Sodium Hydroxide → 5-Carboxy-2-fluorobenzenesulfinic acid

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence