Hydrochloric Acid → Methyl 7-[(4-ethoxybenzyl)oxy]-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid

関与物質

反応条件

反応手順

Into a suspension of methyl 7-[(4-ethoxybenzyl)oxy]-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylate (200 mg) in THF/methanol (6/3 ml) was added at room temperature an aqueous solution (0.7 ml) of potassium carbonate (137 mg), and the resulting mixture was stirred at 70° C. for 16.5 hours. After cooling to room temperature, 1 N hydrochloric acid was added to the reaction mixture, which was extracted with ethyl acetate. The organic layer was washed with water and 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 methyl 7-[(4-ethoxybenzyl)oxy]-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid (147 mg) as colorless crystals.

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