Synthesis of carbamates from aliphatic amines and dimethyl carbonate catalyzed by acid functional ionic liquids

Selective synthesis of carbamates from amines and dimethyl carbonate were studied in the presence of various ionic liquids as catalysts. The –SO3H-functionalized ionic liquid was found to be the most active catalyst among the applied ionic liquids, and nearly 100% conversion and 95% selectivity were achieved when using 1,6-hexanediamine as reactant. The acid functional ionic liquid catalyst system is also readily separable and reusable after reaction. © 2007 Elsevier B.V. All rights reserved.