Chlorotrimethylsilane → (5-Bromo-1,3-phenylene)bis(trimethylsilane)

HRID 1017143Notes

Reaction equation

HRID 1017143 reaction equation
[Br:1][C:2]1[CH:7]=[C:6](Br)[CH:5]=[C:4](Br)[CH:3]=1.C([Li])CCC.[CH3:15][Si:16]([CH3:19])([CH3:18])Cl>C(OCC)C>[CH3:15][Si:16]([CH3:19])([CH3:18])[C:4]1[CH:3]=[C:2]([Br:1])[CH:7]=[C:6]([Si:16]([CH3:19])([CH3:18])[CH3:15])[CH:5]=1

Participants

5

Conditions

Temperature
-70 °C

Procedure

1,3,5-Tribromobenzene (125 g, 0.4 mol) was dissolved in anhydrous diethylether (1 L), and cooled to −70° C. n-butyllithium (250 mL. 1.6 M in hexanes. 0.4 mol) was added dropwise over a one-hour period keeping the temperature near −70° C. The solution was stirred for an additional 20 minutes at −70° C. and then warmed to −10° C. over a two-hour period. The solution was then recooled to −70° C. and trimethylchlorosilane (45 g, 0.4 mol) was added over a one-hour period. The solution was stirred and allowed to warm to room temperature overnight. The solution was cooled to −70° C. and an additional 0.4 mol n-butyllithium was added over a one-hour period. The resulting slurry was stirred for one hour at −70° C., warmed to −10° C. over a one-hour period and then recooled to −70° C. An additional 0.4 mol of trimethylchlorosilane was added and the slurry was allowed to warm to room temperature overnight. The mixture was quenched with water and the layers were separated. The organic layer was washed twice with sodium bicarbonate solution and with salt brine then dried over magnesium sulfate. The solvents were evaporated under vacuum and the product distilled twice under vacuum to yield 85.2 g (70%) of a colorless liquid. b.p. 100-105° C. at 0.5 mmHg.

Workup

  1. additionwas added dropwise over a one-hour period
  2. customnear −70° C
  3. temperaturewarmed to −10° C. over a two-hour period
  4. customwas then recooled to −70° C.
  5. stirringThe solution was stirred
  6. temperatureto warm to room temperature overnight
  7. temperatureThe solution was cooled to −70° C.
  8. stirringThe resulting slurry was stirred for one hour at −70° C.
  9. temperaturewarmed to −10° C. over a one-hour period
  10. customrecooled to −70° C
  11. temperatureto warm to room temperature overnight
  12. customThe mixture was quenched with water
  13. customthe layers were separated
  14. washThe organic layer was washed twice with sodium bicarbonate solution and with salt brine
  15. dry with materialthen dried over magnesium sulfate
  16. customThe solvents were evaporated under vacuum
  17. distillationthe product distilled twice under vacuum

Sources & evidence

ORD record
ord-8c666c335e334f1ea09aae3a88e659a9
Source dataset
uspto-grants-2002_11
Patent number
US06479424B1

Reaction notes

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