Used primarily as a key intermediate in the synthesis of photoacid generators (PAGs) for advanced photolithography processes, especially in semiconductor manufacturing. Its sulfonyl chloride group readily reacts to form sulfonate esters that decompose upon UV exposure, releasing strong acids to catalyze chemical changes in photoresist materials. This makes it valuable in creating high-resolution patterns on microchips. Also employed in organic synthesis as a protecting group reagent due to its selective deprotection under mild conditions, particularly in peptide and nucleotide chemistry. Its nitro and methoxy substituents enhance photoreactivity and solubility, improving performance in light-sensitive applications.