无机碱催化胺与CO2有效转化制备有机脲化合物

Preparation of organic urea compounds by efficient conversion of amines and CO2 catalyzed by inorganic bases

摘要:

本文直接以CO2和有机胺为原料制备有机脲类化合物,反应过程中无任何脱水剂参与,通过优化反应的温度、压力、浓度、时间、溶剂、催化剂与助剂种类及用量等因素,获得了最佳反应条件：在温度为190℃、二氧化碳压力为4.5MPa、以无机碱Cs2CO3为催化剂、Bu4NBr为助剂、N-甲基吡咯烷酮(NMP)为溶剂,反应浓度为6.67 mmol/mL的条件下反应6小时,以良好的产率制备了15种对称型不同烷基或芳基取代的有机脲类化合物,分离产率可达42%~80%,采用1H NMR和13C NMR对其结构进行了表征,并分析了反应可能的机理。该方法具有方便高效、环境友好和原子经济的特点。关键词：二氧化碳；有机胺；无机碱；对称型有机脲；机理中图分类号：O622 文献标识码： A 文章编号：1003-5214 (2020) 01-0000-00

Abstract:

Organic urea compounds were prepared directly using CO2 and organic amines as raw materials without any dehydrating agent participating in the reaction process, the optimal reaction conditions were obtained by optimizing factors such as temperature, pressure, concentration, time, solvent, type and dosage of catalysts and additives. The reaction conditions were as follows: at a temperature of 190℃, carbon dioxide pressure of 4.5 MPa, inorganic base Cs2CO3 as catalyst, Bu4NBr as additive, and N-methyl pyrrolidone (NMP) as solvent, reaction concentration of 6.67mmol/mL, after 6 hours of reaction, 15 symmetric organic urea compounds with different alkyl or aryl substitutions were prepared in good yields, with yields ranging from 55% to 80%. Their structures were characterized using 1H NMR and 13C NMR, and possible reaction mechanisms were analyzed. This method has the characteristics of convenience, efficiency, environmental friendliness, and atomic economy.