Synthesis 2007(24): 3773-3775  
DOI: 10.1055/s-2007-990895
SHORTPAPER
© Georg Thieme Verlag Stuttgart · New York

A Convenient Preparation of 7-Bromo-2H-1,4-benzothiazine-3,5,8(4H)-trione and Its Application in the Synthesis of the Conaquinone B Skeleton

Ricardo A. Tapia*, Lorena Villalobos, Cristian Salas
Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 2609441, Chile
Fax: +56(2)6864744; e-Mail: rtapia@puc.cl.;
Further Information

Publication History

Received 11 May 2007
Publication Date:
15 November 2007 (online)

Abstract

7-Bromo-2H-1,4-benzothiazine-3,5,8(4H)-trione was synthesized by reaction of 5-bromo-2-nitro-1,4-benzoquinone with methyl thioglycolate followed by reductive cyclization and oxidation. The Diels-Alder reaction of the product quinone with myrcene afforded the expected naphthothiazine.