Sodium triacetoxyborohydride → 2(R)-(3,4-methylenedioxy-benzylamino)-3-methylbutyric acid benzyl ester

HRID 1760801Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1760801
[CH2:1]([O:8][C:9](=[O:15])[C@@H:10]([CH:12]([CH3:14])[CH3:13])[NH2:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(O[BH-](O[C:26](=[O:28])[CH3:27])OC(=O)C)(=O)C.[Na+]>C(Cl)Cl>[CH2:1]([O:8][C:9](=[O:15])[C@H:10]([NH:11][CH2:14][C:12]1[CH:13]=[CH:27][C:26]2[O:28][CH2:1][O:8][C:9]=2[CH:10]=1)[CH:12]([CH3:13])[CH3:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Komponenten

4

Edukt 2

HCID 5049666Sodium triacetoxyborohydrideHCID 7350007Benzyl D-valinate

Produkt 1

HCID 542486302(R)-(3,4-methylenedioxy-benzylamino)-3-methylbutyric acid benzyl esterAusbeute 170,1 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

To a solution of D-valine benzyl ester free base (12.92 g, 62 mmol) in dry methylene chloride (120 mL) was added 3,4-(methylenedioxy)phenyl methanol (9.45 g, 62 mmol) and sodium triacetoxyborohydride (18.50 g, 86.8 mmol). After 15 h, the reaction mixture was quenched with saturated aqueous sodium bicarbonate (120 mL) and the aqueous layer was separated and extracted with methylene chloride. The combined methylene chloride layers were washed with brine, dried over magnesium sulfate, and concentrated. The residue was chromatographed (300 g SiO2, 5% ethyl acetate-hexanes) to afford 2(R)-(3,4-methylenedioxy-benzylamino)-3-methylbutyric acid benzyl ester (18 g) as a colorless oil.

Aufarbeitung

  1. customthe reaction mixture was quenched with saturated aqueous sodium bicarbonate (120 mL)
  2. customthe aqueous layer was separated
  3. extractionextracted with methylene chloride
  4. washThe combined methylene chloride layers were washed with brine
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated
  7. customThe residue was chromatographed (300 g SiO2, 5% ethyl acetate-hexanes)

Quellen und Nachweise

ORD-Eintrag
ord-7899147583564fc9b107d96c0c869468
Quelldatensatz
uspto-grants-2005_01
Patentnummer
US06844366B2

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