反应详情

Dissolve N-benzyl-2-(4-hydroxy-phenyl)-propionamide (13.25 g, 51.9 mmol) in anhydrous tetrahydrofuran (100 mL) and add via a cannula to borane-tetrahydrofuran complex (10M in tetrahydrofuran, 300 mL, 300 mmol) under nitrogen. Heat the reaction to reflux for 18 h under nitrogen. Cool the reaction to 0° C. and quench with 6 M hydrochloric acid. Concentrate the tetrahydrofuran on a rotary evaporator to give the crude product. Add water (50 mL) and tetrahydrofuran (30 mL) to the crude product and heat the reaction to reflux for 1 h. Cool the reaction to room temperature and adjust the pH to pH=8 with 5 N sodium hydroxide. Add brine (200 mL) and extract with ethyl acetate (3× 200 mL). Dry the ethyl acetate extracts over magnesium sulfate, filter, and concentrate on a rotary evaporator to give the crude product. Purify the crude product by flash chromatography on silica gel eluting with 0.7% concentrated ammonium hydroxide/7% ethanol/chloroform to yield 6.55 g (52%) of 4-(2-benzylamino-1-methyl-ethyl)-phenol: HPLC (30/70 to 90/10 ACN/(0.1% TFA in water) Zorbax SB-Phenyl Column 4.6 mm×15 cm×5 micron: Retention time: 3.08 minutes, Purity: 99.6%; mass spectrum (ion spray): m/z=242.1 (M+1).

1. temperatureHeat
2. customthe reaction
3. temperatureto reflux for 18 h under nitrogen
4. temperatureCool
5. customthe reaction to 0° C.
6. customquench with 6 M hydrochloric acid
7. concentrationConcentrate the tetrahydrofuran
8. customon a rotary evaporator
9. customto give the crude product
10. customthe reaction
11. temperatureto reflux for 1 h
12. temperatureCool
13. customthe reaction to room temperature
14. extractionAdd brine (200 mL) and extract with ethyl acetate (3× 200 mL)
15. dry with materialDry the ethyl acetate
16. filtrationfilter
17. concentrationconcentrate on a rotary evaporator
18. customto give the crude product
19. customPurify the crude product by flash chromatography on silica gel eluting with 0.7% concentrated ammonium hydroxide/7% ethanol/chloroform