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Synthesis 2006(7): 1077-1082  
DOI: 10.1055/s-2006-926385
PAPER
© Georg Thieme Verlag Stuttgart · New York

A New Synthesis of 4H-1,4-Benzothiazine Derivatives Based on Ring Closure of EWG-Stabilized (2-Isocyanophenylthio)methyl Anions

Kazuhiro Kobayashi*, Kazutaka Hayashi, Daisuke Iitsuka, Osamu Morikawa, Hisatoshi Konishi
Department of Materials Science, Faculty of Engineering, Tottori University, Koyama-minami, Tottori 680-8552, Japan
Fax: +81(857)315263; e-Mail: kkoba@chem.tottori-u.ac.jp;
Further Information

Publication History

Received 6 October 2005
Publication Date:
08 March 2006 (online)

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Abstract

2-Cyano(phenylsulfinyl-, p-nitrophenyl-, or o-nitrophen­yl-)methylthiophenyl isocyanides were synthesized from 2-aminobenzenethiols and were shown to undergo ring closure to 2,4-disubstituted 4H-1,4-benzothiazine derivatives by deprotonation of the hydrogen adjacent to the sulfur atom with sodium hydride or potassium tert-butoxide, followed by trapping with various electrophiles.

Key words

benzothiazine - carbanion - heterocycle - isocyanide - ring closure

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