作者:Andrey V. Bogolubsky、Sergey V. Ryabukhin、Sergey E. Pipko、Oleg Lukin、Alexander Shivanyuk、Dmytro Mykytenko、Andrey Tolmachev
DOI:10.1016/j.tet.2011.03.101
日期:2011.5
versatile method for the synthesis of unsymmetrical ureas from readily available reagents is reported. In the first step trifluoroethylchloroformate is reacted with a stoichiometric amount of a primary amine to give an intermediate trifluoroethyl carbamate. The addition of a second amine (primary or secondary) to the trifluoroethyl carbamate furnishes corresponding unsymmetrical ureas in 75–85% yield. A
报道了一种由容易获得的试剂合成不对称脲的简便而通用的方法。在第一步中,使三氟乙基氯甲酸酯与化学计算量的伯胺反应,得到中间体三氟乙基氨基甲酸酯。在氨基甲酸三氟乙酯中添加第二种胺(伯胺或仲胺)可提供相应的不对称脲,产率为75-85%。简单的后处理程序,获得的高收率和分离产物的纯度适用于具有高结构和功能多样性的不对称脲组合库的平行合成。