3-sulphobenzoic acid

Grayish-white solid. Stable but hygroscopic in air. Mp 98C, anhydrous form melts at 141C. Soluble in water, alcohol; insoluble in benzene.

3-Sulfobenzoic Acid is used in preparation of Proline derivatives for inhibition of β-Lactamase.

Derivative for surface-active agents.

3-sulphobenzoic acid is produced by the direct sulfonation of benzoic acid with oleum in ca. 85 % yield. 3-Sulfobenzoic acid is chiefly used for the production of 3-hydroxybenzoic acid by alkali fusion.