US 12,421,180 B2
Processes for producing Z-1,1,1,4,4,4-hexafluorobut-2-ene and intermediates for producing same
Sheng Peng, Hockessin, DE (US); and Allen Capron Sievert, Elkton, MD (US)
Assigned to THE CHEMOURS COMPANY FC, LLC, Wilmington, DE (US)
Appl. No. 17/601,515
Filed by THE CHEMOURS COMPANY FC, LLC, Wilmington, DE (US)
PCT Filed Apr. 3, 2020, PCT No. PCT/US2020/026692
§ 371(c)(1), (2) Date Oct. 5, 2021,
PCT Pub. No. WO2020/206335, PCT Pub. Date Oct. 8, 2020.
Claims priority of provisional application 62/829,854, filed on Apr. 5, 2019.
Prior Publication US 2022/0194882 A1, Jun. 23, 2022
Int. Cl. C07C 17/087 (2006.01); C07C 17/04 (2006.01); C07C 17/20 (2006.01); C07C 17/25 (2006.01); C07C 17/269 (2006.01); C07C 17/354 (2006.01)
CPC C07C 17/087 (2013.01) [C07C 17/04 (2013.01); C07C 17/206 (2013.01); C07C 17/25 (2013.01); C07C 17/269 (2013.01); C07C 17/354 (2013.01)] 13 Claims
 
1. A process to produce Z-1,1,1,4,4,4-hexafluoro-2-butene comprising: (a′) contacting trichloroethylene in the presence of a dimerization catalyst to produce a product mixture comprising 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az), wherein the dimerization catalyst comprises iron or copper; (a) contacting 1,1,2,4,4-pentachlorobuta-1,3-diene produced in step (a′) with hydrogen fluoride in the liquid phase in the presence of a fluorination catalyst to produce a product mixture comprising 2-chloro-1,1,1,4,4,4-hexafluorobutane (HCFC-346mdf); (b) contacting 2-chloro-1,1,1,4,4,4-hexafluorobutane with base to produce a product mixture comprising E-1,1,1,4,4,4-hexafluoro-2-butene (E-1336mzz); (c) contacting E-1, 1,1,4,4,4-hexafluoro-2-butene with a chlorine source in the presence of a catalyst to produce a product mixture comprising 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane (HCFC-336mdd); (d) contacting 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane with a base to produce a product mixture comprising 1,1,1,4,4,4-hexafluoro-2-butyne; and (e) contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen to produce a product mixture comprising Z-1,1,1,4,4,4-hexafluoro-2-butene, wherein step (a′) is performed in the presence of pentachloroethane, wherein the weight ratio of pentachlororethane to trichloroethylene is from about 0.001 to about 1.