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• 23474-98-8 2-amino-5-chlorobenzenethiol 
• 95-24-9 6-chloro-2-aminobenzothiazole 

Relevant academic research and scientific papers

Facile synthesis of bioactive 4H-[1,4]-benzothiazines under solvent free conditions

An efficient method for synthesis of 4H-[1,4]-benzothiazines under solvent free conditions has been developed. The oxidative condensation of 2-aminobenzenethiols with β-diketones/β-ketoesters in presence of catalytic amount of hydrazine hydrate yields the 4H-[1,4]-benzothiazines. The reaction is accelerated by microwave irradiation under solvent free conditions in presence of an energy transfer agent DMF to get the product in high yield. The 2-aminobenzenethiazole required for the synthesis of 4H-[1,4]-benzothiazines are also obtained by a new method instead of presently used time consuming and low yielding method. The structure of the synthesized compounds has been characterized by IR, NMR, mass spectral studies and elemental analysis.

Synthesis of a series of 2,3-disubstituted 4H-1,4-benzothiazines and X-ray crystal structure of ethyl 7-chloro-3-methyl-4H-1,4-benzothiazine-2-carboxylate

The reaction between 2-aminobenzenethiol and ethyl acetoacetate is studied under a variety of conditions, and a procedure for the exclusive synthesis of 1,4-benzothiazines by the neat reaction of substituted aminothiols with β-ketoesters and β-dicarbonyl compounds in 85-96% yield is described. With microwave heating, even when both the reactants are solid, yields are high, reaction times brief, and work-up easy. A facile reaction is also observed even in a solid-state reaction. The molecular structure of ethyl 7-chloro-3-methyl-4H-1,4-benzothiazine-2-carboxylate (4d) was determined by single-crystal X-ray diffraction.

Diamagnetic Susceptibilities of 4H-1,4-Benzothiazines

The experimental diamagnetic susceptibilities of a number of 4H-1,4-benzothiazines (I) have been measured.Diamagnetic susceptibilities of compounds (I) have also been estimated considering these molecules to be made of two structural units; one consisting of o-aminobenzenethiol containing the substituents and the other consisting of β-diketones/β-ketoesters.Diamagnetic susceptibily contributions of these two structural units have been calculated.The divergence between calculated and experimental values of diamagnetic susceptibilities of I is less than 1.5percent.Such an excellent agreement between calculated and experimental values is attributed to the fact that almost all the structural interactions caused by substituents have been accounted for in these calculations by considering the above two structural units.

A CONVENIENT AND SINGLE STEP SYNTHESIS OF SUBSTITUTED 4H-BENZOTHIAZINES.

A simple one step synthesis is reported for substituted 4H-benzothiazines involving the condensation of 5-(chloro, bromo, methyl, methoxy, ethoxy)-, 4-methyl- and 3-(chloro and methoxy)-2-aminobenzenethiols with acetylacetone/ethyl acetoacetate/dibenzoylmethane in DMSO.