Process for producing 1,1,1,4,4,4-hexafluorobuta-2-ene

Abstract

To provide a composition that meets the low ozone depletion standard and has a low global warming potential. [Solution] The present invention provides a composition comprising 1,1,2,4,4-pentachlorobuta-1,3-diene, E-1,1,2,3,4-pentachlorobuta-1,3-diene, and Z-1,1,2,3,4-pentachlorobuta-1,3-diene, a process for producing 1,1,2,4,4-pentachlorobuta-1,3-diene, and a process for producing Z-1,1,1,4,4,4-hexafluorobuta-2-ene.

Description

Technical Field

[0001] The disclosure herein relates particularly to processes for generating E- and Z-1,1,1,4,4,4-hexafluoro-2-butene from starting materials including 1,1,2,4,4-pentachlorobuta-1,3-diene. The disclosure further provides a process for generating 1,1,2,4,4-pentachlorobuta-1,3-diene.

Background Art

[0002] Over the past few decades, efforts have been made in many industries to find alternatives to ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). CFCs and HCFCs have been used in a wide variety of applications, including as refrigerants, cleaning agents, blowing agents for thermoplastic and thermosetting foams, heat transfer media, gas dielectrics, aerosol propellants, fire extinguishing and fire suppressing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasives, and replacement desiccants. In the search for alternatives to these multi-purpose compounds, the use of hydrofluorocarbons (HFCs) has received attention in many industries. HFCs have a zero ozone depletion potential and are thus not affected by the current regulatory phasedown as a result of the Montreal Protocol.

[0003] In addition to the problem of ozone depletion, another environmental problem associated with many of these applications is global warming. Therefore, there is a need for compositions that meet low ozone depletion standards and have a low global warming potential. Certain hydrofluoroolefins are thought to meet both of these goals. Accordingly, there is a need for manufacturing processes that provide intermediates useful for generating hydrofluoroolefins and chlorine-free hydrofluoroolefins. These materials have no ozone depletion potential and a low global warming potential.

[0004] Embedding by reference All publications, patents, and patent applications referenced herein are incorporated by reference to the same extent as each individual publication, patent, or patent application is specifically and individually indicated as being incorporated by reference. In the event of any conflict, this application shall prevail, including any definitions herein. [Overview of the Initiative] [Means for solving the problem]

[0005] This disclosure provides a process for producing hydrofluoroolefin E-1,1,1,4,4,4-hexafluorobuta-2-ene (E-CF3CH=CHCF3, E-HFO-1336mzz, E-1336mzz). This process includes contacting 1,1,2,4,4-pentachlorobuta-1,3-diene (CCl2=CClCH=CCl2, HCC-2320az) with hydrogen fluoride (HF) in the gas phase in the presence of a fluorination catalyst to produce a product mixture containing E-CF3CH=CHCF3. In some embodiments, the product mixture further comprises Z-1,1,1,4,4,4-hexafluoro-2-chloro-2-butene (Z-CF3CCl=CHCF3, Z-HCFO-1326mxz, Z-1326mxz).

[0006] [ka]

[0007] In some embodiments, the fluorination catalyst is a chromium-based catalyst. The chromium catalyst may be supported or unsupported chromium oxyfluoride or chromium oxide. If supported, the chromium oxyfluoride or chromium oxide catalyst may be supported on activated carbon, graphite, fluorinated graphite, or fluorinated alumina.

[0008] In some embodiments, the product mixture further comprises Z-1326mxz. In some embodiments, E-1336mzz is produced with a selectivity of over 90%, over 95%, or over 99% relative to Z-1336mzz. In some embodiments, the product contains at least 99.5% E-1336mzz based on gas chromatography analysis.

[0009] In some embodiments, E-1336mzz is recovered from the product mixture. In some embodiments, E-1336mzz may be used for other purposes, such as a foaming agent or a heat transfer fluid.

[0010] In some embodiments, 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az, 2320az) is produced by a process involving the dimerization of trichloroethylene (TCE). The process for producing 2320az includes contacting TCE in the presence of a catalyst to produce a product mixture containing 2320az.

[0011] [ka]

[0012] In some embodiments, the dimerization of TCE is carried out in the presence of pentachloroethane (CCl3CHCl2, HCC-120) to accelerate the dimerization process.

[0013] In certain embodiments, 2320az is produced with a selectivity of at least 80%, and in some embodiments, the selectivity is greater than 90%, greater than 95%, greater than 99%, or greater than 99.5%. In certain embodiments, 2320az is recovered from the product mixture. In some embodiments, unreacted TCE is recovered and reused.

[0014] A process for producing E-1336mzz is provided herein, comprising: (a) contacting trichloroethylene in the presence of a catalyst and optionally pentachloroethane (CHCl2CCl3) to produce a product mixture containing 2320az; and (b) contacting 2320az with hydrogen fluoride in the gas phase in the presence of a catalyst to produce a product mixture containing E-1336mzz.

[0015] Further, a process is provided for producing Z-1,1,1,4,4,4-hexafluorobuta-2-ene (Z-CF3CH=CHCF3, Z-HFO-1336mzz, Z-1336mzz). This process comprises (a) contacting trichloroethylene in the presence of a catalyst and optionally pentachloroethane to produce a product mixture containing 2320az; (b) contacting 2320az with hydrogen fluoride in the gas phase in the presence of a catalyst to produce a product mixture containing E-1336mzz; and (c) contacting E-1336mzz with chlorine to produce 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane (CF3CHClCHClCF3, HCFC-336mzz). The process includes (d) a step of producing a product mixture containing (c) (1), (c) a step of contacting 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane with a base to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3), and (e) a step of optionally contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen in the presence of a catalyst to produce a product mixture containing Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0016] This disclosure further provides compositions produced according to the processes disclosed herein. [Modes for carrying out the invention]

[0017] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variations thereof are intended to encompass non-exclusive inclusion. For example, a process, method, article, or apparatus containing a list of elements is not necessarily limited to these elements and may include other elements not expressly described for or specific to such process, method, article, or apparatus.

[0018] Where a quantity, concentration, or other value or parameter is given as a range, a preferred range, or a list of preferred upper and / or preferred lower values, these shall be understood to specifically disclose all ranges formed by any pair of any upper or preferred upper range values ​​and any lower or preferred lower range values, regardless of whether the ranges are disclosed separately. Where a numerical range is described herein, unless otherwise indicated, this range is intended to encompass its endpoints and all integers and fractions within that range.

[0019] "Recovery" means, when recovering E-1,1,1,4,4,4-hexafluoro-2-butene or Z-1,1,1,4,4,4-hexafluoro-2-butene, which are useful as starting materials for subsequent reaction steps, or for example as a refrigerant, foaming agent, solvent, fire extinguishing agent, or electron gas, to sufficiently isolate the desired product so that it can be used for its intended purpose.

[0020] The details of the recovery process depend on the compatibility of the product mixture with the reaction conditions of subsequent reaction steps. For example, if the product is formed in a reaction medium that is different from or incompatible with subsequent reaction steps, the recovery process may include separating the desired product from the product mixture containing the reaction medium. This separation may be carried out simultaneously with the contacting step when the desired product is volatile under the reaction conditions. The volatilization of the desired product can constitute the isolation and thus the recovery of the desired product. If the vapor contains other materials intended to be separated from the desired product, the desired product may be separated, for example, by selective distillation.

[0021] The process of recovering the desired product from the product mixture preferably includes separating the desired product from the catalyst or other components of the product mixture used to produce the desired product or produced in the process.

[0022] The present disclosure provides, inter alia, a process for producing E-1336mzz in one step. The starting material includes 1,1,2,4,4-pentachlorobuta-1,3-diene, which can be produced from trichloroethylene, and one process is as described herein.

[0023] Production of 1,1,2,4,4-pentachlorobuta-1,3-diene (2320az) 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az or 2320az) can be produced according to the present disclosure by dimerization of trichloroethylene (TCE). In some embodiments, a process for producing a product mixture containing 2320az is provided, which includes contacting TCE with a dimerization catalyst at a high temperature.

[0024] In some embodiments, the dimerization catalyst contains iron. The iron dimerization catalyst may contain metallic iron from any source (including combinations of sources) and may also contain iron powder, iron wire, iron mesh, or iron shavings. The iron catalyst may also contain iron salts such as ferric chloride or ferrous chloride (FeCl3 or FeCl2, respectively).

[0025] In some embodiments, the dimerization catalyst contains copper. The copper dimerization catalyst may contain metallic copper from any source (including combinations of sources), and may also contain, for example, copper powder or copper wire. The copper catalyst may also contain a cuprous or cupric salt, such as cuprous chloride or cupric chloride (CuCl or CuCl2, respectively).

[0026] This process is preferably carried out in an anhydrous environment. For example, when using ferric chloride, the ferric chloride is preferably anhydrous.

[0027] In some embodiments, the dimerizing catalyst has a specific concentration relative to the moles of the TCE reactant used. Therefore, in some embodiments where the catalyst includes a metallic iron catalyst, the weight ratio of the Fe wire (or Fe powder) catalyst to the TCE is approximately 0.0001 to approximately 1. In other embodiments, the weight ratio of the iron catalyst to the TCE is approximately 0.01 to 1.

[0028] In some embodiments, the dimerization catalyst contains ferric chloride, and the weight ratio of ferric chloride to TCE is about 0.00001 to about 1. For example, the weight ratio of ferric chloride to TCE is about 0.00001 to about 0.002, while in another example, the weight ratio is about 0.00005 to about 0.001. In yet another example, the weight ratio of ferric chloride to TCE is about 0.0001 to about 1, while in yet another example, the ratio of ferric chloride to TCE is about 0.00015 to about 1.

[0029] In some embodiments, trichloroethylene is contacted with a dimerization catalyst and pentachloroethane. Pentachloroethane (HCC-120) accelerates the reaction to produce a product mixture containing 2320 az. In certain embodiments, the weight ratio of HCC-120 to TCE is about 0.001 to about 1. In other embodiments, the weight ratio of HCC-120 to TCE is about 0.005 to about 1.

[0030] The dimerization of TCE occurs at high temperatures, for example, in the range of approximately 210 to 235°C. The temperature may be above 200°C. The temperature may be below 245°C.

[0031] Pressure is typically autogenous.

[0032] The contact (residence) time is typically about 0.5 to 10 hours.

[0033] In some embodiments, the conversion rate of TCE is at least 15%, or at least 30%, or at least 50%. In some embodiments, the selectivity for 2320az is at least 80%, or at least 85%, or at least 90%.

[0034] By-products in the dimerization reaction may include tetrachloroethane isomers, tetrachlorobutadiene isomers, hexachlorobutene isomers, and trichloroethylene oligomers. The product mixture containing 2320az may further contain E-1,1,2,3,4-pentachloro-1,3-butadiene or Z-1,1,2,3,4-pentachloro-1,3-butadiene. Therefore, in one embodiment, there exists a composition containing 1,1,2,4,4-pentachlorobuta-1,3-diene, E-1,1,2,3,4-pentachlorobuta-1,3-diene, and Z-1,1,2,3,4-pentachlorobuta-1,3-diene.

[0035] The process may further include, for example, a process for producing E-1336mzz, HCFC-336mdd, 1,1,1,4,4,4-hexafluoro-2-butyne, and HFO-Z-1336mzz as described herein, recovering 2320az from the product mixture and then using the recovered 2320az as a starting material.

[0036] The process for recovering 2320az from the product mixture may include one or any combination of purification techniques known in the art, such as distillation. By “recovering” 2320az from the product mixture, a product containing at least 95%, or at least 97%, or at least 99% 2320az is produced.

[0037] In certain embodiments, the process for producing 2320az may further include the steps of recovering trichloroethylene from the product mixture and reusing the recovered trichloroethylene in the dimerization process described herein.

[0038] In certain embodiments, the process for producing 2320az may further include the steps of recovering the hexachlorobutene isomer from the product mixture and reusing the recovered hexachlorobutene isomer in the dimerization process described herein.

[0039] In certain embodiments, the process for producing 2320az may further include the steps of recovering pentachloroethane from the product mixture and reusing the recovered pentachloroethane in the dimerization process described herein.

[0040] If present, other products such as E-1,1,2,3,4-pentachloro-1,3-butadiene and Z-1,1,2,3,4-pentachloro-1,3-butadiene can also be recovered.

[0041] Formation of E-1,1,1,4,4,4-hexafluoro-2-butene A fluorination process is provided herein, comprising contacting 1,1,2,4,4-pentachlorobuta-1,3-diene (2320az) with HF in the presence of a fluorination catalyst to provide a product mixture containing E-HFO-1336mzz. In this process, the E isomer of 1336mzz is produced as the dominant 1336mzz isomer.

[0042] The fluorination catalyst that can be used in the gas-phase reaction of the present invention may be selected from carbon; graphite; alumina; fluorinated alumina; aluminum fluoride; alumina supported on carbon; aluminum fluoride supported on carbon; fluorinated alumina; magnesium fluoride supported on aluminum fluoride; metals (including elemental metals, metal oxides, metal halides, and / or other metal salts); metals supported on aluminum fluoride; metals supported on fluorinated alumina; metals supported on alumina; and metals supported on carbon; and mixtures of metals.

[0043] Suitable metals for use in fluorination catalysts (optionally supported on alumina, aluminum fluoride, alumina fluoride, or carbon) include chromium, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, manganese, rhenium, scandium, yttrium, lanthanum, titanium, zirconium, and hafnium, copper, silver, gold, zinc, and / or metals having atomic numbers from 58 to 71 (i.e., lanthanide metals). Preferably, when used on a support, the total metal content of the catalyst is about 0.1 to about 20% by weight based on the total weight of the catalyst, and typically about 0.1 to about 10% by weight based on the total weight of the catalyst.

[0044] Useful fluorination catalysts for this process include chromium-based catalysts such as chromium oxyfluoride or chromium oxide, which may be unsupported or supported on a carrier such as activated carbon, graphite, fluorinated graphite, or fluorinated alumina. The chromium catalyst may be used alone or in the presence of a co-catalyst selected from nickel, cobalt, manganese, or zinc salts. In some embodiments, the chromium catalyst is high-surface-area chromium oxide, or chromium / nickel (Cr / Ni / AlF3) on alumina fluoride, the production of which is reported in European Patent No. 486,333.

[0045] Chromium oxyfluoride catalysts can be prepared by treating Cr2O3 (chromium oxide) with HF, CCl3F, or hydrofluorocarbons. In some embodiments of the present invention, chromium oxyfluoride catalysts are prepared by treating dry Cr2O3 with a fluorinating agent such as CCl3F or HF. This treatment can be achieved by placing Cr2O3 in a suitable container (which may be a reactor used to carry out the fluorination reaction) and then passing HF over the dry Cr2O3 at a suitable temperature (e.g., about 200°C to 450°C) for a suitable time (e.g., about 15 to 300 minutes).

[0046] In other embodiments of the present invention, the chromium oxyfluoride catalyst is prepared by treating Cr2O3 with hydrofluorocarbon at high temperature. In other embodiments of the present invention, the chromium oxyfluoride catalyst is prepared in situ. Cr2O3 is commercially available from Engelhard Corporation (Iselin, NJ).

[0047] Cr2O3 may also be produced by processes known in the art.

[0048] The chromium catalyst is typically preferably activated before use by a process that includes heating the chromium catalyst to a temperature of 350-400°C for a certain period of time under a flow of nitrogen, and then heating the catalyst for an additional period of time under a flow of HF and nitrogen or HF and air.

[0049] In some embodiments, gas-phase fluorination can be carried out in a reaction zone including any reaction vessel of an appropriate size for the scale of the reaction. In some embodiments, the reaction zone is a reaction vessel made of a corrosion-resistant material. In some embodiments, these materials include nickel-based alloys such as Hastelloy®, nickel-chromium alloys commercially available from Special Metals Corp. under the trademark Inconel® (hereinafter, "Inconel®") or nickel-copper alloys commercially available from Special Metals Corp. (New Hartford, New York) under the trademark Monel®, or vessels lined with fluoropolymers. In other embodiments, the reaction vessel may be made of stainless steel, particularly austenitic stainless steel, and other structural materials including copper-clad steel.

[0050] The molar ratio of HF to 2320az is about 1 to about 35 in some embodiments. In other embodiments, the molar ratio of HF to 2320az is about 1 to about 25. HF may be added in an amount of 10 to 30 moles per mole of 2320az.

[0051] In some embodiments, the fluorination process is carried out at high temperatures, for example, in the range of 275 to 375°C. In some embodiments, the temperature may be above 375°C. In other embodiments, the temperature may be below 275°C. In other embodiments, the temperature is in the range of 300 to 350°C.

