Used primarily as a reagent in organic synthesis, it serves to introduce the tosyl group, which acts as a protecting group for alcohols and amines. It is widely employed in the preparation of sulfonate esters and sulfonamides, important intermediates in pharmaceutical manufacturing. Its reactivity makes it valuable in the activation of hydroxyl groups for nucleophilic substitution reactions. Commonly used in the production of dyes, agrochemicals, and certain active pharmaceutical ingredients where controlled functional group transformation is required.