Used primarily as a key intermediate in the synthesis of pharmaceuticals and agrochemicals. Its sulfonyl chloride group readily reacts with amines to form sulfonamides, which are important structural motifs in many biologically active compounds. It is particularly valuable in the development of selective serotonin reuptake inhibitors (SSRIs) and other central nervous system agents. The bromine substituent allows for further functionalization via cross-coupling reactions such as Suzuki or Heck reactions, enabling the construction of complex aromatic systems. Also employed in the preparation of fluorescent probes and functionalized polymers due to its reactivity and stability under various reaction conditions.