Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/25—Preparation of halogenated hydrocarbons by splitting-off hydrogen halides from halogenated hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C21/00—Acyclic unsaturated compounds containing halogen atoms
  • C07C21/02—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds
  • C07C21/18—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds containing fluorine
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C21/00—Acyclic unsaturated compounds containing halogen atoms
  • C07C21/02—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds
  • C07C21/19—Halogenated dienes
  • C07C21/20—Halogenated butadienes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/584—Recycling of catalysts

Definitions

• the present invention relates to novel fluorobutenes. Furthermore, it relates to a process for producing a fluorobutene by a dehydrofluorination with a raw material of a polyfluorobutane.
• Fluorobutenes are useful as monomers for fluorine-containing polymers, synthesized intermediates/building blocks for producing fluorine-containing intermediates, and raw materials for producing hydrofluorocarbons.
• Thermal dehydrofluorination is a well-known process for synthesizing olefins. Dehydrochlorination is widely used for forming a carbon-carbon multiple bond. Furthermore, there are several examples of thermal dehydrochlorination process used for producing fluoroolefins. On the other hand, almost all of thermal dehydrofluorinations are impractical based on a general knowledge due to their low conversion and low selectivity.
• Another means for producing fluoroolefins by dehydrofluorination is a process by contact with a base.
• a base-used dehydrofluorination gives in many cases isomers that are different from products obtained by a thermal dehydrofluorination process, and therefore it has been difficult to say that it is an efficient production process of necessary fluoroolefins.
• (E)- and (Z)-1,1;1,3-tetrafluoro-2-butenes which are novel compounds, are given by heating 1,1,1,3,3-pentafluorobutane and that selectivity of (E)- and (Z)-1,1,1,3-tetrafluoro-2-butenes particularly improves by bringing 1,1,1,3,3-pentafluorobutane with a base (“a second process”), thereby completing the present invention.
• the present invention provides 2,4,4,4-tetrafluoro-1-butene and (E)- and (Z)-1,1,1,3-tetrafluoro-2-butenes, which are useful novel compounds as fluorine-containing intermediates, using a low-price polyfluorobutane as the raw material and using a thermal (non-catalytic) dehydrofluorination and a base-contact dehydrofluorination. Furthermore, the present invention provides processes for producing these 2,4,4,4-tetrafluoro-1-butene and (E)- and (Z)-1,1,1,3-tetrafluoro-2-butenes, which can be conducted in an industrial scale.
• This first process is achieved by heating 1,1,1,3,3-pentafluorobutane, which is industrially available as 365mfc, at from about 200° C. to about 700° C.
• the temperature of this dehydrofluorination it can generally be conducted in a range of about 200° C. to about 700° C., preferably 300° C.-600° C. It is effective to maintain the reaction temperature in a range of 400° C.-550° C. in order to obtain the optimum conversion and selectivity.
• base refers to a substance known as a basic substance.
• base a compound showing a pH of 8 or higher, when dissolved in water to a have a concentration of 0.1 mol dm ⁇ 3 , corresponds thereto. Even when the reaction is conducted under a condition under which such base is not coexistent, the cleavage of a carbon-carbon bond is prevented, and it is possible to obtain 2,4,4,4-tetrafluoro-1-butene with high selectivity.
• the reaction manner of the first process is either flow type or batch type.
• flow type is more preferable. It becomes necessary in general to have pressurization in the reaction of batch type. In contrast, the reaction of flow type proceeds sufficiently under normal pressure. Therefore, flow type is advantageous from the viewpoint of operability.
• the flow-type reaction is achieved by heating and vaporizing 1,1,1,3,3-pentafluorobutane and by allowing it to flow through a thermal reaction tube.
• the thermal reaction tube must be constructed from a material that is resistant against the contact with hydrogen fluoride even at high reaction temperature. In some cases, this is filled with a filler that has resistance against hydrogen fluoride, in order to improve the mixing effect and the thermal contact, and that is preferable in general.
• a nickel alloy for the reaction tube and Monel•Pro-pack for the filler, it is not limited to this.
• raw material input standard contact time is defined as follows. That is, “the value obtained by subtracting the solid phase volume occupied by the filler from the inside volume of the reaction tube” is referred to as “column volume”, and in the following it is represented by A, too.
• volume volume the volume of the raw material gas introduced into the reaction tube per second
