Used primarily as an intermediate in the synthesis of sulfa drugs and other pharmaceuticals. It plays a key role in the preparation of sulfonylurea compounds, which are important in the development of herbicides and antidiabetic medications. Its reactivity allows for the introduction of sulfonyl chloride functional groups into complex molecules, facilitating the formation of sulfonamide bonds widely found in bioactive compounds. Commonly employed in organic synthesis for constructing agrochemicals, dyes, and functional polymers due to its ability to modify aromatic frameworks.