4,4′-二苯甲烷二胺与碳酸二甲酯合成4,4′-二苯甲烷二氨基甲酸甲酯

Synthesis of Dimethyl 4,4′-Diphenylmethanedicarbamate by the Reaction of 4,4′-Diphenylmethanediamine with Dimethyl Carbonate

研究了无水乙酸锌〔Zn(CH3COO)2〕催化下4,4′-二苯甲烷二胺(MDA)与碳酸二甲酯(DMC)合成4,4′-二苯甲烷二氨基甲酸甲酯(MDC)的反应。用高效液相色谱/质谱/质谱联用仪对反应体系副产物进行了检测分析。结果表明,MDC生成的适宜工艺条件为:催化剂用量n〔Zn(CH3COO)2〕∶n(MDA)=5∶1,反应物配比n(DMC)∶n(MDA)=20∶1,反应温度180℃,反应时间2 h。在该条件下MDC收率为98%,MDA转化率100%。分析结果表明,主要副产物为单氨基甲酸酯和3种N-甲基化物。在上述基础上,讨论了N-甲基化物可能的生成机制和副产物的形成对MDC生成的影响。

Dimethyl 4, 4′-diphenylmethanedicarbamate （ MDC ） was synthesized from 4, 4′- diphenylmethanediamine （MDA） and dimethyl carbonate （DMC） over anhydrous zinc acetate. The optimum reaction conditions were n[ Zn （ CH3COO ） 2 ] ：n （ MDA ） = 5 ： 1, n （ DMC ） ： n （ MDA ） = 20： 1, reaction temperature 180 ℃ and reaction time 2 h. The yield of MDC was 98% while the conversion of MDA was 100% under these conditions. Meanwhile,the results of HPLC/MS/MS showed that the byproducts consisted of mono carbamate and three N-methylated derivatives. Based on works aforementioned, the possible formation mechanism of N-methylated derivatives and the effect of byproduct formation on the yield of MDC were discussed.