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Methanesulfonyl_chloride

Methanesulfonyl chloride

Methanesulfonyl chloride

IUPAC name	Methanesulfonyl chloride
Other names	Mesyl chloride
Identifiers
CAS number	124-63-0
SMILES	CS(Cl)(=O)=O
Properties
Molecular formula	CH₃ClO₂S
Molar mass	114.56 g/mol
Appearance	liquid
Density	1.480 g/mL
Boiling point	60 °C (21 mm Hg)
Hazards
Main hazards	Lachrymator, Highly toxic, corrosive
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Methanesulfonyl chloride is a compound containing a sulfonyl chloride used to make methanesulfonates and to generate sulfene.

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Preparation, manufacture and handling

Methanesulfonyl chloride is highly toxic, moisture sensitive, corrosive, and a lachrymator. It should be stored in dry location, preferably in a dessicator. It is manufactued either via direct synthesis from methane and sulfuryl chloride in a radical reaction (1):

CH_{4 (g)} + SO₂Cl_{2 (g)} → CH₃SO₂Cl + HCl_(g) (1)

other method of manufacture starts with methanesulfonic acid, which is accessible out of methane and sulfur trioxide (2) or by vigorous oxidation of methanethiol (3):

CH_{4 (g)} + SO_{3 (g)} → CH₃SO₃H_(l) (2)

CH₃SH + HNO₃ → CH₃SO₃H + H₂O + NO_x (3)

methanesulfonic acid prepared is reacted with thionyl chloride (4) or phosgene (5) to form mesyl chloride:

CH₃SO₃H + SOCl₂ → CH₃SO₂Cl + SO₂ + HCl (4)

CH₃SO₃H + COCl₂ → CH₃SO₂Cl + CO₂ + HCl (5)

Applications

Methanesulfonates

The main use of methanesulfonyl chloride is the formation of methanesulfonates from alcohols and a non-nucleophilic base.^[1] Methanesulfonates are used as intermediates in substitution reactions, elimination reactions, reductions, and rearrangement reactions. When treated with a Lewis acid, oxime methanesulfonates will undergo a facile Beckmann rearrangement.^[2]

Methanesulfonates have been occasionally used as a protecting group for alcohols. It is stable to acidic conditions and is cleaved back to the alcohol using sodium amalgam.^[3]

Methanesulfonamides

Methanesulfonyl chloride will react with amines to form a methanesulfonamide. Unlike, a methanesulfonate, a methanesulfonamide is a very stable functional group under both acidic and basic conditions. When used as a protecting group, they can be converted back to amines using lithium aluminium hydride or a dissolving metal reduction.^[4]

Addition to alkynes

In the presence of copper(II) chloride, methanesulfonyl chloride will add across alkynes to form β-chloro sulfones.^[5]

Formation of heterocycles

Upon treatment with a base, such as triethylamine, methanesulfonyl chloride will undergo an alpha-elimination to form sulfene. Sulfene can undergo cycloadditions to form various heterocycles. α-Hydroxyketones react with sulfene to form five-membered sultones.^[6]

Miscellaneous

Forming acyliminium ions from α-hydroxyamides can be done using methanesulfonyl chloride and a base, typically triethylamine.^[7]

References

^ Furst, A.; Koller, F. Helv. Chim. Acta 1947, 30, 1454.
^ Maruoke, K.; Miyazaki, T.; Ando, M.; Matsumura, Y.; Sakane, S.; Hattori, K.; Yamamoto, H. J. Am. Chem. Soc. 1983, 105, 2831.
^ Webster, K. T.; Eby, R.; Schuerch, C. Carbohydr. Res. 1983, 123, 335.
^ Merlin, P.; Braekman, J. C.; Daloze, D. Tetrahedron Lett. 1988, 29, 1691.
^ Amiel, Y. Tetrahedron Lett. 1971, 661.
^ Potonay, T.; Batta, G.; Dinya, Z. J. Heterocycl. Chem. 1988, 25, 343.
^ Chamgerlin, A. R.; Nguyen, H. D.; Chung, J. Y. L. J. Org. Chem. 1984, 49, 1682.

Category: Reagents for organic chemistry

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Methanesulfonyl_chloride". A list of authors is available in Wikipedia.