Hexamethyldisilazane → Lithium bis(trimethylsilyl)amide

HRID 37597Notes

Reaction equation

HRID 37597 reaction equation
[CH3:1][Si:2]([CH3:9])([CH3:8])[NH:3][Si:4]([CH3:7])([CH3:6])[CH3:5].[Li:10].[H][H]>CCCCCC>[CH3:1][Si:2]([CH3:9])([CH3:8])[NH:3][Si:4]([CH3:7])([CH3:6])[CH3:5].[Li:10]

Participants

5

Reactant 3

HCID 13838HexamethyldisilazaneHCID 3028194LithiumHCID 178418361HCID 178418361, compound

Product 1

HCID 57426343Lithium bis(trimethylsilyl)amideYield 90%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Conditions

Temperature
225 °C

Procedure

To 288 ml of hexamethyldisilazane (220 g, 1.36 mole) in a 1-liter Parr reactor was charged 7.00 g of lithium metal (1.00 mole) under an argon atmosphere, with a backpressure of approximately 150 psig. The mixture was slowly heated to 225° C. over a 1 to 2 hour period. At this temperature and pressure, the reaction was allowed to proceed for approximately 16 hours with stirring and venting of hydrogen. The reaction mixture was then cooled to below 40° C. and hexane solvent (300 ml) was added to dissolve the product. Filtration to remove any unreacted lithium metal followed by evaporation under vacuum (2 mm Hg) at 110° C. provided approximately 150 g of lithium hexamethyldisilazane solid (approximately 0.90 mole, >90% yield, total base analysis: 101.3% of the theoretical value).

Workup

  1. temperatureThe reaction mixture was then cooled to below 40° C.
  2. dissolutionto dissolve the product
  3. filtrationFiltration
  4. customto remove any unreacted lithium metal
  5. customfollowed by evaporation under vacuum (2 mm Hg) at 110° C.

Sources & evidence

ORD record
ord-81d1ec6e8dcd41e79148a0c6e3f05be2
Source dataset
uspto-grants-1995_05
Patent number
US05420322

Reaction notes

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