PAPER	Synthesis 2004: 1655-1663   DOI: 10.1055/s-2004-829130
© Georg Thieme Verlag Stuttgart · New York
Optimisation of the Synthesis of Guanidines from Amines via Nitroguanidines Using 3,5-Dimethyl-N-nitro-1H-pyrazole-1-carboxamidine
Joel A. Castillo-Meléndez*, Bernard T. Golding*
School of Natural Sciences - Chemistry, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, UK e-Mail: Joel.Castillo@hut.fi; e-Mail: B.T.Golding@ncl.ac.uk ;
Received 10 March 2004

Abstract

The synthesis of the useful reagent for the preparation of guanidines, 3,5-dimethyl-N-nitro-1-pyrazole-1-carboxamidine (DMNPC), has been optimised. A detailed protocol for using this reagent for the preparation in pure form of a range of guanidines via nitroguanidines is described. A comparison has been made regarding efficiency between DMNPC and the guanidinylating reagents N,N′-bis-Boc-1-pyrazole-1-carboxamidine (2) and N,N′-bis-Boc-N′-triflylguanidine (3).

Key words

guanidinylation - 3,5-dimethyl-N-nitro-1-pyrazole-1-carboxamidine - hydrogenolysis - ion exchange chromatography