Low-Temperature Synthesis of Tetraalkylureas from Secondary Amines and Carbon Dioxide

Abstract

The reaction of dialkylamines with CO(2) giving tetraalkylureas can be performed at 60 degrees C. The reaction requires CCl(4), is weakly promoted by DMAN or PPh(3), and is not promoted by a Pd catalyst. A two-step procedure, in which dialkylammonium dialkylcarbamate is produced in situ and then reacted with CCl(4) and free dialkylamine, gave greater yields of urea than a simple single-stage procedure.