Solvent-free synthesis of substituted ureas from CO2 and amines with a functional ionic liquid as the catalyst

摘要

The synthesis of disubstituted ureas from amines and CO2 were carried out using a basic ionic liquid (IL) 1-n-butyl-3-methyl imidazolium hydroxide ([Bmim]OH) as the catalyst.The effects of reaction time,amount of [Bmim]OH,reaction temperature,pressure,and solvent on yields of the products were investigated.The results indicated that aliphatic amines,cyclohexylamine,and benzylamine could be converted to the corresponding ureas selectively in moderate yields under solvent-free conditions without using any dehydrating regent.The IL could be reused after a simple separation procedure.