Chlorotrimethylsilane → (2,3-Difluoro-5-methylphenyl)trimethylsilane

HRID 451704Notes

Reaction equation

HRID 451704 reaction equation
C(NC(C)C)(C)C.[Li]CCCC.[F:13][C:14]1[CH:19]=[CH:18][C:17]([CH3:20])=[CH:16][C:15]=1[F:21].[CH3:22][Si:23](Cl)([CH3:25])[CH3:24].[NH4+].[Cl-]>C1COCC1.CCCCCC.O>[F:13][C:14]1[C:15]([F:21])=[CH:16][C:17]([CH3:20])=[CH:18][C:19]=1[Si:23]([CH3:25])([CH3:24])[CH3:22]

Participants

9

Reactant 5

HCID 6397ChlorotrimethylsilaneHCID 7912DiisopropylamineHCID 25517Ammonium ChlorideHCID 27334003,4-DifluorotolueneHCID 178418339Butyllithium

Product 1

HCID 59201735(2,3-Difluoro-5-methylphenyl)trimethylsilaneYield 129.8%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent3×HCID 8058HexaneSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of diisopropylamine (20.2 g, 0.2 mol) in THF (500 mL) cooled with an ice-water bath was added a solution of n-BuLi in hexane (2.5 M, 80 mL) dropwise for over 30 min. The mixture was stirred in the ice bath for 30 min then cooled to −78° C. A solution of 1,2-difluoro-4-methylbenzene (12.8 g, 0.1 mol) in THF (80 mL) was added dropwise, after 20-30 min, a solution of TMSCl (21.6 g, 0.2 mol) in THF (20 mL) was added dropwise. The mixture was stirred at −78° C. for 2-3 h. Sat. NH4Cl (300 mL) was added to the mixture, diluted with water (200 mL) and extracted with ether. The ether layer was washed with brine and dried over Na2SO4, the solvent was removed to give (2,3-difluoro-5-methylphenyl)trimethylsilane (26 g, 100%), which was used for the next step without purification. 1H NMR (CDCl3) δ 6.90 (m, 2H), 2.40 (s, 3H), 0.33 (s, 9H).

Workup

  1. extractionextracted with ether
  2. washThe ether layer was washed with brine
  3. dry with materialdried over Na2SO4
  4. customthe solvent was removed

Sources & evidence

ORD record
ord-d4d4e712f9004d17a1dabace5677fca6
Source dataset
uspto-grants-2013_07
Patent number
US08487108B2

Reaction notes

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