Widely used in organic synthesis, particularly as a reagent for introducing sulfonate groups into aromatic compounds. It serves as an intermediate in the production of dyes, pharmaceuticals, and functional polymers due to its ability to form sulfonated esters and amides under mild conditions. Its anhydride functionality allows for efficient coupling reactions with alcohols and amines, making it valuable in the development of water-soluble compounds and surfactants. Additionally, it is employed in the synthesis of certain biologically active molecules where the sulfonate group enhances solubility or binding properties.