Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/35—Preparation of halogenated hydrocarbons by reactions not affecting the number of carbon or of halogen atoms in the reaction
  • C07C17/354—Preparation of halogenated hydrocarbons by reactions not affecting the number of carbon or of halogen atoms in the reaction by hydrogenation

Definitions

• compositions that meet both low ozone depletion standards as well having low global warming potentials.
• Certain hydrofluoroolefins are believed to meet both goals.
• manufacturing processes that provide halogenated hydrocarbons and fluoroolefins that contain no chlorine that also have a low global warming potential.
• the process is a method for synthesizing fluorinated alkenes in a continuous process, contacting a fluorinated alkyne of the formula R 1 C ⁇ C R 2 , wherein R 1 and R 2 are independently selected from CF 3 , C 2 F 5 , C 3 F 7 , and C 4 F 9 , in a reaction zone, in the gas phase with substantially one equivalent or less of hydrogen in the presence of a Lindlar catalyst.
• the process is a method for the synthesis of fluorinated alkenes from the corresponding fluorinated alkynes in high selectivity by selective hydrogenation in the presence of particular catalysts.
• the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion.
• a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
• “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
• a reaction zone may be a reaction vessel fabricated from nickel, iron, titanium or their alloys, as described in U. S. Patent No. 6,540,933, incorporated herein by reference.
• a reaction vessel of these materials e.g., a metal tube
• alloys it is meant a nickel alloy containing from about 1 to about 99.9 weight percent nickel, an iron alloy containing about 0.2 to about 99.8 weight percent iron, and a titanium alloy containing about 72 to about 99.8 weight percent titanium.
• a Lindlar catalyst is a heterogeneous palladium catalyst on a calcium carbonate support, which has been deactivated or conditioned with a lead compound.
• the lead compound can be lead acetate, lead oxide, or any other suitable lead compound.
• the catalyst is prepared by reduction of a palladium salt in the presence of a slurry of calcium carbonate, followed by the addition of the lead compound.
• the palladium salt in palladium chloride.
• the catalyst is deactivated or conditioned with quinoline.
• the amount of palladium on the support is typically 5% by weight but may be any catalytically effective amount.
• fluohnated alkenes are synthesized by contacting fluorinated alkynes of the structure R 1 C ⁇ C R 2 , wherein R 1 and R 2 are independently selected from CF 3 , C 2 F 5 , C 3 F 7 , and C 4 F 9 with hydrogen in the presence of a selective catalyst.
• Representative fluorinated alkynes include alkynes selected from the group consisting of hexafluoro-2-butyne, octafluoro-2-pentyne, decafluoro-2-hexyne, decafluoro-3-hexyne, dodecafluoro-2-heptyne, dodecafluoro-3-heptyne, tetradecafluoro-3-octyne and tetradecafluoro-4-octyne.
• Hexafluoro-2-butyne is readily available by dechlorination of
• CFC-1316mxx is readily prepared from CF3CCI3 as disclosed in U.S. Patent 5,919,994, which disclosure is herein incorporated by reference.
• Octafluoro-2-pentyne can be prepared from 1 ,1 ,1 ,2,2,3,4,5,5,5- decafluoropentane by dehydofluroinating twice in the presence of base, or zeolites, as disclosed in Japanese patent 2004292329.
• the catalyst of the process is a Lindlar catalyst.
• the amount of the catalyst used is from about 0.5% by weight to about 4% by weight of the amount of the fluorinated alkyne.
• the amount of the catalyst used is from about 1 % by weight to about 3% by weight of the amount of the fluorinated alkyne.
• the amount of the catalyst used is from about 1 % to about 2% by weight of the amount of the fluorinated alkyne.
• the reaction is conducted in a solvent.
• the solvent is an alcohol.
• Typical alcohol solvents include ethanol, /-propanol and n-propanol.
• 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.
• the process is conducted in a batchwise process.
• the process is conducted in a continuous process in the gas phase.
• reaction of the fluorinated alkynes with hydrogenation in the presence of the catalyst should be done with addition of hydrogen in portions, with increases in the pressure of the vessel of no more than about 100 psi with each addition.
• the addition of hydrogen is controlled so that the pressure in the vessel increases no more than about 50 psi with each addition.
• hydrogen can be added in larger increments for the remainder of the reaction.
• hydrogen can be added in larger increments for the remainder of the reaction.
• hydrogen can be added in larger increments for the remainder of the reaction.
• the larger increments of hydrogen addition can be 300 psi. In another embodiment, the larger increments of hydrogen addition can be 400 psi.
• the amount of hydrogen added is about one molar equivalent per mole of fluorinated alkyne. In another embodiment, the amount of hydrogen added is from about 0.9 moles to about 1.3 moles, per mole of fluorinated alkyne. In yet another embodiment, the amount of hydrogen added is from about 0.95 moles to about 1.1 moles, per mole of fluorinated alkyne. In yet another embodiment, the amount of hydrogen added is from about 0.95 moles to about 1.03 moles, per mole of fluorinated alkyne.
