反应详情

Ethyl 7-(4-propoxyphenyl)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxlate (495 g, 1.24 mol) was dissolved in 4.95 L of tetrahydrofuran and 2.48 L of methanol. Crystals were formed by adding a potassium carbonate (342 g, 2.47 mol) solution in 4.2 L of water and the mixture was heated under reflux for 6.5 hours. Under reflux, 1.85 L of a 3N hydrochloric acid was dropped to form crystals. After cooling, 84 ml of a 6N hydrochloric acid was added at room temperature (pH 2-3) and stirred for 1 hour while cooling in ice. After filtration, the residue was washed with 2.97 L of a mixed solution of tetrahydrofuran/methanol/water=1/1/3 . After vacuum drying (40° C.), 443 g (Yield 96%) of 7-(4-propoxyphenyl)-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid was obtained as pale yellowish white crystals.

1. customCrystals were formed
2. temperaturethe mixture was heated
3. temperatureunder reflux for 6.5 hours
4. temperatureUnder reflux
5. customto form crystals
6. temperatureAfter cooling
7. temperaturewhile cooling in ice
8. filtrationAfter filtration
9. washthe residue was washed with 2.97 L of a mixed solution of tetrahydrofuran/methanol/water=1/1/3
10. customAfter vacuum drying (40° C.)