Related to mesylate is the
mesyl (Ms) 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 (
antiarrhythmic) drugs, as a
sulfonamide moiety. Examples include
sotalol,
ibutilide,
sematilide,
dronedarone,
dofetilide,
E-4031, and
bitopertin. ==Pharmaceutical preparations==