Synthesis, Table of Contents 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 KonishiDepartment of Materials Science, Faculty of Engineering, Tottori University, Koyama-minami, Tottori 680-8552, JapanFax: +81(857)315263; e-Mail: kkoba@chem.tottori-u.ac.jp; Recommend Article Abstract Buy Article All articles of this category 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 Full Text References References For biological activities of 4H-1,4-benzothiazine derivatives, see: 1a Armenise D. Trapani G. Arrivo V. Laraspata E. Morlacchi F. J. Heterocycl. Chem. 2000, 37: 1611 1b Cecchetti V. Calderone V. Tabarrini O. Sabatini S. Filipponi E. Testai L. Spogli R. Martinotti E. Fravolini A. J. Med. Chem. 2003, 46: 3670 For previous reports on the synthesis and biological activity of 4H-1,4-benzothiazine-2-carbonitrile derivatives, see: 1c Kano S. Yuasa Y. Ono T. Shibuya S. Heterocycles 1979, 12: 681 1d Liso G. Trapani G. Berardi V. Latrofa A. Marchini P. J. Heterocycl. Chem. 1980, 17: 793 1e Schou SC. Hansen HC. Tagmose TM. Boonen HCM. Worsaae A. Drabowski M. Wahl P. Arkhammar POG. Bodvarsdottir T. Antonine M.-H. Lebrun P. Hansen JB. Bioorg. Med. Chem. 2005, 13: 141 2a Pippich S. Bartsch H. Heterocycles 1996, 43: 1967 2b Gupta R. Verma PS. Gupta RR. Heterocycl. Commun. 1998, 5: 479 2c Sharma PR. Gupta V. Gautam DC. Gupta RR. Phosphorus, Sulfur Silicon Relat. Elem. 2003, 178: 1483 ; and references cited therein 3 Kay DP. Kennewell PD. Westwood R. J. Chem. Soc., Perkin Trans. 1 1982, 1879 4 Cadman MLF. Crombie L. Freeman S. Mistry J. J. Chem. Soc., Perkin Trans. 1 1995, 1397
