Process for the preparation of an anhydrous and aqueous 3-chloro-2-sulfopropionic acid reagent and isolation of the crystalline acid

Abstract

An improved and novel process for the preparation of an aqueous 3-chloro-2-sulfopropionic acid reagent involves the formation of a reaction mixture by adding acrylic acid to chlorosulfonic acid maintained at about 45.degree. to 130.degree. C., maintaining the mixture at about 60.degree.-130.degree. C. for about 2-6 hours, and adding sufficient water to the resulting anhydrous reagent to decompose the unreacted chlorosulfonic acid and dilute the reagent to a solids content of about 50-95%, preferably 70-90%. The reagent may be vacuum stripped to remove residual hydrochloric acid. Crystalline 3-chloro-2-sulfopropionic acid may be isolated from the aqueous reagent at a solids content above 80% and below 95%, preferably at 85%.

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