Mesylate

[2] Mesylate esters are generally prepared by treating an alcohol and methanesulfonyl chloride in the presence of a base, such as triethylamine.

The shortened term itself was coined by Helferich et al. in 1938 similarly to tosyl adopted earlier.

[5] 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.

[citation needed] Ice core samples from a single spot in Antarctica were found to have tiny inclusions of magnesium methanesulfonate dodecahydrate.