反应详情

To a mixture of ethyl 7-(4-(tert-butoxycarbonyl)-2-nitrophenoxy)-6,8-dichlorochroman-4-carboxylate (2.70 g, 5.27 mmol) in 25 mL of THF and 25 mL of saturated ammonium chloride was added zinc dust (3.45 g, 52.7 mmol) under argon. After 1 hour at ambient temperature, the reaction was diluted with ethyl acetate and filtered. The biphasic filtrate was separated and the organic layer was washed with brine. The organic layer was dried over sodium sulfate, filtered and concentrated. The crude product was dissolved in dichloromethane, concentrated onto silica gel and purified by flash column chromatography, eluting with 20% ethyl acetate in hexanes to give ethyl 7-(2-amino-4-(tert-butoxycarbonyl)phenoxy)-6,8-dichlorochroman-4-carboxylate (2.20 g, 86.5% yield) as a white foam. MS (ESI) m/z=482 (M+H).

1. filtrationfiltered
2. customThe biphasic filtrate was separated
3. washthe organic layer was washed with brine
4. dry with materialThe organic layer was dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. dissolutionThe crude product was dissolved in dichloromethane
8. concentrationconcentrated onto silica gel
9. custompurified by flash column chromatography
10. washeluting with 20% ethyl acetate in hexanes