Used primarily as an intermediate in organic synthesis, especially in the pharmaceutical industry for constructing sulfonamide-based drugs. It reacts with amines to form sulfonamides, which are key structural motifs in many bioactive molecules, including antibiotics and anti-inflammatory agents. Also employed in the preparation of dyes and agrochemicals due to its ability to introduce sulfonyl functional groups. Its reactivity makes it valuable in the development of specialty chemicals requiring selective sulfonylation.