反应详情

(6-Hydroxy-1-benzofuran-3-yl)acetic acid (9.85 g, 51.3 mmol) was suspended in methanol (45 mL), concentrated sulfuric acid (5 mL) was added, and the mixture was heated under reflux for 4 hr. The reaction mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with diethyl ether. The extract was washed successively with saturated aqueous sodium hydrogencarbonate and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=10:90-50:50.), and the obtained crystals were recrystallized from ethyl acetate-hexane to give the title compound (7.38 g, yield 70%) as pale-yellow prisms.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 4 hr
3. concentrationThe reaction mixture was concentrated under reduced pressure, water
4. additionwas added
5. extractionthe mixture was extracted with diethyl ether
6. washThe extract was washed successively with saturated aqueous sodium hydrogencarbonate and saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by silica gel column chromatography (ethyl acetate:hexane=10:90-50:50.)
10. customthe obtained crystals were recrystallized from ethyl acetate-hexane