Non-phosgene route to unsymmetrical ureas from N-Cbz-α-amino acid amides

Abstract

A convenient method toward the synthesis of α-amino acid-derived unsymmetrical ureas 2 is described herein. This route involves an interesting rearrangement of amides of N-Cbz-α-amino acids 1, which presumably entails the intermediacy of hydantoins that is followed by hydrolysis to afford unsymmetrical ureas 2 in quantitative yields and high purity. © 2013 Elsevier Ltd. All rights reserved.