Sulfonyl or sulphonyl chlorides are reactive derivatives of sulphonic acids and are used to prepare sulphonamides. The sulphonamide group is relatively stable, and found in many marketed drugs, such as antibacterial agents, diuretics, anti-convulsants and PDE-5 inhibitors. The EnamineStore contains a wide range of readily available sulfonyl chlorides: these contain groups like protected amines, nitriles, alicyclic and heterocyclic ring systems. We suggest the following selected compounds for your review: