Allyl bromide → HCID 54486338, compound

HRID 2270501Notes

Reaction equation

HRID 2270501 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:4]=1[CH2:5][CH2:6][C:7](=[O:13])[CH2:8]2.[Li+].[CH3:15][CH:16]([N-]C(C)C)[CH3:17].[CH2:22](Br)[CH:23]=[CH2:24]>C1COCC1.C1CCCCC1>[CH3:1][O:2][C:3]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:4]=1[CH2:5][CH2:6][C:7](=[O:13])[C:8]2([CH2:24][CH:23]=[CH2:22])[CH2:17][CH:16]=[CH2:15]

Participants

6

Reactant 3

HCID 7841Allyl bromideHCID 2591945-Methoxy-2-tetraloneHCID 2724682Lithium diisopropylamide

Product 1

HCID 54486338HCID 54486338, compoundYield 32.5%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8078CyclohexaneSolvent

Procedure

To a solution of 5.3 g (30 mmol) 5-methoxy-2-tetralone in 45 mL THF in a three-neck round-bottomed flask, equipped with a gas inlet and septum, was added 22 mL LDA (33 mmol, 1.5 M in cyclohexane, at −30° C. under a nitrogen atmosphere. The solution was allowed to warm to 0° C. over a thirty-minute period and 3.4 mL (39 mmol) allylbromide was added. TLC analysis was used to monitor the reaction. After five hours of stirring, the reaction mixture was quenched with 10% sodium bisulfate to pH 2-3. After removal of THF under reduced pressure, the mixture was extracted with ethyl acetate (2×1 L) and the combined organic layers were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. The resulting oil was purified by liquid chromatography on 800 g of silica gel 60 (230-400 m), eluting with 1 L of hexane and 5 L of hexane-ethyl acetate (19:1), and collecting 40 mL fractions. Fractions 45-87 gave 2.5 g (32.5%) of pure 1,2,3,4-tetrahydro-5-methoxy-2-oxo-1,1-di-(2-propenyl)-naphthalene as a near colorless oil and fractions 88-140 gave 1.07 g (16.5%) of pure 1,2,3,4-tetrahydro-5-methoxy-2-oxo-12-propenyl)naphthalene as a light yellow oil.

Workup

  1. customat −30° C.
  2. additionwas added
  3. customthe reaction
  4. customthe reaction mixture was quenched with 10% sodium bisulfate to pH 2-3
  5. customAfter removal of THF under reduced pressure
  6. extractionthe mixture was extracted with ethyl acetate (2×1 L)
  7. washthe combined organic layers were washed with brine
  8. dry with materialdried (MgSO4)
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customThe resulting oil was purified by liquid chromatography on 800 g of silica gel 60 (230-400 m)
  12. washeluting with 1 L of hexane and 5 L of hexane-ethyl acetate (19:1)
  13. customcollecting 40 mL fractions

Sources & evidence

ORD record
ord-2c0b84e20e7145f7b5afb2ddaf79d26e
Source dataset
uspto-grants-2001_12
Patent number
US06331636B1

Reaction notes

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