Hydrochloric Acid → 2,3-Difluorobenzene-1,4-diol

HRID 6333

Reaction equation

HRID 6333 reaction equation
[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[CH:4][C:3]=1[OH:9].[K].Cl.S([O-])([O-])=[O:13].[Na+].[Na+]>[OH-].[Na+].C1(C)C=CC=CC=1>[F:1][C:2]1[C:7]([F:8])=[C:6]([OH:13])[CH:5]=[CH:4][C:3]=1[OH:9]

Participants

7

Reactant 4

HCID 313Hydrochloric Acid2×HCID 24437Sodium SulfiteHCID 808792,3-DifluorophenolHCID 5462222Potassium

Product 1

HCID 110299702,3-Difluorobenzene-1,4-diol

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 14798Sodium HydroxideSolvent

Procedure

1 mol of 2,3-difluorophenol is dissolved in 1 l of 10% sodium hydroxide solution, and a saturated aqueous solution of 1.1 mol of potassium peroxodisulphate is added dropwise over the course of 4 hours with ice cooling. During this addition, the temperature must not exceed 20o The mixture is stirred overnight at room temperature and neutralized using hydrochloric acid, and unreacted starting material is extracted with ether. 3 1 of toluene and 2 mol of sodium sulphite are added to the aqueous phase, and the mixture is strongly acidified using 1 1 of concentrated hydrochloric acid and refluxed for 20 minutes. After cooling, the toluene layer is separated off, the aqueous phase is extracted with ether in a perforator, and 2,3-difluorohydroquinone is obtained by evaporating the combined toluene and ether extracts.

Workup

  1. additionDuring this addition
  2. extractionis extracted with ether
  3. temperaturerefluxed for 20 minutes
  4. temperatureAfter cooling
  5. customthe toluene layer is separated off
  6. extractionthe aqueous phase is extracted with ether in a perforator

Sources & evidence

ORD record
ord-32048f4b38654a34b265cba539771b47
Source dataset
uspto-grants-1993_09
Patent number
US05248447

Linked notes

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