Hydrogen Bromide → 2,5-Bis(trifluoromethyl)bromobenzene

HRID 1417527Notes

Reaction equation

HRID 1417527 reaction equation
[BrH:1].[F:2][C:3]([F:16])([F:15])[C:4]1[CH:10]=[CH:9][C:8]([C:11]([F:14])([F:13])[F:12])=[CH:7][C:5]=1N.N([O-])=O.[Na+]>O.[Cu]>[F:2][C:3]([F:16])([F:15])[C:4]1[CH:10]=[CH:9][C:8]([C:11]([F:14])([F:13])[F:12])=[CH:7][C:5]=1[Br:1]

Participants

6

Reactant 3

HCID 260Hydrogen Bromide3×HCID 7198182,5-Bis(trifluoromethyl)anilineHCID 23668193Sodium Nitrite

Product 1

HCID 27347632,5-Bis(trifluoromethyl)bromobenzene

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 962WaterSolvent2×

Procedure

A suspension of the HBr salt of 2,5-bis-trifluoromethylaniline (1.0 gm, 4.4 mmol) was prepared by addition of 48% HBr (3 gm, 17.5 mmol) and 5 mL of water. This was cooled in an ice bath while a solution of sodium nitrite (335 mg, 4.8 mmol) in 1 mL of water was added dropwise. The reaction was stirred a farther 0.5 hr at which time copper powder (1 gm) and another 3 gm portion of 48% HBr were added. The reaction was heated to reflux and after 10 min the distillate was collected until no organic material was evident with the water. The distillate was extracted twice with ether and the ether layers were washed with brine, dried over sodium sulfate, combined and evaporated. The residue was purified by flash chromatography (5% ethyl acetate/hexanes) to afford the title compound as an oil. NMR (CDCl3): δ 7.68 (d, 1H, J=8 Hz), 7.81 (d, 1H, J=8 Hz), 7.96 (s, 1H).

Workup

  1. additionwas added dropwise
  2. temperatureThe reaction was heated
  3. temperatureto reflux and after 10 min the distillate
  4. customwas collected until no organic material
  5. extractionThe distillate was extracted twice with ether
  6. washthe ether layers were washed with brine
  7. dry with materialdried over sodium sulfate
  8. customevaporated
  9. customThe residue was purified by flash chromatography (5% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-f890d777f47742b6a857b311e422bd22
Source dataset
uspto-grants-1999_03
Patent number
US05877191

Reaction notes

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