[0052] In some embodiments, the fluorination process is carried out at a pressure in the range of 0 to 200 psi (0 to 1.4 MPa).

[0053] In some embodiments, the contact time for the fluorination process may be about 3 to about 120 seconds. In other embodiments, the contact time for the fluorination process may be about 20 to about 100 seconds. In other embodiments, the contact time for the fluorination process may be about 50 to about 80 seconds.

[0054] In one embodiment, the product mixture containing E-1336mzz includes HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), HFC-356mff (1,1,1,4,4,4-hexafluorobutane, CF3CH2CH2CF3), and Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CH3). C This further includes F3).

[0055] In another embodiment, the product mixture containing E-1336mzz is Z-1336mzz (Z-1,1,1,4,4,4-hexafluoro-2-butene, cis-CF3CH=CHCF3), HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), HFC-356mff (1,1,1,4,4,4-hexafluorobutene). It further contains ruolobutane (CF3CH2CH2CF3), Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), HCFO-1335, and E-HCFO-1326mxz (cis-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3).

[0056] HCFO-1335 is one or more of the following: E- and / or Z-HCFO-1335mzz(CF3CH=CHCF2Cl) and E- and / or Z-HCFO-1335mzx(CF3CH=CClCF2H).

[0057] In another embodiment, the product mixture containing E-1336mzz is Z-1336mzz (Z-1,1,1,4,4,4-hexafluoro-2-butene, cis-CF3CH=CHCF3), HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), HFC-356mff (1,1,1,4,4,4-hexafluorobutane, CF3CH2CH2CF3), Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), HCFO-1335, E-HCFO- It further includes 1326mxz (cis-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), 1327mz (Z and E isomers of 1,1,1,2,4,4,4-heptafluoro-1-butene), 346mdf, 143a (1,1,1-trifluoroethane), 236fa (1,1,1,3,3,3-hexafluoropropane), 1233xf (2-chloro-3,3,3-trifluoropropene), 1317 (chloroheptafluorobutene), 1314 (tetrachlorochlorotetrafluorobutene), and 1325 (dichloropentafluorobutene).

[0058] HCFO-1335 is one or more of the following: E- and / or Z-HCFO-1335mzz (E- and / or Z-1-chloro-1,1,4,4,4-pentafluorobutene, CF3CH=CHCF2Cl) and E- and / or Z-HCFO-1335mzx (E- and / or Z-2-chloro-1,1,4,4,4-pentafluorobutene, CF3CH=CClCF2H).

[0059] In one embodiment, there exists a composition comprising E-1,1,1,4,4,4-hexafluoro-2-butene, 1,1,1,2,2,4,4,4-octafluorobutane, 1,1,1,4,4,4-hexafluorobutane, and Z-2-chloro-1,1,1,4,4,4-hexafluorobutene.

[0060] In one embodiment, there exists a composition comprising E-1,1,1,4,4,4-hexafluoro-2-butene, Z-1,1,1,4,4,4-hexafluoro-2-butene, 1,1,1,2,2,4,4,4-octafluorobutane, 1,1,1,4,4,4-hexafluorobutane, Z-2-chloro-1,1,1,4,4,4-hexafluorobutene, E-2-chloro-1,1,1,4,4,4-hexafluorobutene, and HCFO-1335.

[0061] In one embodiment, E-1,1,1,4,4,4-hexafluoro-2-butene, Z-1,1,1,4,4,4-hexafluoro-2-butene, 1,1,1,2,2,4,4,4-octafluorobutane, 1,1,1,4,4,4-hexafluorobutane, Z-2-chloro-1,1,1,4,4,4-hexafluorobutene, E-2-chloro-1,1,1,4,4,4-hexafluorobutene, HCFO-1335, Z There are compositions that include - and E-1,1,1,2,4,4,4-heptafluoro-1-butene, 2-chloro-1,1,1,4,4,4-hexafluorobutane, 1,1,1-trifluoroethane, 1,1,1,3,3,3-hexafluoropropane, 2-chloro-3,3,3-trifluoropropene, chloroheptafluorobutene, tetrachlorochlorotetrafluorobutene, and dichloropentafluorobutene.

[0062] In some embodiments, E-CF3CH=CHCF3(E-1336mzz) is generated with selectivity exceeding 90%, 92%, 94%, 95%, 96%, 97%, 98%, or 99% for Z-1336mzz.

[0063] The process may further include a step of recovering E-1336mzz from the product mixture in order to reduce other components of the product mixture. The process for recovering E-1336mzz may include one or any combination of purification techniques known in the art, such as distillation. By “recovering” E-1336mzz from the product mixture, a product containing at least 98.5%, or at least 99%, or at least 99.5% E-1336mzz is produced.

[0064] In certain embodiments, the process for producing E-1336mzz may further include the steps of recovering 2320az from the product mixture and reusing the recovered 2320az in the fluorination process described herein.

[0065] In certain embodiments, the process for producing E-1336mzz may further include the steps of recovering an incompletely fluorinated product from the product mixture and reusing the recovered incompletely fluorinated product in the fluorination process described herein. An incompletely fluorinated product means fluorinated butanes and butenes having fewer than six fluorine substituents. An example of an incompletely fluorinated product is HCFO-1335 (chloropentafluorobutene, C4H2F5Cl).

[0066] In some embodiments, the process for producing E-1336mzz includes (a) contacting trichloroethylene in the presence of a dimerization catalyst to produce a product mixture containing 2320az, and (b) contacting the 2320az produced in step (a) with hydrogen fluoride in the gas phase in the presence of a fluorination catalyst to produce a product mixture containing E-1336mzz. Optionally, 2320az is recovered after step (a) and before step (b).

[0067] In some embodiments, the process for producing E-1336mzz includes (a) contacting trichloroethylene in the presence of a dimerizing catalyst and pentachloroethane to produce a product mixture containing 2320az, and (b) contacting the 2320az produced in step (a) with hydrogen fluoride in the gas phase in the presence of a fluorinating catalyst to produce a product mixture containing E-1336mzz. Optionally, 2320az is recovered after step (a) and before step (b).

[0068] Modifications of the process elements in steps (a) and (b) are disclosed herein above. The purity of 2320az is typically at least 97% before proceeding to step (b).

[0069] In some embodiments, the product mixture of step (a) containing 2320az undergoes a recovery step before step (b). In some embodiments, 2320az is recovered from the product mixture of step (a). Techniques for recovering 2320az from the product mixture include distillation and other techniques known to those skilled in the art.

[0070] In some embodiments, the conversion rate of TCE is less than 100%, and unreacted TCE is present in the product mixture of step (a). In some embodiments, the process further includes, between step (a) and step (b), step (a') of recovering unreacted TCE from the product mixture of step (a), and step (a") of reusing the recovered TCE in step (a). Techniques for recovering TCE from the product mixture of step (a) include distillation and other techniques known to those skilled in the art.

[0071] In some embodiments, the process further includes (c) contacting E-1336mzz with a chlorine source to produce a product mixture containing 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane (CF3CHClCHClCF3, HCFC-336mdd); (d) contacting 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane with a base to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3); and (e) contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen to produce a product mixture containing Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0072] Process steps (c), (d), and (e) may be carried out as described in International Publication No. 2015 / 142981.

[0073] Generation of HCFC-336mdd The reaction of E-1336mzz with a chlorine source to produce a product mixture containing 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane (CF3CHClCHClCF3, HCFC-336mdd) is a chlorination process in which a chlorine source is reacted with E-1336mzz to produce a product mixture containing the desired HCFC-336mdd product. This process may be carried out in the liquid phase or gas phase of a liquid medium, respectively, preferably in the presence of a chlorination catalyst or using photoinitiation. An example of a liquid medium is the E-1336mzz reactant itself.

[0074] Photoinitiation is carried out in a suitable photoinitiation apparatus including a light source, a chlorine (Cl2) source, and E-1336mzz (the material to be chlorinated), as described, for example, in International Publication No. 2006 / 069108(A1).

[0075] Suitable chlorination catalysts include Lewis acids such as transition metal chlorides or aluminum chloride.

[0076] The catalyst for this chlorination process in the liquid phase may be selected from ferric chloride, chromium chloride, alumina chloride, cupric chloride, and combinations of two or more of these. The catalyst for this chlorination process in the gas phase may be selected from ferric chloride, chromium chloride, alumina chloride, cupric chloride, and combinations of two or more of these supported on carbon.

