Chlorotrimethylsilane → Ethanone, 2-bromo-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-

HRID 900227Notes

Reaction equation

HRID 900227 reaction equation
[C:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[O:10][CH2:9][C:8]=2[CH:15]=1)(=[O:3])[CH3:2].C[Si](C)(C)N[Si](C)(C)C.[Na].C[Si](Cl)(C)C.[Br:31]Br>C1COCC1>[Br:31][CH2:2][C:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[O:10][CH2:9][C:8]=2[CH:15]=1)=[O:3]

Participants

6

Reactant 4

HCID 6397ChlorotrimethylsilaneHCID 24408BromineHCID 218806101-(2,2-Dimethyl-2,4-dihydro-1,3-benzodioxin-6-yl)ethan-1-oneHCID 45051731Sodium hexamethyidisilazane

Product 1

HCID 11150315Ethanone, 2-bromo-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To the product of step (b) (23.4 g, 0.113 mol) in 600 mL of THF at −78° C. was added 135 mL of 1.0 M sodium hexamethyldisilazane in THF (Sigma-Aldrich). After 1 hour, trimethylsilyl chloride (15.8 mL, 0.124 mol) was added. After another 30 minutes, bromine (5.82 mL, 0.113 mol) was added. After 10 minutes, the reaction was quenched by diluting the reaction mixture with diethyl ether and pouring it onto 500 mL of 5% aqueous Na2SO3 premixed with 500 mL of 5% aqueous NaHCO3. The phases were separated and the organic phase was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to give the title compound as an oil that solidified upon storage in the freezer.

Workup

  1. waitAfter another 30 minutes
  2. waitAfter 10 minutes
  3. customthe reaction was quenched
  4. additionby diluting the reaction mixture with diethyl ether
  5. additionpouring it onto 500 mL of 5% aqueous Na2SO3
  6. additionpremixed with 500 mL of 5% aqueous NaHCO3
  7. customThe phases were separated
  8. washthe organic phase was washed with brine
  9. dry with materialdried over Na2SO4
  10. filtrationfiltered
  11. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-7d7ccb25dd2f4dd182331a1f6f634cf5
Source dataset
uspto-grants-2008_04
Patent number
US07358244B2

Reaction notes

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