221541-78-2

Upstream product

• 221541-76-0 4,7-dimethoxy-2-phenyl-1,3-benzothiazole 
• 221541-74-8 N-(4-bromo-2,5-dimethoxyphenyl)thiobenzamide 
• 221541-72-6 N-(4-Bromo-2,5-dimethoxyphenyl)benzamide 
• 102-56-7 2,5-dimethoxyaniline 
• 98-88-4 benzoyl chloride 
• 135-45-5 N-(2,5-Dimethoxyphenyl)benzamide 
• 221541-73-7 N-(2,5-dimethoxyphenyl)thiobenzamide 

Downstream Products

• 221541-83-9 6-Bromo-4,7-dioxo-2-phenylbenzothiazole 

Relevant academic research and scientific papers

Conversion of thiobenzamides to benzothiazoles via intramolecular cyclization of the aryl radical cation

A new and general method has been developed for the intramolecular cyclization of thiobenzamides to benzothiazoles via aryl radical cations as reactive intermediates. The method utilizes phenyliodine(III) bis(trifluoroacetate) (PIFA) in trifluoroethanol or cerium ammonium nitrate (CAN) in aqueous acetonitrile at room temperature to effect cyclization within 30 min in moderate yields.

Reactions of some N-(2,5-dimethoxyaryl)thiobenzamides: En route to an analogue of kuanoniamine A

The reactions of some N-(2,5-dimethoxyaryl) thiobenzamides were studied. It was found that nitration of 2-aryl-4,7-dimethoxybenzothiazoles produced a mixture of 5- and 6-nitrobenzothiazoles which were distinguished by synthesis of the 2-aryl-4,7-dimethoxy-6-nitrobenzothiaoles by oxidative cyclization of the corresponding nitrothiobenzanilides. The results showed that the cyclization of arylthioanilides was influenced by the nature of the ring substituents.

Synthesis, and structure verification of an analogue of kuanoniamine A

Synthesis of 9-phenyl-7H-benzothiazolo[4,5,6-y][2,7]naphthyridin-7-one 11, an analogue of kuanoniamine A 8, is described. The synthesis involves a hetero Diels-Alder reaction of crotonaldehyde dimethylhydrazone with 4,7-dioxo-2-phenylbenzothiazole 18a or with 6-bromo-4,7-dioxo-2-phenylbenzothiazole 18b followed by annelation of the appropriate adduct. Reaction with 18a produced two sets of regioisomers-the thiazoloquinolinediones 19a,b, and the dimethylamino dioxobenzothiazoles 23a,b. The structure of 23b was determined by single-crystal X-ray structure analysis. Verification of the other structures, and methods used to improve the Diels-Alder reaction are described.