[0077] The temperature and pressure conditions of the chlorination process are preferably selected to be effective in producing HCFC-336mdd with high selectivity. In carrying out the process in a liquid phase, such as supplied by E-1336mzz, the process is preferably carried out in a closed pressurized reactor where the internal pressure is sufficient to maintain the liquid state. The pressure inside the reactor may be self-pressure or high pressure. When the process is carried out in a liquid medium, the desired product HCFC-336mdd can be recovered from the reactor by purging unreacted chlorine and distilling off unreacted E-1336mzz. If the catalyst is present in a sufficiently high concentration from the product mixture before, during, or after distillation to precipitate, the catalyst can be filtered. Alternatively, the catalyst may remain in the distillation heel.

[0078] The process may be carried out in a vapor state (phase) using a tubular reactor. A chlorination catalyst, such as a Lewis acid, may be positioned in the reactor for effective contact with the chlorine source and E-1336mzz, which are simultaneously supplied to the reactor at a temperature and residence time effective for producing the desired HCFC-336mdd reaction product with the desired selectivity. The temperature of the chlorination process is maintained by applying heat to the reactor. Preferably, the process temperature is in the range of 100°C to 200°C. The pressure inside the tubular reactor is preferably about 0.1 to 1 MPa. HCFC-336mdd may be recovered from this product mixture by distillation.

[0079] The chlorine source can be selected from chlorine, N-chlorosuccinimide, t-butyl hypochlorite, oxalyl chloride, and sulfuryl chloride.

[0080] In one embodiment, the reaction of E-1336mzz with a chlorine source is carried out in the presence of a chlorination catalyst, and the chlorine source is chlorine (Cl2). In another embodiment, the reaction of E-1336mzz with a chlorine source is carried out in the absence of a chlorination catalyst, and the chlorine source is chlorine (Cl2).

[0081] In one embodiment, the reaction of E-1336mzz with a chlorine source is carried out using photoinitiation in the presence of ultraviolet irradiation, and the chlorine source is chlorine.

[0082] In one embodiment, the reaction of E-1336mzz with a chlorine source is carried out in the absence of a chlorination catalyst, and the chlorine source is N-chlorosuccinimide, t-butyl hypochlorite, oxalyl chloride, or sulfuryl chloride.

[0083] The process may further include a step of recovering HCFC-336mdd from the product mixture to reduce other components of the product mixture. The process for recovering HCFC-336mdd may include one or any combination of purification techniques known in the art, such as distillation. By “recovering” HCFC-336mdd from the product mixture, a product containing at least 98.5%, or at least 99%, or at least 99.5% HCFC-336mdd is produced. In some embodiments, E-1336mzz may be recovered and reused in the process or used for another purpose.

[0084] The chlorination of E-1336mzz preferably provides a selectivity for HCFC-336mdd of at least 85%, more preferably at least 90%, and most preferably at least 95%, regardless of whether the reaction is carried out in the liquid phase or the gas phase.

[0085] The product mixture containing 336mdd may further contain one or more of HCFC-336mfa (2,2-dichloro-1,1,1,4,4,4-hexafluorobutane, CF3CCl2CH2CF3) and HCFC-326mda (2,3,3-trichloro-1,1,1,4,4,4-trifluoropropane, CF3CHClCCl2CF3), which can be recovered from the product mixture. Alternatively, HCFC-336mfa and / or HCFC-326mda may be retained in the product mixture and carried over to a subsequent step for producing hexafluoro-2-butyne.

[0086] In certain embodiments, the process for producing 336mdd may further include the steps of recovering unconverted E-1336mzz from the chlorination product mixture and reusing the recovered E-1336mzz in the chlorination process described herein.

[0087] In some embodiments, unconverted E-1336mzz is recovered from the product mixture. In some embodiments, E-1336mzz may be used for other purposes, such as a foaming agent or a heat transfer fluid.

[0088] Formation of 1,1,1,4,4,4-hexafluoro-2-butyne This disclosure further provides a process comprising the step of contacting HCFC-336mdd with a base in a dehydrochlorination reaction to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3). The base is preferably a basic aqueous medium. This reaction step is preferably carried out in the presence of a catalyst. Preferably, the basic aqueous medium contains an aqueous solution of an alkali metal hydroxide or alkali metal halide salt or another base. Preferably, the catalyst is a phase-transfer catalyst. As used herein, a phase-transfer catalyst is intended to mean a substance that facilitates the transfer of ionic compounds between an organic phase and an aqueous phase. In this step, the organic phase contains the HCFC-336mdd reactant, and the aqueous phase contains a basic aqueous medium. The phase-transfer catalyst facilitates the reaction of these dissimilar and incompatible components.

[0089] While various phase transfer catalysts can function in various ways, their mechanisms of action do not limit their usefulness in this invention, as long as they promote the dehydrochlorination reaction.

[0090] A preferred phase transfer catalyst is a quaternary alkylammonium salt. In some embodiments, at least one alkyl group of the quaternary alkylammonium salt contains at least eight carbon atoms. An example of a quaternary alkylammonium salt in which three alkyl groups contain at least eight carbon atoms is trioctylmethylammonium chloride. Aliquat® 336 is a commercially available phase transfer catalyst containing trioctylmethylammonium chloride. An example of a quaternary alkylammonium salt in which four alkyl groups contain at least eight carbon atoms is tetraoctylammonium salt. The anion of such a salt may be a halide such as a chloride or bromide, hydrogen sulfate, or any other commonly used anion. Specific quaternary alkylammonium salts include tetraoctylammonium chloride, tetraoctylammonium hydrogen sulfate, tetraoctylammonium bromide, methyltrioctylammonium chloride, methyltrioctylammonium bromide, tetradecylammonium chloride, tetradecylammonium bromide, and tetradodecylammonium chloride. According to such embodiments, the phase transfer catalyst and reaction conditions are preferably effective in achieving a conversion rate of at least 50% of HCFC-336mdd per hour.

[0091] In other embodiments, the alkyl group of the quaternary alkylammonium salt contains 4 to 10 carbon atoms, and a nonionic surfactant is present in an aqueous basic medium. According to such embodiments, the phase transfer catalyst and reaction conditions are preferably effective in achieving a conversion rate of at least 20% of HCFC-336mdd per hour. The anion of the quaternary alkylammonium salt containing 4 to 10 carbon atoms in the alkyl group may be a halide such as a chloride or bromide, hydrogen sulfate, or any other commonly used anion. The above quaternary alkylammonium salts can be used in this embodiment as long as these alkyl groups contain 4 to 10 carbon atoms. Specific additional salts include tetrabutylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium bisulfate.

[0092] Preferred nonionic surfactants include ethoxylated nonylphenol or ethoxylated C 12 ~C 15 Examples include linear aliphatic alcohols. Examples of nonionic surfactants include Bio-soft® N25-9 and Makon® 10, which are available from Stepan Company (Northfield, IL) and are useful in this invention.

[0093] In some embodiments, the quaternary alkylammonium salt is added in an amount of 0.5 to 2 mole percent of HCFC-336mdd. In other embodiments, the quaternary alkylammonium salt is added in an amount of 1 to 2 mole percent of HCFC-336mdd. In yet another embodiment, the quaternary alkylammonium salt is added in an amount of 1 to 1.5 mole percent of HCFC-336mdd. In some embodiments, the quaternary alkylammonium salt is added in an amount of 1 to 1.5 mole percent of HCFC-336mdd, and the weight of the nonionic surfactant added is 1 to 2 times the weight of the quaternary alkylammonium salt. These amounts apply to each of the above embodiments of the quaternary alkylammonium salt used.

[0094] In some embodiments, the reaction is carried out at a temperature of about 60-90°C, most preferably 70°C.

[0095] A basic aqueous medium is a liquid (whether it is a solution, dispersion, emulsion, or suspension, etc.) that is primarily an aqueous liquid with a pH greater than 7. In some embodiments, the basic aqueous solution has a pH greater than 8. In some embodiments, the basic aqueous solution has a pH greater than 10. In some embodiments, the basic aqueous solution has a pH between 10 and 13. In some embodiments, the basic aqueous solution contains a small amount of an organic liquid that may be miscible or immiscible with water. In some embodiments, the liquid in the basic aqueous solution is at least 90% water. In some embodiments, the water is tap water, and in other embodiments, the water is deionized water or distilled water.

[0096] The base is selected from alkali metals, alkaline earth metals, and hydroxides, oxides, carbonates, or phosphates of mixtures thereof. In some embodiments, the base is selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, trisodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, and mixtures thereof.

[0097] These embodiments of the basic aqueous medium and base are applicable to all of the above-described phase transition catalysts, amounts, and reaction conditions. The selectivity for the formation of 1,1,1,4,4,4-hexafluoro-2-butyne is preferably at least 85%.

[0098] In some embodiments, the dehydrochlorination of 336 mdd to 1,1,1,4,4,4-hexafluoro-2-butyne is carried out in the presence of an alkali metal halide salt. The alkali metal may be sodium or potassium. The halide may be a chloride or bromide. A preferred alkali metal halide salt is sodium chloride. Although not bound by any particular theory, alkali metal halide salts are thought to stabilize the phase transfer catalyst. The dehydrochlorination reaction itself produces alkali metal chlorides, particularly sodium chloride when sodium hydroxide is used as the base, but the addition of additional sodium chloride yields the further effect of increasing the yield of 1,1,1,4,4,4-hexafluoro-2-butyne. In some embodiments, the alkali metal halide is added at about 25 to about 100 equivalents per mole of phase transfer catalyst. In other embodiments, the alkali metal halide is added at about 30 to about 75 equivalents per mole of phase transfer catalyst. In yet another embodiment, alkali metal halides are added in an amount of about 40 to 60 equivalents per mole of the phase transfer catalyst. These amounts apply to each of the quaternary alkylammonium salts described above.

[0099] The product 1,1,1,4,4,4-hexafluoro-2-butyne (boiling point -25°C) can be recovered from the product mixture by distillation, in which case the butyne can be evaporated from the aqueous medium and then condensed. Furthermore, the product mixture may also contain 1,1,1,4,4,4-hexafluoro-2-chloro-2-butene (HCFO-1326, Z isomer, E isomer, or a mixture thereof), which can be separated from the product mixture and reused in a process step that includes contacting HCFC-336mdd with a base in a dehydrochlorination reaction to produce a product mixture containing CF3C≡CCF3.

[0100] Formation of Z-1,1,1,4,4,4-hexafluoro-2-butene The disclosure further provides a hydrogenation process comprising the step of contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen to produce a product mixture containing Z-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz). This process is preferably carried out in the presence of a catalyst for converting alkynes to alkenes.

[0101] In some embodiments, the hydrogenation of 1,1,1,4,4,4-hexafluoro-2-butyne is carried out as a batch process in the liquid phase.

[0102] In some embodiments, the hydrogenation of 1,1,1,4,4,4-hexafluoro-2-butyne is carried out as a continuous process in the gas phase.

[0103] In some embodiments, the catalyst for converting alkynes to alkenes is a palladium catalyst, such as palladium dispersed on aluminum oxide or titanium silicate, doped with silver and / or lanthanide. The amount of palladium dispersed on the aluminum oxide or titanium silicate is relatively low. In some embodiments, the amount of palladium is about 100 ppm to about 5000 ppm. In other embodiments, the amount of palladium is about 200 ppm to about 5000 ppm. In some embodiments, the palladium catalyst is doped with at least one of silver, cerium, or lanthanum. In some embodiments, the molar ratio of cerium or lanthanum to palladium is about 2:1 to about 3:1. In some embodiments, the molar ratio of silver to palladium is about 0.5:1.0.

[0104] Another embodiment of the alkyne-to-alkane catalyst is the Lindler catalyst, which is a heterogeneous palladium catalyst supported on a calcium carbonate carrier, inactivated or conditioned with a lead compound. The lead compound may be lead acetate, lead oxide, or any other suitable lead compound. In some embodiments, the catalyst is produced by reducing a palladium salt in the presence of a calcium carbonate slurry, followed by the addition of a lead compound. In some embodiments, the palladium salt is in palladium chloride.

[0105] In other embodiments, the Lindler catalyst is further inactivated or conditioned with quinoline. The amount of palladium supported on the support is typically about 5% by weight, but may be any catalytically effective amount. In other embodiments, the amount of palladium supported on the support in the Lindler catalyst is greater than 5% by weight. In yet another embodiment, the amount of palladium supported on the support may be about 5% to about 1% by weight.

[0106] In some embodiments, the amount of catalyst used is about 0.5% to about 4% by weight of the amount of 1,1,1,4,4,4-hexafluoro-2-butyne. In other embodiments, the amount of catalyst used is about 1% to about 3% by weight of the amount of butyne. In yet another embodiment, the amount of catalyst used is about 1% to about 2% by weight of the amount of butyne.

[0107] In some embodiments, this reaction step is a batch reaction carried out in the presence of a solvent. In one such embodiment, the solvent is an alcohol. Typical alcoholic solvents include ethanol, i-propanol, and n-propanol. In other embodiments, the solvent is a fluorocarbon or hydrofluorocarbon. Typical fluorocarbons or hydrofluorocarbons include 1,1,1,2,2,3,4,5,5,5-decafluoropentane and 1,1,2,2,3,3,4-heptafluorocyclopentane.

[0108] In some embodiments, the reaction of 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen is preferably carried out with the addition of hydrogen in small increments, such that each addition does not increase the pressure in the container by more than about 100 psi (0.69 MPa). In other embodiments, the addition of hydrogen is controlled so that each addition does not increase the pressure in the container by more than about 50 psi (0.35 MPa). In some embodiments, after sufficient hydrogen has been consumed in the hydrogenation reaction and at least 50% of the butyne has been converted to Z-1336mzz, hydrogen can be added to the reaction residue in larger increments. In other embodiments, after sufficient hydrogen has been consumed in the hydrogenation reaction and at least 60% of the butyne has been converted to the desired butene, hydrogen can be added to the reaction residue in larger increments. In yet another embodiment, after sufficient hydrogen has been consumed in the hydrogenation reaction and at least 70% of the butyne has been converted to the desired butene, hydrogen can be added to the reaction residue in larger increments. In some embodiments, a larger increment of hydrogenation may be 300 psi (2.07 MPa). In other embodiments, a larger increment of hydrogenation may be 400 psi (2.76 MPa).

[0109] In some embodiments, the molar ratio is about 1 mole of hydrogen for about 1 mole of 1,1,1,4,4,4-hexafluoro-2-butyne. In other embodiments, the molar ratio of hydrogen to butyne is about 0.9 moles to about 1.3 moles. In yet another embodiment, the amount of hydrogen added is about 0.95 moles of hydrogen for about 1.1 moles of butyne. In yet another embodiment, the amount of hydrogen added is about 0.95 moles of hydrogen for about 1.03 moles of butyne.

[0110] In some embodiments, hydrogenation is carried out at ambient temperature (15°C to 25°C). In other embodiments, hydrogenation is carried out at a temperature higher than the ambient temperature. In yet another embodiment, hydrogenation is carried out at a temperature lower than the ambient temperature. In yet another embodiment, hydrogenation is carried out at a temperature lower than approximately 0°C.

[0111] In the continuous process embodiment, a mixture of 1,1,1,4,4,4-hexafluoro-2-butyne and hydrogen is passed through a reaction zone containing a catalyst. A reaction vessel, such as a metal tube, may be used and filled with the catalyst to form the reaction zone. In some embodiments, the molar ratio of hydrogen to butyne is about 1:1. In other embodiments of the continuous process, the molar ratio of hydrogen to butyne is less than 1:1. In yet another embodiment, the molar ratio of hydrogen to butyne is about 0.67:1.0.

[0112] In some embodiments of the continuous process, the reaction zone is maintained at ambient temperature. In another embodiment of the continuous process, the reaction zone is maintained at a temperature of 30°C. In yet another embodiment of the continuous process, the reaction zone is maintained at a temperature of approximately 40°C.

[0113] In some embodiments of the continuous process, the flow rates of 1,1,1,4,4,4-hexafluoro-2-butyne and hydrogen are maintained so that the residence time in the reaction zone is approximately 30 seconds. In other embodiments of the continuous process, the flow rates of butyne and hydrogen are maintained so that the residence time in the reaction zone is approximately 15 seconds. In yet another embodiment of the continuous process, the flow rates of butyne and hydrogen are maintained so that the residence time in the reaction zone is approximately 7 seconds.

[0114] It is understood that increasing the flow rate of 1,1,1,4,4,4-hexafluoro-2-butyne and hydrogen into the reaction zone shortens the residence time in the reaction zone. As the flow rate increases, the amount of butyne hydrogenated per unit time increases. Since hydrogenation is exothermic, at higher flow rates, it may be desirable to provide an external cooling source in the reaction zone to maintain the desired temperature, depending on the length and diameter of the reaction zone and its heat dissipation capacity.

