Ethyl Bromide → HCID 12231552, compound

HRID 2396384Notes

Reaction equation

HRID 2396384 reaction equation
[CH2:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][C:2]1=[O:11].[Li+].[CH3:13][CH:14]([N-]C(C)C)[CH3:15].C(Br)C.[CH2:23]1[CH2:27]OC[CH2:24]1>C1CCCCC1>[O:11]=[C:2]1[CH2:3][CH2:4][C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[C:1]1([CH2:27][CH:23]=[CH2:24])[CH2:15][CH:14]=[CH2:13]

Participants

6

Reactant 4

HCID 6332Ethyl BromideHCID 8028TetrahydrofuranHCID 682662-TetraloneHCID 2724682Lithium diisopropylamide

Product 1

HCID 12231552HCID 12231552, compound

Reagents, catalysts & solvents 1

HCID 8078CyclohexaneSolvent

Procedure

To a solution of 7.3 g (50 mmol) 2-tetralone in 75 ml THF in a three-neck round-bottomed flask, equipped with a gas inlet and septum, was added 36.7 mL LDA (55 mmol, 1.5M in cyclohexane, at -30° C. under a nitrogen atmosphere. The solution was allowed to warm to 0° C. over a thirty-minute period and 5.6 mL (65 mmol) ethyl bromide was added. TLC analysis was used to monitor the reaction. After stirring for 24 hours at room temperature, the reaction mixture was quenched with 10% sodium bisulfate to pH2-3. 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 crude product was purified by liquid chromatography on 800 g of silica gel 60 (230-400 m), eluting with 1 L hexane, followed by 5 L of 5% ethyl acetate/hexane, and collecting 40 mL fractions. Fractions 41-64 gave 4.2 g (37%) of pure and 1,2,3,4-tetrahydro-2-oxo-1,1-di-(2-propenyl)naphthalene as a colorless oil and fractions 65-82 gave 3.1 g (33%) of pure 1,2,3,4-tetrahydro-2-oxo-1-(2-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 pH2-3
  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 crude product was purified by liquid chromatography on 800 g of silica gel 60 (230-400 m)
  12. washeluting with 1 L hexane
  13. customcollecting 40 mL fractions

Sources & evidence

ORD record
ord-784a43b3b1934015ba80dcbf2e6b0add
Source dataset
uspto-grants-1996_02
Patent number
US05491236

Reaction notes

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