Methanesulfonic anhydride

Methanesulfonic anhydride

Names
Preferred IUPAC name Methanesulfonic anhydride
Other names methanesulfonic acid methylsulfonyl ester
Identifiers
CAS Number	7143-01-3  Y
3D model (JSmol)	Interactive image
ChemSpider	73591  Y
ECHA InfoCard	100.027.675
PubChem CID	81560
UNII	J492U7J4PB  Y
CompTox Dashboard (EPA)	DTXSID70864010
InChI InChI=1S/C2H6O5S2/c1-8(3,4)7-9(2,5)6/h1-2H3 Y Key: IZDROVVXIHRYMH-UHFFFAOYSA-N Y InChI=1/C2H6O5S2/c1-8(3,4)7-9(2,5)6/h1-2H3 Key: IZDROVVXIHRYMH-UHFFFAOYAS
SMILES O=S(=O)(OS(=O)(=O)C)C
Properties
Chemical formula	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]
Solubility in water	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). Y  verify  (what is  YN ?) Infobox references

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

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

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

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

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

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

• Methanesulfonyl chloride
• Disulfuric acid
• Sodium pyrosulfate
• Acetic anhydride
• Trifluoromethanesulfonic anhydride

References

1. 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 .
2. Field, Lamar; Settlage, Paul H. (March 1954). "Alkanesulfonic Acid Anhydrides". Journal of the American Chemical Society. 76 (5): 1222–1225. Bibcode:1954JAChS..76.1222F. doi:10.1021/ja01634a005.
3. 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. Bibcode:1955JAChS..77..170F. doi:10.1021/ja01606a053. ISSN   0002-7863.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.