Used as a key intermediate in the synthesis of pharmaceuticals, particularly in the development of sulfonamide-based drugs. It serves as a sulfonylating agent in organic reactions, enabling the introduction of the 4-fluorobenzenesulfonyl group to amines and alcohols. Widely applied in medicinal chemistry for protease inhibitor design due to its ability to act as an electrophilic warhead. Also employed in chemical biology for activity-based protein profiling, where it labels serine hydrolases and other reactive enzymes in complex biological samples. Its fluorine atom allows for potential use in PET imaging probe development. Stable under standard conditions and suitable for use in multi-step synthetic sequences.