Synthesis 2008(8): 1257-1261  
DOI: 10.1055/s-2008-1042945
PAPER
© Georg Thieme Verlag Stuttgart · New York

Iodobenzene-Catalyzed Preparation of 3,4-Dihydro-1H-2,1-benzothiazine 2,2-Dioxides from 2-Aryl-N-methoxyethanesulfonamides with m-Chloro­peroxybenzoic Acid

Atsushi Moroda, Hideo Togo*
Graduate School of Science, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522, Japan
e-Mail: togo@faculty.chiba-u.jp;
Further Information

Publication History

Received 19 November 2007
Publication Date:
18 March 2008 (online)

Abstract

Iodobenzene-catalyzed cyclization of 2-aryl-N-meth­oxyethanesulfonamides with m-chloroperoxybenzoic acid results in the corresponding 1-methoxy-3,4-dihydro-1H-2,1-benzothiazine 2,2-dioxides in moderate to good yields. In this reaction, reactive hypervalent iodine [(hydroxy)(tosyloxy)iodo]benzene, formed in situ, reacts with the 2-aryl-N-methoxyethanesulfonamides in an electrophilic manner at the aromatic ring to give the corresponding 1-methoxy-3,4-dihydro-1H-2,1-benzothiazine 2,2-dioxides.