PAPER	Synthesis 2004: 37-42   DOI: 10.1055/s-2003-44374
© Georg Thieme Verlag Stuttgart · New York
Reagents for Efficient Conversion of Amines to Protected Guanidines
Tomasz Gers, Danuta Kunce, Paweł Markowski, Jan Izdebski*
Laboratory of Peptides, Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland Fax: +48(22)8225996; e-Mail: izdebski@chem.uw.edu.pl;
Received 16 June 2003

Abstract

Two new guanidinylation reagents, N,N′-bis(ortho-chloro-Cbz)-S-methylisothiourea and N,N′-bis(ortho-bromo-Cbz)-S-methylisothiourea, were compared with the already known N,N′-bis(Boc)-S-methylisothiourea and N,N′-bis(Cbz)-S-methylisothiourea. The new reagents proved to be superior to the known reagents. The reactions with all the new reagents were accelerated by addition of DMAP. N,N′-Bis(ortho-chloro-Cbz)- and N,N′-bis(ortho-bromo-Cbz)guanidines are stable when treated with trifluoroacetic acid and can be converted to guanidines by hydrogenolysis.

Key words

guanidine - guanidinylation - guanylation - isothiourea - protecting groups