(Z)-1,1,1,4,4,4-Hexafluoro-2-butene and a process for producing an intermediate

Abstract

A method for the production of (Z)-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz) is described, utilizing readily available halogenated starting materials, such as 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) and carbon tetrachloride.

Description

Technical Field

[0001] The present disclosure relates to processes used to produce (Z)-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz) and processes used to produce intermediates useful in such production. In particular, the present disclosure relates to a process for producing (Z)-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz) from readily available halogenated alkanes.

Background Art

[0002] The fluorocarbon industry has, over the past few decades, as a result of the Montreal Protocol, been working to find alternative refrigerants for ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that are being phased out. The solution for many applications has been to commercialize hydrofluorocarbon (HFC) compounds for use as refrigerants, solvents, fire extinguishants, blowing agents, and propellants. These new compounds, such as the most widely used HFC refrigerants today, HFC-134a and HFC-125, have an ozone depletion potential of zero and are thus not affected by current regulations that are being phased out as a result of the Montreal Protocol.

[0003] In addition to the problem of ozone depletion, another environmental problem in many of these applications is global warming. Accordingly, there is a need for compositions that meet low ozone depletion standards and have a low global warming potential (GWP). Certain hydrofluoroolefin compositions are thought to meet both of these goals. Accordingly, there is also a need for an economical manufacturing process to provide these compositions.

[0004] (Z)-1,1,1,4,4,4-Hexafluoro-2-butene (Z-1336mzz) is a hydrofluoroolefin having uses in refrigerants, heat transfer compositions, working fluids for thermodynamic cycles (e.g., heating or cooling cycles), aerosol propellants, blowing agents (expanding agents), solvents, cleaning agents, dispersion media, replacement desiccants, buffing abrasives, polymerization media, blowing agents for polyolefins and polyurethanes, gas dielectrics, working fluids for power cycles, fire extinguishing agents, and fire suppressants in liquid or gaseous form. The GWP of cis-HFO-1336mzz is estimated to be less than 10 for a 100-year planning horizon from its lifetime in the atmosphere.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the art, there is a need for a process capable of efficiently and economically producing (Z)-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz).

Means for Solving the Problems

[0006] The present disclosure provides a process for the production of the hydrofluoroolefin Z-1,1,1,4,4,4-hexafluoro-2-butene (Z-CF3CH=CHCF3, Z-1336mzz) and for the production of intermediates useful in its production. The processes described herein provide cost-effective synthetic routes to Z-1336mzz starting from CF3CCl3 and CH2=CCl2 or CCl4 and CF3Cl=CH2.

[0007] In one embodiment, 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane (CCl3CH2 CClA process for producing a product mixture comprising 2CF3, 333jfa) involves contacting an alkane halide with an olefin in the presence of a mononitrile and a catalyst comprising copper(II) chloride, wherein the alkane halide is selected from 1,1,1-trichloro-2,2,2-trifluoroethane (CF3CCl3, 113a) and carbon tetrachloride (CCl4). When the alkane halide is 1,1,1-trichloro-2,2,2-trifluoroethane, the olefin is vinylidene chloride (CH2=CCl2, VDC). When the alkane halide is carbon tetrachloride, the olefin is 2-chloro-3,3,3-trifluoropropene (CF3CCl=CH2, 1233xf).

[0008] In one embodiment, the process involves contacting 333jfa produced as described above herein with hydrogen fluoride (HF) in the gas phase or liquid phase in the presence of a fluorination catalyst under certain conditions to produce a product mixture comprising 2,2-dichloro-1,1,1,4,4,4-hexafluorobutane (CF3CCl2CH2CF3, 336mfa).

[0009] In one embodiment, the process involves contacting 336mfa produced as described above herein with a base and optionally a phase transfer catalyst to produce a product mixture comprising 1,1,1,4,4,4-hexafluorobutyne.

[0010] In one embodiment, 1,1,1,4,4,4-hexafluoro-2-butyne is reacted with hydrogen and a hydrogenation catalyst to produce a product mixture comprising Z-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz).

[0011] The present disclosure is about (a) contacting an alkane halide with an olefin in the presence of (a) a mononitrile and a catalyst containing copper(II) chloride, wherein the alkane halide is selected from 1,1,1-trichloro-2,2,2-trifluoroethane and carbon tetrachloride, and when the alkane halide is 1,1,1-trichloro-2,2,2-trifluoroethane, the olefin is vinylidene chloride, and when the alkane halide is carbon tetrachloride, the olefin is 2-chloro-3,3,3-trifluoropropene, to produce a product mixture containing 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane; (b) contacting 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane with hydrogen fluoride in the gas phase or liquid phase in the presence of a fluorination catalyst under certain conditions to produce a product mixture containing 2,2-dichloro-1,1,1,4,4,4-hexafluorobutane; (c) contacting 2,2-dichloro-1,1,1,4,4,4-hexafluorobutane with a base and a phase transfer catalyst to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne; and (d) contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen and a hydrogenation catalyst to produce a product mixture containing Z-1,1,1,4,4,4-hexafluoro-2-butene. A process for the production of Z-1,1,1,4,4,4-hexafluoro-2-butene is provided, which includes the above steps.

[0012] In any of the aforementioned processes, the desired product can be recovered from the product mixture containing such a desired product.

