Tertiary amines promoted synthesis of symmetrical 1,3-disubstituted ureas

Symmetrical 1,3-disubstituted ureas and cyclic ureas have been synthesized from corresponding isocyanates and diisocyanates by a new versatile, simple and quick method in the presence of tertiary amines at room temperature. The method under investigation has several advantages over the existing techniques, as it is simple to carry out; does not require complicated equipment; work-up is simple, as it does not use expensive chemicals. Moreover, the yields are almost quantitative. It has a potential for commercial applications in pharmaceutical chemistry.