Used primarily as an intermediate in the synthesis of pharmaceuticals and agrochemicals. Its sulfonyl chloride group readily reacts with amines to form sulfonamides, which are key 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 presence of the chloro and methoxy substituents allows for further functionalization or modulation of electronic properties, enhancing its utility in medicinal chemistry. Also employed in the preparation of dyes and specialty polymers where sulfonyl-based linkages improve thermal and chemical stability.