Cryogenically controlled direct fluorination apparatus

Abstract

An apparatus and process useful in direct fluorination of a variety of compositions, as well as the fluorinated compositions themselves. The apparatus comprises a cryogenic zone reactor, such as a packed column reactor, divided into a plurality of independently controllable cryogenic temperature zones. Means are also provided to introduce a reactant to be fluorinated as well as to introduce a mixture of fluorine gas and an inert gas. The direct fluorination process is carried out in the reactor as described above. At least the first zone of the reactor is chilled to a temperature below the freezing point of the reactant to be fluorinated. The reactant is then introduced into the reactor wherein it condenses upon a suitably provided fluorination surface, such as copper column packings. A mixture of fluorine gas and an inert gas, with the fluorine gas initially comprising a very small percentage of the mixture, but gradually increasing as fluorination proceeds, is then introduced into the reactor. After some degree of fluorination has been achieved in the first zone, it is allowed to warm whereas other zones in the reactor are cooled. The resulting temperature gradients cause the partially fluorinated materials to volatilize and move along the column. As the volatilized, partially fluorinated materials enter the subsequent chilled zone, they condense on a fresh fluorination surface and are further fluorinated. The temperature gradients are repeated as necessary to achieve the degree of fluorination desired. New fluorinated compounds are also disclosed. These include: perfluoro-2-methoxyethyl ether; perfluoro-1,4-dioxane; perfluoro-2,5-diketohexane; perfluorohexamethylethane; and monohydropentadecafluoroadamantane. Additionally, new syntheses for trifluoroacetic acid are disclosed. One synthesis comprises producing perfluoroethyl acetate by direct fluorination using a cryogenic zoner reactor, followed by hydrolysis of perfluoroethyl acetate. A second synthesis comprises fluorinating an acyl chloride followed by hydrolysis of the resulting acyl fluoride.

Dependencies are inferred from the claim text.