Trifluoromethanesulfonic Acid - Syntheses

Syntheses

Trifluoromethanesulfonic acid was first synthesized in 1954 by Haszeldine and Kidd by the following reaction:

Trifluoromethanesulfonic acid is produced industrially by electrochemical fluorination (ECF) of methanesulfonic acid:

CH₃SO₃H + 4 HF → CF₃SO₂F + H₂O + 1.5 H₂

The resulting CF₃SO₂F is hydrolyzed, and the resulting triflate salt is preprotonated. Alternatively, trifluoromethanesulfonic acid arises by oxidation of trifluoromethylsulfenyl chloride:

CF₃SCl + 2 Cl₂ + 2 H₂O → CF₃SO₂OH + 4 HCl

Triflic acid is purified by distillation from triflic anhydride.