• B the volume of the raw material gas introduced into the reaction tube per second
• the thus calculated “raw material input standard contact time” is not particularly limited. In the case of maintaining the reaction temperature in a range of 400° C.-550° C. as mentioned above, from about 60 column volume to 300 column volume per hour (about 12 seconds to 60 seconds in raw material input contact time) is preferable. The introduction with from about 90 column volume to about 200 column volume per hour (about 18 seconds to 40 seconds in raw material input contact time) is more preferable. On the other hand, when the raw material input contact time exceeds 200 seconds, side reactions tend to occur. When the raw material input contact time is less than 1 second, conversion is low. Therefore, it is not preferable.
• the optimum contact time depends on the temperature (reaction temperature), shape and filler of the reaction tube. Therefore, it is desirable to set the optimum value by suitably adjusting the raw material supply rate raw material input contact time) for each set temperature, each reaction tube shape and each filler type. In conducting the present invention, a person skilled in the art is not prevented from such optimization. In general, the adoption of a contact time capable of obtaining a raw material conversion of 25% or higher is preferable from the viewpoint of the recovery and the reuse of the unreacted raw material. More preferably, it is adjusted so that the conversion becomes 70% or more.
• reaction pressure may be lower or higher than the atmospheric pressure or under atmosphere, under the atmospheric pressure is generally preferable. It is also possible to conduct the reaction in the presence of an inert gas (such as nitrogen and argon) that is stable under the reaction conditions or in the presence of an excessive HF.
• an inert gas such as nitrogen and argon
• the dehydrofluorination process of this invention can be conducted in a gas phase using a well-known chemical engineering apparatus.
• the reaction tube, a related raw-material introduction system, an outflow system and a related unit are made of a material strong against hydrogen fluoride.
• typical materials particularly stainless steel material such as austenite-type, or high nickel alloy and copper clad steel such as Monel nickel-copper alloy, Hastelloy nickel alloy and Inconel nickel-chromium alloy can be exemplified. However, it is not limited to this.
• 1,1,1,3,3-pentafluorobutane (the raw material) and (E)- and (Z)-1,1,1,3-tetrafluoro-2-butenes (by-products) are coexistent with the target product, 2,4,4,4-tetrafluoro-1-butene.
• the present inventors found that these compounds have boiling points sufficiently different from each other and do not cause azeotropic phenomena (2,4,4,4-tetrafluoro-1-butene boiling point: 29-30° C., 1,1,1,3,3-pentafluorobutane boiling point: 40° C.
• thermo dehydrofluorination of 1,1,1,3,3-pentafluorobutane (the first process) and a dehydrofluorination of 1,1,1,3,3-pentafluorobutane by a base (the second process) are complementary, and it becomes possible to produce useful, different positional isomers of tetrafluorobutene.
• alkali metal hydroxides potassium hydroxide, lithium hydroxide and the like
• alkali metal carbonates sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate and the like
• alkali earth metal hydroxides calcium hydroxide, magnesium hydroxide and the like
• organic bases tertiary amines such as triethylamine, tributylamine, and trimethylamine
• primary amines such as monoethylamine, monobutylamine, cyclohexylamine, and aniline
• secondary amines such as diethylamine and dibutylamine
• aromatic bases such as pyridine, picoline, lutidine, and ethylpyridine
• strong bases such as guanidine and 1,8-diazabicyclo[5.4.0]dec-7-ene (DBU)) or other strong bases (such as sodium methoxide, sodium
• the reaction is achieved by bringing the raw material 1,1,1,3,3-pentafluorobutane with a base, it is desirable to gradually mix both in order to maintain the reaction conditions mildly.
• a process such as a gradual addition of the raw material 1,1,1,3,3-pentafluorobutane with stirring of a base-containing liquid.
• the reaction it is also possible to allow the reaction to proceed by adding a base to the raw material 1,1,1,3,3-pentafluorobutane.
• the base can be used as an aqueous solution or a simple substance, and it is possible to add a phase transfer catalyst.
• 85% potassium hydroxide melts by heating to 100° C. or higher, it is convenient that this liquid in the melted condition is stirred and the raw material 1,1,1,3,3-pentafluorobutane is added dropwise thereto.
• the base may be used as a solution by dissolving it in a solvent.
• a solvent there may be used water, ethers (e.g., diethyl ether, dibutyl ether, methyl butyl ether, phenetole, dioxane, tetrahydrofuran, tetrahydropyran, anisole, benzyl ether, glymes (e.g., monoglyme, diglyme, and triglyme)) and halogen-containing solvents (e.g., methylene chloride, 1,1-dichloroethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, chlorobenzene, 1,4-bis(trifluoromethyl)benzene) and the like.
• ethers e.g., diethyl ether, dibutyl ether, methyl butyl ether, phenetole, dioxane, t
• phase-transfer catalyst e.g., 18-crown-6, dibenzo-18-crown-6, dicyclohexano-18-crown-6, 12-crown-4,15-crown-5, dibenzo-24-crown-8, tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, ethyltributylammonium bromide, tetraphenylammonium bromide, and tetraphenylphosphonium bromide).
• a commonly-transfer catalyst e.g., 18-crown-6, dibenzo-18-crown-6, dicyclohexano-18-crown-6, 12-crown-4,15-crown-5, dibenzo-24-crown-8, tetraethylammonium chloride, tetrae
• reaction temperature of the process for producing (E)- and (Z)-1,1,1,3-tetrafluoro-2-butenes by the contact with this base from 0° C. to 300° C. is preferable, and more preferably it is a range of from 30° C. to 250° C.
• the reaction pressure may be lower or higher than atmospheric pressure. In general, the vicinity of atmospheric pressure is simple and preferable.
• reaction time the reaction is fast under a heated condition, and the reaction occurs immediately when the raw material and a base are mixed together. Therefore, as shown in the after-mentioned Example 2, a process is simple, in which mixing of the raw material and a base is conducted under an open condition (atmospheric pressure), and a mixed gas of the raw material and the product is cooled down, thereby collecting it as a liquid (reaction mixture).
• a dehydrofluorination process of the second process can be conducted by a batch manner or in a continuous reaction apparatus using a known chemical engineering technique.
• the apparatus and its related raw material introducing line, the outflow line, and related units should be made from a material that is resistant against strong bases.
• Typical examples of the material are stainless steel, carbon steel, or high nickel alloys such as Monel-nickel copper alloy, Hastelloy-nickel alloy and Inconel nickel-chromium alloy, and copper clad steel. In limited cases, it is possible to use glass or glass-lined steel.
• the recovered raw material 1,1,1,3,3-pentafluorobutane can be reused as a reaction raw material of the first process or second process.
• HF hydrogen fluoride
• the inside volume of the reaction tube in the present example is 261 cm 3 , and the volume (“column volume”) except the solid phase section of the filler is 253 cm 3 .
• the raw material input standard contact time is from 29 seconds (1-4) to 32 seconds (1-1).
• GC % refers to areal % of each component of the above reaction mixture measured by FID. TABLE Temp. 365 mfc CF 3 CH 2 CF ⁇ CH 2 (E)-CF 3 CH ⁇ CFCH 3 (Z)-CF 3 CH ⁇ CFCH 3 No. ° C. GC % GC % GC % GC % 1-1 450 73.7 18.6 3.8 2.7 1-2 470 69.5 23.4 4.3 2.8 1-3 500 63.5 29.6 4.3 1.3 1-4 520 36.4 56.9 3.4 1.6
• a (polytetrafluoroethylene) coating magnetic stirring bar, a dropping funnel (under the liquid level), and a Vigreux column were attached to a 250 ml flask.
• the outlet of the column was passed into an oil bubbler, and it was connected to a collector cooled down to ⁇ 78° C.
• 80 g of 85% potassium hydroxide (in the form of flakes) were added to the flask, and it was heated to 210° C. using an oil bath, followed by gradual dropping of 1,1,1,3,3-pentafluorobutane.
• the products and the unreacted raw material were collected by the collector.
• the obtained mixture contained seven kinds of products in addition to the raw material.
• 1,1,1,4,4,4-hexafluorobutane was gasified by the same process as that of Example 1 and introduced at a flow rate such that the contact time became 30 seconds.
• the gas, which had passed the tube, was passed through water in order to remove hydrogen fluoride (HF), followed by drying with calcium sulfate and then gas chromatograph analysis.
• HF hydrogen fluoride
• the gas chromatograph area of the raw material 1,1,1,4,4,4-hexafluorobutane was 43.2%, and 30.6% 3,3,3-trifluoropropene and 17.1% trifluoromethane were additionally detected.
• the target 1,1,4,4,4-pentafluoro-1-butene was not detected.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Related Child Applications (2)

Publications (1)

Family

ID=33415908

Family Applications (3)

Family Applications After (2)

Country Status (4)

Cited By (6)

Families Citing this family (18)

Citations (2)

Family Cites Families (6)

• 2003
  • 2003-04-29 US US10/424,982 patent/US20050119512A1/en not_active Abandoned
• 2004
  • 2004-04-28 WO PCT/US2004/013029 patent/WO2004096737A2/en not_active Ceased
  • 2004-04-28 JP JP2006513380A patent/JP4511527B2/ja not_active Expired - Fee Related
  • 2004-04-28 EP EP04750779A patent/EP1618083A4/en not_active Withdrawn
  • 2004-04-28 US US10/554,783 patent/US7482499B2/en not_active Expired - Fee Related
• 2006
  • 2006-08-21 US US11/506,963 patent/US7259281B2/en not_active Expired - Fee Related

Patent Citations (2)

Also Published As

Similar Documents

Legal Events