[0115] The conditions of the contact step, including the selection of the catalyst, are preferably selected to produce Z-1336mzz with a selectivity of at least 85%, more preferably at least 90%, and most preferably at least 95%.

[0116] In some embodiments, Z-1336mzz can be recovered at the completion of a batch or continuous isomerization process through any conventional process, such as fractional distillation. Unconverted hexafluoro-2-butyne may be recovered and reused in the hydrogenation process. In other embodiments, at the completion of a batch or continuous hydrogenation process, Z-1336mzz is of sufficient purity to not require further purification steps. [Examples]

[0117] material Trichloroethylene, ferric chloride, chromium chloride, alumina chloride, cupric chloride, chlorine, pentachloroethane (HCC-120), octylmethylammonium chloride (Aliquat® 336), NaOH, Lindler catalyst, K2HPO4, and KH2PO4 are available from Sigma Aldrich (St. Louis, MO). Hydrogen fluoride and E-1,1,1,4,4,4-hexafluoro-2-butene are available from Synquest Labs, Inc. (Alachua, FL).

[0118] GC analysis of Examples 1-4 was performed using Agilent® 5975GC and RESTEK Rtx-1 columns.

[0119] Example 1: Preparation of 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az) Trichloroethylene (100 g, 0.76 mol) was added to a shaker tube containing 30 mg of anhydrous FeCl3. The reaction mixture was heated at 230°C for 2 hours. The contents of the reactor were cooled to room temperature and analyzed by GC to determine the conversion and selectivity. The results are shown in Table 1.

[0120] Example 2: Preparation of 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az) Trichloroethylene (100 g, 0.76 mol) was added to a shaker tube containing 1 g of iron wire. The reaction mixture was heated at 230°C for 2 hours. The contents of the reactor were cooled to room temperature and analyzed by GC to determine the conversion and selectivity. The results are shown in Table 1.

[0121] Example 3: Preparation of 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az) Trichloroethylene (100 g, 0.76 mol) was added to a shaker tube containing 20 mg of anhydrous FeCl3 and 1 g of HCC-120. The reaction mixture was heated at 230°C for 2 hours. The contents of the reactor were cooled to room temperature and analyzed by GC to determine the conversion and selectivity. The results are shown in Table 1.

[0122] Example 4: Preparation of 1,1,2,4,4-pentachlorobuta-1,3-diene (HCC-2320az) Trichloroethylene (100 g, 0.76 mol) was added to a shaker tube containing 1 g of iron wire and 1 g of HCC-120. The reaction mixture was heated at 230°C for 2 hours. The contents of the reactor were cooled to room temperature and analyzed by GC to determine the conversion and selectivity. The results are shown in Table 1.

[0123] [Table 1]

[0124] As can be seen from Table 1, when FeCl3 or Fe-ray catalyst is used, the presence of HCC-120 increases the conversion rate of trichloroethylene to 2320 az.

[0125] Example 5: Preparation of E-1,1,1,4,4,4-hexafluoro-2-butene An Inconel® tube (OD 0.5 inch, length 15 inch, wall thickness 0.34 inch) was packed with 12 cc (16.35 g) of chromium oxide catalyst. The reactor was heated to 275°C in a Lindbergh furnace, and 2320 az (prepared according to the above example) was supplied at 0.09 mL / hour, while HF gas was supplied at 5.3 sccm (standard cubic centimeters / min) through a vaporizer controlled at 200°C. During operation, the temperature was increased to 325°C. All sample experiments were performed at 1–2 psig (7–14 kPa). Reactor effluent was analyzed online using Agilent® 6890 GC / 5973 MS and Restek® PC2618 5% Krytox® CBK-D / 60 / 80 6 m × 2 mm ID 1 / 8” OD packed columns purged with 30 sccm of helium. Operating conditions are provided in Table 2. Samples were taken at 1-hour intervals. Sample analysis results are provided in Table 3.

[0126] [Table 2]

[0127] [Table 3] * Other compounds include 1327mz (Z and E isomers of 1,1,1,2,4,4,4-heptafluoro-1-butene), 346mdf (1,1,1,4,4,4-hexafluorobutane), 143a (1,1,1-trifluoroethane), 236fa (1,1,1,3,3,3-hexafluoropropane), 1233xf (2-chloro-3,3,3-trifluoropropene), 1317 (chloroheptafluorobutene), 1314 (tetrachlorochlorotetrafluorobutene), and 1325 (dichloropentafluorobutene).

[0128] Example 6: Liquid phase preparation of 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane (HCFC-336mdd) In this embodiment, E-1336mzz is catalytically and thermally chlorinated in the liquid phase to produce HCFC-336mdd. A Lewis acid catalyst is used.

[0129] A liquid-phase reaction was carried out in a Hastelloy® C reactor. The liquid medium was the E-1336mzz reactant. When used, the catalyst was present in the liquid phase. The contents of the reactor were transferred to a cylinder and analyzed by GC to determine the conversion and selectivity. HCFC-336mdd was recovered from the reaction by purging unreacted chlorine, distilling off unreacted E-1336mzz, and filtering out the catalyst. The reaction conditions and results are shown in Table 4.

[0130] [Table 4]

[0131] For each of Examples 6-1 to 6-6, E-1336mzz (20 g, 0.122 mol) and chlorine (8.65 g, 0.122 mol) were heated to a specified temperature in a Hastelloy® C reactor for a specified time in the presence of FeCl3, CrCl3, AlCl3, or CuCl2 catalyst (0.4 g, 0.0025 mol). The specified temperatures and times are provided in Table 4.

[0132] For Examples 6-7 and 6-8, E-1336mzz (20 g, 0.122 mol) and chlorine (8.65 g, 0.122 mol) were heated in a 210 mL Hastelloy® C reactor for 2 hours to the temperature specified in Table 2. No catalyst was present.

[0133] A comparison of the results from Examples 6-1 to 6-8 indicates a preference for reactions carried out in the presence of a catalyst and at a temperature of at least 130°C or at least 150°C.

[0134] Example 7: Vapor phase preparation of 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane (HCFC-336mdd) The gas-phase reaction procedure was as follows: Inconel® tubing (OD 0.5 inch, length 15 inch, wall thickness 0.34 inch) was filled with 2 cc (1.10 gm) of ferric chloride on acid-washed Takeda® carbon. The reactor was heated to 125°C in a Lindbergh furnace, and CF3CH=CHCF3 (E-1336 mzz) was supplied at 2.42–4.83 mL / hour, while chlorine gas was supplied at 6.2–13.0 sccm (standard cubic centimeters / min) through a vaporizer controlled at 80°C. During operation, the temperature was increased to 175°C. All subsequent experiments were performed at 49–51 psig (0.34–0.35 MPa). Reactor effluent was analyzed online using Agilent® 6890 GC / 5973 MS and Restek® PC2618 5% Krytox® CBK-D / 60 / 80 6 m × 2 mm ID 1 / 8” OD packed columns purged with 30 sccm of helium. HCFC-336 mdd was recovered by distillation.

[0135] The data is shown in Table 5. Samples were collected at one-hour intervals.

[0136] [Table 5]

[0137] In Table 5, 236fa (HFC-236fa, 1,1,1,3,3,3-hexafluoropropane) and 123 (HCFC-123, 2,2-dichloro-1,1,1-trifluoroethane) are impurities in the feed to the reactor.

[0138] The reaction conditions resulting from a reactor temperature of 175°C and a contact time of 27-29 seconds yield the best selectivity for the production of HCFC-336mdd.

[0139] Example 8: Preparation of 1,1,1,4,4,4-hexafluorobutane (HCFC-336mdd) In this embodiment, the reaction is photoinitiated.

[0140] The 50-gallon (190 L) stirred reaction vessel consisted of a column with a cooling jacket, an overhead condenser, an immersion tube, and a quartz lightwell. The lightwell was fitted with a 450-watt mercury arc lamp.

[0141] The reactor was filled with 158 kg of E-1336 mzz, and the liquid was cooled to 0°C. The stirrer was operated at 100 rpm, the overhead condenser was cooled to approximately -20°C, and the lights were turned on. 69 kg of chlorine was slowly added to this system over 51 hours through immersion tubes, using a feed rate controlled for temperature and pressure. The temperature and pressure of the liquid reaction were kept below 10°C and 1 psig (0.07 MPa), respectively.

