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, tetrasubstitutedureas 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, tetrasubstitutedureas in excellent yields.