Talk:Hexafluoro-2-propanol
From Wikipedia, the free encyclopedia
 |
Hexafluoro-2-propanol is within the scope of WikiProject Chemicals, a daughter project of WikiProject Chemistry, which aims to improve Wikipedia's coverage of chemicals. To participate, help improve this article or visit the project page for details on the project. | ||
|
Article Grading: The article has not been rated for quality and/or importance yet. Please rate the article and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article.. |
|||
[edit] Preparation and safety details
I contracted the description of the preparative routes. In so doing I removed a big section that was unreferenced and unsupported by the usually encyclopedic Ullmann's Industrial Chem series. But I may have erred in my quest for improved readability. So here is the removed text, in the event that some specialist (with references, ideally) chooses to reinstate this material:
- "The first step in the synthesis of hexafluoro-2-propanol is oxidation of hexafluoropropylene to yield an impure mixture consisting of hexafluoro-2-propanone and residual hexafluoropropylene. This can be done by direct oxidation of hexafluoropropylene using aluminum oxide. The mixture of products thus obtained has to be subsequently reduced in order to hydrogenate hexafluoro-2-propanone to hexafluoro-2-propanol: this is usually achieved by using strong hydrogenating agents such as sodium borohydride in a methanol solution or lithium aluminum hydride or sodium hydride in presence of a reaction promoting solvent such as diethyl ether, methanol, isopropyl alcohol, or tetrahydrofuran. Alternatively catalysts such as Raney nickel or platinum on barium sulfate or palladium on barium sulfate can be employed successfully for direct hydrogenation of hexafluoro-2-propanone. After reduction hexafluoro-2-propanol can be readily separated from residual amounts of hexafluoro-2-propanone and hexafluoropropylene since it has a much higher boiling point than hexafluoro-2-propanone and hexafluoropropilene will outgas easily at about room temperature.
As an alternative hexafluoro-2-propanone mixed with hydrogen fluoride can also be obtained starting from hexachloroacetone.
A different synthetic route to obtain hexafluoro-2-propanol is disclosed in the "US Patent 4,647,706": chemical compounds of the generic formula (CF3)2C-OH-OR (where R represents an hydrogen atom or an alkyl group having from one to eight carbon atoms) are subjected to catalytic hydrogenation in the presence of palladium deposited on activated carbon and of a tertiary aliphatic amine co-catalyst such as triethylamine."
- The safety aspects also appear to be overstated, Ullmann's again: "The acute toxicity of 1,1,1,3,3,3-hexafluoro-2-propanol [920-66-1] is also low, but the substance is a strong skin and eye irritant."
