Synthesis of N?-protected-L-lysine and ?-benzyl-L-glutamate N-carboxyanhydrides (NCA) by carbamoylation and nitrosation

• Published in: Amino acids Vol. 27; no. 2; pp. 161 - 167
• Main Authors: Vayaboury, W., Giani, O., Collet, H., Commeyras, A., Schu, F.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Nature B.V 01.10.2004
• ISSN: 0939-4451; 1438-2199
• DOI: 10.1007/s00726-004-0112-6

This paper reports on an original process to synthesize N-carboxyanhydrides, which consists of nitrosating N-carbamoylamino acids with a NO/O^sub 2^ gas mixture in acetonitrile. The synthesis of several N-carbamoylamino acids of L-lysine was described using potassium cyanate in water. The latter were then nitrosated to yield the corresponding NCA with more or less efficiency. Indeed, the NCA carrying an acid-sensitive protecting group led to a partial deprotection to give the L-lysine NCA salt. The NCA of N^sub ^-trifluoroacetyl-L-lysine, N^sub ^-benzyloxycarbonyl-L-lysine and γ-benzyl-L-glutamate were successfully synthesized with satisfactory yields. Their polymerizability was compared to that of the N^sub ^-trifluoroacetyl-L-lysine NCA initiated by n-hexylamine in N,N-dimethylformamide. It also showed that this new process of NCA synthesis could be applied to the synthesis of polypeptides and more generally to the protein chemistry.[PUBLICATION ABSTRACT]