苯基脲与甲醇合成苯氨基甲酸甲酯的研究

Synthesis of Methyl N-Phenyl Carbamate from Methanol and Phenyl Urea

采用苯基脲与甲醇反应合成了苯氨基甲酸甲酯 ,考察了不同催化剂、原料配比及反应工艺条件的影响 ,确定了适宜的合成条件 ,并根据产物分布对催化反应机理进行了初步探讨 .结果表明 ,以 Pb O为催化剂 ,于 1 40℃反应 4h后 ,苯基脲转化率为 95 .2 % ,苯氨基甲酸甲酯收率为 80 .6% .

In this paper, methyl N-phenyl carbamate(MPC) was firstly synthesized from methanol and phenyl urea. The effects of catalysts, including PbO, Pb 3O 4, Pb/SiO 2, ZnCl 2, FeCl 3, Mo/HZSM-5 and Pb/HZSM-5, material ratio and reaction condition on the synthesis of MPC were investigated, and the optimum reaction conditions were obtained. It was found that PbO showed a higher catalytic activity and MPC selectivity than those of other catalysts. The selectivity of MPC decreased while the conversion of phenyl urea increased with the increase of reaction temperature. Prolonging the reaction time enhanced the conversion of phenyl urea while suppressed the formation of MPC. Higher methanol/phenyl urea molar ratio favored the formation of MPC. The conversion of phenyl urea and the yield of methyl N-phenyl carbamate were reached 95.2% and 80.6%, respectively, under the optimum reaction conditions at 140 ℃ after 4 h reaction. The reaction mechanism was discussed based on the distribution of products.