49634-65-3

Upstream product

• 78742-17-3 2-isopropyl-2-phenyl-2,3-dihydro-1,3-benzothiazole 
• 137-07-5 2-amino-benzenethiol 
• 611-70-1 phenyl isopropyl ketone 

Downstream Products

• 49634-66-4 2,2-dimethyl-3-phenyl-3,4-dihydro-2H-benzo[1,4]thiazine 
• 56553-67-4 4-ethyl-2,2-dimethyl-3-phenyl-3,4-dihydro-2H-benzo[1,4]thiazine 

Relevant academic research and scientific papers

Umpolung Strategy with 2-Aminothiophenols: Access to 2-Arylbenzothiazine Derivatives from Alkyl Aryl Ketones

Strong Br?nsted acids were found to catalyze the oxidative condensation of 2-aminothiophenols with aryl alkyl ketones in DMSO to provide a wide range of complex 2-arylbenzothiazines. With acetophenones, dimeric 2-arylbenzothiazines were formed. On the other hand, the reaction with propiophenones resulted in 2:1 adducts whereas 1:1 adducts were produced with isobutyrophenones, benzoylacetonitrile and ethyl benzoylacetate. (Figure presented.).

Oxidative Ring-Expansion of Benzothiazolines into 1,4-Benzothiazines

By treatment in boiling DMSO, benzothiazolines 1 yield 1,4-benzothiazines 4 in some cases together with benzothiazoles.Two competiting pathways, namely oxidative ring-expansion and decomposition of benzothiazoline accounting for the formation of 4 and benzothiazoles, respectively, are suggested.