2-Chloropyrimidine-5-sulfonyl chloride is primarily used as a key intermediate in organic synthesis, particularly in the pharmaceutical and agrochemical industries. It is employed in the preparation of various sulfonamide derivatives, which are essential in the development of drugs and pesticides. The compound is also utilized in the synthesis of biologically active molecules, including inhibitors and other therapeutic agents, due to its reactive sulfonyl chloride group. Additionally, it finds application in the modification of peptides and proteins, aiding in the study of biochemical processes and drug discovery. Its versatility makes it a valuable reagent in the construction of complex organic molecules.