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

関与物質

反応条件

反応手順

To methyl 7-(3,4-diethoxybenzyloxy)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylate (818 mg) dissolved in THF-methanol (15-7.5 ml) was added a 2 M aqueous solution of potassium carbonate (1.5 ml), and the resulting mixture was stirred at 60° C. for 14 hours. The reaction mixture was treated with 1 N hydrochloric acid to bring the pH to 2. The resulting mixture was extracted with ethyl acetate, and the organic layer was washed with an aqueous saturated solution of sodium chloride and was dried with anhydrous magnesium sulfate. After evaporation under reduced pressure to remove the solvent, the precipitated crystals were washed with hexane-ethyl acetate to obtain 7-(3,4-diethoxybenzyloxy)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid (3.02 g) as white crystals.

情報源と証拠