Synlett 2016; 27(18): 2591-2596
DOI: 10.1055/s-0035-1562478
letter
© Georg Thieme Verlag Stuttgart · New York

Facile Guanidine Formation under Mild Acidic Conditions

Kohei Takeuchi
b   Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
,
Atsushi Nakayama
a   Department of Phamaceutical Science, Tokushima University, 1-78 Shomachi, Tokushima 770-8505, Japan   Email: namba@tokushima-u.ac.jp
,
Keiji Tanino
c   Department of Chemistry, Faculty of Science, Hokkaido University, Kita-ku, Sapporo 060-0810   Japan   Email: ktanino@sci.hokudai.ac.jp
,
Kosuke Namba*
a   Department of Phamaceutical Science, Tokushima University, 1-78 Shomachi, Tokushima 770-8505, Japan   Email: namba@tokushima-u.ac.jp
› Author Affiliations
Further Information

Publication History

Received: 31 May 2016

Accepted after revision: 23 June 2016

Publication Date:
01 August 2016 (online)


Abstract

An efficient method for converting isothioureas into guanidines was developed. The use of amine salts of bis(trifluoromethanesulfonyl)imide as a nitrogen source was found to induce an efficient conversion under weak acidic conditions at 50 °C. The conversion was applicable to the various amines and carbamate-protected thioureas, and various carbamate-protected cyclic guanidines were obtained in high yields. In particular, ammonium bis(trifluoromethanesulfonyl)imide salt is a useful N1 source with which to construct monoprotected cyclic guanidines.

Supporting Information