Used primarily as an intermediate in the synthesis of sulfonamide-based pharmaceuticals and agrochemicals. Its reactive sulfonyl chloride group allows for easy attachment to amines, forming sulfonamides that are key structural motifs in drug development. Commonly employed in the preparation of bioactive molecules, including antifungal agents and enzyme inhibitors. Also utilized in research settings for labeling and modifying biomolecules due to its selective reactivity. Handling requires caution due to its moisture sensitivity and potential irritant properties.