Methanesulfonic anhydride
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| Names | |
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| Preferred IUPAC name
Methanesulfonic anhydride | |
| Other names
methanesulfonic acid methylsulfonyl ester
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.027.675 |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C2H6O5S2 | |
| Molar mass | 174.19 g·mol−1 |
| Appearance | White solid |
| Density | 0.92 g/ml[1] |
| Melting point | 69.5–70 °C (157.1–158.0 °F; 342.6–343.1 K)[2] |
| Hydrolysis | |
| Solubility | Soluble in most aprotic organic solvents |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Methanesulfonic anhydride (Ms2O) is the acid anhydride of methanesulfonic acid. Like methanesulfonyl chloride (MsCl), it may be used to generate mesylates (methanesulfonyl esters).
Preparation & purification
[edit]Ms2O may be prepared by the dehydration of methanesulfonic acid with phosphorus pentoxide.[2]
- P2O5 + 6 CH3SO3H → 3 (CH3SO2)2O + 2 H3PO4
Ms2O can be purified by distillation under vacuum (distillation of a solid) or by recrystallization from Methyl tert-butyl ether/toluene.
Reactions & Applications in synthesis
[edit]Passage of hydrogen chloride through molten Ms2O yields MsCl.[3]
Similar to MsCl, Ms2O can perform mesylation of alcohols to form sulfonates. Use of Ms2O avoids the alkyl chloride, which often appears as a side-product when MsCl is used.[4] Unlike MsCl, Ms2O may not be suitable for mesylation of the unsaturated alcohols.[5]
Examples of mesylation of alcohols with Ms2O:
- Octadecyl methanesulfonate was prepared from octadecanol in pyridine.[5]
- Secondary alcohol at the anomeric carbon of 2,3,4,5-O-Benzyl-protected glucose reacted to form a glycosyl mesylate, which was found to be more stable than its triflate counterpart, in 2,4,6-collidine.[6]
Ms2O also converts amines to sulfonamides.[7]
Aromatic sulfonation
[edit]Assisted by Lewis acid catalyst, Friedel-Crafts methylsulfonation of aryl ring can be achieved by Ms2O. In contrast to MsCl, either activated or deactivated benzene derivatives can form the corresponding sulfonatesin satisfactory yields with Ms2O.[8]
Examples of aromatic sulfonation with Ms2O:
- Sulfonation of chlorobenzene resulted in addition of methylsulfonyl group at para and ortho positions (with respect to chloride), with a ratio of 2 to 1, respectively; while reaction with Meta-dichlorobenzene gave monosulfonylated product at C4 position.[8]
- With sulfuric acid, di-aryl sulfones were synthesized.[9]
Esterification
[edit]Ms2O catalyzes the esterification of alcohols by carboxylic acids. 2-Naphthyl acetate was prepared from 2-naphthol and glacial (anhydrous) acetic acid in the presence of Ms2O. Both alcohols on ethylene glycol successfully benzoylated with benzoic acid and Ms2O. However, for free alcohols on monosaccharides, the acetylation was not completed.[2]
Oxidation of alcohols
[edit]Like Pfitzner–Moffatt oxidation and Swern oxidation, with DMSO, Ms2O can oxidize primary and secondary alcohols to aldehydes and ketones, respectively, in HMPA.[10] This method applies to benzylic alcohol.[10] HMPA may be substituted by dichloromethane but may result in more side-products.[10]
See also
[edit]- Methanesulfonyl chloride
- Disulfuric acid
- Sodium pyrosulfate
- Acetic anhydride
- Trifluoromethanesulfonic anhydride
References
[edit]- ^ Wachtmeister, C. A.; Pring, B.; Osterman, Siv; Ehrenberg, L.; Brunvoll, J.; Bunnenberg, E.; Djerassi, Carl; Records, Ruth (1966). "The Synthesis of Some Tritium-labelled Mutagenic Alkyl Alkanesulfonates". Acta Chemica Scandinavica. 20: 908–910. doi:10.3891/acta.chem.scand.20-0908.
- ^ a b c Field, Lamar; Settlage, Paul H. (March 1954). "Alkanesulfonic Acid Anhydrides". Journal of the American Chemical Society. 76 (5): 1222–1225. doi:10.1021/ja01634a005.
- ^ Field, Lamar; Settlage, Paul H. (January 1955). "Reaction of Methanesulfonic Anhydride with Hydrogen Halides 1". Journal of the American Chemical Society. 77 (1): 170–171. doi:10.1021/ja01606a053. ISSN 0002-7863.
- ^ Baumann, W. J.; Jones, L. L.; Barnum, B. E.; Mangold, H. K. (1 November 1966). "The formation of alkyl and alkenyl methanesulfonates and their reduction to hydrocarbons". Chemistry and Physics of Lipids. 1 (1): 63–67. doi:10.1016/0009-3084(66)90008-9. ISSN 0009-3084.
- ^ a b Cegla, Gad; Mangold, Helmut K. (1 May 1973). "A new procedure for the preparation of alkyl methanesulfonates". Chemistry and Physics of Lipids. 10 (4): 354–355. doi:10.1016/0009-3084(73)90059-5. ISSN 0009-3084.
- ^ Leroux, Jacques; Perlin, Arthur S. (1 November 1978). "Synthesis of glycosyl halides and glycosides via 1-O-sulfonyl derivatives". Carbohydrate Research. 67 (1): 163–178. doi:10.1016/S0008-6215(00)83739-8. ISSN 0008-6215.
- ^ Lis, Randall; Morgan, Thomas K.; Marisca, Anthony J.; Gomez, Robert P.; Lind, Joan M.; Davey, David D.; Phillips, Gary B.; Sullivan, Mark E. (October 1990). "Synthesis of novel (aryloxy)propanolamines and related compounds possessing both class II and class III antiarrhythmic activity". Journal of Medicinal Chemistry. 33 (10): 2883–2891. doi:10.1021/jm00172a033. ISSN 0022-2623. PMID 1976812.
- ^ a b Vaillancourt, Valerie; Cudahy, Michele M. (15 April 2001). "Methanesulfonic Anhydride". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons, Ltd: rm068. doi:10.1002/047084289x.rm068. ISBN 0-471-93623-5.
- ^ Tyobeka, Themba E.; Hancock, Richard A.; Weigel, Helmut (1 January 1980). "Novel sulphonylating reagent: sulphuric acid–hexafluoroacetic anhydride". Journal of the Chemical Society, Chemical Communications (3): 114–115. doi:10.1039/C39800000114. ISSN 0022-4936.
- ^ a b c Albright, J. Donald (June 1974). "Sullfoxonium salts as reagents for oxidation of primary and secondary alcohols to carbonyl compounds". The Journal of Organic Chemistry. 39 (13): 1977–1979. doi:10.1021/jo00927a054. ISSN 0022-3263.