1,4-Benzothiazines-A Biologically Attractive Scaffold.

1,4-benzothiazine (1,4-B), a pharmacophore of anti-psychotic drug phenothiazines, is a vital class of heterocyclic compounds implicating versatile biological activities. The aim of this review article is to summarize various synthetic strategies, biological activities and structure activity relationship concerning the bioactive heterocycle, 1,4-B. Synthetic chemists have discovered numerous routes for the syntheses of various 1,4-B analogues that show excellent activities through multiple mechanisms. The direct comparison of activities with the parent 1,4-B derivatives enables a systematic analysis of the structure activity relationship (SAR) among the series. This review article is an effort to compile the progress in the chemistry, biological activity and SAR of 1,4-benzothiazine in a systematic way. The previously explored insights included in this article collectively suggests that 1,4-benzothiazines (1,4-Bs), besides offering several interesting biological activities, have a tremendous ability to regulate various types of cancer. The previous work on the present nucleus summarized in this article will help the researchers to design their work based on 1,4-benzothiazine ring.