Bromide ion → 1-[2-(2-Methoxyethoxy)ethoxy]-4-(prop-2-en-1-yl)benzene

HRID 982458Notes

Reaction equation

HRID 982458 reaction equation
[Mg].[CH3:2][O:3][CH2:4][CH2:5][O:6][CH2:7][CH2:8][O:9][C:10]1[CH:15]=[CH:14][C:13](Br)=[CH:12][CH:11]=1.BrCCBr.[Br-].[CH2:22](Br)[CH:23]=[CH2:24]>O1CCCC1.C(OCC)C.C1C=CC=CC=1>[CH3:2][O:3][CH2:4][CH2:5][O:6][CH2:7][CH2:8][O:9][C:10]1[CH:15]=[CH:14][C:13]([CH2:24][CH:23]=[CH2:22])=[CH:12][CH:11]=1

Participants

9

Reactant 5

HCID 259Bromide ionHCID 78391,2-DibromoethaneHCID 7841Allyl bromideHCID 5462224Magnesium2×HCID 14026184HCID 14026184, compound

Product 1

HCID 679331341-[2-(2-Methoxyethoxy)ethoxy]-4-(prop-2-en-1-yl)benzeneYield 47.1%

Reagents, catalysts & solvents 3

HCID 241BenzeneSolventHCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

Magnesium turnings (0.83g, 0.032 mol) and 10 mL of anhydrous tetrahydrofuran (THF) were placed in a dry 3-necked round bottom flask. The mixture was stirred under reflux in an argon atmosphere for about 20 minutes. The previously prepared 4-[2-(2-methoxyethoxy)ethoxy]bromobenzene (7-Og, 0.025 mol) in 30 mL of anhydrous THF was slowly dripped into the stirring magnesium mixture. A small amount (about 0.1 mL) of 1,2-dibromoethane was initially added to start the Grignard reaction. After the bromide was added, the mixture was refluxed overnight under an argon atmosphere. The mixture was then cooled to -78° C. and 15 mL (0.17 mol) of allyl bromide in 30 mL of spectral grade benzene was added. The resulting mixture was stirred and allowed to slowly warm to room temperature and then refluxed overnight. The mixture was cooled and exacted with ethyl ether. The ethyl ether layer was washed with aqueous 3N hydrochloric acid, aqueous saturated brine and then with water until the organic layer was neutral. The ethyl ether solution was dried over anhydrous magnesium sulfate and the solvent was removed. The product was distilled to give 2.78 g (47%) of the desired 3-(4-[2-(2-methoxyethoxy) ethoxy]phenyl]-1-propene, bp 105°-113° C./0.2mm; NMR(δ): 3.30(2H,d), 3.36(3H,s), 3.46-3.92(6H,m), 4.12(2H,m), 5.00(2H,m), 5.95(1H,m), 6.80(2H,d), 7.04(2H,d).

Workup

  1. temperatureunder reflux in an argon atmosphere for about 20 minutes
  2. customthe Grignard reaction
  3. temperaturethe mixture was refluxed overnight under an argon atmosphere
  4. stirringThe resulting mixture was stirred
  5. temperatureto slowly warm to room temperature
  6. temperaturerefluxed overnight
  7. temperatureThe mixture was cooled
  8. washThe ethyl ether layer was washed with aqueous 3N hydrochloric acid, aqueous saturated brine
  9. dry with materialThe ethyl ether solution was dried over anhydrous magnesium sulfate
  10. customthe solvent was removed
  11. distillationThe product was distilled

Sources & evidence

ORD record
ord-772e262083e74571983eda9470f75870
Source dataset
uspto-grants-1991_02
Patent number
US04996277

Reaction notes

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