Synfacts 2009(2): 0138-0138  
DOI: 10.1055/s-0028-1087570
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

The Gewald Synthesis of 2-Aminothiophenes using Activated Sulfur

Contributor(s): Victor Snieckus, Toni Rantanen
M. Feroci*, I. Chiarotto, L. Rossi, A. Inesi*
University ”La Sapienza", Rome and Università degli Studi, L’Aquila, Italy
Further Information

Publication History

Publication Date:
22 January 2009 (online)


Reported is the use of an activated form of sulfur in the classical Gewald synthesis of substituted 2-aminothiophenes from ylidene­malononitriles which are easily obtained from ­malononitrile and the corresponding ketones. ­Activation of elemental sulfur was carried out by means of electrogenerated cyanomethyl anion, obtained by galvanostatic reduction from MeCN/Et4NPF6 system. The substrate scope was poorly studied as only two examples were reported involving a different ylidene (R¹ = CONH2 or CO2Et).