• the hydrogenation is performed at ambient temperature. In another embodiment, the hydrogenation is performed at above ambient temperature. In yet another embodiment, the hydrogenation is performed at below ambient temperature. In yet another embodiment, the hydrogenation is performed at a temperature of below about 0° C.
• a mixture of fluorinated alkyne and hydrogen are passed through a reaction zone containing the catalyst. In one embodiment, the molar ratio of hydrogen to fluorinated alkyne is about 1 :1. In another embodiment of a continuous process, the molar ratio of hydrogen to fluorinated alkyne is less than 1 :1. In yet another embodiment, the molar ratio of hydrogen to fluorinated alkyne is about 0.67:1.0.
• the reaction zone is maintained at ambient temperature. In another embodiment of a continuous process, the reaction zone is maintained at a temperature of 30 0 C. In yet another embodiment of a continuous process, the reaction zone is maintained at a temperature of about 40 0 C.
• the flow rate of fluorinated alkyne and hydrogen is maintained so as to provide a residence time in the reaction zone of about 30 seconds. In another embodiment of a continuous process, the flow rate of fluorinated alkyne and hydrogen is maintained so as to provide a residence time in the reaction zone of about 15 seconds. In yet another embodiment of a continuous process, the flow rate of fluorinated alkyne and hydrogen is maintained so as to provide a residence time in the reaction zone of about 7 seconds.
• contact time in the reaction zone is reduced by increasing the flow rate of fluorinated alkyne and hydrogen into the reaction zone. As the flow rate is increased this will increase the amount of fluorinated alkyne being hydrogenated per unit time. Since the hydrogenation is exothermic, depending on the length and diameter of the reaction zone, and its ability to dissipate heat, at higher flow rates it may be desirable to provide a source of external cooling to the reaction zone to maintain a desired temperature.
• the amount of palladium on the support in the Lindlar catalyst is 5% by weight. In another embodiment, the amount of palladium on the support in the Lindlar catalyst is greater than 5% by weight. In yet another embodiment, the amount of palladium on the support can be from about 5% by weight to about 1 % by weight.
• the cis-dihydrofluoroalkene upon completion of a batch-wise or continuous hydrogenation process, can be recovered through any conventional process, including for example, fractional distillation. In another embodiment, upon completion of a batch-wise or continuous hydrogenation process, the cis-dihydrorofluoroalkene is of sufficient purity to not require further purification steps.
• Example 1 demonstrates the selective hydrogenation of hexafluoro- 2-butyne.
• Example 2 demonstrates the hydrogenation of hexafluoro-2-butyne with 2% catalyst by weight.
• Example 3 demonstrates the hydrogenation of octafluoro-2-pentyne with 1 % catalyst by weight.
• Analysis of the product by gas chromatography indicated that 96.7% of octafluoro-2-pentyne is converted into CiS-CF 3 CH CHCF 2 CF 3 , with 1.8% of saturated CF 3 CH 2 CH 2 CF 2 CF 3 .
• Example 4 demonstrates the hydrogenation of hexafluoro-2-butyne with 1 % catalyst by weight.
• Example 5 demonstrates the hydrogenation of decafluoro-3- hexyne.
• Example 6 demonstrates the hydrogenation of hexafluoro-2-butyne in a continuous process to produce a mixture of cis- and trans-1 ,1 ,1 ,4,4,4- hexafluoro-2-butene.
• Hastelloy tube reactor 10" long with a 5" O. D. (outside diameter) and 0.35" wall thickness was filled with 10 g of Lindlar catalyst.
• the catalyst was conditioned at 70 0 C with a flow of hydrogen for 24 hours. Then a flow of a 1 :1 mole ratio of hexafluoro-2-butyne and hydrogen was passed through the reactor at 30 0 C at a flow rate sufficient to provide a 30 second contact time.
• the product mixture was collected in a cold trap after exiting the reactor and analyzed by gas chromatography.
• Example 7 demonstrates the hydrogenation of hexafluoro-2-butyne in a continuous process with a 15 second contact time.
• Example 8 demonstrates the hydrogenation of hexafluoro-2-butyne in a continuous process with a hydrogen:alkyne mole ratio of 0.67:1.
• Example 9 demonstrates the hydrogenation of hexafluoro-2-butyne in a continuous process with a 7 second contact time.
• the procedure of example 6 was followed, with the exception that the flow rate was adjusted to provide a contact time of 7 seconds.
• the reaction was slightly exothermic, with the reactor warming to 42 0 C.
• Hastelloy shaker tube Into a 400ml Hastelloy shaker tube was loaded with 2g of Lindlar catalyst, 3Og of hexafluoro-2-butyne. The shaker was pressurized up to 300psi with H 2 . The pressure suddenly rose to 4000 psi, and the temperature of the reactor contents went up to 7O 0 C. Black powder was recovered as a product.

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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
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• 2008
  • 2008-05-23 BR BRPI0822248A patent/BRPI0822248A2/pt not_active IP Right Cessation
  • 2008-05-23 JP JP2011510476A patent/JP5828761B2/ja not_active Expired - Fee Related
  • 2008-05-23 EP EP08756152A patent/EP2303818A1/de not_active Withdrawn
  • 2008-05-23 MX MX2010012799A patent/MX2010012799A/es active IP Right Grant
  • 2008-05-23 WO PCT/US2008/064609 patent/WO2009142642A1/en active Application Filing
  • 2008-05-23 CN CN2008801293981A patent/CN102036938A/zh active Pending
  • 2008-05-23 CA CA2722711A patent/CA2722711A1/en not_active Abandoned
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