Hexafluoroacetone
- HFA
- Perfluoroacetone
- Hexafluoro -2-propanone
- C3F6O
- C6H6F12O5 ( sesquihydrate )
- 684-16-2
- 13098-39-0 ( sesquihydrate )
Colorless liquid ( sesquihydrate )
- Gaseous
- Liquid ( sesquihydrate )
- -129 ° C
- 11-20 ° C ( sesquihydrate )
-26 ° C
- 0.60 MPa ( 21.1 ° C)
- 202 hPa ( sesquihydrate at 20 ° C)
Soluble in water
Risk
Template: Infobox chemical / molecular formula search available
Hexafluoroacetone (HFA) is a derivative of acetone, in which all the hydrogen atoms are replaced by fluorine. As a fine chemical, it is commercially available as sesquihydrate, ie with formal 1,5 molecules of water per molecule. It serves as a building block in the synthesis of fluorine-containing organic compounds. As crosslinking agents for rubbers as well as monomers for the preparation of polyamides are produced by reaction with aromatics. Furthermore, the Deutero- hydrate is used as NMR solvent and as a reagent in the protective group technique use.
Production
For the preparation of hexafluoroacetone by isomerizing hexafluoro- 1 ,2- epoxypropane, is selected most technically. So it is obtained by the reaction in the presence of Lewis acid catalysts such as Al2O3, TiO2, WO2, AlCl3, AlBr3, SnCl4, VOCl3, TiCl4, FeCl3, CuCl2 or ZrOCl2.
A laboratory method based on the reaction of Perfluoropropene with sulfur and potassium fluoride and subsequent ring opening of the dithietane with potassium fluoride and potassium iodate to the HFA.
Properties
In hexafluoroacetone the carbonyl carbon atom is electron deficient and therefore reactive towards nucleophiles such as self- aromatics or olefins by its neighboring trifluoromethyl radicals. With water to form stable hydrates. HFA analog reacts with ammonia to form the corresponding hemiaminals (CF3) 2C ( OH) (NH2), its dehydration with phosphorus oxychloride ( POCl 3 ) provides the hexafluoro-2- propylimin (CF3) 2CNH.
Since HFA has no adjacent to the carbonyl group hydrogen atoms, it shows no comparable to keto -enol tautomerism behavior.
Use
Has an importance HFA as an electrophilic reagent for the substitution of aromatics. It generally reacts in the presence of acids to the corresponding hexafluoro-2- hydroxy-2- aryl compounds which serve as intermediates in the synthesis of active ingredients.
The hydroperoxide of the HFA, so the hydrogen peroxide adduct, is a potent epoxidizing agent.
The reduction of HFA with lithium aluminum hydride or sodium borohydride provides the important solvent, hexafluoro-2 -propanol.