Methanesulfonyl chloride

Methanesulfonyl chloride
IUPAC name

Methanesulfonyl chloride
Other names

Mesyl chloride
Identifiers
CAS number 124-63-0 Y
ChemSpider 29037 N
Jmol-3D images Image 1
Properties
Molecular formula CH3ClO2S
Molar mass 114.56 g/mol
Appearance liquid
Density 1.480 g/mL
Boiling point

161 °C (730 mm Hg)
Hazards
Main hazards Lachrymator,
Highly toxic,
corrosive
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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

Contents

Preparation, manufacture and handling

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

CH4 (g) + SO2Cl2 (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):

CH4 (g) + SO3 (g) → CH3SO3H (l) (2)
CH3SH + HNO3 → CH3SO3H + H2O + NOx (3)

The 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 in the presence of 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 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

  1. ^ Furst, A.; Koller, F. (1947). "Über Steroide und Sexualhormone. Ein neuer Weg zur Herstellung der α-Oxyde von Cholesterin und trans-Dehydro-androsteron". Helv. Chim. Acta 30 (6): 1454. doi:10.1002/hlca.19470300609. 
  2. ^ Maruoka, K.; Miyazaki, T.; Ando, M.; Matsumura, Y.; Sakane, S.; Hattori, K.; Yamamoto, H. (1983). "Organoaluminum-promoted Beckmann rearrangement of oxime sulfonates". J. Am. Chem. Soc. 105 (9): 2831. doi:10.1021/ja00347a052. 
  3. ^ Webster, K. T.; Eby, R.; Schuerch, C. (1983). "Selective demesylation of 2-O-(methylsulfonyl)-?-mannopyranoside derivatives with sodium amalgam and 2-propanol". Carbohydr. Res. 123 (2): 335. doi:10.1016/0008-6215(83)88490-0. 
  4. ^ Merlin, P.; Braekman, J. C.; Daloze, D. (1988). "Stereoselective synthesis of (±)-tetraponerine-8, a defence alkaloid of the ant Tetraponera sp". Tetrahedron Lett. 29 (14): 1691. doi:10.1016/S0040-4039(00)82019-5. 
  5. ^ Amiel, Y. (1971). "Addition of sulfonyl chlorides to acetylenes". Tetrahedron Lett. 12 (8): 661. doi:10.1016/S0040-4039(01)96524-4. 
  6. ^ Potonay, T.; Batta, G.; Dinya, Z. (1988). "Flavonoids. 41. Stereospecific synthesis of 2,3-dihydro-c-3-substituted-t-3-methyl-r-2-phenyl-4H-1-benzopyran-4-ones". Journal of Heterocyclic Chemistry 25: 343. doi:10.1002/jhet.5570250158. 
  7. ^ Chamberlin, A. R.; Nguyen, H. D.; Chung, J. Y. L. (1984). "Cationic cyclization of ketene dithioacetals. A general synthesis of pyrrolizidine, indolizidine, and quinolizidine alkaloid ring systems". J. Org. Chem. 49 (10): 1682. doi:10.1021/jo00184a002.