1,1-Dibromoethane → HCID 21709879, compound

HRID 650884Notes

Reaction equation

HRID 650884 reaction equation
[C:1]([Si:7]([CH3:19])([CH3:18])[O:8][C:9]1[CH2:10][C:11]2[C:16]([CH:17]=1)=[CH:15][CH:14]=[CH:13][CH:12]=2)([CH2:4][CH2:5][CH3:6])([CH3:3])[CH3:2].[Li][CH2:21][CH2:22][CH2:23][CH3:24].Br[CH:26](Br)[CH3:27]>C1COCC1>[C:1]([Si:7]([CH3:19])([CH3:18])[O:8][C:9]1[CH:10]([CH:23]([CH:22]2[C:21]3[C:16](=[CH:15][CH:14]=[CH:13][CH:12]=3)[CH:17]=[C:9]2[O:8][Si:7]([CH3:18])([CH3:19])[C:1]([CH2:2][CH2:26][CH3:27])([CH3:4])[CH3:3])[CH3:24])[C:11]2[C:16]([CH:17]=1)=[CH:15][CH:14]=[CH:13][CH:12]=2)([CH2:4][CH2:5][CH3:6])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 112011,1-DibromoethaneHCID 21709886HCID 21709886, compoundHCID 178418339Butyllithium

Product 1

HCID 21709879HCID 21709879, compoundYield 52.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 2-(t-hexyldimethylsiloxy)indene (68.62 g, 250.0 mmol) in THF (250 mL) at 0° C. was added dropwise n-BuLi (100.0 mL of a 2.5 M solution in hexanes, 250.0 mmol), and the reaction mixture was stirred overnight at room temperature. The resulting solution was then cooled to −80° C. and treated dropwise with a solution of dibromoethane (23.48 g, 125.0 mmol) in THF (100 mL). After completed addition the reaction mixture was stirred overnight at room temperature and washed with saturated ammonium chloride solution (350 mL). Solvents from the organic phase were evaporated, and the product was dissolved in Et2O (350 mL), washed with water (2×300 mL) and dried over sodium sulphate. Repeated crystallizations at −15° C. afforded 37.48 g (52.2%) of the title compound as off-white crystals. The first crystalline fraction consisted of diastereomerically pure material that was used for spectral characterization. EIMS (calcd/found): m/e 574.3662/574.3659. 1H NMR (CDCl3, δ): 7.22-7.07 (m, 6H); 6.97 (td, 3J=7.4 Hz, 4J=1.2 Hz, 2H); 5.65 (s, 2H); 3.15 (m, 2H); 1.91-1.84 (m, AA′, 2H); 1.67 (sept, 3J=6.8 Hz, 2H); 1.57-1.50 (m, BB′, 2H); 0.89 (m, 24H); 0.27 (s, 6H); 0.24 (s, 6H). 13C NMR (CDCl3, δ): 164.75; 144.45; 140.58; 126.46; 122.60; 122.33; 118.68; 104.96; 49.24; 33.93; 25.03; 24.32; 20.14; 20.02; 18.51; 18.47; −2.66; −2.95.

Workup

  1. temperatureThe resulting solution was then cooled to −80° C.
  2. additionaddition the reaction mixture
  3. stirringwas stirred overnight at room temperature
  4. washwashed with saturated ammonium chloride solution (350 mL)
  5. customSolvents from the organic phase were evaporated
  6. dissolutionthe product was dissolved in Et2O (350 mL)
  7. washwashed with water (2×300 mL)
  8. dry with materialdried over sodium sulphate
  9. customcrystallizations at −15° C.

Sources & evidence

ORD record
ord-bec8a3783bb94128ab177c458d615a99
Source dataset
uspto-grants-2001_08
Patent number
US06277778B1

Reaction notes

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