278170-90-4

Upstream product

• 209736-46-9 6,7,8,9-Tetrafluoro-3-methyl-4H-benzopyrano<3,4-d>isoxazol-4-one 
• 137-07-5 2-amino-benzenethiol 
• 209736-53-8 3-acetimidoyl-5,6,7,8-tetrafluoro-4-hydroxy-2H-chromen-2-one 

Relevant academic research and scientific papers

Reactions of 4-hydroxy-5,6,7,8-tetrafluorocoumarin derivatives with S-nucleophiles

In the reactions with o-aminothiophenol, 4-hydroxy-(3-(imino)acetyl)-5,6,7,8-tetrafluorocoumarins give products of S-substitution at the C-7 atom. 7-Substituted 5,6,8-trifluorocoumarins form benzothiazole as a result of heterocyclic ring opening; 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone undergoes acid splitting to 2-(2-hydroxy-3,4,5,6-tetrafluorophenyl)benzothiazole. Under alkaline conditions, S-substituted coumarins decompose to acetophenone. In an acid medium, 4-hydroxy-3-iminoacetyl-5,6,8-trifluoro-7-(2-aminophenylthio)coumarin affords 7-(2-aminophenylthio)-2-methyl-5,6,8-trifluorochromone. 4-Hydroxy-5,6-difluoro-2-H-pyrano[6,5-a]phenothiazin-2-one was isolated from condensation of 7-(2-aminophenylthio)-4-hydroxy-5,6,8-trifluorocoumarin in the presence of NaH. Reactions of 3-acetyl(iminoacetyl)-4-hydroxy-5,6,7,8-tetrafluorocoumarins and 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone with 2-mercaptoethanol result in the formation of 5,7,8-trisubstituted derivatives. Interaction of 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone with 2-mercaptoethanol, mercaptoacetic acid and 1,2-ethanedithiol leads to the formation of the 7-substituted products. Acyl-lactone rearrangement of mono- and trisubstituted chromones gives the corresponding coumarins.

Derivatives of 4-hydroxy-5,6,7,8-tetrafluorocoumarin in reactions with o-aminothiophenol

The derivatives of 4-hydroxy-5,6,7,8-tetrafluorocoumarin in reactions with o-aminothiophenol yield products of S-substitution at C7 atom, 7-substituted 5,6,8-trifluorocoumarins afford benzothiazoles as a result of cleavage of the pyrone cycle, 2-methyl-3-ethoxycarbonyl-5,6,7,8-tetrafluorochromone undergoes acidic cleavage to 2-(2-hydroxy-3,4,5,6-tetrafluorophenyl)benzothiazole. S-Substituted coumarins in alkaline media suffer decomposition to acetophenone. In acidic media 3-iminoacetyl-4-hydroxy-5,6,8-trifluoro-7-(2-aminophenylthio)coumarin affords 2-methyl-5,6,8-trifluoro-7-(2-aminophenylthio)chromone. In condensation of 4-hydroxy-5,6,8-trifluoro-7-(2-aminophenylthio)coumarin in the presence of NaH was isolated 4-hydroxy-5,6-difluoro-2H-pyrano[6,5-a]phenothiazin2-one.