Benzyl Bromide → 1-Benzyl-2,5-dimethoxy-3,4,6-trimethylbenzene

HRID 1646816

Reaktionsgleichung

Reaktionsgleichung von HRID 1646816
C([Li])CCC.CCCCCC.Br[C:13]1[C:18]([CH3:19])=[C:17]([O:20][CH3:21])[C:16]([CH3:22])=[C:15]([CH3:23])[C:14]=1[O:24][CH3:25].[CH2:26](Br)[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1>O1CCCC1>[CH2:26]([C:13]1[C:18]([CH3:19])=[C:17]([O:20][CH3:21])[C:16]([CH3:22])=[C:15]([CH3:23])[C:14]=1[O:24][CH3:25])[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1

Komponenten

6

Edukt 4

HCID 7498Benzyl BromideHCID 8058HexaneHCID 2973651-Bromo-2,5-dimethoxy-3,4,6-trimethylbenzeneHCID 178418339Butyllithium

Produkt 1

HCID 190880201-Benzyl-2,5-dimethoxy-3,4,6-trimethylbenzeneAusbeute 83 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Versuchsvorschrift

A 24.1 ml (38.6 mmole) of n-butyllithium.hexane solution was added dropwise to 10.0 g (38.6 mmole) of 1-bromo-2,5-dimethoxy-3,4,6-trimethylbenzene dissolved in anhydrous tetrahydrofuran (100 ml), under an atmosphere of argon at -40° C. over the period of 10 minutes, followed by stirring for another 20 minutes. Then, 3.32 g (38.6×0.6 mmole) of cuprous bromide was added, followed by stirring at -40° to -20° C. for 1 hour. After addition of a solution of 6.60 g (38.6 mmole)of benzyl bromide in tetrahydrofuran (15 ml), the cooling bath was removed, the reaction solution was stirred at 70° C. for 1 hour and cooled with ice, followed by addition of 1N hydrochloric acid (50 ml) and stirring. The tetrahydrofuran was distilled off under reduced pressure, and isopropyl ether was added to the residue. The insoluble matter was filtered through a bed of Hyflo Supercell, and the isopropyl ether layer was separated out, washed with water and aqueous sodium chloride solution successively, dried (magnesium sulfate) and evaporated. The residual solution was distilled under reduced pressure to give 8.62 g (83%) of 1-benzyl-2,5-dimethoxy-3,4,6-trimethylbenzene, b.p.140°-142° C. (0.3 torr) and m.p. 70° to 71° C.

Aufarbeitung

  1. stirringby stirring at -40° to -20° C. for 1 hour
  2. customthe cooling bath was removed
  3. stirringthe reaction solution was stirred at 70° C. for 1 hour
  4. temperaturecooled with ice
  5. additionfollowed by addition of 1N hydrochloric acid (50 ml)
  6. stirringstirring
  7. distillationThe tetrahydrofuran was distilled off under reduced pressure, and isopropyl ether
  8. additionwas added to the residue
  9. filtrationThe insoluble matter was filtered through a bed of Hyflo Supercell
  10. customthe isopropyl ether layer was separated out
  11. washwashed with water and aqueous sodium chloride solution successively
  12. dry with materialdried (magnesium sulfate)
  13. customevaporated
  14. distillationThe residual solution was distilled under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-31e41d4c65794895913db98c9a65d90c
Quelldatensatz
uspto-grants-1993_01
Patentnummer
US05180742

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