Trifluoroacetic acid
Overview
 
Trifluoroacetic acid is the simplest stable perfluorinated carboxylic acid
Perfluorinated carboxylic acid
Perfluorinated carboxylic acids , or perfluorocarboxylates are fully fluorinated organofluorine compounds—or perfluorinated compounds—with carboxylic acid or carboxylate functional groups. PFCAs are fluorocarbon derivatives...

 chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

, with the formula CF3CO2H. It is a strong carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

 due to the influence of the electronegative
Electronegativity
Electronegativity, symbol χ , is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself. An atom's electronegativity is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus...

 trifluoromethyl
Trifluoromethyl
Trifluoromethyl is a functional group in organofluorines that has the formula -CF3. The naming of is group is derived from the methyl group , by replacing each hydrogen atom by a fluorine atom. The trifluomethyl group has a significant electronegativity that is often described as being...

 group. TFA is almost 100,000-fold more acidic than acetic acid
Acetic acid
Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

. TFA is widely used in organic chemistry
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...

.
Trifluoroacetic acid is prepared industrially by the electrofluorination of acetyl chloride
Acetyl chloride
Acetyl chloride, CH3COCl, also known as ethanoyl chloride or acyl chloride, is an acid chloride derived from acetic acid. It belongs to the class of organic compounds called acyl halides. It is a colorless liquid. Acetyl chloride does not exist in nature, because contact with water would hydrolyze...

 and acetic anhydride
Acetic anhydride
Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula 2O. Commonly abbreviated Ac2O, it is the simplest isolatable acid anhydride and is a widely used reagent in organic synthesis...

, followed by hydrolysis of the resulting trifluoroacetyl fluoride:
+ 4 → + 3 +
+ → +


Where desired, this compound may be dried by addition of trifluoroacetic anhydride
Trifluoroacetic anhydride
Trifluoroacetic anhydride is the acid anhydride of trifluoroacetic acid. In particular, trifluoroacetic anhydride is the perfluorinated derivative of acetic anhydride. Like many acid anhydrides, it may be used to introduce the corresponding trifluoroacetyl group. The corresponding trifluoroacetyl...

.

An older route to TFA proceeds via the oxidation of 1,1,1-trifluoro-2,3,3-trichloropropene with potassium permanganate
Potassium permanganate
Potassium permanganate is an inorganic chemical compound with the formula KMnO4. It is a salt consisting of K+ and MnO4− ions. Formerly known as permanganate of potash or Condy's crystals, it is a strong oxidizing agent. It dissolves in water to give intensely purple solutions, the...

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