1,2-Dibromoethane → 8-Bromo-2,3-dihydro-1,4-benzodioxine-6-carbaldehyde

HRID 15324

Reaktionsgleichung

Reaktionsgleichung von HRID 15324
[Br:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([OH:11])[C:9]=1[OH:10])[CH:5]=[O:6].C(=O)([O-])[O-].[Cs+].[Cs+].Br[CH2:19][CH2:20]Br>CN(C)C=O>[Br:1][C:2]1[C:9]2[O:10][CH2:19][CH2:20][O:11][C:8]=2[CH:7]=[C:4]([CH:5]=[O:6])[CH:3]=1

Komponenten

5

Edukt 3

HCID 78391,2-DibromoethaneHCID 10796Cesium carbonateHCID 854055-Bromo-3,4-dihydroxybenzaldehyde

Produkt 1

HCID 166371768-Bromo-2,3-dihydro-1,4-benzodioxine-6-carbaldehydeAusbeute 75 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6228DimethylformamideLösungsmittel

Versuchsvorschrift

To a solution of 3-bromo-4,5-dihydroxybenzaldehyde (11.5 g, 0.52 mol) in dimethylformamide (220 ml) was added cesium carbonate (50.7 g, 1.56 mol). The mixture was stirred at ambient temperature for 30 min, then 1,2-dibromoethane (12.76 g, 0.68 mol) were added. After heating at 80° for 4 h, the dimethylformamide was removed under reduced pressure. The residue was partitioned between water and ethyl acetate, and the organic layer was washed with brine and dried. The crude product was purified by flash column chromatography (silica gel, 4:1 hexane:ethyl acetate) to give the desired compound as an off-white solid (9.57 g, 75%).

Aufarbeitung

  1. temperatureAfter heating at 80° for 4 h
  2. customthe dimethylformamide was removed under reduced pressure
  3. customThe residue was partitioned between water and ethyl acetate
  4. washthe organic layer was washed with brine
  5. customdried
  6. customThe crude product was purified by flash column chromatography (silica gel, 4:1 hexane:ethyl acetate)

Quellen und Nachweise

ORD-Eintrag
ord-1485c067dc3942858e5d7f74b0bdc26e
Quelldatensatz
uspto-grants-2010_06
Patentnummer
US07732461B2

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