PAPER	Synthesis 2006: 461-466   DOI: 10.1055/s-2006-926284
© Georg Thieme Verlag Stuttgart · New York
Amidination of Amines under Microwave Conditions Using Recyclable Polymer-Bound 1H-Pyrazole-1-carboxamidine
Wladimir Solodenkoa, Patrick Brökera, Josef Messingerb, Uwe Schönb, Andreas Kirschning*a
a Institut für Organische Chemie, Universität Hannover, Schneiderberg 1b, 30167 Hannover; Germany Fax: +49(511)7623011; e-Mail: andreas.kirschning@oci.uni-hannover.de; b Solvay Pharmaceuticals Research Laboratories, Hans-Böckler-Allee 20, 30173 Hannover, Germany
Received 18 July 2005

Abstract

A convenient one-step transformation of primary and secondary amines into the corresponding unprotected guanidines using 4-benzyl-3,5-dimethyl-1H-pyrazole-1-carboxamidine and its polymer-bound variant is described. The scopes and limitations of the method, the microwave-assistance of amidination as well as a recycling protocol are examined.

Key words

amines - guanidines - polymer-bound reagent - microwave-assisted synthesis - reagent regeneration