Graphene Oxide (GO) as Sustainable Heterogeneous Carbocatalyst for Synthesis of Organic Carbamates Using Urea and Alcohols under Mild Reaction Conditions

A 2-Dimensional sp(2)-hybridised carbon based material graphene oxide (GO) was synthesized and characterized by various instrumental techniques viz. FTIR, PXRD, Raman, FESEM and HRTEM. The metal free environmentally benign carbocatalyst was fruitfully used as catalyst for the synthesis of primary carbamates from alcohols in presence of non hazardous cheap carbonyl source urea. Both aromatic (bezylic as well as phenolic) and aliphatic alcohols produced moderate to very high yield (53-95 %) of corresponding carbamates through this catalytic reaction. The used GO catalyst is very straightforward to recover from reaction mixture via centrifugation method. The heterogeneous and reusability nature of the catalyst exists several cycles of catalytic reaction. We check six cycles of the catalytic reaction and the activity of the catalyst after 6(th) cycle does not alter very significantly.