Hexamethyldisilazane → α-Ethyl-4-(trimethylsilyl)benzenemethanamine

HRID 1768559Notes

Reaction equation

HRID 1768559 reaction equation
C[Si](C)(C)[NH:3][Si](C)(C)C.[CH2:10]([Li])[CH2:11][CH2:12][CH3:13].[CH3:15][Si:16]([CH3:26])([CH3:25])[C:17]1[CH:24]=[CH:23]C(C=O)=[CH:19][CH:18]=1.[Li]N([Si](C)(C)C)[Si](C)(C)C.C([Mg]Br)C>O1CCCC1>[CH2:12]([CH:11]([C:10]1[CH:23]=[CH:24][C:17]([Si:16]([CH3:26])([CH3:25])[CH3:15])=[CH:18][CH:19]=1)[NH2:3])[CH3:13]

Participants

7

Reactant 5

HCID 13838HexamethyldisilazaneHCID 6375734-(Trimethylsilyl)benzaldehydeHCID 178418261HCID 178418261, compoundHCID 178418339ButyllithiumHCID 178418443HCID 178418443, compound

Product 1

HCID 18948862α-Ethyl-4-(trimethylsilyl)benzenemethanamine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of hexamethyldisilazane (4.3 mL, 20 mmole) in tetrahydrofuran (5 mL) at 0° C. was added n-butyllithium (8.4 mL of 2.5M, 21 mmole) dropwise. The mixture was allowed to warm to room temperature for 20 minutes and then recooled to 0° C. In a separate flask, the product of Step B (3.0 g, 17 mmole) in tetrahydrofuran (10 mL) was cooled to 0° C. The lithiohexamethyldisilazane solution was added via cannula to the aldehyde solution. The reaction mixture was warmed to 22° C. for 20 minutes and then ethyl magnesium bromide (14 mL of 3.0M, 42 mmole) was added dropwise. After heating the mixture at reflux for 12 hours, it was cooled and quenched with saturated aqueous ammonium chloride solution. The aqueous phase was separated and extracted with ether. Combination of the organic phases, drying (MgSO4), and concentration gave a crude residue which was chromatographed on silica gel with ethyl acetate. The desired product was obtained as a colorless oil (0.95 g, 27% yield).

Workup

  1. customrecooled to 0° C
  2. temperatureThe reaction mixture was warmed to 22° C. for 20 minutes
  3. temperatureAfter heating the mixture
  4. temperatureat reflux for 12 hours
  5. temperatureit was cooled
  6. customquenched with saturated aqueous ammonium chloride solution
  7. customThe aqueous phase was separated
  8. extractionextracted with ether
  9. customCombination of the organic phases, drying
  10. concentration(MgSO4), and concentration
  11. customgave a crude residue which
  12. customwas chromatographed on silica gel with ethyl acetate

Sources & evidence

ORD record
ord-2304eb37c795410bad994baf4eab8c70
Source dataset
uspto-grants-1995_01
Patent number
US05378708

Reaction notes

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