Used primarily as a key intermediate in organic synthesis, particularly in the production of pharmaceuticals and agrochemicals. It serves as a sulfonating agent, enabling the introduction of the sulfonyl group into various organic compounds, which is crucial for creating sulfonamides and other derivatives. These derivatives are often utilized in the development of drugs with antibacterial, antiviral, or anti-inflammatory properties. Additionally, it finds application in the synthesis of dyes and pigments, where sulfonyl groups enhance stability and color properties. Its reactivity with amines and alcohols makes it valuable in constructing complex molecular structures in research and industrial settings.