Mesylate
In organosulfur chemistry, a mesylate is any salt or ester of methanesulfonic acid. In salts, the mesylate is present as the anion. When modifying the international nonproprietary name of a pharmaceutical substance containing the group or anion, the spelling used is sometimes mesilate.
Mesylate esters are a group of organic compounds that share a common functional group with the general structure, abbreviated, where R is an organic substituent. Mesylate is considered a leaving group in nucleophilic substitution reactions.
Preparation
Mesylate esters are generally prepared by treating an alcohol and methanesulfonyl chloride in the presence of a base, such as triethylamine.Mesyl
Related to mesylate is the mesyl or methanesulfonyl functional group. The shortened term itself was coined by Helferich et al. in 1938 similarly to tosyl adopted earlier. Methanesulfonyl chloride is often referred to as mesyl chloride.Whereas mesylates are often hydrolytically labile, mesyl groups, when attached to nitrogen, are resistant to hydrolysis. This functional group appears in a variety of medications, particularly cardiac drugs, as a sulfonamide moiety. Examples include sotalol, ibutilide, sematilide, dronedarone, dofetilide, E-4031, and bitopertin.