A novel non-phosgene approach to the synthesis of methyl N-phenyl carbamate by a reaction of methanol with phenylurea

A novel non-phosgene process for the synthesis of methyl N-phenyl carbamate (MPC) by a reaction of phenylurea with methanol was studied. The reaction between phenylurea and methanol was found to be a spontaneous reaction that took place in the absence of catalyst and gave MPC as the main product. Addition of a catalyst markedly influenced the reaction behavior. A basic catalyst greatly enhanced the yield of MPC, whereas an acidic catalyst promoted the formation of aniline and methyl carbamate. Moderate strength of basicity showed the best catalytic performance in the cases studied. The mechanism of reaction and catalyst functioning was discussed.