Methyl iodide → 9-Methyl-2,7-bis(trimethylsilyl)-9H-fluorene

HRID 2373088Notes

Reaction equation

HRID 2373088 reaction equation
[CH3:1][Si:2]([CH3:21])([CH3:20])[C:3]1[CH:15]=[CH:14][C:13]2[C:12]3[C:7](=[CH:8][C:9]([Si:16]([CH3:19])([CH3:18])[CH3:17])=[CH:10][CH:11]=3)[CH2:6][C:5]=2[CH:4]=1.[CH2:22]([Li])CCC.CI>CCOCC>[CH3:17][Si:16]([CH3:19])([CH3:18])[C:9]1[CH:10]=[CH:11][C:12]2[C:13]3[C:5](=[CH:4][C:3]([Si:2]([CH3:21])([CH3:20])[CH3:1])=[CH:15][CH:14]=3)[CH:6]([CH3:22])[C:7]=2[CH:8]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 12982931HCID 12982931, compoundHCID 178418339Butyllithium

Product 1

HCID 199026729-Methyl-2,7-bis(trimethylsilyl)-9H-fluoreneYield 98.7%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

To a solution of 1.0 g of 2,7-bis(trimethylsilyl)fluorene in 15 mL of dry ether was added dropwise 2.8 mL of 1.3 M n-butyllithium at 0° C. The mixture was stirred at room temperature for 3 hours, cooled to 0° C., and treated with a solution of 0.25 mL of methyl iodide in 5 mL of dry ether over a period of 5 minutes. The mixture was stirred at room temperature for 8 hours and washed with 2% Na2S2O3 (10 mL) and water (2×10 mL). The pooled aqueous layer was extracted with ether (2×15 mL). The combined organic extracts were dried over MgSO4 and the solvent was evaporated under reduced pressure to give 1.03 g (98.7%) of the crude 2,7-bis(trimethylsilyl)-9-methylfluorene as a yellow oil which was chromatographed on silica gel (230-400 mesh, 2×40-cm packed column) with an eluant consisting of Skelly B--dichloromethane (6:1) to give 0.78 g (74.7%) of the crude hydrocarbon as a colorless oil. Crystallization from 95% ethanol gave 0.69 g (66.1%) of the pure 2,7-bis(trimethyl-silyl)-9-methylfluorene as white needles, m.p. 107°-108.5° C.; 1H NMR (CDC13): δ 0.34 (s, 18H, SiMe3), 1.58 (d, 3H, CH3), 3.96 (q, 1H, CH), 7.40-7.90 (m, 6H, aryl).

Workup

  1. temperaturecooled to 0° C.
  2. stirringThe mixture was stirred at room temperature for 8 hours
  3. washwashed with 2% Na2S2O3 (10 mL) and water (2×10 mL)
  4. extractionThe pooled aqueous layer was extracted with ether (2×15 mL)
  5. dry with materialThe combined organic extracts were dried over MgSO4
  6. customthe solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-e4dceb1c161c4ff695bd4eafc726c357
Source dataset
uspto-grants-1992_03
Patent number
US05101059

Reaction notes

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