Trifluoroacetone

For the abbreviation TFA, or another perfluoro compound, see TFA (disambiguation) and Trifluoroacetic acid.
On Wikipedia, TFA refers to Today's featured article.
1,1,1-Trifluoroacetone
Names
Preferred IUPAC name
1,1,1-Trifluoropropan-2-one
Other names
Trifluoracetone, TFA
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.006.370 Edit this at Wikidata
EC Number
  • 207-005-9
UNII
  • InChI=1S/C3H3F3O/c1-2(7)3(4,5)6/h1H3
    Key: FHUDAMLDXFJHJE-UHFFFAOYSA-N
  • CC(=O)C(F)(F)F
Properties
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:
GHS02: Flammable GHS07: Exclamation mark
Danger
H224, H315, H319, H335
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).

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]

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

References

  1. ^ "1,1,1-Trifluoracetone 95%". dk.vwr.com. Retrieved 6 June 2017.
  2. ^ a b Günter Siegemund; Werner Schwertfeger; Andrew Feiring; Bruce Smart; Fred Behr; Herward Vogel; Blaine McKusick (2002). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_349. ISBN 978-3-527-30673-2.
  3. ^ Prakash, G. K.Surya; Wang, Fang (2011). "1,1,1-Trifluoroacetone". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn01348. ISBN 978-0-471-93623-7.
  4. ^ Mello, Rossella; Martínez-Ferrer, Jaime; Asensio, Gregorio; González-Núñez, María Elena (2007). "Oppenauer Oxidation of Secondary Alcohols with 1,1,1-Trifluoroacetone as Hydride Acceptor". J. Org. Chem. 24 (72): 9376–9378. doi:10.1021/jo7016422. PMID 17975928.
  5. ^ "Concise synthesis of enantiopure alpha-trifluoromethyl alanines, diamines, and amino alcohols by the Strecker-type reaction". sigmaaldrich.com. Retrieved 6 June 2017.