17584-59-7

Upstream product

• 616-02-4 citraconic acid anhydride 
• 137-07-5 2-amino-benzenethiol 
• 7190-67-2 threo-2-methyl-3-(2-nitro-phenylsulfanyl)-succinic acid anhydride 
• 7190-68-3 erythro-2-methyl-3-(2-nitro-phenylsulfanyl)-succinic acid 

Downstream Products

• 7197-00-4 2-(3-Oxo-2H-3,4-dihydro-benzo-1,4-thiazin-2-yl)-propionsaeure-methylester 
• 7197-00-4 2-(3-Oxo-2H-3,4-dihydro-benzo-1,4-thiazin-2-yl)-propionsaeure-methylester 
• 820968-52-3 3-methyl-2H-furo[3,2-b][1,4]benzothiazin-2-one 
• 17547-89-6 Methyl α-(2,3-dihydro-3-oxo-1,4-benzothiazin-2-yl)propionate 

Relevant academic research and scientific papers

A synthesis of a novel heterocyclic system: 2H-furo[3,2-b][1,4] benzothiazin-2-one

A synthesis of 3-methyl-2H-furo[3,2-b][1,4]benzothiazin-2-ones (10a,b) is described. o-Aminothiophenols (1a,b) undergo condensation with citraconic anhydride followed by cyclization and oxidation of the resulting 2-(3,4-dihydro-2H-1,4-benzothiazin-2-yl)propanoic acids (5) with thionyl chloride gives moderate yield of 10a,b.

Regioselective reactions of o-aminothiophenol with unsymmetrical maleic anhydrides

Maleic anhydride (MA; Ia) and its methyl (MMA; Ib), dimethyl (DMMa; Ic), phenyl (PMA; Id) and phenylmethyl (PMMA; Ie) derivatives react with o-aminothiophenol (o-ATP) to yield benzothiazines (IIIa-e) via Michael-type addition.In contrast, its oxygenated derivatives react with o-ATP to furnish benzothiazoles (IVf-h) apparently by a different pathway.

Reactions of Cyclic Anhydrides: Part VIII - Formation of 2-Oxobenzothazines from o-Aminothiophenol and Maleic Anhydride Derivatives

Reaction of o-aminothiophenol (o-ATP) with maleic anhydride, maleic acid or fumaric acid furnishes 2-(oxobenzothiazinyl)acetic acid (Ia); with methyl hydrogenmaleate or methyl hydrogenfumarate, a mixture of Ia and its methyl ester Ib (80 : 20 and 65 : 35