[0013] The above general description and the following "Detailed Description of the Invention" are merely illustrative and explanatory and do not limit the present disclosure as defined by the appended claims. Other features and advantages of the processes disclosed herein will become apparent from the following more detailed description of the preferred embodiments in conjunction with the present disclosure.

Detailed Description of the Invention

[0014] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof are intended to cover non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements, and may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive "or" and not an exclusive "or." For example, the condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0015] The transitional phrase "consisting of" excludes any unrecited element, step, or ingredient. In a claim, such a phrase limits the claim to the recited materials or steps and excludes additional unrecited materials or steps, except for impurities ordinarily associated with the recited materials. When the phrase "consists of" appears in a clause within the body of a claim rather than immediately following the preamble, the phrase limits only the elements recited in that clause; other elements are not excluded from the scope of the claim as a whole. The transitional phrase "consisting essentially of" is used to define compositions and methods that include materials, steps, mechanisms, components, or elements in addition to those literally disclosed, provided that these additional materials, steps, mechanisms, components, or elements do not materially affect the operative mechanism for achieving any of the desired results of the basic and novel features, particularly of the processes disclosed herein. The term "consisting essentially of" has a meaning intermediate between "comprising" and "consisting of."

[0016] Also, the use of "a" or "an" is employed to describe the elements and components described in this specification. This is merely for convenience and is for giving the general meaning of the scope of the present disclosure. This description should be construed to include one or at least one, and the singular form also includes the plural form unless it is obvious that it has a different meaning.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, but the preferred methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entirety unless specifically cited in a particular paragraph. In case of conflict, this specification, including definitions, will control. Further, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0018] An exemplary synthetic process for preparing a composition (product mixture) containing (Z)-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz) is provided. Embodiments of the present disclosure include synthetic routes to 1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz) starting from readily available halogen compounds, CCl4, CF3CCl3, CH2=CCl2, CF3CCl=CH2.

[0019] The processes disclosed herein are suitable for reaction conditions of temperature and pressure and can be carried out in a reactor made of a material resistant to the reactants and products used. The reactor can be composed of a material resistant to the corrosive effect of hydrogen fluoride, such as, for example, stainless steel, Hastelloy®, Inconel®, Monel®, gold or gold-plated material, or quartz. The reaction may be carried out batchwise, continuously, semi-continuously, or a combination thereof. Suitable reactors include batch reaction vessels and tubular reactors.

[0020] "Recover" means to sufficiently isolate the desired product so that it can be made available for its intended use, as a starting material for subsequent reaction steps, or as a composition, for example, as a refrigerant or a blowing agent or a solvent or a fire extinguishing agent or an electronic gas or for other uses, or for useful Z-1,1,1,4,4,4-hexafluoro-2-butene in a composition.

[0021] The details of the recovery step depend on the compatibility of the product mixture with the reaction conditions of subsequent reaction steps. For example, if the product is produced in a reaction medium that is different from or incompatible with subsequent reaction steps, the recovery step 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 volatile product contains undesirable components, the desired product can be separated, for example, by selective distillation.

[0022] The step of recovering the desired product from the product mixture preferably includes separating the desired product from a catalyst or other components of the product mixture used to produce the desired product or produced in the process.

[0023] The present disclosure provides, inter alia, a process for producing Z-1336mzz and a process for producing an intermediate for producing Z-1336mzz. Such processes use low-cost and readily available starting materials such as 1,1,1-trichloro-2,2,2-trifluoroethane and carbon tetrachloride.

[0024] 1,1,1,3,3-Pentachloro-4,4,4-trifluorobutane (CCl3CH2 CCl 2CF3, 333jfa) production In an embodiment for producing 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane (CF3CCl2CH2CCl3, 333jfa), as shown in Scheme (1A), in the presence of a catalyst comprising copper(II) chloride and mononitrile, at a temperature and pressure sufficient to form 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane, 1,1,1-trichloro-2,2,2-trifluoroethane (CF3CCl3, 113a) is placed in a reactor, heated, and contacted with vinylidene chloride (CH2=CCl2, VDC).

[0025]

Chemical formula

[0026] In an alternative embodiment for producing 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane, as shown in Scheme (1B), in the presence of a catalyst comprising copper(II) chloride and mononitrile, at a temperature and pressure sufficient to form 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane, carbon tetrachloride (CCl4) is placed in a reactor, heated, and contacted with 2-chloro-3,3,3-trifluoropropene (CF3CCl=CH2, 1233xf).

[0027]

Chemical formula

[0028] In some embodiments, the addition of the above-mentioned halogenated alkane to the olefin can be carried out at a temperature of about 50°C to about 150°C. In some embodiments, the temperature is 50 to 130°C. In some embodiments, the reaction is carried out as a batch reaction, and the reaction time can be up to 2 hours, up to 5 hours, up to 10 hours, up to 15 hours, up to 18 hours, up to 20 hours, up to 22 hours, up to 24 hours, less than 36 hours, less than 32 hours, less than 28 hours, less than 26 hours, and combinations thereof.

[0029] In some embodiments, the reaction can be carried out at a reactor pressure of 1 pound per square inch gauge (psig) to 300 pounds per square inch gauge (psig) (about 7 to about 2000 kPa).

