Methyl fluorosulfonate

Methyl fluorosulfonate

File:Methyl fluorosulfonate.png
File:Methyl-fluorosulfonate-3D-balls.png
Names
Preferred IUPAC name Methyl sulfurofluoridate
Other names Methyl fluorosulphonate Fluorosulfonic acid, methyl ester Methyl fluorosulphate Magic methyl
Identifiers
CAS Number	421-20-5 checkY
3D model (JSmol)	Interactive image
ChemSpider	9486 checkY
ECHA InfoCard
E number
PubChem CID	9870
UNII	N015VFJ94Z checkY
CompTox Dashboard (EPA)	{{#property:P3117}}
InChI InChI=1S/CH3FO3S/c1-5-6(2,3)4/h1H3 checkY Key: MBXNQZHITVCSLJ-UHFFFAOYSA-N checkY InChI=1/CH3FO3S/c1-5-6(2,3)4/h1H3 Key: MBXNQZHITVCSLJ-UHFFFAOYAW
SMILES FS(=O)(=O)OC
Properties
Chemical formula	CH3FO3S
Molar mass	114.09 g·mol−1
Density	1.45 g/mL
Boiling point	93 °C (199 °F; 366 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). checkY verify (what is checkY☒N ?) Infobox references

Methyl fluorosulfonate, also known as magic methyl, is the organic compound with the formula FSO₂OCH₃. It is a colorless liquid that is used as a strong methylating agent in organic synthesis. Because of several fatal industrial accidents involving this compound, it has largely been replaced by the related reagent methyl trifluoromethanesulfonate.

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 with fluorosulfonic acid.

Methyl fluorosulfonate is a highly electrophilic reagent for methylation. It is ranked as less powerful than methyl trifluoromethanesulfonate.

Toxicity

Toxicity of this reagent is equivalent to that of phosgene with an inhaled LC₅₀ (rat, 1 hour) of about 5 ppm. Several cases of poisoning resulting in death from pulmonary edema have been reported.