TFA - Trifluoroacetic Acid - C2HF3O2

🏾 Contents :

◉ Définition

TFA or Trifluoroacetic Acid is an organofluorine compound (contains a carbon-fluorine bond) with the chemical formula C2HF3O2 . It is a strong carboxylic acid due to the presence of three fluorine atoms, which are strongly electronegative. Compared to acetic acid, trifluoroacetic acid is approximately 100,000 times more potent.

Trifluoroacetic acid was discovered by Swarts in 1922, and is widely used in organic synthesis as a solvent or as an acid catalyst for various organic transformations.

TFA, discovered at the beginning of the 20th century, is prepared industrially by the electrofluorination of acetyl chloride or acetic anhydride, followed by the hydrolysis of the resulting trifluoroacetyl fluoride.


CAS number 76-05-1
Molecular mass 114.0233 g/Mol
Formula C2HF3O2
PKa 0.3
Synonyms Perfluoroacetic acid, Trifluoracetic acid, Trifluoroethanoic acid
TFA : trifluoroacetic acid


◉ Applications and uses of trifluoroacetic acid

Trifluoroacetic acid is mainly intended for the production of new pesticides, drugs and dyes, and also has great potential for application and development in the fields of materials and solvents.

Many chemical transformations must be performed using TFAs, including rearrangements, functional group deprotections, oxidations, reductions, condensations, hydroarylations, and trifluoromethylations.


In chromatography


Removal of protecting groups

◉ Properties of Trifluoroacetic Acid

It is a colorless, volatile fuming liquid with an odor similar to that of acetic acid. It is hygroscopic and has a stimulating smell. It is miscible with water, fluorinated alkanes, methanol, benzene, ether, carbon tetrachloride and hexane. It can partially dissolve an alkane with more than six carbons as well as carbon disulfide.

TFA is a stronger acid than acetic acid, having an acid ionization constant, Ka, which is about 34,000 times higher, because the highly electronegative fluorine atoms and the attracting nature resulting electron from the trifluoromethyl group weakens the oxygen-hydrogen bond (allowing greater acidity) and stabilizes the anionic conjugate base.

It is stable at a temperature above 205℃ stable. But its ester and amide derivatives are easily subject to hydrolysis, which allows them to prepare carbohydrates, amino acids and peptide derivatives in acid or anhydride form. It dehydrates easily under the action of phosphorus pentoxide and is transformed into trifluoroacetic anhydride.

It is common to remove excess TFA by evaporation because other reagent removal methods are often affected by this organic acid.


  1. Trifluoroacetic acid: A unique solvent for atom transfer radical cyclization reactions
  2. SusanaGuzman - Effect of trifluoroacetic acid on the properties of polyvinyl alcohol and polyvinyl alcohol-cellulose composites
  3. R.McClain - High-Throughput Purification in Support of Pharmaceutical Discovery
  4. Pubchem - TFA
  5. Simón E.López - Trifluoroacetic acid: Uses and recent applications in organic synthesis
  6. chemicalbook - Trifluoroacetic acid
  7. the merck index
  8. CHEBI - 45892 - trifluoroacetic acid
  9. WebBook de Chimie NIST - trifluoroacetic acid
  10. - Cationic Rearrangements