Two-step synthesis of amino-methyl-N-phenylcarbamate from toluidine: New preparative method and mechanism

Abstract

Amino-methyl-N-phenylcarbamate (TMC) is an important organic intermediate. In this study, a new two-step route, i.e., methoxycarbonylation and direct amination reaction, was designed for synthesis of TMC. During this process, p-Toluidine first reacted with dimethyl carbonate to form metholylcarbamate (MTCM), and then MTCM further converted to TMC via direct amination reaction. It was found that in methoxycarbonylation process, Zn(OAc)2 catalyst was a better choice and p-Toluidine was almost completely converted into MTCM, corresponding to 99% p-Toluidine conversion and 95.4% MTCM yield. As for direct amination reaction, Fe-V/ZSM-5 bimetallic catalyst was selected and high yield of total TMC was obtained at 69.6%. The catalyst characterization results showed that the synthesized bimetallic catalysts retained the structural features of ZSM-5, while the abundance of metal ions on the surface promoted the reaction