Hydrochloric Acid → 7-(4-Propoxyphenoxy)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a solution of methyl 7-(4-propoxyphenoxy)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylate (0.31 g) in THF-methanol (5-2.5 ml) was added at room temperature a 1 M aqueous solution of potassium carbonate (1.5 ml), and the resulting mixture was stirred at 65° C. for 40 hours. After cooling to room temperature, 1 N hydrochloric acid (10 ml) was added to the reaction mixture, which was extracted with ethyl acetate. The organic layer was washed with an aqueous saturated solution of sodium chloride and was dried with magnesium sulfate. After concentration under reduced pressure, the precipitated crystals were collected by filtration. The crystals were washed with diisopropyl ether to obtain 7-(4-propoxyphenoxy)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid (226 mg) as light yellow crystals.

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