Used primarily as a key intermediate in the synthesis of pharmaceutical compounds, particularly in the development of receptor antagonists and enzyme inhibitors. Its sulfonyl chloride group readily reacts with amines and alcohols, making it valuable for constructing sulfonamide and sulfonate ester linkages in drug molecules. It is also employed in radiolabeling and tracer studies due to the presence of iodine, allowing for detection or imaging applications in biological systems. Additionally, it serves in the preparation of functionalized aromatic compounds for use in medicinal chemistry and biochemical research.