Boron tribromide → Diethyl 2-(2,6-difluoro-4-hydroxyphenyl)malonate

HRID 1786299Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1786299
[F:1][C:2]1[CH:7]=[C:6]([O:8]C)[CH:5]=[C:4]([F:10])[C:3]=1[CH:11]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:12]([O:14][CH2:15][CH3:16])=[O:13].B(Br)(Br)Br.C(=O)(O)[O-].[Na+]>C(Cl)Cl>[F:1][C:2]1[CH:7]=[C:6]([OH:8])[CH:5]=[C:4]([F:10])[C:3]=1[CH:11]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:12]([O:14][CH2:15][CH3:16])=[O:13]

Komponenten

5

Edukt 3

HCID 25134Boron tribromideHCID 516892Sodium BicarbonateHCID 11174138Diethyl 2-(2,6-difluoro-4-methoxyphenyl)malonate

Produkt 1

HCID 16103023Diethyl 2-(2,6-difluoro-4-hydroxyphenyl)malonateAusbeute 94,7 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

To a solution of diethyl 2-(2,6-difluoro-4-methoxyphenyl)malonate (2.11 g, 7.0 mmol) in 60 mL of methylene chloride at −78° C. is added boron tribromide (2.65 mL, 28 mmol) dropwise. The mixture is then stirred at −78° C. for 10 minutes, warmed to 0° C., and stirred at 0° C. for 1 h. A 5% aqueous solution of sodium bicarbonate is added slowly to quench the reaction. The product is extracted with ethyl acetate. The combined organic extracts are washed with saturated sodium chloride, dried over magnesium sulfate, and concentrated to a residue. The residue is chromatographed over silica gel, eluting with a gradient of 10% ethyl acetate in hexanes to 30% ethyl acetate in hexanes. Concentration provides diethyl 2-(2,6-difluoro-4-hydroxyphenyl)malonate as a colorless oil (1.91 g). MS: m/z 287.2 (M−H).

Aufarbeitung

  1. temperaturewarmed to 0° C.
  2. stirringstirred at 0° C. for 1 h
  3. customto quench
  4. customthe reaction
  5. extractionThe product is extracted with ethyl acetate
  6. washThe combined organic extracts are washed with saturated sodium chloride
  7. dry with materialdried over magnesium sulfate
  8. concentrationconcentrated to a residue
  9. customThe residue is chromatographed over silica gel
  10. washeluting with a gradient of 10% ethyl acetate in hexanes to 30% ethyl acetate in hexanes
  11. concentrationConcentration

Quellen und Nachweise

ORD-Eintrag
ord-46c8f9dfedd640ea8424108be2403a20
Quelldatensatz
uspto-grants-2009_03
Patentnummer
US07507739B2

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