[0030] The mononitrile can be selected from acetonitrile, propionitrile, and butyronitrile. In some embodiments, the mononitrile is propionitrile. The molar ratio of the mononitrile to the Cu(II) catalyst is 10 or more and 25 or less. This ratio can be 10 to 20, or 15 to 25, or 15 to 20.

[0031] The process for producing 333jfa can further include, for example, as described herein, the step of recovering 333jfa from the product mixture before using the recovered 333jfa as a starting material in the processes for producing HCFC-336mfa, 1,1,1,4,4,4-hexafluoro-2-butyne, and HFO-Z-1336mzz. The process for recovering 333jfa from the product mixture can include one or any combination of purification techniques known in the art, such as distillation. By "recovering" 333jfa from the product mixture, a product containing at least 95%, or at least 97%, or at least 99% of 333jfa is produced.

[0032] Production of 2,2-dichloro-1,1,1,4,4,4-hexafluorobutane (CF3CCl2CH2CF3, 336mfa) In one embodiment, 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane (333jfa) is the subject of a fluorination reaction. In this embodiment, 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane is contacted with hydrogen fluoride (HF) in the presence of a fluorination catalyst at a temperature and pressure sufficient to form a product containing 2,2-dichloro-1,1,1,4,4,4-hexafluorobutane as shown in Scheme (2).

[0033]

Chemical formula

[0034] The reaction with HF can be carried out in the gas phase or the liquid phase. A liquid medium may be added to the liquid-phase reaction. Examples of the liquid medium are the 333jfa reactant itself. The gas-phase or liquid-phase reaction contains a fluorination catalyst.

[0035] The fluorination reaction can be carried out in a reaction zone containing a reaction vessel of any size appropriate for the scale of the reaction. In some embodiments, the reaction zone contains a reaction vessel constructed of a corrosion-resistant material. In some embodiments, these materials include alloys such as nickel-based alloys like Hastelloy®, nickel-chromium alloys commercially available under the trademark Inconel® from Special Metals Corp., or nickel-copper alloys commercially available under the trademark Monel® from Special Metals Corp. (New Hartford, New York), or the vessel has a fluoropolymer lining. In other embodiments, the reaction vessel may be made of other structural materials including stainless steel, particularly austenitic types, and copper-clad steel.

[0036] In the catalytic gas-phase fluorination process, the fluorination catalyst can be selected from carbon, graphite, alumina, fluorinated alumina, aluminum fluoride, alumina supported on carbon, aluminum fluoride supported on carbon, fluorinated alumina supported on carbon, 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.

[0037] Suitable metals for use in a gas-phase fluorination catalyst (optionally supported on alumina, aluminum fluoride, fluorinated alumina, 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 with atomic numbers 58-71 (i.e., lanthanide metals). Preferably, when used on a support, the total metal content of the catalyst is from about 0.1 to about 20 weight percent, typically from about 0.1 to about 10 weight percent, based on the total weight of the catalyst.

[0038] Fluorination catalysts useful in the gas-phase process include chromium-based catalysts such as chromium oxyfluoride or chromium oxide, which may or may not be 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 cocatalyst 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 fluorinated alumina, the production of which is reported in European Patent No. 486,333.

[0039] The chromium oxyfluoride catalyst can be produced by processes known to those skilled in the art, such as treating Cr2O3 (chromium oxide) with HF, CCl3F, or hydrofluorocarbon, as disclosed in, for example, International Publication No. 2012 / 067864 (A1).

[0040] The chromium catalyst is preferably activated before use, as disclosed in, for example, U.S. Patent No. 9,302,962.

[0041] In the gas-phase fluorination process, the molar ratio of HF to 333jfa in some embodiments can be from about 1 to about 35. In other embodiments, the molar ratio of HF to 333jfa is from about 1 to about 25. HF can be added in an amount of 10 to 30 moles per mole of 333jfa.

[0042] In some embodiments, the gas-phase fluorination process is carried out at a high temperature, for example, in the range of 150 to 400 °C or 275 to 375 °C. In some embodiments, the temperature ranges from 300 to 350 °C.

[0043] In some embodiments, the gas-phase fluorination process is carried out at a pressure in the range of 0 to 200 psi (0 to 1.4 MPa). In some embodiments, the reaction is carried out substantially at atmospheric pressure.

[0044] In some embodiments, the contact time of the gas-phase fluorination process can be from about 1 second to about 100 seconds. In some embodiments, the contact time of the gas-phase fluorination process can be from about 10 seconds to about 100 seconds, or from 10 seconds to 30 seconds. In other embodiments, the contact time of the gas-phase fluorination process can be from 50 seconds to about 80 seconds.

[0045] The gas-phase fluorination reaction may further include recovering 336mfa from the product mixture to reduce other components of the product mixture. The process for recovering 336mfa may include one or any combination of purification techniques known in the art, such as distillation. By "recovering" 336mfa from the product mixture, a product containing at least 98.5% or at least 99 or at least 99.5% of 336mfa is produced.

[0046] In the catalytic liquid-phase fluorination process, the fluorination catalyst may include a Lewis acid catalyst such as a metal halide. The halide may be selected from fluoride, chloride, and bromide. The metal halide may be a transition metal halide or other metal halide. Examples of transition metal chlorides include halides of titanium, tantalum, niobium, tin, tungsten, and antimony. Another suitable metal halide catalyst is boron trifluoride.

