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

HRID 902905

Reaktionsgleichung

Reaktionsgleichung von HRID 902905
[Br-:1].[K+].N[C@@H:4]([C:12]([OH:14])=[O:13])[CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.N([O-])=O.[Na+]>S(=O)(=O)(O)O>[Br:1][C@H:4]([CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)[C:12]([OH:14])=[O:13]

Komponenten

5

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

Potassium bromide (24.49 g, 0.21 moles) was first dissolved in a 2.50 N aqueous solution of sulfuric acid (120 mL). To this stirring solution was then added D-phenylalanine (10.00 g, 60.54 mmoles). After the addition, the mixture was cooled down to 0° C. and sodium nitrite (6.27 g., 90.87 mmoles) was added in small portions during 30 minutes. A strong bubbling was observed. The reaction was kept at this temperature for 50 minutes, and it was then allowed to proceed at room temperature for another 60 minutes. The crude product was isolated using standard work up and the obtained residue was purified by flash chromatography (SiO2, 30% ethyl acetate-70% hexanes) to give 7.20 g (51.9% yield) of the title compound as a yellowish oil: 1H NMR (CDCl3, 300 MHz) □ 10.86 (br s, 1H), 7.31 (m, 5H), 4.48 (t, 1H), 3.51 (dd, 1H), 3.29 (dd, 1H); 13C NMR (CDCl3, 75 MHz) □175.29, 136.26, 129.10, 128.69, 127.42, 44.83, 40.62.

Aufarbeitung

  1. additionAfter the addition
  2. customA strong bubbling
  3. waitto proceed at room temperature for another 60 minutes
  4. customThe crude product was isolated
  5. customthe obtained residue was purified by flash chromatography (SiO2, 30% ethyl acetate-70% hexanes)

Quellen und Nachweise

ORD-Eintrag
ord-7032ca5b14e5440d92c258596283f81f
Quelldatensatz
uspto-grants-2008_04
Patentnummer
US07365091B2

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