Sulfuric Acid → 2,3-Difluoro-6-nitrophenol

HRID 486971Notes

Reaction equation

HRID 486971 reaction equation
F[C:2]1[C:7]([F:8])=[C:6]([F:9])[CH:5]=[CH:4][C:3]=1[N+:10]([O-:12])=[O:11].[OH-].[Na+].S(=O)(=O)(O)[OH:16]>O>[F:8][C:7]1[C:6]([F:9])=[CH:5][CH:4]=[C:3]([N+:10]([O-:12])=[O:11])[C:2]=1[OH:16]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 698711,2,3-Trifluoro-4-nitrobenzene

Product 1

HCID 27337452,3-Difluoro-6-nitrophenolYield 85%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
40 °C

Procedure

1.77 kg (10 mol) of 2,3,4-trifluoronitrobenzene are added to 2 l of water, and the mixture is warmed to 40° C. and vigorously stirred. 1760 g (22 mol) of 31.7% strength sodium hydroxide solution are then added dropwise in such a way that the temperature does not rise above 60° C. After about 2 h, GC checking no longer shows any starting compound. The reaction mixture is brought to pH 2.5 using 70% strength sulfuric acid. Steam is then passed into the solution, the product passing over with the steam. The separated solution is cooled to 10° C. with stirring and the precipitated solid is filtered off with suction. The water having a residual content of about 0.1% of 2,3-difluoro-6-nitrophenol can be used in a subsequent batch. 1.48 kg of 2,3-difluoro-6-nitrophenol having a purity >99.9% (GC) are obtained after drying (melting point 64° C.), which corresponds to a yield of 85% of theory.

Workup

  1. customdoes not rise above 60° C
  2. temperatureThe separated solution is cooled to 10° C.
  3. stirringwith stirring
  4. filtrationthe precipitated solid is filtered off with suction

Sources & evidence

ORD record
ord-bc14ded7f70249b1aa9cba74b85bbd62
Source dataset
uspto-grants-1994_03
Patent number
US05292967

Reaction notes

Loading…