Water → Benzoic acid, 3-sulfo-, sodium salt (1:1)

Participants

Reaction Conditions

Reaction Steps

360 g of 26.4% strength sodium chloride solution, prepared from 95.0 g of sodium chloride and 265.0 g of water, and 332 g of crude 3-(chlorosulfonyl)benzoic acid (water content: 39.2%) (corresponding to 201.8 g (0.92 mol) of 100% 3-(chlorosulfonyl)benzoic acid) are introduced into a 1 l four-neck flask fitted with stirrer, internal thermometer and reflux condenser. The reaction mixture is heated to 100° C. and stirred for a further 45 minutes at this temperature. The mixture is then allowed to cool over about 1 hour to 40° C. Subsequently it is cooled with an ice bath to <5° C. and stirred for a further 30 minutes at this temperature. The precipitated product is filtered off with suction and washed with 256 g of 5% strength sodium chloride solution, prepared from 12.8 g of sodium chloride and 243.2 g of water and cooled to 5° C., in two portions. The filter cake is dried at 100° C./100 torr (13.16 kPa). 196.3 g of sodium 3-sulfobenzoate are obtained with a purity of 95% and a sodium chloride content of 3.9% (corresponding to 186.5 g (0.83 mol) of 100% sodium 3-sulfobenzoate). The yield is 90.9% of theoretical. 345 g of mother liquor and 318 g of wash liquor are produced.

Provenance & Evidence