Synthesis 2009(24): 4167-4174  
DOI: 10.1055/s-0029-1217059
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

The Synthesis of 2-Cyano-cyanothioformanilides from 2-(4-Chloro-5H-1,2,3-dithiazol-5-ylideneamino)benzonitriles Using DBU

Sophia S. Michaelidou, Panayiotis A. Koutentis*
Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
Fax: +357(22)892809; e-Mail: koutenti@ucy.ac.cy;
Further Information

Publication History

Received 30 June 2009
Publication Date:
19 October 2009 (online)

Abstract

A series of 2-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)benzonitriles were prepared from the reaction of 4,5-dichloro-1,2,3-dithiazolium chloride (Appel salt) and the corresponding anthranilonitriles. Reaction of the 1,2,3-dithiazolimines with DBU (3 equiv) at -5 ˚C gave the corresponding 2-cyano-cyanothioformanilides in near quantitative yields. Treatment of 2-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)benzonitrile with DBU (4 equiv) at -5 to +20 ˚C gave 2-isothiocyanatobenzonitrile in 96% yield. The latter compound was also formed directly from 2-cyano-cyanothioformanilide on treatment with DBU (1 equiv) in 95% yield. A tentative mechanism for the DBU-mediated dithiazole to cyanothioformanilide transformation is proposed and all compounds were fully characterized.