[0142] After chlorine addition was complete, the lights were turned off and the solution was heated to room temperature. The system was evacuated to the surroundings through a caustic scrubber and the crude reaction mixture was de-invented into a storage container. Three batches of the resulting crude reaction mixture (663 kg / 422 L) were combined, and then the crude reaction mixture was slowly added through an immersion tube to a 200-gallon (750 L) stirring vessel equipped with a bottom discharge valve. HCFC-336mdd was recovered by filling with 80-gallon (300 L) of 10% K2HPO4 / KH2PO4 aqueous solution. After the addition, the mixture was vigorously stirred for 3 hours, and then the stirring was stopped. The lower organic phase was then decanted from the reactor to determine the phase change using conductivity measurement. The resulting neutralized organic oil was a water-white liquid with a pH of 5-6. The oil was dried by passing it through a molecular sieve bed and stored for final purification. The yield of isolated chemicals across 7 batches was 98%. The resulting GC assay (%FID) was 93.5% of the combination of two 336mdd diastereomers, with the remainder of the assay being approximately 6% heavy unknown substances presumed to be oligomers of the product / starting material, resulting in a reaction selectivity of 93.5%. Final purification was performed by distillation.

[0143] Example 9.1,1,1,4,4,4-Hexafluoro-2-butyne HCFC-336mdd was produced using the gas-phase process described in Example 7 according to the specific information in Table 4, and a selectivity of 99.4% for HCFC-336mdd was obtained.

[0144] At room temperature, in the presence of Aliquat® 336 trioctylmethylammonium chloride (0.53 g, 0.001325 mol), HCFC-336mdd (23.5 g, 0.1 mol) and water (5.6 mL) were mixed with an aqueous NaOH solution (22 mL, 0.22 mol). After addition, the reaction temperature was raised to 70°C, and the reaction was monitored using gas chromatography. The reaction was completed after 2 hours, and 14 g of 1,1,1,4,4,4-hexafluoro-2-butyne product (conversion: 100%; yield: 86%) was recovered using a dry eye trap. Butyne was purified by distillation.

[0145] Example 10: Preparation of Z-1,1,1,4,4,4-hexafluoro-2-butene The desired Z isomer of 1,1,1,4,4,4-hexafluoro-2-butyne was produced by reacting 1,1,1,4,4,4-hexafluoro-2-butene with hydrogen using the following procedure: 5 g of Lindlar (5% Pd supported on lead-poisoned CaCO3) catalyst was packed into a 1.3 L rocker bomb. 480 g (2.96 mol) of hexafluoro-2-butyne was added to the rocker. The reactor was cooled (-78°C) and evacuated. After warming the bomb to room temperature, H2 was slowly added in increments not exceeding Δp = 50 psi (0.35 MPa). A total of 3 mol of H2 was added to the reactor. Gas chromatography analysis of the crude product revealed that the mixture consisted of CF3C≡CCF3 (0.236%), the trans isomer E-CF3CH=CHCF3 (0.444%), saturated CF3CH2CH2CF3 (1.9%)CF2=CHCl, impurities derived from the starting butyne (0.628%), and the cis isomer Z-CF3CH=CHCF3 (96.748%).

[0146] Distillation of the crude product yielded 287 g (59% yield) of 100% pure cis-CF3CH=CHCF3 (boiling point 33.3°C). MS: 164[MI], 145[M-19], 95[CF3CH=CH], 69[CF3]. NMR 1 H: 6.12 ppm (multiplet) 19 F: -60.9 ppm (triplet J = 0.86 Hz). The selectivity of this reaction for the formation of the Z isomer was 96.98%. The Z isomer was recovered by distillation.

