1,3,5-Tribromobenzene → 3,5-Dibromo-alpha-(4-fluorophenyl)benzenemethanol

HRID 53323

Reaktionsgleichung

Reaktionsgleichung von HRID 53323
C([Li])CCC.Br[C:7]1[CH:12]=[C:11]([Br:13])[CH:10]=[C:9]([Br:14])[CH:8]=1.[F:15][C:16]1[CH:23]=[CH:22][C:19]([CH:20]=[O:21])=[CH:18][CH:17]=1>CCCCCC.CCOCC>[Br:14][C:9]1[CH:8]=[C:7]([CH:20]([C:19]2[CH:22]=[CH:23][C:16]([F:15])=[CH:17][CH:18]=2)[OH:21])[CH:12]=[C:11]([Br:13])[CH:10]=1

Komponenten

6

Edukt 3

HCID 122791,3,5-TribromobenzeneHCID 680234-FluorobenzaldehydeHCID 178418339Butyllithium

Produkt 1

HCID 199623533,5-Dibromo-alpha-(4-fluorophenyl)benzenemethanolAusbeute 87,2 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 3283Diethyl EtherLösungsmittelHCID 8058HexaneLösungsmittel

Versuchsvorschrift

A 2.5M solution of n-butyllithium in hexane (44.0 ml) was added dropwise to a stirred suspension of 1,3,5-tribromobenzene (31.5 g) in dry ether (1000 ml) at -78° C. under an atmosphere of dry nitrogen. The resulting mixture was stirred at this temperature for 30 minutes and the 4-fluorobenzaldehyde (13.65 g) was added dropwise. Stirring at -78° C. was continued for a further 30 minutes and then the reaction was quenched by the addition of water. The temperature was allowed to reach room temperature and the organic layer was separated and dried (MgSO4). Evaporation of the solvent gave an oil which was chromatographed on silica gel. The column was eluted with dichloromethane/hexane (1:5), gradually increasing the ratio of solvents to 2:3. The product fractions were combined, evaporated and the residue was triturated with hexane to give the title compound (31.42 g), m.p. 92°-93° C. Found: C,43.75; H,2.43. C13H9Br2OF requires C,43.37; H,2.52%.

Aufarbeitung

  1. stirringStirring at -78° C.
  2. waitwas continued for a further 30 minutes
  3. customthe reaction was quenched by the addition of water
  4. customto reach room temperature
  5. customthe organic layer was separated
  6. dry with materialdried (MgSO4)
  7. customEvaporation of the solvent
  8. customgave an oil which
  9. customwas chromatographed on silica gel
  10. washThe column was eluted with dichloromethane/hexane (1:5)
  11. temperaturegradually increasing the ratio of solvents to 2:3
  12. customevaporated
  13. customthe residue was triturated with hexane

Quellen und Nachweise

ORD-Eintrag
ord-b4e48c84258f420eb82815a11ed661a9
Quelldatensatz
uspto-grants-1997_04
Patentnummer
US05618941

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