tert-butyl 3-(4-cyano-5-phenylisothiazol-3-yl)carbazate叔丁基3 -(4-cyano-5-phenylisothiazol-3-yl)carbazate.pdfVIP

Molbank 2009, M628 OPEN ACCESS molbank ISSN 1422-8599 /journal/molbank Short Note tert-Butyl 3-(4-Cyano-5-phenylisothiazol-3-yl)carbazate Heraklidia A. Ioannidou and Panayiotis A. Koutentis * Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus * Author to whom correspondence should be addressed; E-Mail: koutenti@ucy.ac.cy. Received: 22 September 2009 / Accepted: 10 October 2009 / Published: 12 October 2009 Abstract: 3-Iodo-5-phenylisothiazole-4-carbonitrile 1 reacts with tert-butyl carbazate via a Buchwald C-N style coupling to afford tert-butyl 3-(4-cyano-5-phenylisothiazol-3-yl)- carbazate 2 in 70% yield. Keywords: isothiazole; hydrazine; Buchwald coupling We recently attempted to synthesize 3-hydrazinyl-5-phenylisothiazole-4-carbonitrile by reaction of 3-chloro-5-phenylisothiazole-4-carbonitrile with hydrazine, but obtained instead 3-amino-5- phenylpyrazole-4-carbonitrile [1]. A more detailed investigation of this isothiazole to pyrazole transformation, led to the preparation of both 4-bromo-5-phenyl and 4,5-diphenylisothiazol-3-yl- hydrazines by treating the respective 3-haloisothiazoles with anhydrous hydrazine for short durations at elevated temperatures [2]. Despite this success, attempts to prepare the desired 3-hydrazinyl-5- phenylisothiazole-4-carbonitrile were unsuccessful. An alternative strategy to access 3-hydrazinyl-5-phenylisothiazole-4-carbonitrile involved preparing the title compound via modified Buch