2,4-Difluoro-5-nitrophenol → 5-Amino-2,4-difluorophenol

HRID 257233Notes

Reaction equation

HRID 257233 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([F:8])[C:5]([N+:9]([O-])=O)=[CH:4][C:3]=1[OH:12].[H][H]>CO.[Ni]>[F:1][C:2]1[CH:7]=[C:6]([F:8])[C:5]([NH2:9])=[CH:4][C:3]=1[OH:12]

Participants

5

Reactant 2

HCID 109210242,4-Difluoro-5-nitrophenolHCID 178418361HCID 178418361, compound2×

Product 1

HCID 27829995-Amino-2,4-difluorophenolYield 90.5%

Reagents, catalysts & solvents 2

HCID 935NickelCatalystHCID 887MethanolSolvent

Procedure

24 g of 2,4-Difluoro-5-nitrophenol, dissolved in 120 ml of methanol, are subjected to hydrogenation at a hydrogen pressure of 20-40 bar at 25°-45° C. in the presence of 2 g of Raney nickel. When constant pressure is reached (i.e. when the take-up of hydrogen is complete), the pressure is released and the mixture is cooled, the solution is free from catalyst by filtration, and the methanol is subsequently removed by distillation at reduced pressure. 18 g (GC purity 97.5%) of 2,4-difluoro-5-aminophenol are obtained.

Workup

  1. temperaturethe mixture is cooled
  2. filtrationthe solution is free from catalyst by filtration
  3. customthe methanol is subsequently removed by distillation at reduced pressure

Sources & evidence

ORD record
ord-99b09020e315492bb74399ae53d7de75
Source dataset
uspto-grants-1993_11
Patent number
US05260474

Reaction notes

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