Fluorinated propenes from pentafluoropropane

• US 5,986,151 A
• Filed: 08/28/1998
• Issued: 11/16/1999
• Est. Priority Date: 02/05/1997
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Original Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Inventors: Van Der Puy, Michael
• Primary Examiner(s): SIEGEL, ALAN M
• Application Number:
  US09/143,133
• Time in Patent Office: 445 Days
• Field of Search: 570/156, 570/158, 570/175
• US Class Current: 570/175
• CPC Class Codes: C07C 17/25 by splitting-off hydrogen halides from halogenated hydrocarbons
• CPC Class Codes: C07C 17/354 by hydrogenation
• CPC Class Codes: C07C 19/08 containing fluorine
• CPC Class Codes: C07C 21/18 containing fluorine

Abstract

A process for the preparation of fluorinated propanes and propenes. CF₃ CH═CH₂ is produced from CF₃ CH₂ CHF₂ by the sequential steps of dehydrofluorination, a reduction, and a second dehydrofluorination in which the same catalyst is preferably used for each step. Preferably the catalysts is palladium on carbon. The process provides the steps of passing CF₃ CH₂ CHF₂ over a Pd/C catalyst to form CF₃ CH═CHF; hydrogenating CF₃ CH═CHF over a Pd/C catalyst to give CF₃ CH₂ CH₂ F; and passing CF₃ CH₂ CH₂ F over a Pd/C catalyst to give CF₃ CH═CH₂.

Claims

1. A method for producing 1,1,1-trifluoropropene which comprises dehydrofluorinating 1,1,1,3,3-pentafluoropropane in the presence of a catalyst comprising palladium on carbon under conditions sufficient to thereby produce 1,1,1,3-tetrafluoropropene, and then reducing the 1,1,1,3-tetrafluoropropene under conditions sufficient to produce 1,1,1,3-tetrafluoropropane, and then dehydrofluorinating 1,1,1,3-tetrafluoropropane under conditions sufficient to produce 1,1,1,-trifluoropropene.

2. The method of claim 1 wherein each reaction is conducted in the presence of a catalyst which comprises palladium on carbon.