{{Short description|Chemical compound (CH3SO2Cl)}} {{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 414714059 | ImageFileL1 = Methanesulfonyl Chloride Structural Formulae.svg | ImageClassL1 = skin-invert | ImageFileR1 = Mesyl-chloride-3D-vdW.png | ImageClassR1 = bg-transparent | PIN = Methanesulfonyl chloride | OtherNames = Mesyl chloride |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 29037 | EC_number = 204-706-1 | PubChem = 31297 | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 124-63-0 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = B17EWY1R7Q | UNNumber = 3246 | StdInChI=1S/CH3ClO2S/c1-5(2,3)4/h1H3 | StdInChIKey = QARBMVPHQWIHKH-UHFFFAOYSA-N | SMILES = CS(Cl)(=O)=O }} |Section2={{Chembox Properties | Formula = {{chem2|CH3SO2Cl}} | C=1|H=3|Cl=1|O=2|S=1 | Appearance = colorless liquid | Odor = Pungent, unpleasant<ref>{{cite web | url=https://pubchem.ncbi.nlm.nih.gov/compound/Methanesulfonyl-chloride#section=Physical-Description | title=Methanesulfonyl chloride }}</ref> | Density = 1.480 g/cm<sup>3</sup> | MeltingPt = {{convert|−32|C|F K}}<ref>{{cite web | url=https://pubchem.ncbi.nlm.nih.gov/compound/Methanesulfonyl-chloride#section=Decomposition | title=Methanesulfonyl chloride }}</ref> | BoilingPtC = 161 | BoilingPt_notes = (at 730 mmHg) | Solubility = Reacts<ref>cameochemicals.noaa.gov/chemical/11835</ref><ref>{{cite web |url=http://www.conncoll.edu/offices/envhealth/MSDS/chemistry/M/methanesulfonylchloride.htm |title=MSDS |accessdate=2013-01-14 |url-status=dead |archiveurl=https://web.archive.org/web/20050430205030/http://www.conncoll.edu/offices/envhealth/MSDS/chemistry/M/methanesulfonylchloride.htm |archivedate=2005-04-30 }}</ref> | SolubleOther = Soluble in alcohol, ether and most organic solvents<ref>{{cite web | url=https://pubchem.ncbi.nlm.nih.gov/compound/Methanesulfonyl-chloride#section=Solubility | title=Methanesulfonyl chloride }}</ref> }} |Section3={{Chembox Hazards | GHS_ref=[https://pubchem.ncbi.nlm.nih.gov/compound/31297#section=GHS-Classification] | GHSPictograms = {{GHS05}}{{GHS06}}{{GHS07}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|290|300|301|302|311|312|314|317|330|335|412}} | PPhrases = {{P-phrases|234|260|261|262|264|264+265|270|271|272|273|280|284|301+316|301+317|301+330+331|302+352|302+361+354|304+340|305+354+338|316|317|319|320|321|330|333+317|361+364|362+364|363|390|403+233|405|406|501}} | MainHazards = Lachrymator, highly toxic, corrosive | FlashPt = >{{convert|110|C|F K}}<ref>{{cite web | url=https://pubchem.ncbi.nlm.nih.gov/compound/Methanesulfonyl-chloride#section=Decomposition | title=Methanesulfonyl chloride }}</ref> | AutoignitionPt = }} |Section4={{Chembox Related | OtherAnions = Methanesulfonyl fluoride | OtherCations = }} }}
'''Methanesulfonyl chloride''' ('''mesyl chloride''') is an organosulfur compound with the formula {{chem2|CH3SO2Cl}}. Using the organic pseudoelement symbol Ms for the methanesulfonyl (or mesyl) group {{chem2|CH3SO2}}–, it is frequently abbreviated MsCl in reaction schemes or equations. It is a colourless liquid that dissolves in polar organic solvents but is reactive toward water, alcohols, and many amines. The simplest organic sulfonyl chloride, it is used to make methanesulfonates and to generate the elusive molecule sulfene (methylenedioxosulfur(VI)).<ref name=eEROS>Valerie Vaillancourt, Michele M. Cudahy, Matthew M. Kreilein and Danielle L. Jacobs "Methanesulfonyl Chloride" in E-EROS Encyclopedia for Reagents in Organic Synthesis {{doi|10.1002/047084289X.rm070.pub2}}</ref>
==Preparation== It is produced by the reaction of methane and sulfuryl chloride in a radical reaction: :{{chem2|CH4 + SO2Cl2 → CH3SO2Cl + HCl}} Another method of production entails chlorination of methanesulfonic acid with thionyl chloride or phosgene: :{{chem2|CH3SO3H + SOCl2 → CH3SO2Cl + SO2 + HCl}} :{{chem2|CH3SO3H + COCl2 → CH3SO2Cl + CO2 + HCl}}
==Reactions== Methanesulfonyl chloride is a precursor to many compounds because it is highly reactive. It is an electrophile, functioning as a source of the "CH<sub>3</sub>SO<sub>2</sub><sup>+</sup>" synthon.<ref name=eEROS/>
===Methanesulfonates=== Methanesulfonyl chloride is mainly used to give methanesulfonates by its reaction with alcohols in the presence of a non-nucleophilic base.<ref>{{cite journal |author1=Furst, A. |author2=Koller, F. | journal = Helv. Chim. Acta | year = 1947 | volume = 30 | pages = 1454–60 | doi = 10.1002/hlca.19470300609 |pmid=20272042 | title = Über Steroide und Sexualhormone. Ein neuer Weg zur Herstellung der α-Oxyde von Cholesterin und trans-Dehydro-androsteron | issue = 6}}</ref> In contrast to the formation of toluenesulfonates from alcohols and ''p''-toluenesulfonyl chloride in the presence of pyridine, the formation of methanesulfonates is believed to proceed via a mechanism wherein methanesulfonyl chloride first undergoes an E1cB elimination to generate the highly reactive parent sulfene ({{chem2|CH2\dSO2}}), followed by attack by the alcohol and rapid proton transfer to generate the observed product. This mechanistic proposal is supported by isotope labeling experiments and the trapping of the transient sulfene as cycloadducts.<ref>{{Cite journal|last=King|first=James Frederick|date=1975-01-01|title=Return of sulfenes|journal=Accounts of Chemical Research|volume=8|issue=1|pages=10–17|doi=10.1021/ar50085a002|issn=0001-4842}}</ref> center|frameless|300x300px
Methanesulfonates are used as intermediates in substitution reactions, elimination reactions, reductions, and rearrangement reactions. When treated with a Lewis acid, oxime methanesulfonates undergo facile Beckmann rearrangement.<ref>{{cite journal | title = Organoaluminum-promoted Beckmann rearrangement of oxime sulfonates |author1=Maruoka, K. |author2=Miyazaki, T. |author3=Ando, M. |author4=Matsumura, Y. |author5=Sakane, S. |author6=Hattori, K. |author7=Yamamoto, H. | journal = J. Am. Chem. Soc. | year = 1983 | volume = 105 | pages = 2831 | doi = 10.1021/ja00347a052 | issue = 9|bibcode=1983JAChS.105.2831M }}</ref>
Methanesulfonates are occasionally used as a protecting group for alcohols. They are stable to acidic conditions and is cleaved back to the alcohol using sodium amalgam.<ref>{{cite journal |author1=Webster, K. T. |author2=Eby, R. |author3=Schuerch, C. | journal = Carbohydr. Res. | year = 1983 | volume = 123 | pages = 335 | doi = 10.1016/0008-6215(83)88490-0 | title = Selective demesylation of 2-O-(methylsulfonyl)-?-mannopyranoside derivatives with sodium amalgam and 2-propanol | issue = 2}}</ref>
===Methanesulfonamides=== Methanesulfonyl chloride react with primary and secondary amines to give methanesulfonamides. Unlike methanesulfonates, methanesulfonamides are very resistant toward hydrolysis under both acidic and basic conditions.<ref name=eEROS/> When used as a protecting group, they can be converted back to amines using lithium aluminium hydride or a dissolving metal reduction.<ref>{{cite journal |author1=Merlin, P. |author2=Braekman, J. C. |author3=Daloze, D. | journal = Tetrahedron Lett. | year = 1988 | volume = 29 | pages = 1691 | doi = 10.1016/S0040-4039(00)82019-5 | title = Stereoselective synthesis of (±)-tetraponerine-8, a defence alkaloid of the ant Tetraponera sp | issue = 14|url=https://dipot.ulb.ac.be/dspace/bitstream/2013/86366/4/f79ac533-3e8d-47e0-be96-c1b6b6dda75c.txt | hdl = 2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/86366 | hdl-access = free }}</ref>
===Addition to alkynes=== In the presence of copper(II) chloride, methanesulfonyl chloride will add across alkynes to form β-chloro sulfones.<ref>{{cite journal | author = Amiel, Y. | journal = Tetrahedron Lett. | year = 1971 | pages = 661–663 | doi = 10.1016/S0040-4039(01)96524-4 | title = Addition of sulfonyl chlorides to acetylenes | volume = 12 | issue = 8}}</ref>
===Formation of heterocycles=== Upon treatment with a base, such as triethylamine, methanesulfonyl chloride will undergo an elimination to form sulfene. Sulfene can undergo cycloadditions to form various heterocycles. α-Hydroxyketones react with sulfene to form five-membered sultones.<ref>{{cite journal |author1=Potonay, T. |author2=Batta, G. |author3=Dinya, Z. | journal = Journal of Heterocyclic Chemistry | year = 1988 | volume = 25 | pages = 343–347 | doi = 10.1002/jhet.5570250158 | title = Flavonoids. '''41'''. Stereospecific synthesis of 2,3-dihydro-''c''-3-substituted-''t''-3-methyl-''r''-2-phenyl-4''H''-1-benzopyran-4-ones}}</ref>
===Miscellaneous=== Forming acyliminium ions from α-hydroxyamides can be done using methanesulfonyl chloride and a base, typically triethylamine.<ref>{{cite journal |author1=Chamberlin, A. R. |author2=Nguyen, H. D. |author3=Chung, J. Y. L. | title = Cationic cyclization of ketene dithioacetals. A general synthesis of pyrrolizidine, indolizidine, and quinolizidine alkaloid ring systems | journal = J. Org. Chem. | year = 1984 | volume = 49 | pages = 1682 | doi = 10.1021/jo00184a002 | issue = 10}}</ref>
==Safety== Methanesulfonyl chloride is highly toxic by inhalation, corrosive, and acts as a lachrymator. It reacts with nucleophilic reagents (including water) in a strongly exothermic manner. When heated to decomposition point, it emits toxic vapors of sulfur oxides and hydrogen chloride.<ref>{{cite web | url=https://pubchem.ncbi.nlm.nih.gov/compound/Methanesulfonyl-chloride#section=Decomposition | title=Methanesulfonyl chloride }}</ref>
==References== {{Reflist}}
Category:Reagents for organic chemistry Category:Sulfonyl halides Category:Mesyl compounds