Trifluoroacetone

Trifluoroacetone (1,1,1-trifluoroacetone) is an organofluorine compound with the chemical formula CF₃C(O)CH₃.^[1] The compound is a colorless liquid with chloroform-like odour.^[2]

1,1,1-Trifluoroacetone

Names
Preferred IUPAC name 1,1,1-Trifluoropropan-2-one
Other names Trifluoracetone, TFA
Identifiers
CAS Number	421-50-1 Y
3D model (JSmol)	Interactive image
ChemSpider	21111803
ECHA InfoCard	100.006.370
EC Number	207-005-9
PubChem CID	9871
UNII	K987U5C2CX Y
CompTox Dashboard (EPA)	DTXSID9059963
InChI InChI=1S/C3H3F3O/c1-2(7)3(4,5)6/h1H3 Key: FHUDAMLDXFJHJE-UHFFFAOYSA-N
SMILES CC(=O)C(F)(F)F
Properties
Chemical formula	C3H3F3O
Molar mass	112.051 g·mol−1
Appearance	Colorless liquid
Density	1.252 g/mL
Melting point	−78 °C (−108 °F; 195 K)
Boiling point	21–24 °C (70–75 °F; 294–297 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H224, H315, H319, H335
Precautionary statements	P210, P261, P303, P338, P351
Flash point	−30 °C (−22 °F; 243 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation, reactions, uses

Trifluoroacetone is produced from trifluoroacetoacetic acid, which is synthesized by condensation of ethyl trifluoroacetate and ethyl acetate:

CF₃CO₂C₂H₅ + CH₃CO₂C₂H₅ → CF₃C(O)CH₂CO₂C₂H₅ + C₂H₅OH

Hydrolysis of the keto-ester, followed by decarboxylation affords trifluoroacetone:

CF₃C(O)CH₂CO₂C₂H₅ + H₂O → CF₃C(O)CH₂CO₂H + C₂H₅OH

CF₃C(O)CH₂CO₂H → CF₃C(O)CH₃ + CO₂

Alternatively, addition of methylmagnesium iodide to trifluoroacetic acid gives the ketone according to this idealized equation:^[2]

CF₃CO₂H + 2 CH₃MgI → CF₃C(O)CH₃ + MgI₂ + CH₄ + MgO

Reactions

Many studies report on the reactions of trifluoroacetone.^[3] It is less prone to hydrate than hexafluoroacetone and more electrophilic than acetone itself. Unlike both of those ketones, trifluoroacetone is prochiral.

Hydrogenation of trifluoroacetone over platinum catalyst gives trifluoroisopropanol. The reduction can also be achieved asymmetrically. Similarly, alkylation with Grignard reagents provides a route to tertiary alcohols. Alkylation and arylation can be achieved using malonate anions and arenes/AlCl₃, respectively.

Trifluoroacetone has been converted to the dioxirane using oxone.

It serves as an oxidizing agent in Oppenauer oxidation.^[4]

Trifluoracetone is also used in a synthesis of 2-trifluoromethyl-7-azaindoles starting with 2,6-dihalopyridines. The derived chiral imine is used to prepare enantiopure α-trifluoromethyl alanines and diamines by a Strecker reaction followed by either nitrile hydrolysis or reduction.^[5]

See also

• Hexafluoroacetone
• Trifluoroacetic acid – also abbreviated TFA