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Methyl fluorosulfonate

Methyl fluorosulfonate
IUPAC name Methyl fluorosulfonate
Other names Methyl fluorosulphonate; fluorosulfonic acid, methyl ester; methyl fluorosulphate
CAS number 421-20-5
Molecular formula CH3O3FS
Molar mass 114.09 g/mol
Density 1.45 g/mL
Boiling point

93 °C

Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Methyl fluorosulfonate, (also known as magic methyl, a name coined by George Olah) has the chemical formula F-SO2-OCH3. It is used as a powerful (about four orders of magnitude more reactive than methyl iodide) methylating reagent.

Methyl fluorosulfonate is prepared by distillation from an equimolar mixture of fluorosulfonic acid and dimethyl sulfate.

The compound is acutely toxic (LD50 (rat) ~ 5 ppm), causing irritation of the respiratory tract and pulmonary edema, presumably through alkylation of lipids in the cell membranes.[1]


  1. ^ Hite, M.; Rinehart, W.; Braun, W.; Peck, H. (1979). "Acute toxicity of methyl fluorosulfonate (Magic Methyl)". AIHA Journal 40 (7): 600-603. PMID 484483.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Methyl_fluorosulfonate". A list of authors is available in Wikipedia.
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