Used primarily as an intermediate in organic synthesis, especially in the preparation of dyes, pharmaceuticals, and agrochemicals. Its sulfonyl chloride group readily reacts with amines to form sulfonamides, which are key structural motifs in many biologically active compounds. It is also employed in the development of sulfa drugs and as a derivatizing agent in analytical chemistry to detect and quantify amines. Due to the electron-withdrawing nitro group and the methyl substituent, it offers selective reactivity useful in multi-step synthesis. Commonly handled under anhydrous conditions due to sensitivity to moisture.