Metaansulfonüülkloriid

Metaansulfonüülkloriid, also known as mesyl chloride, is a chemical compound with the formula CH3SO2Cl. It is a colorless liquid with a pungent odor and is highly reactive. It is a derivative of methanesulfonic acid and is an important reagent in organic synthesis.

In organic chemistry, metaansulfonüülkloriid is commonly used as a sulfonating agent. It reacts with alcohols to form methanesulfonates, also known as mesylates. These mesylate groups are excellent leaving groups in nucleophilic substitution reactions, making them useful for transforming alcohols into other functional groups. For example, a mesylate can be readily displaced by a halide ion, an amine, or a cyanide ion. This transformation is a key step in the synthesis of many pharmaceutical compounds and other fine chemicals.

Metaansulfonüülkloriid is also employed in the protection of amines. It reacts with primary and secondary amines to form methanesulfonamides (mesylamides). These sulfonamides are stable under a variety of reaction conditions and can be removed later in the synthetic sequence if necessary.

Due to its reactivity, metaansulfonüülkloriid must be handled with care. It is corrosive and can cause severe burns. It reacts exothermically with water and other protic solvents, releasing hydrochloric acid. Appropriate personal protective equipment, such as gloves, eye protection, and a fume hood, should be used when working with this compound. It is typically stored in a cool, dry place, away from moisture and incompatible materials.