An efficient new protocol for the formation of unsymmetrical tri- and tetrasubstituted ureas
作者:Robert A. Batey、V. Santhakumar、Chiaki Yoshina-Ishii、Scott D. Taylor
DOI:10.1016/s0040-4039(98)01330-6
日期:1998.8
A new method for producing unsymmetrical, tetrasubstituted ureas from N, N′-carbonyldiimidazole (CDI) is presented. Carbamoyl imidazolium salts are prepared from the reaction of CDI with a secondary amine, followed by alkylation with MeI. Secondary amines add with ease to imidazolium salts at room temperature to give unsymmetrical, tetrasubstituted ureas in excellent yields.
提出了一种由N,N'-羰基二咪唑(CDI)生产不对称四取代脲的新方法。氨基甲酰基咪唑鎓盐是由CDI与仲胺反应,然后与MeI烷基化制备的。在室温下,仲胺可以轻松地添加到咪唑鎓盐中,从而以极高的收率得到不对称的四取代脲。