A general and practical method for the preparation of unsymmetrically substituted ureas has been developed. By the reactions of acetoacetanilides with various amines including primary/secondary amines, a series of substituted aryl ureas were achieved in high yields. Acetoacetanilide substrates can be considered as masked reagents that liberate reactive isocyanates in situ.
Regioselective bromination of aryl ureas with Phenyliodine(III) diacetate and potassium bromide
作者:Chun-Meng Wang、Jian-Yao Du、Jin-Yang Zhang、Kai-Xiang Tang、Tian-Hong Gao、Yun-Gen Xu、Li-Ping Sun
DOI:10.1016/j.tet.2019.130621
日期:2019.11
An efficient regioselective and operationally simple urea bromination method utilizing PIDA and potassium bromide is reported. This protocol proved to be effective on a broad range of substituted ureas in acetone at room temperature, forming the p-brominated compounds in 44–86% yields.