Used primarily as a key intermediate in the synthesis of biologically active compounds, especially in pharmaceutical research. Its sulfonyl chloride group readily reacts with amines and alcohols, making it valuable for constructing sulfonamide and sulfonate ester derivatives. These transformations are commonly employed in the development of kinase inhibitors and other targeted therapies in medicinal chemistry. The bromine substituent allows for further functionalization via cross-coupling reactions such as Suzuki or Heck reactions, enabling rapid diversification of molecular structures during drug discovery. Also utilized in the preparation of fluorescent probes and agrochemicals due to its aromatic and reactive dual functionality.