Chlorotrimethylsilane → 2-(2-Bromo-4-chlorophenyl)ethanamine

HRID 1047971Notes

Reaction equation

HRID 1047971 reaction equation
[BH4-].[Li+].Cl[Si](C)(C)C.[Br:8][C:9]1[CH:14]=[C:13]([Cl:15])[CH:12]=[CH:11][C:10]=1[CH:16]=[CH:17][N+:18]([O-])=O>C1COCC1>[Br:8][C:9]1[CH:14]=[C:13]([Cl:15])[CH:12]=[CH:11][C:10]=1[CH2:16][CH2:17][NH2:18]

Participants

5

Reactant 3

HCID 6397ChlorotrimethylsilaneHCID 4148881Lithium borohydrideHCID 670801942-Bromo-4-chloro-1-(2-nitrovinyl)benzene

Product 1

HCID 582446382-(2-Bromo-4-chlorophenyl)ethanamineYield 87.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a stirred suspension of lithium borohydride (0.39 g; 18.0 mmol) in 25 mL THF at ambient temperature was added chlorotrimethylsilane (3.9 g; 36.0 mmol), dropwise over 2 minutes. Gas was evolved and the mixture warmed slightly. After stirring for 20 minutes, gas evolution had ceased, and argon gas was bubbled through the mixture for 2 minutes to try to remove the remaining trimethylsilane that had formed. A solution of 2-bromo-4-chloro-1-(2-nitrovinyl)benzene (1.18 g; 4.5 mmol) in 20 mL tetrahydrofuran was then added dropwise with stirring at ambient temperature over 4 minutes. The resulting mixture was stirred and heated to reflux. After 2 hours, the heat was removed, and after cooling to ambient temperature, the mixture was cooled in an ice bath and carefully quenched with 25 mL methanol. The solvent was evaporated, and the residue was partitioned between 50 mL of 20% KOH and 25 mL of dichloromethane. The organic layer was dried over sodium sulfate and evaporated to give 0.92 g of 2-(2-bromo-4-chlorophenyl)ethanamine as a cloudy yellow oil. MS (apci, pos) m/z=234.

Workup

  1. temperaturethe mixture warmed slightly
  2. customargon gas was bubbled through the mixture for 2 minutes
  3. customto remove the remaining trimethylsilane that
  4. customhad formed
  5. stirringwith stirring at ambient temperature over 4 minutes
  6. stirringThe resulting mixture was stirred
  7. temperatureheated to reflux
  8. waitAfter 2 hours
  9. customthe heat was removed
  10. temperaturethe mixture was cooled in an ice bath
  11. customcarefully quenched with 25 mL methanol
  12. customThe solvent was evaporated
  13. customthe residue was partitioned between 50 mL of 20% KOH and 25 mL of dichloromethane
  14. dry with materialThe organic layer was dried over sodium sulfate
  15. customevaporated

Sources & evidence

ORD record
ord-2e146798e9c04ad6ba3d58f4b5e65cb6
Source dataset
uspto-grants-2013_10
Patent number
US08569522B2

Reaction notes

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