Water → 3-(3,5-Dimethoxyphenyl)-1-propene

HRID 602071

Reaction equation

HRID 602071 reaction equation
Br[C:2]1[CH:3]=[C:4]([O:10][CH3:11])[CH:5]=[C:6]([O:8][CH3:9])[CH:7]=1.[F-].[Cs+].[CH2:14](B1OC(C)(C)C(C)(C)O1)[CH:15]=[CH2:16].O>C1COCC1>[CH2:16]([C:2]1[CH:3]=[C:4]([O:10][CH3:11])[CH:5]=[C:6]([O:8][CH3:9])[CH:7]=1)[CH:15]=[CH2:14]

Participants

6

Procedure

5-Bromo-1,3-dimethoxybenzene (2.13 g, 9.8 mmol), CsF (2.88 g, 19.0 mmol), and Pd(Ph3)4 (0.57-1.13 g, 0.5-1.0 mmol) were weighed into a flame-dried Schlenk flask and put under a flow of argon. THF (80 mL) was added to the flask via syringe, and the resulting suspension was stirred for 30 min at room temperature. Allyl boronic acid pinacol ester (2.96 g, 17.6 mmol) in THF (40 ml) was added and the resulting mixture was heated to reflux for 30 h. Another portion of CsF (2.88 g, 19.0 mmol) and Pd(Ph3)4 (0.57-1.13 g, 0.5-1.0 mmol) were added and the reaction was continued to reflux for 24 h. The reaction mixture was diluted with petroleum ether (100 ml) followed by H2O (100 ml). The layers were separated and the aqueous layer was extracted with petroleum ether (2×80 ml). The combined organic layers were washed with H2O (100 ml), and brine (100 ml). The solution was dried over MgSO4 and evaporated to dryness. The crude product was purified by column chromatography (silica, eluent: hexanes/benzene=3:2) to give 1.60 g (92%) of 5-Allyl-1,3-dimethoxybenzene. 1H NMR (CDCl3): δ 3.33 (d, J=6.7 Hz, 2H, CH2CH═CH2), 3.77 (s, 6H, OCH3), 5.02-5.11 (m, 2H, CH2CH═CH2), 5.89-5.99 (m, 1H, CH2CH═CH2), 6.33-6.38 (m, 3H).

Workup

  1. temperaturethe resulting mixture was heated
  2. temperatureto reflux for 30 h
  3. temperatureto reflux for 24 h
  4. customThe layers were separated
  5. extractionthe aqueous layer was extracted with petroleum ether (2×80 ml)
  6. washThe combined organic layers were washed with H2O (100 ml), and brine (100 ml)
  7. dry with materialThe solution was dried over MgSO4
  8. customevaporated to dryness
  9. customThe crude product was purified by column chromatography (silica, eluent: hexanes/benzene=3:2)

Sources & evidence

ORD record
ord-a987c29846f147358011d16accbd6264
Source dataset
uspto-grants-2011_03
Patent number
US07902417B2

Linked notes

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