[0147] Other Embodiments 1. In some embodiments, the present disclosure provides a fluorination process for producing E-1,1,1,4,4,4-hexafluorobuta-2-ene, comprising the step of contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with hydrogen fluoride in a reaction zone in the gas phase in the presence of a fluorination catalyst to produce a product mixture containing E-1,1,1,4,4,4-hexafluorobuta-2-ene. 2. In some embodiments, the fluorination catalyst is selected from carbon; graphite; alumina; fluorinated alumina; aluminum fluoride; alumina supported on carbon; aluminum fluoride supported on carbon; fluorinated alumina; magnesium fluoride supported on aluminum fluoride; metals (including elemental metals, metal oxides, metal halides, and / or other metal salts); metals supported on aluminum fluoride; metals supported on fluorinated alumina; metals supported on alumina; and metals supported on carbon; and mixtures of metals. 3. The process according to Embodiment 1 or 2, wherein HF is added in an amount of 10 to 30 moles per mole of 1,1,2,4,4-pentachlorobuta-1,3-diene. 4. The process according to Embodiment 1, 2, or 3, carried out at a temperature in the range of 300 to 350°C. The process according to Embodiment 1, 2, 3, or 4, carried out at a pressure in the range of 5.0 to 200 psi (0 to 1.4 MPa). 6. The process according to Embodiment 1, 2, 3, 4, or 5, wherein the fluorination catalyst contains a metal. 7. The process according to Embodiment 6, wherein the metal is supported on aluminum fluoride, alumina fluoride, or carbon. 8. The process according to Embodiment 1, 2, 3, 4, or 5, wherein the fluorination catalyst is a chromium-based catalyst. 9. The process according to Embodiment 8, wherein the fluorination catalyst comprises chromium oxyfluoride or chromium oxide. 10. The process according to Embodiment 9, wherein a fluorinating catalyst is supported. 11. The process according to Embodiment 9, wherein the fluorination catalyst is supported on a carrier selected from activated carbon, graphite, fluorinated graphite, and fluorinated alumina. 12. The process according to Embodiment 9, wherein the fluorinating catalyst is not supported. 13. The process according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein HF is added in an amount of 10 to 30 moles per mole of 1,1,2,4,4-pentachlorobuta-1,3-diene. 14. The process according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 13, carried out at a temperature in the range of 300 to 350°C. 15. The process according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 13, or 14, further comprising the step of producing 1,1,2,4,4-pentachlorobuta-1,3-diene by contacting trichloroethylene with an iron-containing dimerization catalyst to produce a product mixture containing 1,1,2,4,4-pentachlorobuta-1,3-diene. 16. The process according to Embodiment 15, wherein trichloroethylene is contacted with an iron-containing dimerization catalyst and pentachloroethane. 17. In some embodiments, the present disclosure is a process for producing E-1,1,1,4,4,4-hexafluoro-2-butene, the process is (a) A step of producing 1,1,2,4,4-pentachlorobuta-1,3-diene by contacting trichloroethylene with a dimerization catalyst to produce a product mixture containing 1,1,2,4,4-pentachlorobuta-1,3-diene, (b) A process is provided which includes the step of contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with HF in the presence of a chromium oxyfluoride catalyst to produce a product containing E-1,1,1,4,4,4-hexafluorobuta-2-ene, wherein the process is a gas-phase process. 18. In some embodiments, the present disclosure is a process for producing E-1,1,1,4,4,4-hexafluoro-2-butene, the process is (c) A step of producing 1,1,2,4,4-pentachlorobuta-1,3-diene by contacting trichloroethylene with a dimerization catalyst and pentachloroethane to produce a product mixture containing 1,1,2,4,4-pentachlorobuta-1,3-diene, (d) A process is provided which includes the step of contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with HF in the presence of a chromium oxyfluoride catalyst to produce a product containing E-1,1,1,4,4,4-hexafluorobuta-2-ene, wherein the process is a gas-phase process. 19. The process according to Embodiment 17 or 18, further comprising step (a') between step (a) and step (b), which includes recovering unreacted trichloroethylene from the product mixture of step (a). 20. The process according to Embodiment 17 or 18, further comprising, between step (a) and step (b), step (a') of recovering unreacted trichloroethylene from the product mixture of step (a), and step (a") of reusing the recovered trichloroethylene in step (a). 21. The process according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, or 20, further comprising the steps of recovering E-1,1,1,4,4,4-hexafluorobuta-2-ene from the product mixture in order to reduce other components of the product mixture, and / or purifying the product mixture containing E-1,1,1,4,4,4-hexafluorobuta-2-ene. 22. In some embodiments, the present disclosure provides a process for producing 1,1,2,4,4-pentachlorobuta-1,3-diene, comprising the step of contacting trichloroethylene with a dimer catalyst comprising pentachloroethane and iron to produce a product mixture comprising 1,1,2,4,4-pentachlorobuta-1,3-diene. 23. In some embodiments, the present disclosure is a process for producing Z-1,1,1,4,4,4-hexafluorobuta-2-ene, (a) A step of producing 1,1,2,4,4-pentachlorobuta-1,3-diene by contacting trichloroethylene with a dimerization catalyst to produce a product mixture containing 1,1,2,4,4-pentachlorobuta-1,3-diene, (b) A gas-phase process comprising contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with HF in the presence of a fluorination catalyst to produce a product mixture containing E-1,1,1,4,4,4-hexafluoro-2-butene, (c) A step of contacting E-1,1,1,4,4,4-hexafluoro-2-butene with a chlorine source to produce a product mixture containing 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane, (d) A step of contacting 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane with a base to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne, (e) A process is provided comprising the step of contacting 1,1,1,4,4,4-hexafluoro-2-butyne with H2 to produce a product mixture containing Z-1,1,1,4,4,4-hexafluorobuta-2-ene. 24. The process according to Embodiment 23, further comprising the step of recovering 1,1,2,4,4-pentachlorobuta-1,3-diene from the product mixture of step (a). 25. The process according to Embodiment 23 or 24, further comprising the step of recovering trichloroethylene from the product mixture of step (a). 26. The process according to Embodiment 23, 24, or 25, further comprising the step of recovering E-1,1,1,4,4,4-hexafluoro-2-butene from the product mixture of step (b). 27. The process according to Embodiments 23, 24, 25, or 26, further comprising the step of recovering 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane from the product mixture of step (c). 28. The process according to Embodiments 23, 24, 25, 26, or 27, further comprising the step of recovering 1,1,1,4,4,4-hexafluoro-2-butyne from the product mixture of step (d). 29. The process according to Embodiments 23, 24, 25, 26, 27, or 28, further comprising the step of recovering Z-1,1,1,4,4,4-hexafluoro-2-butene from the product mixture of step (e). 30. In some embodiments, the present disclosure provides a product mixture comprising E-1336mzz, Z-1336mzz (cis-CF3CH=CHCF3), HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), and one or more of HFC-356mff (1,1,1,4,4,4-hexafluorobutane, or CF3CH2CH2CF3), Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), HCFO-1335, and E-HCFO-1326mxz (cis-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3). HCFO-1335 may contain one or more of the following: HCFO-1335mzz(CF3CH=CHCF2Cl), HCFO-1335mzx, (CF3CH=CClCF2H), E-HCFO-1335mzz, Z-HFO1335mzz, E-HCFO-1335mzx, and Z-HCFO-1335mzx. 31. In some embodiments, the present disclosure includes E-1336mzz, Z-1336mzz (cis-CF3CH=CHCF3), HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), HFC-356mff (1,1,1,4,4,4-hexafluorobutane, or CF3CH2CH2CF3), Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), HCFO-1335, E A product mixture is provided which contains two or more of the following: -HCFO-1326mxz (cis-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), wherein HCFO-1335 contains one or more of the following: HCFO-1335mzz (CF3CH=CHCF2Cl), HCFO-1335mzx, (CF3CH=CClCF2H), E-HCFO-1335mzz, Z-HFO1335mzz, E-HCFO-1335mzx, and Z-HCFO-1335mzx. 32. In some embodiments, the present disclosure includes E-1336mzz, Z-1336mzz (cis-CF3CH=CHCF3), HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), HFC-356mff (1,1,1,4,4,4-hexafluorobutane, or CF3CH2CH2CF3), Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), HCFO-1335, E A product mixture is provided which contains three or more of the following: -HCFO-1326mxz (cis-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), wherein HCFO-1335 contains one or more of the following: HCFO-1335mzz (CF3CH=CHCF2Cl), HCFO-1335mzx, (CF3CH=CClCF2H), E-HCFO-1335mzz, Z-HFO1335mzz, E-HCFO-1335mzx, and Z-HCFO-1335mzx. 33. In some embodiments, the present disclosure includes E-1336mzz, Z-1336mzz (cis-CF3CH=CHCF3), HFC-338mf (1,1,1,2,2,4,4,4-octafluorobutane, CF3CH2CF2CF3), HFC-356mff (1,1,1,4,4,4-hexafluorobutane, or CF3CH2CH2CF3), Z-HCFO-1326mxz (trans-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), and HCFO-133 5. A product mixture containing E-HCFO-1326mxz (cis-2-chloro-1,1,1,4,4,4-hexafluorobutene, CF3CCl=CHCF3), wherein HCFO-1335 contains one or more of HCFO-1335mzz (CF3CH=CHCF2Cl), HCFO-1335mzx, (CF3CH=CClCF2H), E-HCFO-1335mzz, Z-HFO1335mzz, E-HCFO-1335mzx, and Z-HCFO-1335mzx. 34. In one embodiment, there exists a composition comprising E-1,1,1,4,4,4-hexafluoro-2-butene, 1,1,1,2,2,4,4,4-octafluorobutane, 1,1,1,4,4,4-hexafluorobutane, and Z-2-chloro-1,1,1,4,4,4-hexafluorobutene. 35. Embodiment 34 further comprises Z-1,1,1,4,4,4-hexafluoro-2-butene, E-2-chloro-1,1,1,4,4,4-hexafluorobutene, and HCFO-1335. 36. Embodiment 35 further comprises a composition containing Z- and E-1,1,1,2,4,4,4-heptafluoro-1-butene, 2-chloro-1,1,1,4,4,4-hexafluorobutane, 1,1,1-trifluoroethane, 1,1,1,3,3,3-hexafluoropropane, 2-chloro-3,3,3-trifluoropropene, chloroheptafluorobutene, tetrachlorochlorotetrafluorobutene, and dichloropentafluorobutene.

[0148] While the present invention has been described in conjunction with its detailed description, it should be understood that the foregoing description is intended to illustrate, and not limit, the scope of the invention as defined by the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims. It should be understood by those skilled in the art that any feature described herein with respect to any particular aspect and / or embodiment of the invention can be combined with one or more other features of any other aspect and / or embodiment of the invention described herein, and can be modified as appropriate to ensure the suitability of the combination. Such combinations are considered to be part of the invention as contemplated by this disclosure.

Claims

1. A process for producing 1,1,2,4,4-pentachlorobuta-1,3-diene, comprising the step of contacting trichloroethylene with pentachloroethane and a dimerization catalyst to produce a product mixture containing 1,1,2,4,4-pentachlorobuta-1,3-diene.

2. A process for producing Z-1,1,1,4,4,4-hexafluorobuta-2-ene, (a) A step of contacting trichloroethylene with a dimerization catalyst to produce a product mixture containing 1,1,2,4,4-pentachlorobuta-1,3-diene, (b) A step in which the process is a gas-phase process, in which 1,1,2,4,4-pentachlorobuta-1,3-diene is contacted with HF in the presence of a fluorination catalyst to produce a product mixture containing E-1,1,1,4,4,4-hexafluoro-2-butene, (c) A step of contacting E-1,1,1,4,4,4-hexafluoro-2-butene with a chlorine source to produce a product mixture containing 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane, (d) A step of contacting 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane with a base to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne, (e) 1,1,1,4,4,4-hexafluoro-2-butyne H 2 A step of bringing it into contact with to produce a product mixture containing Z-1,1,1,4,4,4-hexafluorobuta-2-ene, A process that includes this.

3. The process according to claim 2, further comprising the steps of: recovering 1,1,2,4,4-pentachlorobuta-1,3-diene from the product mixture of step (a); recovering trichloroethylene from the product mixture of step (a); recovering E-1,1,1,4,4,4-hexafluoro-2-butene from the product mixture of step (b); recovering 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane from the product mixture of step (c); recovering 1,1,1,4,4,4-hexafluoro-2-butyne from the product mixture of step (d); or recovering Z-1,1,1,4,4,4-hexafluoro-2-butene from the product mixture of step (e).

4. The process according to claim 2, further comprising: recovering 1,1,2,4,4-pentachlorobuta-1,3-diene from the product mixture of step (a); recovering trichloroethylene from the product mixture of step (a); recovering E-1,1,1,4,4,4-hexafluoro-2-butene from the product mixture of step (b); recovering 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane from the product mixture of step (c); recovering 1,1,1,4,4,4-hexafluoro-2-butyne from the product mixture of step (d); and recovering Z-1,1,1,4,4,4-hexafluoro-2-butene from the product mixture of step (e).

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