Cesium carbonate → Methyl 3-(hydroxymethyl)-5-methylbenzoate

HRID 14122

Reaktionsgleichung

Reaktionsgleichung von HRID 14122
Br[C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([CH2:12][OH:13])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].[C:14](=O)([O-])[O-].[Cs+].[Cs+].C(=O)([O-])[O-].[K+].[K+].CB1OB(C)OB(C)O1>O1CCOCC1>[OH:13][CH2:12][C:10]1[CH:9]=[C:4]([CH:3]=[C:2]([CH3:14])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6]

Komponenten

6

Edukt 4

HCID 10796Cesium carbonateHCID 11430Potassium CarbonateHCID 574072TrimethylboroxineHCID 11356988Methyl 3-bromo-5-(hydroxymethyl)benzoate

Produkt 1

HCID 21086184Methyl 3-(hydroxymethyl)-5-methylbenzoate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 312751,4-DioxaneLösungsmittel

Versuchsvorschrift

To a stirred solution of methyl 3-bromo-5-(hydroxymethyl)benzoate (4.53 g, 18.5 mmol) in dioxane (74 mL) is added cesium carbonate (6.0 g, 18.5 mmol), potassium carbonate (5.1 g, 37 mmol), and palladium(0)tetrakis(triphenylphosphine) (2.1 g, 1.85 mmol), followed by trimethyl boroxine (5.1 mL, 37 mmol). The reaction mixture is refluxed for 12 h, cooled to room temperature, and then partitioned between water and ethyl acetate. The organic layer is washed with water and brine, dried (magnesium sulfate), filtered, and concentrated under reduced pressure. The black oil is adsorbed onto silica gel followed by purification by flash column chromatography (silica, 25% ethyl acetate/hexanes) to provide the title compound. 1H NMR (300 MHz, CDCl3) δ 7.75 (s, 1H), 7.65 (s, 1H), 7.39 (s, 1H), 5.31 (br s, 1H), 4.53 (s, 1H), 3.84 (s, 3H), 2.36 (s, 3H).

Aufarbeitung

  1. temperatureThe reaction mixture is refluxed for 12 h
  2. custompartitioned between water and ethyl acetate
  3. washThe organic layer is washed with water and brine
  4. dry with materialdried (magnesium sulfate)
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customfollowed by purification by flash column chromatography (silica, 25% ethyl acetate/hexanes)

Quellen und Nachweise

ORD-Eintrag
ord-24bd8b96751c4203a4cbb24cfac9f02d
Quelldatensatz
uspto-grants-2010_06
Patentnummer
US07727997B2

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