反应详情

To a stirred solution of ethyl 8-bromo-7-(4-(tert-butoxycarbonyl)-2-nitrophenoxy)-6-chlorochroman-4-carboxylate (2.00 g, 3.59 mmol) in tetrahydrofuran (15 mL) at ambient temperature was added zinc dust (4.70 g, 71.8 mmol), followed by saturated ammonium chloride solution (7.5 mL). The resulting mixture was stirred at ambient temperature for 1 hour. The mixture was filtered through a glass microfibre filter to remove the insoluble zinc solids, and the solids were washed twice with tetrahydrofuran. The combined filtrate and washings were concentrated to remove most of the tetrahydrofuran, and the residue was partitioned between ethyl acetate (100 mL) and water (50 mL). The organic layer was washed with brine (50 mL), then dried over sodium sulfate and concentrated to afford ethyl 7-(2-amino-4-(tert-butoxycarbonyl)phenoxy)-8-bromo-6-chlorochroman-4-carboxylate as a light brown glass (1.61 g, 85% yield).

1. filtrationThe mixture was filtered through a glass microfibre
2. filtrationfilter
3. customto remove the insoluble zinc solids
4. washthe solids were washed twice with tetrahydrofuran
5. concentrationThe combined filtrate and washings were concentrated
6. customto remove most of the tetrahydrofuran
7. customthe residue was partitioned between ethyl acetate (100 mL) and water (50 mL)
8. washThe organic layer was washed with brine (50 mL)
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated