反应详情

温度

60 °C

Ethyl 8-(benzyloxy)-2,3-dihydro-1-benzoxepine-4-carboxylate (2.5 g) was dissolved in trifluoroacetic acid (10 mL), and 42% hydrobromic acid (0.5 mL) was added, and the mixture was heated at 60° C. for 30 min. The mixture was concentrated and extracted with ethyl acetate. The organic layer was washed with water and back-extracted with 1 M aqueous sodium hydroxide solution. The aqueous layer was acidified with hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with water and brine, and dried over magnesium sulfate, and the solvent was evaporated. The residue was dissolved in ethanol (100 mL), and thionyl chloride (1 mL) was added dropwise under ice-cooling. The mixture was stirred overnight at room temperature, and the solvent was evaporated. The residue was purified by silica gel column chromatography (ethyl acetate:hexane) to give crude crystals. The crystals were recrystallized from ethyl acetate-hexane to give the title compound (0.39 g) as crystals.

1. concentrationThe mixture was concentrated
2. extractionextracted with ethyl acetate
3. washThe organic layer was washed with water
4. extractionback-extracted with 1 M aqueous sodium hydroxide solution
5. extractionextracted with ethyl acetate
6. washThe organic layer was washed with water and brine
7. dry with materialdried over magnesium sulfate
8. customthe solvent was evaporated
9. dissolutionThe residue was dissolved in ethanol (100 mL)
10. additionthionyl chloride (1 mL) was added dropwise under ice-
11. temperaturecooling
12. customthe solvent was evaporated
13. customThe residue was purified by silica gel column chromatography (ethyl acetate:hexane)
14. customto give crude crystals
15. customThe crystals were recrystallized from ethyl acetate-hexane