Hydrochloric Acid → 4-BROMO-2-ETHYLBENZALDEHYDE

HRID 341705Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 341705
[Br:1][C:2]1[CH:7]=[CH:6][C:5](I)=[C:4]([CH2:9][CH3:10])[CH:3]=1.C([Li])CCC.CN(C)[CH:18]=[O:19].Cl>O1CCCC1>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:18]=[O:19])=[C:4]([CH2:9][CH3:10])[CH:3]=1

Komponenten

6

Edukt 4

HCID 313Hydrochloric AcidHCID 6228DimethylformamideHCID 27613964-Bromo-2-ethyl-1-iodobenzeneHCID 178418339Butyllithium

Produkt 1

HCID 532567934-BROMO-2-ETHYLBENZALDEHYDEAusbeute 93,9 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
-75 °C

Versuchsvorschrift

To a solution of 4-bromo-2-ethyl-1-iodobenzene (75 g, 0.24 mol) in tetrahydrofuran (375 ml) at −75° C. is added n-butyl lithium (1.6 M in hexanes, 196 ml, 0.31 mol) dropwise, maintaining the temperature of the reaction mixture below −70° C. When the addition is complete the mixture is stirred at −75° C. for an additional 30 minutes and then N,N-dimethylformamide (70.7 g, 0.97 mol) is added dropwise. After the addition is complete the reaction is stirred at −75° C. for 2 hours, then allowed to warm to room temperature for 2 hours. The mixture is cooled in an ice bath and acidified with 0.5 N aqueous hydrochloric acid. The mixture is extracted with ethyl acetate (3×500 ml) and the organic fractions are combined, washed with brine, and dried over anhydrous sodium sulphate. The mixture is filtered and the filtrate is evaporated under reduced pressure. The residue is purified by column chromatography on silica gel to give 4-bromo-2-ethylbenzaldehyde (48 g) as an oil.

Aufarbeitung

  1. temperaturemaintaining the temperature of the reaction mixture below −70° C
  2. additionWhen the addition
  3. additionAfter the addition
  4. stirringis stirred at −75° C. for 2 hours
  5. temperatureto warm to room temperature for 2 hours
  6. temperatureThe mixture is cooled in an ice bath
  7. extractionThe mixture is extracted with ethyl acetate (3×500 ml)
  8. washwashed with brine
  9. dry with materialdried over anhydrous sodium sulphate
  10. filtrationThe mixture is filtered
  11. customthe filtrate is evaporated under reduced pressure
  12. customThe residue is purified by column chromatography on silica gel

Quellen und Nachweise

ORD-Eintrag
ord-168a041df191467580a2b6487df0aa77
Quelldatensatz
uspto-grants-2014_11
Patentnummer
US08895761B2

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