Chlorosulfonic acid

Chlorosulfonic acid (CAS 7790-94-5), also known as chlorosulfuric acid or CSA, is a highly reactive sulfonating and chlorosulfonating agent.

Where is Chlorosulfonic acid used?

• Agrochemical synthesis: herbicide and pesticide intermediates, particularly sulfonamide-class compounds
• Pharmaceuticals: sulfonyl chloride intermediates feeding into APIs and specialty drug substances
• Textile and leather: precursor to synthetic dyes and optical brighteners
• Polymers: sulfonation of polystyrene and similar backbones for ion-exchange resins and proton-exchange membranes
• It introduces sulfonic or sulfonyl chloride groups into organic molecules.

Commercial specifications

• Concentrations at or near 99% purity
• Technical grade standard; high-purity grades for pharmaceutical and specialty chemical synthesis
• Packaged in corrosion-resistant containers