Used primarily as a sulfonating agent in organic synthesis, enabling the introduction of sulfonyl functional groups into various compounds. It plays a key role in the preparation of sulfonamides, which are important in pharmaceuticals and agrochemicals due to their biological activity. Commonly employed in the development of medicinal agents, including antimicrobial and anti-inflammatory drugs. Also utilized in the synthesis of dyes and surfactants, where it helps modify solubility and stability properties. Its reactivity makes it valuable in research laboratories for constructing complex molecules requiring sulfonyl linkages.