Sodium Hydroxide → 5-Carboxy-2-fluorobenzenesulfinic acid

HRID 726087Notes

Reaction equation

HRID 726087 reaction equation
S([O-])([O-])=O.[Na+].[Na+].[F:7][C:8]1[CH:16]=[CH:15][C:11]([C:12]([OH:14])=[O:13])=[CH:10][C:9]=1[S:17](Cl)(=[O:19])=[O:18].[OH-].[Na+]>O>[C:12]([C:11]1[CH:15]=[CH:16][C:8]([F:7])=[C:9]([S:17]([OH:19])=[O:18])[CH:10]=1)([OH:14])=[O:13]

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 24437Sodium SulfiteHCID 39298913-(Chlorosulfonyl)-4-fluorobenzoic acid

Product 1

HCID 106796785-Carboxy-2-fluorobenzenesulfinic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
70 °C

Procedure

15.6 g (0.124 mol) of sodium sulfite are dissolved in 120 ml of water at 70° C. While maintaining the temperature, 23.8 g (0.1 mol) of 4-fluoro-3-chlorosulfonylbenzoic acid and 10N NaOH are added simultaneously and in portions such that the pH is kept between 9 and 10 (exothermic reaction). The mixture is stirred for a further 3 hours at 70° C., stirred for a further 15 minutes with active carbon and then filtered. The filtrate is adjusted to pH 0-1 using concentrated hydrochloric acid with external cooling and the crystalline 5-carboxy-2-fluorobenzenesulfinic acid is filtered off.

Workup

  1. additionare added simultaneously and in portions such that the pH
  2. customis kept between 9 and 10 (exothermic reaction)
  3. stirringstirred for a further 15 minutes with active carbon
  4. filtrationfiltered
  5. temperaturewith external cooling
  6. filtrationthe crystalline 5-carboxy-2-fluorobenzenesulfinic acid is filtered off

Sources & evidence

ORD record
ord-1842e1518e2645ee9da1e9584309a52e
Source dataset
uspto-grants-1998_01
Patent number
US05708034

Reaction notes

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