Used primarily as a key intermediate in the synthesis of pharmaceuticals and agrochemicals. Its reactive sulfonyl chloride group enables the formation of sulfonamides, which are common structural motifs in bioactive molecules. It is also employed in the development of dyes and functional materials due to its halogen substituents, which allow further functionalization via cross-coupling reactions. Its selectivity in substitution patterns makes it valuable in fine chemical synthesis for introducing aromatic sulfonyl groups into complex molecules.