D-Phenylalanine → (R)-2-Bromo-3-phenylpropionic acid

HRID 2392949Notes

Reaction equation

HRID 2392949 reaction equation
N([O-])=O.[Na+].N[C@@H:6]([C:14]([OH:16])=[O:15])[CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.[BrH:17].O>>[Br:17][C@H:6]([CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:14]([OH:16])=[O:15]

Participants

4

Reactant 3

HCID 71567D-PhenylalanineHCID 22326455Hydrobromide monohydrateHCID 23668193Sodium Nitrite

Product 1

HCID 11746403(R)-2-Bromo-3-phenylpropionic acidYield 60%

Conditions

Temperature
0 °C

Procedure

Sodium nitrite (27 g in water) is added at 0° C. to a solution of D-phenylalanine (40 g) in a mixture of 48% hydrobromic acid/water (1:1 by volume). The mixture is stirred for 30 minutes at 0° C. and then for 2 hours 30 minutes at a temperature close to 20° C. The reaction mixture is extracted with ether. The organic extracts are washed with water and a saturated sodium chloride solution and then dried over sodium sulphate. After filtration and concentration to dryness, the obtained residue is purified by distillation. (R)-2-Bromo-3-phenylpropanoic acid (33 g) is obtained which has the following characteristics: B.p.1 kPa =154° C.; Rf =0.47 (methylene chloride/methanol). The yield is 60%.

Workup

  1. customfor 2 hours 30 minutes at a temperature close to 20° C
  2. extractionThe reaction mixture is extracted with ether
  3. washThe organic extracts are washed with water
  4. dry with materiala saturated sodium chloride solution and then dried over sodium sulphate
  5. filtrationAfter filtration and concentration to dryness
  6. distillationthe obtained residue is purified by distillation

Sources & evidence

ORD record
ord-bac910cc107346fa9c980a72e6d95cfd
Source dataset
uspto-grants-1998_09
Patent number
US05801274

Reaction notes

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