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

HRID 81796

Reaktionsgleichung

Reaktionsgleichung von HRID 81796
[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 99 %

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 (15.82 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-19b0d65c995544e188c66ebb9ed3d327
Quelldatensatz
uspto-grants-2014_09
Patentnummer
US08846705B2

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