Chlorosulfonyl isocyanate CAS:1189-71-5

Chlorosulfonyl isocyanate (CSI) is a reactive chemical compound characterized by the presence of both chlorosulfonyl (ClSO2) and isocyanate (NCO) functional groups. With the molecular formula ClSO2NCO, it appears as a colorless to pale yellow liquid that is highly soluble in polar solvents. Its dual functionality makes CSI a valuable reagent in organic synthesis, particularly for the preparation of sulfonamide derivatives, which are essential in pharmaceuticals for their antibacterial properties. One of the primary applications of chlorosulfonyl isocyanate lies in the synthesis of sulfonamides, where it acts as a key building block. The reaction of CSI with amines results in the formation of sulfonamides, compounds widely used in drug formulations due to their efficacy against bacterial infections. Additionally, CSI can be employed in the production of various agrochemicals, contributing to the development of herbicides and pesticides. Chlorosulfonyl isocyanate also finds utility in materials science. It can be used in the manufacture of polymers and other materials that require specific chemical modifications. For instance, the incorporation of sulfonyl groups into polymer chains can enhance thermal stability and chemical resistance, making them suitable for demanding applications. Despite its utility, chlorosulfonyl isocyanate poses significant safety risks. It is corrosive, toxic, and can cause severe irritation upon contact with skin or eyes. Therefore, proper safety measures—including personal protective equipment (PPE), adequate ventilation, and emergency protocols—are essential when handling this compound. In summary, chlorosulfonyl isocyanate is an important chemical intermediary with applications in pharmaceuticals and materials science, but its reactivity and toxicity necessitate careful management.