Benzene → N-Methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide

HRID 358378Notes

Reaction equation

HRID 358378 reaction equation
C1C=CC=CC=1.[CH3:7][NH:8][C:9](=[O:14])[C:10]([F:13])([F:12])[F:11].[H-].[Na+].[Si:17](Cl)([C:20]([CH3:23])([CH3:22])[CH3:21])([CH3:19])[CH3:18]>C(#N)C>[CH3:7][N:8]([Si:17]([C:20]([CH3:23])([CH3:22])[CH3:21])([CH3:19])[CH3:18])[C:9](=[O:14])[C:10]([F:13])([F:12])[F:11]

Participants

6

Reactant 4

HCID 241BenzeneHCID 24758Sodium hydrideHCID 28928tert-Butyldimethylsilyl chlorideHCID 69948Acetamide, 2,2,2-trifluoro-N-methyl-

Product 1

HCID 2724275N-Methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To 800 ml of dry benzene:acetonitrile (v/v, 1:1) was added 127 g (1.0 mole) of N-methyl-trifluoroacetamide. To this solution, while stirring and maintaining the temperature at 0 degress C., was slowly added 23.5 g (0.98 mole) of sodium hydride. The solution was then stirred for 4 hours at 4 degrees C. At this time, 173.34 g (1.15 mole) of t-butyldimethylsilyl chloride was added in four equal aliquots over a period of 80 minutes. After the last addition the solution was stirred for 2 hours at 4 degrees C. The precipitate of sodium chloride was then removed from the reaction mixture by filtration under dry nitrogen and the resulting filter cake washed twice with 100 ml each of dry benzene. Washings and filtrate were combined and concentrated. The remaining yellow solution was fractionally distilled with the distillate at 158-172 degrees C. being collected. Redistillation of this fraction gave the desired product.

Workup

  1. temperaturemaintaining the temperature at 0 degress C
  2. stirringThe solution was then stirred for 4 hours at 4 degrees C
  3. additionAfter the last addition the solution
  4. stirringwas stirred for 2 hours at 4 degrees C
  5. customThe precipitate of sodium chloride was then removed from the reaction mixture by filtration under dry nitrogen
  6. filtrationthe resulting filter cake
  7. washwashed twice with 100 ml each of dry benzene
  8. concentrationconcentrated
  9. distillationThe remaining yellow solution was fractionally distilled with the distillate at 158-172 degrees C
  10. custombeing collected
  11. distillationRedistillation of this fraction

Sources & evidence

ORD record
ord-42fe8ff05edf4687a2f49e3dbd7652d5
Source dataset
uspto-grants-1984_08
Patent number
US04467037

Reaction notes

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