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