1. Pharmaceuticals 

• Key Intermediate in Drug Synthesis: Methanesulfonyl chloride is widely used in the pharmaceutical industry as a key intermediate in the synthesis of active pharmaceutical ingredients (APIs), especially sulfonamide drugs and other bioactive compounds.
• Protecting & Activating Agent: It serves as a reagent in organic synthesis for introducing methanesulfonyl (mesyl) groups, which are crucial for modifying drug molecules to improve solubility, bioavailability, and stability.
• Chiral Synthesis & Resolution: Used in asymmetric synthesis and chiral resolution, MSC helps in developing enantiomerically pure pharmaceutical compounds.

2. Chemical Synthesis 

• Alkylation & Acylation Reagent: Methanesulfonyl chloride is used as a powerful alkylating and acylating agent in organic synthesis, helping in the production of various fine chemicals and specialty compounds.
• Precursor for Methanesulfonates: MSC is used to produce methanesulfonate esters, which serve as intermediates in diverse chemical reactions, including nucleophilic substitution and elimination processes.
• Sulfonating Agent: It introduces sulfonyl functional groups in aromatic and aliphatic compounds, enhancing their reactivity in advanced chemical transformations.

3. Agrochemicals 

• Intermediate in Pesticide Synthesis: MSC is a crucial building block in the production of herbicides, insecticides, and fungicides, contributing to the development of selective and effective agrochemical formulations.
• Stabilizing Agent in Agrochemical Formulations: It is used to modify and stabilize certain pesticide molecules, improving their efficacy and shelf life.

4. Water Treatment

• Precursor for Water Treatment Chemicals: Methanesulfonyl chloride is used in the synthesis of sulfonated compounds that act as scale inhibitors and corrosion inhibitors in industrial water treatment processes.