Preparation of organic urea compounds by efficient conversion of amines and CO2 catalyzed by cesium carbonate
Organic urea compounds were prepared directly from CO2 and organic amines without any dehydrating agent participating in the reaction process.With regulation of factors such as temperature,pressure,reactant concentration,time,solvent,type and dosage of catalysts and additives,the optimal reaction conditions were obtained as follows:temperature of 190℃,carbon dioxide pressure of 4.5 MPa,inorganic salt Cs2CO3 as catalyst,n-Bu4NBr as additive,and N-methyl pyrrolidone(NMP)as solvent,amine of 6.67 mol/L,reaction time of 6 h(certain reaction 24 h),15 symmetric organic urea compounds with different alkyl or aryl substitutions prepared under the optimal reaction conditions exhibited separation yields ranging from 42%to 80%.The compounds obtained were then characterized by 1HNMR and 13CNMR,and analyzed for possible reaction mechanism exploration.This method showed characteristics of convenience,efficiency,environmental friendliness,and atomic economy.
carbon dioxideorganic aminesinorganic salt cesium carbonatesymmetric organic ureasmechanismfine chemical intermediates
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