Used primarily as an intermediate in the synthesis of pharmaceuticals, particularly in the production of nonsteroidal anti-inflammatory drugs (NSAIDs) such as meloxicam and piroxicam. Its functional groups allow for easy modification and coupling reactions, making it valuable in constructing heterocyclic compounds. Also employed in the development of agrochemicals and dyes due to its reactivity and ability to form sulfonamide derivatives. Commonly used in organic synthesis for introducing sulfonyl chloride and carboxylic acid functionalities onto aromatic rings.