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

HRID 1677296

Reaktionsgleichung

Reaktionsgleichung von HRID 1677296
[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.[K+].[K+].Br[CH2:19][CH2:20]Br.O>CN(C=O)C>[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

6

Edukt 4

HCID 962WaterHCID 78391,2-Dibromoethane2×HCID 11430Potassium CarbonateHCID 854055-Bromo-3,4-dihydroxybenzaldehyde

Produkt 1

HCID 166371768-Bromo-2,3-dihydro-1,4-benzodioxine-6-carbaldehydeAusbeute 501,6 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6228DimethylformamideLösungsmittel

Reaktionsbedingungen

Temperatur
100 °C

Versuchsvorschrift

To a solution of 3-bromo-4,5-dihydroxy-benzaldehyde (20.78 g, 95 mmol) in 480 ml DMF was added K2CO3 (52.95 g, 383 mmol) followed by 1,2-dibromoethane (8.7 ml, 101 mmol). The mixture was warmed to 100° C. After 18 additional 1,2 dibromoethane (1.0 mL) was added. After 2 h the mixture was poured into water and extracted with ethyl acetate. The combined organics were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The crude solid was purified via flash chromatography (9:1 hexane/ethyl acetate) to give 8-bromo-2,3-dihydro-benzo[1,4]dioxine-6-carboxaldehyde (115.82 g, 99%) as a white solid.

Aufarbeitung

  1. extractionextracted with ethyl acetate
  2. washThe combined organics were washed with brine
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe crude solid was purified via flash chromatography (9:1 hexane/ethyl acetate)

Quellen und Nachweise

ORD-Eintrag
ord-df424fe315204a04bcc9370560c5e194
Quelldatensatz
uspto-grants-2011_08
Patentnummer
US08008313B2

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