[0047] In some embodiments, the fluorination catalyst is selected from SbF5, SbCl5, SbCl3, SnCl4, TaCl5, TiCl4, NbCl5, MoCl6, WCl6, antimony(V) chlorofluoride, and combinations thereof. In some embodiments, the metal halide is SbF5. In some embodiments, the metal halide is TaCl5. In some embodiments, the metal halide is antimony(V) chlorofluoride. In one embodiment, the catalyst includes tantalum pentachloride, antimony pentachloride, or antimony pentafluoride.

[0048] In the liquid-phase fluorination process, hydrogen fluoride is present at a molar ratio of HF to 333jfa of 7:1 to 15:1. In one embodiment, hydrogen fluoride is present at a molar ratio of HF to 333jfa of about 10:1.

[0049] In some embodiments, the liquid-phase fluorination process is carried out at a temperature of 50°C to 160°C. In some embodiments, the temperature may be above 100°C. In other embodiments, the temperature may be below 150°C.

[0050] In some embodiments, the liquid-phase fluorination reaction is carried out at a pressure in the range of 0 to 600 psi (0 to 4.1 MPa). In some embodiments, the reaction is carried out at substantially atmospheric pressure.

[0051] In some embodiments, the contact time of the liquid-phase fluorination reaction is about 1 minute to about 24 hours, or about 10 minutes to about 12 hours, or about 1 hour to about 6 hours.

[0052] When carrying out the process in a liquid medium, the desired product HCFC-336mfa can be recovered from the reactor by purging unreacted chlorine, distilling off unreacted 333jfa, and filtering off the catalyst. When carried out in the liquid phase, the catalyst can be filtered if it is present at a concentration high enough for the catalyst to precipitate from the product mixture before, during, or after distillation. Alternatively, the catalyst may remain in the distillation heel.

[0053] In some embodiments, the product mixture from the fluorination reaction can be subject to recovery and purification steps. Such steps can include washing with water, drying, and distillation.

[0054] The products produced in the gas-phase or liquid-phase fluorination process can include CF3CCl2CH2CF3 (336mfa) and additional compounds selected from CF3CCl2CH2CFCl2, CHF2CH2CCl2CF3, and mixtures thereof.

[0055] Production of 1,1,1,4,4,4-hexafluoro-2-butyne The present disclosure further provides a process for contacting HCFC-336mfa with a base to produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) by a dehydrochlorination reaction as shown in Scheme (3). The base is preferably a basic aqueous medium. This reaction step is preferably carried out in the presence of a phase transfer catalyst.

[0056]

Chemical formula

[0057] The base is a basic aqueous medium containing an aqueous solution of an alkali metal hydroxide or an alkali metal halide salt or other bases. The base can be selected from hydroxides, oxides, carbonates, or phosphates of alkali metals, alkaline earth metals, and mixtures thereof. In some embodiments, the base is selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, potassium carbonate, sodium phosphate, potassium phosphate, or mixtures thereof.

[0058] 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 of 10-13. In some embodiments, the basic aqueous solution contains a small amount of an organic liquid that may or may not be miscible 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.

[0059] This reaction step is preferably carried out in the presence of a phase transfer catalyst. As used herein, a phase transfer catalyst is intended to mean a substance that promotes the transfer of an ionic compound from an aqueous phase to an organic phase. In this step, the organic phase contains the HCFC-336mfa reactant and the aqueous phase contains a basic aqueous medium. The phase transfer catalyst promotes the reaction of these dissimilar and incompatible components. Although various phase transfer catalysts can function in various ways, their mechanism of action does not limit their usefulness in the process of the present disclosure as long as the phase transfer catalyst promotes the dehydrochlorination reaction.

[0060] Suitable phase transfer catalysts include quaternary alkylammonium salts. In some embodiments, the catalyst includes tetrabutylammonium bromide or N-methyl-N,N,N-trioctylammonium chloride. In some embodiments, at least one alkyl group of the quaternary alkylammonium salt contains at least 8 carbons. An example of a quaternary alkylammonium salt in which three alkyl groups contain at least 8 carbon atoms is N-methyl-N,N,N-trioctylammonium chloride sold under the trade name ALIQUAT® 336 by Alfa Aesar-Fisher Scientific. Examples of quaternary alkylammonium salts in which four alkyl groups contain at least 8 carbon atoms include tetraoctylammonium salts.

[0061] The anion of such salts may be a halide such as chloride or bromide, hydrogen sulfate, or any other commonly used anion.

[0062] Specific quaternary alkylammonium salts include tetraoctylammonium chloride, tetraoctylammonium hydrogen sulfate, tetraoctylammonium bromide, methyltrioctylammonium chloride, methyltrioctylammonium bromide, tetradecylammonium chloride, tetradecylammonium bromide, and tetradodecylammonium chloride.

[0063] According to one embodiment, a process for producing a product mixture containing CF3C≡CCF3 involves contacting 336mfa with a base and a phase transfer catalyst under reaction conditions effective to achieve at least 50% conversion of 336mfa per hour.

