Alternatives to Phosgene and Carbon Monoxide: Synthesis of Symmetric Urea Derivatives with Carbon Dioxide in Ionic Liquids

Simple, clean, safe, reproducible, and practical describes the synthesis of disubstituted urea derivatives, which are effectively synthesized from amines and carbon dioxide with a CsOH/ionic-liquid catalyst system. The products are easily separated and the catalytic system can be reused without deactivation (see picture).