Synthetic Utility of carbonyl functionality and its Sulfur analogue in constructing Anticipated Biologically Active Heterocycles

Abstract

The current work illustrates the versatile role of 2-thioxobenzothiazinone moiety in the synthesis of different heterocyclic systems from simple readily obtainable materials. The work can be divided into four main parts:- i- Synthesis of 2-thioxobenzothiazinone and its reactions ii- Synthetic utility and chemical behaviour of 2-hydrazinylbenzothiazinone derivative iii- Synthetic utility and chemical behaviour of 2-(methylthio)-benzothiazinone iv- Study of biological activity of some synthesized compounds First part: Synthesis of 2-thioxobenzothiazinone and its reactions 2-Thioxo-1,2-dihydrobenzo[d][1,3]thiazin-4-one (1) and 1H-benzo[d][1,3]thiazine-2,4-dithione (2) have been synthesized via reaction of anthranilic acid and carbon disulfide (5 mL and / or 10 mL) in alcoholic potassium hydroxide heated to its refluxing temperature, respectively. The reactivity of benzothiazinone 1 towards some nucleophilic reagents namely, hydrazine hydrates and ammonium solution has been investigated and 2-hydrazinylbenzothiazinone derivative 3, and 2-aminoquinazolinone 4, have been obtained respectively. On the other hand the reactivity of benzothiazinone 1 towards some electrophilic reagents namely, methyl iodide in presence of potassium hydroxide and benzyl chloride in acetone containing anhydrous potassium carbonate has been investigated