反应详情

Slurry L-phenylalanine (23.6 g, 143 mmol), 49% hydrobromic acid (500 g), water (500 mL) and concentrated sulfuric acid (50 mL) and cool to -5° C. Add, by dropwise addition, a solution of sodium nitrite (9.87 g, 143 mmol) in water (70 mL) over a period of about 1 hour. Stir at -5° C. to 0° C. overnight extract into ethyl ether (3×250 mL), combine the organic phases and wash with water (1×) and brine (2×). Dry (MgSO4) and evaporate the solvent in vacuo to give 3-phenyl-2(S)-bromopropionic acid as a yellow oil (26 g, 80%).

1. additionAdd, by dropwise addition
2. extractionextract into ethyl ether (3×250 mL)
3. washwash with water (1×) and brine (2×)
4. dry with materialDry (MgSO4)
5. customevaporate the solvent in vacuo