Facile and Selective Synthesis of 2-Substituted Benzimidazoles Catalyzed by FeCl3/ Al2O3

Xiao-Yun Dong,Guo-Feng Chen

doi:10.1155/2012/197174

Abstract

2-Substituted benzimidazoles were synthesized in a single pot from aromatic aldehydes ando-phenylenediamine catalyzed by FeCl3/ Al2O3in DMF at ambient temperature attained good yields and high selectivity.

Highlights

Benzimidazole derivatives are important intermediates with their good biological and pharmacological properties in the organic synthesis[1]
The other method is that benzimidazoles have been prepared by classical cyclocondensation of o-phenylenediamine and aldehydes under oxidative conditions employing sulfamic acids[8], I29, In(OTf)[310], Sc(OTf)[311], activated carbon[12], FeCl3.6H2O13, H2O2/HCl14, sulfonic acid functionalized silica[15], DDQ16, NH4OAc17, IL18,sulfonium bromide[19], iodobenzene diacetate[20], air[21], AlKIT-522, mono and bifunctional solid Catalysts[23], scolecite[24], Copper(I) Chloride[25], manganese(III) acetate[26], silica-supported thionyl chloride[27] and SDS28 as catalysts
Phthalene-2,2'-diol[31] and diphenylmethane[32] to afford the desired products in higher yields. All of these results of FeCl3/Al2O3 spurred us to study its application for the synthesis of benzimidazoles, a very useful intermediates/subunits for the development of molecules of pharmaceutical or biological interest (Scheme 1)

Summary

Introduction

Benzimidazole derivatives are important intermediates with their good biological and pharmacological properties in the organic synthesis[1]. All of these results of FeCl3/Al2O3 spurred us to study its application for the synthesis of benzimidazoles, a very useful intermediates/subunits for the development of molecules of pharmaceutical or biological interest (Scheme 1).

Results

Conclusion