An improved large scale procedure for the preparation of N-Cbz amino acids

A simple and scalable method for the preparation of N-Cbz protected amino acids is presented which uses a mixture of aqueous sodium carbonate and sodium bicarbonate to maintain the appropriate pH during the addition of benzyl chloroformate. The method has been extended to other N-protections and is amenable to large scale preparation of an intermediate toward Zofenopril, an ACE inhibitor. © 2011 Elsevier Ltd. All rights reserved.Ashok D. Pehere and Andrew D. Abellhttp://www.elsevier.com/wps/find/homepage.cws_hom