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 an excellent leaving group in nucleophilic substitution reactions.

Mesyl is the term for the methanesulfonyl or CH₃SO₂- (Ms-) functional group. For example, methanesulfonyl chloride is often referred to as mesyl chloride.

Preparation

Mesylates may be prepared using an alcohol and methanesulfonyl chloride in the presence of a base, often amine bases such as triethylamine.^[2] Mesylates can also be prepared by combining an alcohol, methanesulfonic anhydride and base, although this method is generally used only if the nucleophilicity of chloride is a concern.

See also

• Tosylate

References

1. ^ World Health Organization (February 2006). International Nonproprietary Names Modified. INN Working Document 05.167/3. WHO. http://www.who.int/medicines/services/inn/INNMreview%20paperWkDoc167_Feb06_3_.pdf.  Retrieved December 5, 2008.
2. ^ Rick L. Danheiser, Yeun-Min Tsai, and David M. Fink (1993), "A General Method for the Synthesis of Allenylsilanes: 1-Methyl-1-(trimethylsilyl)allene", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV8P0471 ; Coll. Vol. 8: 471  (a procedure illustrating the use of mesylates)