24270-66-4Relevant academic research and scientific papers
PROCESSES FOR PRODUCING 2,3,3,3-TETRAFLUOROPROPENE AND/OR 1,2,3,3-TETRAFLUOROPROPENE
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Page/Page column 9, (2008/12/05)
A process is disclosed for making CF3CF=CH2 or mixtures thereof with CHF2CF=CHF. This process involves (a) reacting CHCI2CF2CF3, and optionally CHCIFCF2CCIF2, with H2 in the presence of a catalytically effective amount of a hydrogenation catalyst to form CH3CF2CF3 and, when CHCIFCF2CCIF2 is present, CH2FCF2CHF2; (b) dehydrofluorinating CH3CF2CF3, and optionally any CH2FCF2CHF2, from (a) to form a product mixture including CF3CF=CH2 and, if CH2FCF2CHF2 Js present, CHF2CF=CHF; and optionally (c) recovering CF3CF=CH2, or a mixture thereof with CHF2CF=CHF from the product mixture formed in (b) and/or (d) separating at least a portion of any CHF2CF=CHF in the product mixture formed in (b) from the CF3CF=CH2 in the product mixture formed in (b).
PROCESSES FOR PRODUCING AND COMPOSITIONS COMPRISING 2,3,3,3-TETRAFLUOROPROPENE AND/OR 1,2,3,3-TETRAFLUOROPROPENE
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Page/Page column 19-20, (2008/12/05)
A process is disclosed for making CF3CF=CH2 or mixtures thereof with CHF=CFCHF2. The process involves contacting CCI3CF2CF3 and optionally CCI2FCF2CCIF2 with H2 in the presence of a catalyst including a catalytically effective amount of palladium supported on a support of alumina, fluorided aluminaand/or aluminum fluoride, to produce a product mixture including CH2=CFCF3 (and when CCI2FCF2CCIF2 is present, CHF=CFCHF2); recovering CH2=CFCF3 or a mixture thereof with CHF=CFCHF2 from the product mixture; and optionally, separating at least a portion of any CHF=CFCHF2 in the product mixture from the CH2=CFCF3 in the product mixture. The mole ratio of H2 to the total of CCI3CF2CF3 and CCI2FCF2CCIF2 fed to the reaction zone is between about 1 :1 and about 5:1. The present invention also provides another process for making CH2=CFCF3 Or mixtures thereof with CHF=CFCHF2 This process involves (a) reacting CCI3CF2CF3 and optionally CCI2FCF2CCIF2 with H2 in the presence of a catalytically effective amount of a hydrogenation catalyst to form CH3CF2CF3 (and when CCI2FCF2CCIF2 is present, CH2FCF2CHF2); (b) dehydrofluorinating CH3CF2CF3 and optionally any CH2FCF2CHF2 from (a) to form a product mixture including CH2=CFCF3, and if CH2FCF2CHF2 is present, CHF=CFCHF2; (c) recovering CH2=CFCF3 or a mixture thereof with CHF=CFCHF2 from the product mixture formed in (b); and optionally (d) separating at least a portion of any CHF=CFCHF2 in the product mixture formed in (b) from the CH2=CFCF3 in the product mixture formed in (b). The present invention also provides compositions involving CH2=CFCF3 and/or CHF=CFCHF2, including compositions useful as refrigerants, foam blowing agents, cleaning agents and aerosols and azeotropic compositions involving (a) CF2HCF=CFH and (b) HF.
Selective reduction of halopolyfluorocarbons by organosilicon hydrides
Petrov, Viacheslav A.
, p. 7294 - 7297 (2007/10/03)
It is demonstrated that silicon hydrides can be used for reduction of polyfluorinated halocarbons. For example, the reaction between CF3CCl2F and excess triethylsilane, catalyzed by benzoyl peroxide, leads to the formation of a mixture containing CF3CHClF (major), CF3CH2F, and ClSi(C2H5)3. On the other hand, the reaction of chlorofluoroalkanes, containing an internal -CCl2- group readily proceeds with reduction of both chlorines, leading to compounds such as (CF3)2CH2 and CF3CH2C2F5. In contrast to chlorofluoroalkanes, bromofluoroalkanes are much more reactive and reaction with hydrosilane rapidly proceeds without the catalyst at elevated temperature.
Fluorination of propane and propene over cobalt(III) trifluoride and potassium tetrafluorocobaltate(III)
Burdon, James,Garnier, Laurent,Powell, Richard L.
, p. 625 - 632 (2007/10/03)
Fluorination of propane and propene over cobalt(III) fluoride and potassium tetrafluorocobaltate(III) gave complex mixtures of products which have been identified to the 0.5percent level.The reactions are valuelles for preparative purposes.The mechanism of the fluorinations is not a simple F-for-H replacement, but requires an initial conversion of propane into propene followed by carbocation- and radical mediated reactions: the carbocations can be quenched by fluoride ions, rearrange and eliminate, and the radicals can be oxidised to carbocations or quenched by fluorine atoms.Radical quenching tends to predominate late in the fluoronation and carbocation reactions at the beginning.
Reductive dehalogenation of polyhalofluorocarbons with tributyltin hydride
Puy, Michael Van Der,Belter, Randolph K.,Borowski, Ralph J.,Ellis, Lois A. S.,Persichini, Phillip J.,et al.
, p. 59 - 64 (2007/10/02)
The reduction of polyhalofluorocarbons, including ClCF2CFClCF2Cl, (ClCF2CFCl)2, ICH2(CF2)3CH2I and vicinal dichloroperfluorocycloalkanes, with tributyltin hydride gave the corresponding hydrofluorocarbons in good to excellent yield.The results are compared with similar reductions with other reducing agents, and to tin hydride reductions of non-fluorinated analogs. - Keywords: Reductive dehalogenation; Polyfluorocarbons; Tributyltin hydride; NMR spectroscopy; Hydrofluorocarbons
