Chlorotrimethylsilane → Trimethyl{3-methyl-4-[(trimethylsilyl)oxy]phenyl}silane

HRID 2217098Notes

Reaction equation

HRID 2217098 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([OH:8])=[C:4]([CH3:9])[CH:3]=1.C([Li])CCC.[CH3:15][Si:16](Cl)([CH3:18])[CH3:17].[Cl-].[NH4+]>C1COCC1>[CH3:9][C:4]1[CH:3]=[C:2]([Si:16]([CH3:18])([CH3:17])[CH3:15])[CH:7]=[CH:6][C:5]=1[O:8][Si:16]([CH3:18])([CH3:17])[CH3:15]

Participants

6

Reactant 4

HCID 6397ChlorotrimethylsilaneHCID 168964-Bromo-2-methylphenolHCID 25517Ammonium ChlorideHCID 178418339Butyllithium

Product 1

HCID 59824832Trimethyl{3-methyl-4-[(trimethylsilyl)oxy]phenyl}silaneYield 79%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-bromo-2-methylphenol (1.5 g, 8.02 mmol) in THF (16 mL) at −78° C. was added n-butyl lithium (12.5 mL, 1.6 M solution in hexanes, 20.05 mmol) and the reaction was stirred at this temperature for 30 minutes. Trimethylsilyl chloride (2.5 mL, 20.05 mmol) was then added and the resulting mixture was stirred at −78° C. for a further 1.5 hours. The reaction was allowed to warm to room temperature and saturated ammonium chloride solution (10 mL) was added. The mixture was extracted with diethyl ether (2×20 mL) and the combined organic extracts were dried (magnesium sulphate) and concentrated under reduced pressure to give the intermediate 2-methyl-4-(trimethylsilyl)phenoxytrimethylsilane as a pale yellow oil (1.6 g). This intermediate was then diluted with THF (3 mL) and treated with TBAF (6.3 mL, 1.0 M solution in THF, 6.33 mmol) at room temperature. The reaction was stirred at this temperature for 5 minutes and poured into water (10 mL). The aqueous portion was then extracted with ether (3×5 mL) and the combined organic extracts were washed (saturated brine), dried (magnesium sulphate) and concentrated under reduced pressure. The resulting oily residue was pre-adsorbed onto silica and the 2-methyl-4-(trimethylsilyl)phenol isolated by column chromatography (SiO2; light petroleum to 7:3 light petroleum-diethyl ether) as a pale yellow oil (0.78 g, 68%). Rf=0.65 (7:3 light petroleum-diethyl ether, silica). 1H NMR (DMSO-d6): δH 0.17 (9 H, s), 2.1 (3 H, s), 6.77 (1 H, d, J=7.8 Hz), 7.12 (1 H, d, J=7.8 Hz), 7.17 (1 H, s), 9.36 (1 H, s).

Workup

  1. stirringthe resulting mixture was stirred at −78° C. for a further 1.5 hours
  2. extractionThe mixture was extracted with diethyl ether (2×20 mL)
  3. dry with materialthe combined organic extracts were dried (magnesium sulphate)
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-a43e8b811bdd4811b6dd28f3dd3c88c3
Source dataset
uspto-grants-2008_08
Patent number
US07407649B2

Reaction notes

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