Graphene Oxide: An Efficient and Recyclable Nano Catalyst for the Synthesis of 2-Substituted Benzimidazoles from Aldehydes and Diamines at Ambient Temperature

Abstract

The benzimidazoles skeleton, a category of heterocyclic compounds have important biological and pharmaceutical properties such as antihelminthic, antiulcer, diuretic, anticonvulsant, analgesic, antiulcer, antihypertensive, anticoagulant, anticancer, anti-inflammatory, antimicrobial, antiviral, antiparasitic and antioxidant. On the other hand, graphene oxide due to their operational simplicity, easy work up and inherent non-toxic, and possessing a wide variety of functional groups, such as epoxy, hydroxyl, and carboxyl, pays an important role in organic synthesis. Therefore, in this chapter graphene oxide was investigated as an efficient catalytic system for the preparation of benzimidazole compounds via the condensation reaction of o-phenylenediamines with aromatic aldehydes in very good yields at ambient temperature. The results in this method were compared with previously reported in literature respectively. Also graphene oxide was recovered and reused without decreasing in its efficacy for 3 th runs.

Facile and an efficient one-pot synthesis of 2-arylbenzoxazoles promoted by transition metal oxide nano catalyst

“…The biological features exhibited by molecules containing benzoxazole moieties make them desirable candidates for synthesis. The synthesis of benzoxazoles has been the subject of many attempts due to their widespread presence in pharmaceuticals [5,6], natural products, and functional materials. The pharmacological activity of these heterocycles include Antimicrobial agents [7-8], anti-inflammatory, analgesic [6,9], Alzheimer,, Antiprotozoal Agents[12], A distinct and extensive class of antirhino / enteroviral…”