Used primarily as an alkylating agent in organic synthesis, particularly in the pharmaceutical industry for introducing fluorinated alkyl chains into target molecules. Its reactivity allows for efficient coupling with nucleophiles, making it valuable in the preparation of fluorinated analogs of bioactive compounds. The presence of the fluorine atom can enhance metabolic stability and membrane permeability in drug candidates, which is advantageous in medicinal chemistry. Commonly employed in the synthesis of positron emission tomography (PET) tracers, where the fluorine-18 isotope is incorporated for imaging applications. Its sulfonate ester group acts as a good leaving group, facilitating substitution reactions under mild conditions.