[0064] In other embodiments, the alkyl groups of the quaternary alkylammonium salt contain 4 to 10 carbon atoms and a nonionic surfactant is present in the aqueous basic medium. According to such embodiments, the phase transfer catalyst and reaction conditions are preferably effective to achieve a conversion rate of at least 20% of HCFC-336mfa per hour. The anion of the quaternary alkylammonium salt having alkyl groups containing 4 to 10 carbon atoms may be a halide such as chloride or bromide, hydrogen sulfate, or any commonly used anion. The above quaternary alkylammonium salts can be used in this embodiment if these alkyl groups contain 4 to 10 carbon atoms. Specific additional salts include tetrabutylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium hydrogen sulfate.

[0065] Preferred nonionic surfactants include ethoxylated nonylphenol or ethoxylated C12 - C15 linear aliphatic alcohols. Useful nonionic surfactants include Bio-soft® N25-9 and Makon® 10, which are available from Stepan Company, Northfield, IL.

[0066] In some embodiments, the quaternary alkylammonium salt is added in an amount of 0.5 to 2 mole percent of HCFC-336mfa. In other embodiments, the quaternary alkylammonium salt is added in an amount of 1 to 2 mole percent of HCFC-336mfa. In still other embodiments, the quaternary alkylammonium salt is added in an amount of 1 to 1.5 mole percent of HCFC-336mfa. In some embodiments, the quaternary alkylammonium salt is added in an amount of 1 to 1.5 mole percent of HCFC-336mfa, 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.

[0067] In some embodiments, the reaction mixture is heated to a temperature of 50°C to 95°C, preferably to a temperature of about 60°C to 90°C, and most preferably to 70°C.

[0068] In some embodiments, the reactants are heated for about 1 hour to about 10 hours, about 2 hours to about 6 hours, about 4 hours to about 5 hours, and combinations thereof.

[0069] In some embodiments, the reaction is carried out substantially at atmospheric pressure.

[0070] In some embodiments, the base includes a strong base. In some embodiments, the base includes sodium hydroxide or potassium hydroxide.

[0071] In some embodiments, the dehydrochlorination reaction of 336mfa 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 chloride or bromide. The preferred alkali metal halide salt is sodium chloride. Without being bound by any particular theory, the alkali metal halide salt is thought to stabilize the phase transfer catalyst. The dehydrochlorination reaction itself produces sodium chloride when an alkali metal chloride, particularly sodium hydroxide, is used as the base, but adding additional sodium chloride gives the further effect that the yield of 1,1,1,4,4,4-hexafluoro-2-butyne increases. In some embodiments, the alkali metal halide is added in an amount of about 25 to about 100 equivalents per mole of the phase transfer catalyst. In other embodiments, the alkali metal halide is added in an amount of about 30 to about 75 equivalents per mole of the phase transfer catalyst. In still other embodiments, the alkali metal halide is added in an amount of about 40 to about 60 equivalents per mole of the phase transfer catalyst. These amounts apply to each of the quaternary alkylammonium salts described above.

[0072] 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.

[0073] Production of Z-1,1,1,4,4,4-hexafluoro-2-butene The present disclosure further provides a hydrogenation process comprising contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen at a temperature and pressure sufficient to produce a product mixture comprising Z-1,1,1,4,4,4-hexafluoro-2-butene (Z-1336mzz) as shown in Scheme (4). This process is preferably carried out in the presence of a hydrogenation catalyst which is a catalyst for the conversion of an alkyne to an alkene.

[0074]

Chemical formula

[0075] In some embodiments, the hydrogenation catalyst is a palladium catalyst such as a catalyst comprising palladium dispersed on aluminum oxide or titanium silicate doped with silver and / or a lanthanide. The loading of palladium dispersed on aluminum oxide or titanium silicate is relatively low. In some embodiments, the palladium loading is from about 100 ppm to about 5000 ppm. In other embodiments, the palladium loading is from 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 from about 2:1 to about 3:1. In some embodiments, the molar ratio of silver to palladium is about 0.5:1.0.

[0076] In some embodiments, the hydrogenation catalyst comprises Lindlar's (5% Pd on lead-poisoned CaCO3). The lead compound may be lead acetate, lead oxide, or any other suitable lead compound.

[0077] The Lindlar's catalyst may be further deactivated or conditioned with quinoline. The amount of palladium supported on the carrier is typically about 5 wt%, but may be any catalytically effective amount. In some embodiments, the amount of palladium supported on the carrier in the Lindlar's catalyst is greater than 5 wt%. In still other embodiments, the amount of palladium supported on the carrier may be from about 5 wt% to about 1 wt%.

[0078] In some embodiments, the amount of catalyst used is from about 0.5 wt% to about 4 wt% of the amount of 1,1,1,4,4,4-hexafluoro-2-butyne. In other embodiments, the amount of catalyst used is from about 1 wt% to about 3 wt% of the amount of butyne. In still other embodiments, the amount of catalyst used is from about 1 wt% to about 2 wt% of the amount of butyne.

[0079] In some embodiments, the amount of catalyst used is about 0.5 wt% to about 4 wt% of the amount of 1,1,1,4,4,4-hexafluoro-2-butyne. In other embodiments, the amount of catalyst used is about 1 wt% to about 3 wt% of the amount of butyne. In still other embodiments, the amount of catalyst used is about 1 wt% to about 2 wt% of the amount of butyne.

