Mesylate

Structural formula of the mesylate anion

Ball-and-stick model of the mesylate anion

In chemistry, a mesylate is any salt or ester of methanesulfonic acid (CH₃SO₃H). In salts, the mesylate is present as the CH₃SO₃⁻ anion. When modifying the International Nonproprietary Name of a pharmaceutical substance containing the group or anion, the correct spelling is mesilate (as in imatinib mesilate, the mesylate salt of imatinib).^[1]

Mesylate esters are a group of organic compounds that share a common functional group with the general structure CH₃SO₂O–R, abbreviated MsO–R, where R is an organic substituent. Mesylate is considered a leaving group in nucleophilic substitution reactions.

Preparation

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

Mesyl

Related to mesylate, is the mesyl, an abbreviation for methanesulfonyl or CH₃SO₂ (Ms) functional group. For example, methanesulfonyl chloride is often referred to as mesyl chloride. Whereas mesylates are often hydrolytically labile, mesyl groups, when attached to nitrogen are robust with respect to hydrolysis.^[3] This functional group appears in a variety of medications, particularly cardiac (i.e. “antiarrhythmic”) but as sulfonamide moiety. Examples include Sotalol, ibutilide, sematilide, Dronedarone, Dofetilide, E-4031, and Bitopertin .

See also

• Tosylate

References