【摘要】 二苯甲烷二氨基甲酸甲酯(MDC)是非光气法合成二苯甲烷二异氰酸酯(MDI)的中间体。以硫酸为催化剂,盐酸盐为助剂,研究了苯氨基甲酸甲酯(MPC)与甲醛缩合制备MDC的反应。对助剂盐酸盐进行了筛选,发现氯化铜的效果较好,其MPC转化率达96%,4,4-′MDC产率可达76.7%。反应条件为:m(硫酸)∶m(MPC)=4∶1,n(MPC)∶n(HCHO)=1∶1,氯化铜用量为MPC物质的量的5.4%,100℃下反应3 h。将氯化铜分别与氯化镧和氯化亚铈以物质的量的比1∶1复合使用,发现单独使用氯化铜的效果好于复合盐酸盐的效果。分别使用甲醛溶液、三聚甲醛和多聚甲醛为亚甲基化剂,发现价廉易得的甲醛溶液效果最好。更多还原

【Abstract】 Methyl methylene di（phenylene carbamate）（MDC） was the intermediate for synthesis of diphenylmethane diisocyanate via non-phosgene route.Condensation of methyl N-phenyl carbamate（MPC） with formaldehyde to methyl methylene di（phenylene carbamate） catalyzed by sulfuric acid with chloride as the promoter was investigated.CuCl₂ was found to be an effective promoter.4,4′-MDC yield of 76.7% and MPC conversion of 96% were obtained under the following condition:（m（30% H₂SO₄））∶m（MPC） = 4∶1;n（inorganic salt）∶n（MPC） = 5.4∶100;n（MPC）∶（n（HCHO） =） 1∶1,reaction time 4 h,temperature 100 ℃.Effects of different promoters（CuCl₂-LaCl₃,CuCl₂-CeCl₂,CuCl₂） were compared,which showed that CuCl₂ was superior to CuCl₂-LaCl₃ and CuCl₂-（CeCl₂）.Formaldehyde,as methylene agent,was superior to trioxymetylene and paraformaldehyde.更多还原