[0080] In some embodiments, this reaction step is carried out in the presence of a solvent. In such an embodiment, the solvent is an alcohol. Typical alcohol solvents include ethanol, i-propanol, and n-propanol. In other embodiments, the solvent is a fluorocarbon or a 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.

[0081] In some embodiments, the reaction of 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen is preferably carried out while adding hydrogen little by little, and with each addition, the pressure in the container increases by no more than about 100 psi (0.69 MPa). In other embodiments, the addition of hydrogen is controlled such that with each addition, the pressure in the container increases by no 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 in larger increments to the residue of the reaction. 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 in larger increments to the residue of the reaction. In still other embodiments, 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 in larger increments to the residue of the reaction. In some embodiments, the larger increment of hydrogen addition can be 300 psi (2.07 MPa). In other embodiments, the larger increment of hydrogen addition can be 400 psi (2.76 MPa).

[0082] In some embodiments, the molar ratio is about 1 mole of hydrogen to about 1 mole of 1,1,1,4,4,4-hexafluoro-2-butyne. In other embodiments, the molar ratio of hydrogen to butyne is from about 0.9 mole to about 1.3 moles. In still other embodiments, the amount of hydrogen added is about 0.95 moles of hydrogen per about 1.1 moles of butyne. In still other embodiments, the amount of hydrogen added is about 0.95 moles of hydrogen per about 1.03 moles of butyne.

[0083] In some embodiments, the hydrogenation is carried out at ambient temperature (15 °C to 25 °C). In other embodiments, the hydrogenation is carried out at a temperature higher than ambient temperature. In still other embodiments, the hydrogenation is carried out at a temperature lower than ambient temperature. In still other embodiments, the hydrogenation is carried out at a temperature lower than about 0 °C.

[0084] In some embodiments, the reaction vessel containing hexafluoro-2-butyne and the catalyst is cooled to about -78 °C under reduced pressure. Next, the temperature of the reactor may be warmed to room temperature. Next, hydrogen gas may be slowly added to the reaction vessel. In some embodiments, the rate of addition of hydrogen gas is adjusted to provide a change in pressure within the reaction vessel of less than 70 psi, less than 60 psi, and / or less than 50 psi. The addition of hydrogen may be continued until a slight excess of hydrogen is provided to the reaction vessel.

[0085] In embodiments of a continuous process, 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 still other embodiments, the molar ratio of hydrogen to butyne is about 0.67:1.0.

[0086] 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 about 40 °C.

[0087] In some embodiments of the continuous process, the flow rates of 1,1,1,4,4,4-hexafluoro-2-butyne and hydrogen are maintained such that the residence time in the reaction zone is about 30 seconds. In other embodiments of the continuous process, the flow rates of butyne and hydrogen are maintained such that the residence time in the reaction zone is about 15 seconds. In still other embodiments of the continuous process, the flow rates of butyne and hydrogen are maintained such that the residence time in the reaction zone is about 7 seconds.

[0088] It is understood that by increasing the flow rate at which 1,1,1,4,4,4-hexafluoro-2-butyne and hydrogen enter the reaction zone, the contact time in the reaction zone is shortened. As the flow rate increases, the amount of butyne hydrogenated per unit time increases. Since hydrogenation is exothermic, depending on the length and diameter of the reaction zone and its heat dissipation capacity, at higher flow rates, it may be desirable to provide an external cooling source to the reaction zone to maintain the desired temperature.

[0089] In some embodiments, at the completion of a batch or continuous isomerization process, Z-1336mzz can be recovered through any conventional process, including for example fractional distillation. In other embodiments, at the completion of a batch or continuous hydrogenation process, Z-1336mzz has a purity high enough that no further purification steps are required.

[0090] The 1,1,1,4,4,4-hexafluoro-2-butene reaction product can be recovered in high yield and high purity by distillation of the reaction mixture. In some embodiments, the yield of the reaction of Scheme 4 exceeds 95 percent, exceeds 96 percent, exceeds 97 percent, and / or exceeds 98 percent.

Examples

[0091] The concepts described in this specification are further illustrated in the following examples, which do not limit the scope of the present disclosure as set forth in the claims.

[0092] Iron powder, vinylidene chloride, Aliquat® 336, and sodium hydroxide are available from Sigma Aldrich (St. Louis, MO).

[0093] 1,1,1-Trichloro-2,2,2-trifluoroethane (CF3CCl3), 2-chloro-3,3,3-trifluoropropene (CF3CCl=CH2), hydrogen fluoride, and SbCl5 are purchased from Synquest Labs, Inc.

[0094] Example 1 (Comparative). Step 1. VDC insertion of 113a to produce CF3CCl2CH2CCl3 Vinylidene chloride (26 g, 0.265 mol) was added to a mixture of 113a (100 g, 0.53 mol), Fe powder (0.62 g, 0.011 mol), and triphenylphosphine (1.41 g, 0.0054 mol) in a 240 mL Hastelloy reactor. The reactor was heated to 150 °C for 5 hours. The mixture was transferred to a vessel and analyzed by GC: 24% GC yield (30% conversion and 80% selectivity to the product).

