2,1-Benzothiazines, literature

Compounds containing a benzodioxole moiety are oxidized by CYPs to generate a carbene that forms a tightly bound complex with the heme iron, easily measurable by UV-Vis spectroscopy. There are numerous examples in the literature paroxetine, MDP alkylamines, MDP benzothiazines, MDP benzothiazolines and MDP piperazines (see Scheme 11.2) [54—60],... 

In recent years there has been a dramatic increase in the number of literature references to 1,2-benzothiazines (1) and 2,1-benzothiazines (2). Prior to 1956, the only reference was that published in 1923 by von Braun.1 In the last 15 years, however, many publications have presented interesting chemistry and important applications. Much of the literature deals with anti-inflammatory 1,2-benzothiazines ( oxicams ) such as piroxicam. The... 

Literature reports on heterocyclic compounds containing a 1,2- or 2,1-benzothiazine ring have appeared in increasing numbers in recent years. This trend is likely to continue as a result of the anti-inflammatory activity of 4-hydroxy-2H-l,2-benzothiazine-3-carboxamide 1,1-dioxides (the oxicams ). 

After completion of this article, a 21-page review on all possible benzothia-zinone dioxides, including 1,2- and 2,1-, as well as 1,3-, 2,3-, 1,4-, and 2,4-benzothiazinones, appeared.165 By restricting their subject to 3-one and 4-one derivatives, these authors found 71 literature references to the 1,2-and 2,1-benzothiazinone dioxides. The present chapter discusses these references and a significantly larger number of patents and scientific articles dealing with all 2,1- and 1,2-benzothiazines. 

Aminobenzenethiol reacts readily with carbonyl compounds to give 1,3-benzothiazoles (63).106 Certain derivatives of this ring system have been found to undergo ring expansion under specific conditions to give benzothiazines. The first report in the literature of this type of reaction involved the treatment of benzothiazolium salt 64 with base the postulated mechanism12 is shown in Scheme 1. 

Proton NMR spectra of benzothiazines are not discussed in this review because most of the structures in the literature have a fully substituted thiazine ring. However, C NMR has been very effectively used in the structure elucidation of benzothiazines. For example, the data in Table 5... 

Benzothiazines have not been studied since the early 1970s, and there are only a few passing references to these compounds in the literature <9lLA83l>. 

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