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US 5,057,634 AGranted
Multistep synthesis of hexafluoropropylene
AssigneeE. I. Du Pont de Nemours and Company
InventorsJames L. Webster, Elrey L. McCann, Douglas W. Bruhnke, Jan J. Lerou, William H. Manogue, Leo E. Manzer, Steven H. Swearingen, Swiatoslaw Trofimenko, Cristobal Bonifaz
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Abstract
The present invention relates to multistep syntheses of hexafluoropropylene from acyclic three-carbon hydrocarbons or partially halogenated acyclic three-carbon hydrocarbons. In all these syntheses the first step is a vapor-phase chlorofluorination of the starting material to one or more saturated chlorofluorocarbons. Novel catalysts are also provided.
Claims6
A process for the preparation of hexafluoropropylene comprising, under effective reaction conditions:
- (a) chlorofluorinating a member of the group consisting of propane, propylene and partially halogenated C-3 acyclic hydrocarbons, by contacting with hydrogen fluoride and chlorine in a hydrogen fluoride/chlorine ratio of about from 1 to 7 in the presence of a solid metal-containing catalyst, to produce saturated perhalogenated C-3 chlorofluorocarbons;
- (b) hydrofluorinating any chlorofluorocarbons of (a) that are not CF.sub.3 CFClCF.sub.3 to produce CF.sub.3 CFClCF.sub.3 by contacting with hydrogen fluoride in the presence of a catalyst;
- and
- (c) hydrodehalogenating said CF.sub.3 CFClCF.sub.3 to hexafluoropropylene in the presence of hydrogen and a catalyst.
1 more element
Dependencies are inferred from the claim text.