[0095] Example 2. Step 1. VDC insertion of 113a to produce CF3CCl2CH2CCl3 A mixture of vinylidene chloride (2.4 g, 0.025 mol) and 113a (23 g, 0.125 mol) with 3 mL of propionitrile in a 100 mL stainless steel autoclave was heated to 100 o °C for 24 hours in the presence of anhydrous copper(II) chloride (0.34 g, 0.0025 mol). The mixture was transferred to a vessel and analyzed by GC: 32% GC yield (40% conversion, 80% selectivity to the product).

[0096] Example 3 (Comparison). Step 1. Insertion of 2-chloro-3,3,3-trifluoropropene into CCl4 to produce CF3CCl2CH2CCl3 A mixture of 2-chloro-3,3,3-trifluoropropene (32.6 g, 0.25 mol) and CCl4 (77 g, 0.5 mol) was heated to 130 o °C for 5 hours in a 300 mL Hastelloy reactor in the presence of Fe powder (0.62 g, 0.011 mol) and triphenylphosphine (1.40 g, 0.005 mol). The mixture was transferred to a vessel and analyzed by GC: conversion 55% and selectivity to the product 86%.

[0097] Example 4. Step 1. Insertion of 2-chloro-3,3,3-trifluoropropene into CCl4 to produce CF3CCl2CH2CCl3 A mixture of 2-chloro-3,3,3-trifluoropropene (3.3 g, 0.025 mol) and CCl4 (7.7 g, 0.05 mol) was heated to 100°C for 22 hours in the presence of anhydrous copper(II) chloride (0.34 g, 0.0025 mol) in 3 mL of propionitrile in a 100 mL stainless steel autoclave. The mixture was purified by fractionation. The distillation yield for the product was 62%.

[0098] The product CF3CCl2CH2CCl3 was recovered from the product mixtures of Examples 1 - 4 and had the following properties: boiling point 56 - 58°C (13 mmHg); 1H NMR (CDCl3): δ ppm 3.72 (CH2, s); 19F NMR (CDCl3): δ ppm -80.47 (CF3, s); MS (m / z): 248.75 (M+-Cl), 246.75 (M+-Cl-2H).

[0099] Example 5. Step 2: Production of CF3CCl2CH2CF3 (336mfa) by liquid-phase fluorination of CF3CCl2CH2CCl3 using an antimony catalyst A mixture of 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane (2 g, 0.007 mol), anhydrous HF (4.2 g, 0.021 mol), and antimony pentachloride (0.5 g, 0.002 mol) was stirred at 110 °C in a PTFE-lined vessel. The reaction mixture was poured into crushed ice. The organic layer was washed with water (twice) and dried over MgSO4. Distillation at 65 - 68 °C gave 1.9 g of the product (81% yield). The product was recovered and had the following characteristics: 1H NMR (CDCl3): δ ppm 3.15 (q, JHF = 9.4 Hz, CH2); 19F NMR (CDCl3): δ ppm: -62.7 (t, JFH = 9.4 Hz, 2F, CH2CF3), -83.2 (s, 3F, CF3).

[0100] Example 6. Step 2: Production of CF3CCl2CH2CF3 (336mfa) by liquid-phase fluorination of CF3CCl2CH2CCl3 using a tantalum catalyst A mixture of 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane (2 g, 0.007 mol), anhydrous HF (4.2 g, 0.021 mol), and tantalum pentachloride (0.6 g, 0.002 mol) is stirred at 130 °C in a PTFE-lined vessel. The reaction mixture is poured into crushed ice. The organic layer is washed with water (twice) and dried over MgSO4. Distillation at 65 - 68 °C gives 2.1 g of the product (88% yield).

[0101] Example 7. Step 2: Production of CF3CCl2CH2CF3 (336mfa) by gas-phase fluorination of CF3CCl2CH2CCl3 6 cc of Newport chromium catalyst was charged into an Inconel® pipe (OD 0.5 inches, length 10 inches, wall thickness 0.034). The reactor was heated to the target temperature. CF3CCl2CH2CCl3 was supplied via an ISCO pump (4.27 mL / hr) and a vaporizer controlled at 170 °C. The molar ratio of HF / CF3CCl2CH2CCl3 was 10 and the contact time was 10 seconds. The reaction was carried out at 0 psig. The reactor effluent was analyzed online using an Agilent® 6890 GC / 5973 MS, and as a result, the starting material showed a conversion rate of 95%, a selectivity of 70% to 336 mfa, and a selectivity of 30% to 1326 mxz (CF3CCl=CHCF3).

[0102] Example 8. Step 3. Conversion of CF3CCl2CH2CF3 to hexafluoro-2-butyne using Aliquat® 336 quaternary ammonium salt An aqueous NaOH solution (22 mL, 0.22 mol) is added at room temperature to CF3CCl2CH2CF3 (23.5 g, 0.1 mol) and water (5.6 mL) in the presence of Aliquat® 336 quaternary ammonium salt (0.53 g, 0.001325 mol). After addition, the reaction temperature is raised to 70 °C and the reaction is monitored using gas chromatography. The reaction is complete after 2 hours and hexafluorobutyne is collected in a dry ice trap in a yield of over 90%.

