Methyl fluorosulfonate, also known as magic methyl, is the
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
with the formula FSO
2OCH
3. It is a colorless liquid that is used as a strong
methylating agent
In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These t ...
in
organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...
. Because of its extreme toxicity, it has largely been replaced by the related reagent
methyl trifluoromethanesulfonate
Methyl trifluoromethanesulfonate, also commonly called methyl triflate and abbreviated MeOTf, is the organic compound with the formula CF3SO2OCH3. It is a colourless liquid which finds use in organic chemistry as a powerful methylating agent. T ...
.
Synthesis and reactions
It is prepared by distillation of an equimolar mixture of
fluorosulfonic acid and
dimethyl sulfate. It was originally produced by the reaction of
methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...
with
fluorosulfonic acid.
Methyl fluorosulfonate is a highly electrophilic reagent for
methylation. It is ranked as less powerful than methyl trifluoromethanesulfonate.
Toxicity
Similar to
phosgene, it is acutely toxic
[ by inhalation, with an LC50 (rat, 1 hour) of about 5 ppm. Several cases of poisoning resulting in death from ]pulmonary edema
Pulmonary edema, also known as pulmonary congestion, is excessive edema, liquid accumulation in the parenchyma, tissue and pulmonary alveolus, air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia an ...
have been reported.[{{cite journal , author = Hite, M. , author2=Rinehart, W. , author3=Braun, W. , author4=Peck, H. , year = 1979 , title = Acute toxicity of methyl fluorosulfonate (Magic Methyl) , journal = AIHA Journal , volume = 40 , issue = 7 , pages = 600–603 , pmid = 484483 , doi = 10.1080/00028897708984416]
References
Methylating agents
Methyl esters
Sulfonate esters