Water → HCID 133191, compound

HRID 2252341Notes

Reaction equation

HRID 2252341 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]([CH:14]=[CH:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)[CH:6]=[C:7]([O:12]C)[C:8]=1[CH:9]([CH3:11])[CH3:10].B(Br)(Br)Br.O.[OH-].[Na+]>C(Cl)Cl>[C:16]1([CH:15]=[CH:14][C:5]2[CH:4]=[C:3]([OH:2])[C:8]([CH:9]([CH3:10])[CH3:11])=[C:7]([OH:12])[CH:6]=2)[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1

Participants

6

Reactant 4

HCID 962WaterHCID 14798Sodium HydroxideHCID 25134Boron tribromideHCID 66842881HCID 66842881, compound

Product 1

HCID 133191HCID 133191, compoundYield 67.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-78 °C

Procedure

To the crude 1-(3,5-dimethoxy-4-i-propylphenyl)-2-phenylethene (18.07 g) in dry CH2Cl2 (100 mL) at −78° C. under N2 was added BBr3 (5.2 mL, 55 mmol) dropwise. After the reaction was stirred at −78° C. for 1 h, the temperature was allowed to rise to room temperature and the reaction mixture was stirred at room temperature for 2 days. Water was added to quench the reaction, followed by 20% NaOH to adjust pH>12. The organic layer was removed and the aqueous layer was washed with hexane (2×100 mL). The aqueous layer was acidified with 6N HCl to pH 1 and extracted with ether (3×200 mL). The organic layer was separated and washed with water (50 mL) and brine (50 mL) and dried over anhydrous Na2SO4. Evaporation of ether gave a red syrup. Recrystallization with chloroform yielded pure stilbene product 20B (6.92 g) as a white crystal. The mother liquid was concentrated and the residue was recrystallized once more to afford an additional 2.5 g of 20B (total 9.42 g, 67.7% over two steps). 1HNMR (CDCl3, ppm): δ 1.38 (d, J=7.3 Hz, 6H), 3.46 (hept., J=7.3 Hz, 1H), 4.80 (s, 2H), 6.50 (s, 2H), 6.92 (d, J=17.2 Hz, 1H), 6.97 (d, J=17.2 Hz, 1H), 7.25 (m, 1H), 7.34 (m, 2H), 7.52 (m, 2H).

Workup

  1. customto rise to room temperature
  2. stirringthe reaction mixture was stirred at room temperature for 2 days
  3. customto quench
  4. customthe reaction
  5. customThe organic layer was removed
  6. washthe aqueous layer was washed with hexane (2×100 mL)
  7. extractionextracted with ether (3×200 mL)
  8. customThe organic layer was separated
  9. washwashed with water (50 mL) and brine (50 mL)
  10. dry with materialdried over anhydrous Na2SO4
  11. customEvaporation of ether
  12. customgave a red syrup
  13. customRecrystallization with chloroform yielded pure stilbene product 20B (6.92 g) as a white crystal
  14. concentrationThe mother liquid was concentrated
  15. customthe residue was recrystallized once more

Sources & evidence

ORD record
ord-3de06975c79448a7b4a587b103d72422
Source dataset
uspto-grants-2008_01
Patent number
US07321050B2

Reaction notes

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