Used as an intermediate in the synthesis of pharmaceuticals, particularly in the development of sulfa-based drugs. It serves as a building block in organic reactions where sulfonyl groups are needed to modify biological activity. Its reactivity allows for the introduction of the 4-chlorophenylsulfonyl moiety into larger molecules, enhancing their stability or altering solubility. Commonly applied in medicinal chemistry for designing enzyme inhibitors and antimicrobial agents. Also utilized in agrochemical research for developing new active ingredients in crop protection products.