Synthesis of 4-Aryl-4-methyl- and 4,4-Dimethyl-4H-pyrrolo[2,1-c][1,4]benzothiazines by an Easy Five-Step Sequence Starting from 2-Sulfanylbenzenamines

Kazuhiro Kobayashi; Akane Hyota; Hideaki Kondo; Ayumi Imaoka

doi:10.1055/s-0032-1316769

Synthesis, Table of Contents

Synthesis 2012; 44(19): 3019-3026
DOI: 10.1055/s-0032-1316769

paper

Synthesis of 4-Aryl-4-methyl- and 4,4-Dimethyl-4H-pyrrolo[2,1-c][1,4]benzothiazines by an Easy Five-Step Sequence Starting from 2-Sulfanylbenzenamines

Authors

Kazuhiro Kobayashi*

Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan, Fax: +81(857)315263 Email: kkoba@chem.tottori-u.ac.jp
Akane Hyota

Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan, Fax: +81(857)315263 Email: kkoba@chem.tottori-u.ac.jp
Hideaki Kondo

Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan, Fax: +81(857)315263 Email: kkoba@chem.tottori-u.ac.jp
Ayumi Imaoka

Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan, Fax: +81(857)315263 Email: kkoba@chem.tottori-u.ac.jp

Abstract

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Abstract

A convenient process for the synthesis of 4-aryl-4-methyl- and 4,4-dimethyl-4H-pyrrolo[2,1-c][1,4]benzothiazines has been developed. Cyclization of 1-{2-[1-aryl(or methyl)ethenylsulfanyl]phenyl}pyrroles, which are readily obtained by an easy four-step sequence starting from commercially available 2-sulfanylbenzenamines, to the desired heterocycles can be effected in good to excellent yields on treatment with a catalytic amount of hydriodic acid.

Key words

4H-pyrrolo[2,1-c][1,4]benzothiazines - 2-sulfanylbenzenamines - hydriodic acid - magnesium amide - sulfur-stabilized carbenium ion

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References

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