Synthesis of Methyl N-Phenyl Carbamate by Reaction of Aniline and Methyl Carbamate

摘要

Isocyanates are important intermediates for the manufacture of polyurethanes and pesticides. Commercially, isocyanates are synthesized by the reaction of phosgene and primary amines. Considerable interest has been devoted to find non-phosgene synthesis of isocyanates due to the toxicity of phosgene and the corrosion of by-product HCl. Methyl N-phenyl carbamate (MPC) is an important precursor for preparing isocyanates since it produces isocyanates and alcohols in good yields by thermal cracking. Accordingly, some methods without using phosgene for MPC synthesis, such as oxidative carbonylation of amines, reductive carbonylation of nitro compounds, and methoxycarbonylation of amines have previously been reported. In fact, MPC can also be synthesized by the reaction of aniline and methyl carbamate. This method is of significance since methyl carbamate can economically be produced by urea and methanol.