PROCESSES FOR THE PRODUCTION OF Z 1,1,1,4,4,4 HEXAFLUORO 2-BUTENE
Processes are provided for (i) producing Z-1,1,1,4,4,4-hexafluoro-2-butene (Z—CF 3 CH═CHCF 3 ) from E-1,1,1,4,4,4-hexafluoro-2-butene (E-CF 3 CH═CHCF 3 ), comprising the steps of (a) reacting the E-1,1,1,4,4,4-hexafluoro-2-butene (E-CF 3 CH═CHCF 3 ) with chlorine to form dichloro-1,1,1,4,4,4-hexafluorobutane (CF 3 CHClCHClCF 3 ), (b) recovering the dichloro-1,1,1,4,4,4-hexafluorobutane from step (a), (c) reacting the recovered dichloro-1,1,1,4,4,4-hexafluorobutane with base to form 1,1,1,4,4,4-hexafluoro-2-butyne (CF 3 ≡CCF 3 ), (d) recovering the 1,1,1,4,4,4-hexafluoro-2-butyne from step (c) and (e) reacting the recovered hexafluoro-2-butyne with hydrogen to form said Z-1,1,1,4,4,4-hexafluoro-2-butene, optionally wherein said E-1,1,1,4,4,4-hexafluoro-2-butene starting material is obtained by converting 1,1,1,4,4,4-hexafluoro-2-butane (F 3 CHCl 2 ) to a mixture of Z-1,1,1,4,4,4-hexafluoro-2-butene and E-1,1,1,4,4,4-hexafluoro-2-butene and recovering the E-1,1,1,4,4,4-hexafluoro-2-butene from said mixture, whereby the E-1,1,1,4,4,4-hexafluoro-2-butene used in step (a) is the recovered E-1,1,1,4,4,4-hexafluoro-2-butene, and (ii) step (a) as a subcombination of the process (i).
1 - 8 . (canceled)
9 . The process for obtaining dichloro-1,1,1,4,4,4-hexafluorobutane, comprising contacting E-1,1,1,4,4,4-hexafluorobutene with chlorine in either the gas phase, or the liquid phase.
10 . The process of claim 9 wherein said contacting is carried out in the presence of catalyst selected from the group consisting of ferric chloride, chromium chloride, alumina chloride and cupric chloride.
11 . The process of claim 10 wherein the selectivity for the production of dichloro-1,1,1,4,4,4-hexafluorobutane is at least 85%.
12 . The process of claim 10 , wherein said contacting is carried out at a temperature of from 125 C to 175 C.
13 . The process of claim 9 , wherein the process is conducted with exposure to ultraviolet light.
14 . The process of claim 13 wherein the selectivity for the production of dichloro-1,1,1,4,4,4-hexafluorobutane is at least 85%.
15 . The process of claim 13 wherein the selectivity for the production of dichloro-1,1,1,4,4,4-hexafluorobutane is at least 90%.