Tosic Acid-on-Silica Gel:A Cheap and Eco-friendly Catalyst for a Convenient One-pot Synthesis of Substituted Benzimidazoles

摘要

2-Substituted and 1,2-disubstited benzimidazoles were prepared efficiently from o-phenylenediamines and aryl aldehydes using p-toluenesulphonic acid (5 mol%)-on-silica gel as a cheap and environmentally benign catalyst.