Phosgene-Free Synthesis of Carbamates Using CO2 and Titanium Alkoxides

Abstract

Abstract A facile one-pot, phosgene-free method for the synthesis of N-phenylcarbamates is developed. Using this method, various aromatic carbamates could be prepared from aromatic amines, CO2 and metal alkoxides. Aniline reacted with titanium methoxide (Ti(OMe)4) in the presence of CO2 (5 MPa) to give methyl N-phenylcarbamate in 85% yield, in 20 min. Titanium residue could be regenerated by reaction with dimethyl carbonate at 220 °C for 16 h.