Methyl triflate

Methyl trifluoromethanesulfonate

Names
IUPAC name Methyl trifluoromethanesulfonate
Other names Trifluoromethanesulfonic acid, methyl ester Triflic acid, methyl ester, methyl triflate
Identifiers
CAS Number	333-27-7 Y
3D model (Jmol)	Interactive image
ChemSpider	9153 Y
ECHA InfoCard	100.005.793
PubChem CID	9526
InChI InChI=1S/C2H3F3O3S/c1-8-9(6,7)2(3,4)5/h1H3 Y Key: OIRDBPQYVWXNSJ-UHFFFAOYSA-N Y InChI=1/C2H3F3O3S/c1-8-9(6,7)2(3,4)5/h1H3 Key: OIRDBPQYVWXNSJ-UHFFFAOYAL
SMILES COS(=O)(=O)C(F)(F)F
Properties
Chemical formula	C2H3F3O2S
Molar mass	148.10 g·mol−1
Appearance	Colourless Liquid
Density	1.496 g/mL
Melting point	−64 °C (−83 °F; 209 K)
Boiling point	100 °C (212 °F; 373 K)
Solubility in water	Hydrolyzes
Hazards
Main hazards	Corrosive
R-phrases	R10-R34
S-phrases	S26-S36/37/39-S45
Flash point	38 °C (100 °F; 311 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

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 (and dangerous) methylating agent. The compound is closely related to methyl fluorosulfonate (FSO₂OCH₃).

Methyl triflate is commercially available, however it may also be prepared in the laboratory by treating dimethyl sulfate with triflic acid.

The compound hydrolyzes violently upon contact with water:

One ranking of methylating agents is (CH₃)₃O⁺ > CF₃SO₂OCH₃ ≈ FSO₂OCH₃ > (CH₃)₂SO₄ > CH₃I. It will alkylate many functional groups that are only weakly basic such as aldehydes, amides, and nitriles. It does not methylate benzene or the bulky 2,6-di-tert-butylpyridine. Its ability to methylate N-heterocycles is exploited in certain deprotection schemes.