Used as a key intermediate in the synthesis of pharmaceutical compounds, particularly in the development of kinase inhibitors for cancer treatment. Its sulfonyl chloride group readily reacts with amines to form sulfonamides, making it valuable in constructing biologically active molecules. Commonly employed in medicinal chemistry for modifying drug candidates to enhance potency, selectivity, and metabolic stability. Also utilized in the preparation of fluorescent probes and agrochemicals due to its reactive functionality and heterocyclic core.