Hydrogen Bromide → (R)-2-Bromo-3-phenylpropionic acid

Participants

Reaction Conditions

Reaction Steps

Mix D-phenylalanine (186.4 g, 1.128 mol) and 49% hydrobromic acid (372.8 g), cool to -5° C. and add, by dropwise addition, a solution of sodium nitrite (77.9 g) in water (565 mL) over a period of about 1 hour (vigorous gas evolution). Stir at -5° C. to 0° C. for 4 hours, extract into ethyl ether (3×1 L), dry (MgSO4) and evaporate the solvent in vacuo. Purify by chromatography (5% acetic aci/95% methylene chloride) and distillation to give 3-phenyl-2(R)-bromopropionic acid (112 g, 43%); bp 128°-135° C. @ 0.25 torr.

Provenance & Evidence