1,1,1,2,3,3-hexafluoropropane (i.e., CHF.sub.2 CHFCF.sub.3 or HFC-236ea) and 1,1,1,3,3,3-hexafluoropropane (i.e., CF.sub.3 CH.sub.2 CF.sub.3 or HFC-236fa) are useful as refrigerants, fire extinguishants, heat transfer media, gaseous dielectrics, sterilant carriers, polymerization media, particulate removal fluids, carrier fluids, buffing and abrasive agents, displacement drying agents and power cycle working fluids. In particular, HFC-236ea and HFC-236fa are highly effective as refrigerants for use in refrigeration equipment.
U.S. Pat. No. 5,171,901 discloses a process for the preparation of HFC-236fa by contacting a mixture of hexachloropropene and HF with a catalyst consisting of a mixture of CrCl.sub.3 and MgF.sub.2 at temperatures ranging from 350.degree. C. to 500.degree. C. The reaction temperatures and yields of HFC-236fa were as follows: 350.degree. C., none detected; 400.degree. C., 10%; 450.degree. C., 55%; and 500.degree. C., 64%. Other products formed in varying amounts were CF.sub.3 CHClCF.sub.3, CF.sub.3 CCl.sub.2 CF.sub.3, CF.sub.3 CCl.dbd.CF.sub.2, CF.sub.3 CCl.dbd.CClF, and CF.sub.3 CCl.dbd.CCl.sub.2. HFC-236ea has been prepared by the hydrogenation of hexafluoropropane. There is an interest in developing additional, efficient processes for the manufacture of HFC-236ea and HFC-236fa from various starting materials.
USPTO Backgrounds
USPTO Backgrounds