Used primarily as a key intermediate in the synthesis of sulfa drugs, particularly sulfonamide antibiotics. It serves as a sulfonylating agent in organic chemistry, enabling the introduction of sulfonyl chloride functional groups into various compounds. Its high reactivity makes it valuable in the preparation of dyes, agrochemicals, and other fine chemicals. Commonly employed in research laboratories for developing novel pharmaceuticals and in the production of specialty polymers due to its ability to form stable sulfonamide linkages.