possible reuse of the catalyst make these methods an efficient contribution to the current processes within the field of benzimidazole derivatives synthesis.