Used primarily as a sulfonating agent in organic synthesis, this compound is key for introducing sulfonyl functional groups into aromatic and heterocyclic systems. It plays an important role in the development of pharmaceutical intermediates, particularly in the construction of sulfonamide-based drugs which exhibit antimicrobial, anti-inflammatory, or antidiabetic activities. Its reactivity allows for selective derivatization in complex molecule synthesis, making it valuable in medicinal chemistry and drug discovery. Additionally, it serves as a building block in the preparation of fluorescent dyes and agrochemicals due to its stable aromatic backbone and reactive sulfonyl chloride group.