Synthesis of Multifunctionalised 2-Substituted Benzimidazoles Using Copper (II) Hydroxide as Efficient Solid Catalyst

Abstract

Here we demonstrate the synthesis of multifunctionalised benzimidazoles through the coupling of o -phenylenediamine with aldehydes by using Copper (II) hydroxide as an efficient solid catalyst in methanol at room temperature. The Copper (II) hydroxide solid catalyst gave better yields (80% - 99%) in short reaction time (4 - 8 h) . These commercially available cheap catalysts are more active than many reported expensive heterogeneous catalysts. Using the Copper hydroxide fresh catalyst, the yield of product 3a was 98%, while the recovered catalyst in the three subsequent cycles gave the yield of 94%, 90% and 88% respectively.