Used primarily as a sulfonating agent in organic synthesis, enabling the introduction of propanesulfonyl groups into various compounds. Commonly applied in the pharmaceutical industry for modifying drug molecules to improve stability and bioavailability. Also utilized in the preparation of agrochemicals and dyes, where sulfonyl chloride functionality enhances reactivity or structural properties. Its role in peptide chemistry includes protecting group manipulation and activation of carboxylic acids. Handles under anhydrous conditions due to high reactivity with moisture.