[0103] Example 9. Step 3. Conversion of CF3CCl2CH2CF3 to hexafluoro-2-butyne using tetrabutylammonium bromide and a surfactant An aqueous NaOH solution (22 mL, 0.22 mol) is added at room temperature to 336 mfa (23.5 g, 0.1 mol) and water (5.6 mL) in the presence of tetrabutylammonium bromide (0.45 g, 0.001325 mol) and Makon® 10 surfactant (0.7 g). After addition, the reaction temperature is raised to 70 °C and the reaction is monitored using gas chromatography. The reaction is complete after 4.5 hours and hexafluorobutyne is collected in a dry ice trap in a yield of over 90%.

[0104] Example 10. Step 4.1,1,1,4,4,4-Hexafluorobutene Conversion to (Z)-1,1,1,4,4,4-Hexafluoro-2-butene 5 g of Lindlar (5% Pd supported on lead-poisoned CaCO3) catalyst was charged into a 1.3 L rocker bomb. 480 g (2.96 mol) of hexafluoro-2-butene was charged into the rocker. The reactor was cooled to -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 chromatographic analysis of the crude product showed a mixture consisting of CF3C≡CCF3 (0.236%), the trans isomer (E)-CF3CH=CHCF3 (boiling point 33.3 °C, MS: 164 [MI], 145 [M-19], 95 [CF3CH=CH], 69 [CF3]; 1H NMR: 6.12 ppm (multiplet), 19F NMR: -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.

[0105] Note that not all of the operations or examples described above in the general description are necessary, and some part of a particular operation may not be necessary, and one or more additional operations may be performed in addition to the operations described above. Further, the order in which the operations are described is not necessarily the order in which they are performed.

[0106] Benefits, other advantages, and solutions to problems are described above in connection with specific embodiments. However, none of these benefits, advantages, problem solutions, and any features that may give rise to or make more apparent any benefit, advantage, or solution are to be construed as essential, necessary, or indispensable features in part or all of the claims.

[0107] To clarify, it should be understood that the specific features described herein in the context of separate embodiments may also be provided in combination within a single embodiment. Conversely, for the sake of brevity, the various features described in the context of a single embodiment may also be provided separately or in any sub-combination. Further, references to values recited in ranges include each and every value within that range.

[0108] The processes disclosed herein have been described with reference to preferred embodiments, but it will be understood by those skilled in the art that various changes can be made without departing from the scope of the disclosure and equivalents can be used in place of its elements. In addition, many modifications can be made without departing from the essential scope of the disclosure to adapt a particular situation or material to the teachings of the invention.

Claims

1. 1,1,1,3,3 - pentachloro - 4,4,4 - trifluorobutane (CCl 3 CH 2 CCl2CF 3 , 333jfa) to produce a product mixture, the process comprising contacting an alkane halide with an olefin in the presence of a mononitrile and a catalyst comprising copper(II) chloride, said alkane halide being 1,1,1 - trichloro - 2,2,2 - trifluoroethane (CF 3 CCl 3 , 113a) and carbon tetrachloride (CCl 4 ), wherein when the alkane halide is 1,1,1 - trichloro - 2,2,2 - trifluoroethane, the olefin is vinylidene chloride (CH 2 =CCl 2 , VDC), and when the alkane halide is carbon tetrachloride, the olefin is 2 - chloro - 3,3,3 - trifluoropropene (CF 3 CCl = CH 2 , 1233xf), and the mononitrile is propionitrile.

2. The halogenated alkane is 1,1,1-trichloro-2,2,2-trifluoroethane, and the olefin is vinylidene chloride. The process according to claim 1.

3. The halogenated alkane is carbon tetrachloride, and the olefin is 2-chloro-3,3,3-trifluoropropene. The process according to claim 1.

4. The molar ratio of mononitrile to the catalyst is 10 or more and less than 25. The process according to claim 1 or 2.

5. The molar ratio of mononitrile to the catalyst is 10 to 20. The process according to claim 2.

6. Further comprising contacting 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane with hydrogen fluoride (HF) in the gas phase or liquid phase in the presence of a fluorination catalyst to form a product containing 2,2-dichloro-1,1,1,4,4,4-hexafluorobutane. The process according to claim 1.

7. The process of contacting the 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane with HF is carried out in the gas phase. The process according to claim 6.

8. The process of contacting the 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane with HF is carried out in the liquid phase. The process according to claim 6.

9. 2,2-Dichloropentafluorobutane is contacted with a base in the presence of a phase transfer catalyst to further produce a product mixture containing 1,1,1,4,4,4-hexafluoro-2-butyne (CF 3 C≡CCF 3 ), and the phase transfer catalyst is a quaternary ammonium salt. The process according to claim 6.

10. The quaternary ammonium salt includes tetrabutylammonium bromide or N-methyl-N,N,N-trioctylammonium chloride. The method according to claim 9.

11. Further comprising contacting 1,1,1,4,4,4-hexafluoro-2-butyne with hydrogen at a temperature and pressure sufficient to produce a product mixture containing Z-1,1,1,4,4,4-hexafluoro-2-butene. The method according to claim 9.

12. The hydrogenation catalyst is a palladium catalyst, and the palladium catalyst is a Lindlar catalyst, or the palladium catalyst contains palladium dispersed on aluminum oxide or titanium silicate doped with silver and / or a lanthanide. The method according to claim 6.

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