TITLE:
Synthesis of Multifunctionalised 2-Substituted Benzimidazoles Using Copper (II) Hydroxide as Efficient Solid Catalyst
AUTHORS:
Murugulla Adharvana Chari, Zaied-A-Mosaa, Donthabakthuni Shobha, Sridhar Malayalama
KEYWORDS:
o-Phenylenediamine; Aldehydes; Copper (II) Hydroxide; Solid Catalyst; Multifunctionalised Benzimidazoles
JOURNAL NAME:
International Journal of Organic Chemistry,
Vol.3 No.4,
December
27,
2013
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.