1,2-Dibromoethane → 6-Methyl-2,3-dihydro-1,4-benzodioxine

HRID 1244203Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1244203
[CH3:1][C:2]1[CH:3]=[C:4]([OH:9])[C:5](=[CH:7][CH:8]=1)[OH:6].Br[CH2:11][CH2:12]Br.C([O-])([O-])=O.[K+].[K+]>C(O)CO.[I-].[Na+]>[CH3:1][C:2]1[CH:8]=[CH:7][C:5]2[O:6][CH2:11][CH2:12][O:9][C:4]=2[CH:3]=1

Komponenten

6

Edukt 3

HCID 78391,2-DibromoethaneHCID 99584-MethylcatecholHCID 11430Potassium Carbonate

Produkt 1

HCID 124003766-Methyl-2,3-dihydro-1,4-benzodioxineAusbeute 50 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 5238Sodium IodideKatalysatorHCID 174Ethylene GlycolLösungsmittel

Reaktionsbedingungen

Temperatur
130 °C

Versuchsvorschrift

A mixture of 4-methylcatechol (33.04 g, 266.1 mmol), 1,2-dibromoethane (100 g, 532.3 mmol), K2CO3 (75.4 g, 545.5 mmol) and sodium iodide (0.2 g, 1.33 mmol) in ethylene glycol (500 mL) was heated to 130° C. under nitrogen for five hours. The solution was allowed to cool to ambient temperature and stirred overnight. After the mixture was filtered through celite, the solution was diluted with brine (800 mL) and extracted with organic solvents (CH2Cl2/hexane/EtOAc: 1:3:1,3×500 mL). The organic layer was dried over Na2SO4, filtered and concentrated to provide a crude oil. Flash silica gel chromatography eluting with hexane (100%) gradient to ether/hexane (8:2) afforded the title intermediate as a colorless oil 20.0 g (50%).

Aufarbeitung

  1. temperatureto cool to ambient temperature
  2. filtrationAfter the mixture was filtered through celite
  3. additionthe solution was diluted with brine (800 mL)
  4. extractionextracted with organic solvents (CH2Cl2/hexane/EtOAc: 1:3:1,3×500 mL)
  5. dry with materialThe organic layer was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto provide a crude oil
  9. washFlash silica gel chromatography eluting with hexane (100%) gradient to ether/hexane (8:2)

Quellen und Nachweise

ORD-Eintrag
ord-1cd190888ade429190351db08062f863
Quelldatensatz
uspto-grants-2006_10
Patentnummer
US07122526B2

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