{{Short description|Salt or ester of methanesulfonic acid (CH3–SO2–OH)}} {{Use dmy dates|date=April 2023}} [[Image:Mesylate Anion Structural Formulae.svg|thumb|230px|Mesylate anion (structural formula)]] [[Image:Mesylate-anion-3D-balls.png|thumb|230px|Mesylate anion (ball-and-stick model)]]
In organosulfur chemistry, a '''mesylate''' is any salt or ester of methanesulfonic acid ({{chem2|CH3SO3H}}). In salts, the mesylate is present as the {{chem2|CH3SO3-}} anion. When modifying the international nonproprietary name of a pharmaceutical substance containing the group or anion, the spelling used is sometimes '''mesilate''' (as in ''imatinib mesilate'', the mesylate salt of imatinib).<ref>{{cite report |publisher=World Health Organization |title=International Nonproprietary Names Modified |id=INN Working Document 05.167/3 |date=February 2006 |url=https://www.who.int/medicines/services/inn/INNMreview%20paperWkDoc167_Feb06_3_.pdf |access-date=5 December 2008}}</ref>
Mesylate esters are a group of organic compounds that share a common functional group with the general structure {{chem2|CH3SO2O\sR}}, abbreviated {{chem2|MsO\sR}}, where R is an organic substituent. Mesylate is considered a leaving group in nucleophilic substitution reactions.<ref>{{cite book | first1 = Michael B. | last1 = Smith | first2 = Jerry | last2 = March | title = March's Advanced Organic Chemistry | publisher = John Wiley & Sons | year = 2007 | edition=6th | isbn = 978-0-471-72091-1 | page = 497 }}</ref>
==Preparation== Mesylate esters are generally prepared by treating an alcohol and methanesulfonyl chloride in the presence of a base, such as triethylamine.<ref>{{OrgSynth | author1 = Rick L. Danheiser|authorlink1=Rick L. Danheiser|author2= Yeun-Min Tsai|author3=David M. Fink | title = A General Method for the Synthesis of Allenylsilanes: 1-Methyl-1-(trimethylsilyl)allene | lvol = 46 | volpages = 75 | year = 1966 | doi = 10.15227/orgsyn.066.0001}} (a procedure illustrating the use of mesylates).</ref>
==Mesyl== Related to mesylate is the '''mesyl''' (Ms) or methanesulfonyl ({{chem2|CH3SO2}}) functional group. The shortened term itself was coined by Helferich et al. in 1938 similarly to tosyl adopted earlier.<ref>{{Cite journal |last1=Helferich |first1=Burckhardt |last2=Gnüchtel |first2=Alfred |date=1938-04-06 |title=Ester der Methansulfonsäure in der Zuckergruppe |url=https://onlinelibrary.wiley.com/doi/10.1002/cber.19380710403 |journal=Berichte der Deutschen Chemischen Gesellschaft (A and B Series) |language=de |volume=71 |issue=4 |pages=712–718 |doi=10.1002/cber.19380710403 |issn=0365-9488|url-access=subscription }}</ref> 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.<ref>{{cite book | last1=Vaillancourt | first1=Valerie | last2=Cudahy | first2=Michele M. | last3=Kreilein | first3=Matthew M. | last4=Jacobs | first4=Danielle L. | title=Encyclopedia of Reagents for Organic Synthesis | chapter=Methanesulfonyl Chloride | publisher=John Wiley & Sons, Ltd | publication-place=Chichester, UK | date=2007-09-17 | isbn=978-0-471-93623-7 | doi=10.1002/047084289x.rm070.pub2 | url=https://onlinelibrary.wiley.com/doi/10.1002/047084289X.rm070.pub2 }}</ref> 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|date=January 2020}}
==Pharmaceutical preparations== Mesylate salts are often used in preparing the dosage forms of basic drugs. Mesylate salts often yield a higher solubility, and may also excel in other pharmaceutically-relevant factors such as hygroscopicity, clean polymorphic profile, particle size, and flow properties.<ref>{{cite journal |vauthors=Gupta D, Bhatia D, Dave V, Sutariya V, Varghese Gupta S |title=Salts of Therapeutic Agents: Chemical, Physicochemical, and Biological Considerations |journal=Molecules |volume=23 |issue=7 |pages=1719 |date=July 2018 |pmid=30011904 |pmc=6100526 |doi=10.3390/molecules23071719 |doi-access=free}}</ref><ref>{{cite journal |vauthors=Elder DP, Delaney E, Teasdale A, Eyley S, Reif VD, Jacq K, Facchine KL, Oestrich RS, Sandra P, David F |title=The utility of sulfonate salts in drug development |journal=J Pharm Sci |volume=99 |issue=7 |pages=2948–61 |date=July 2010 |pmid=20112423 |doi=10.1002/jps.22058 }}</ref>
==Natural occurrence== Ice core samples from a single spot in Antarctica were found to have tiny inclusions of magnesium methanesulfonate dodecahydrate. This natural phase is recognized as the mineral ernstburkeite. It is extremely rare.<ref>{{cite journal | title = Ernstburkeite, Mg(CH3SO3)2·12H2O, a new mineral from Antarctica |author1=Güner, Fatma Elif Genceli |author2=Sakurai, Toshimitsu |author3=Hondoh, Takeo | journal = European Journal of Mineralogy | volume = 25 | issue = 1 | date = 2013 | pages = 78–83 | doi = 10.1127/0935-1221/2013/0025-2257 | url = https://www.schweizerbart.de/papers/ejm/detail/25/79543/Ernstburkeite_MgCH3SO3212H2O_a_new_mineral_from_Antarctica|bibcode=2013EJMin..25...78G | url-access = subscription }}</ref><ref>{{mindat|id=41897 |title= Ernstburkeite}}</ref>
==See also== *Tosylate *Triflate, the fluorinated analog of mesylate.
==References== {{Reflist}}
Category:Leaving groups Category:Sulfonates Category:Mesyl compounds