Organic compounds -- part of the class 532-570 series – Organic compounds – Halogen containing
Patent
1995-06-27
1997-08-19
Ivy, C. Warren
Organic compounds -- part of the class 532-570 series
Organic compounds
Halogen containing
570176, 570229, C07C 1908
Patent
active
056590938
DESCRIPTION:
BRIEF SUMMARY
This application is a 35 U.S.C. 371 national stage filing of PCT/JP93/0188 published as WO 94/14736 on Jul. 7, 1994.
1. Industrial fields where the invention can be utilized
This invention relates to a method of producing 1,1,1,3,3-pentafluoropropane which is a useful compound usable as a substitute for CFC and HCFC which are utilized for a cooling medium, a blowing agent or a cleaning agent and is particularly useful as a urethane blowing agent, besides, a method of producing 1,1,1,3,3-pentafluoro-2-halogeno-3-chloropropane which can be a synthetic intermediate of 1,1,1,3,3-pentafluoropropane, and a method of producing 1,1,1,2,3,3-hexachloropropene.
2. Prior art
As a method of preparing 1,1,1,3,3-pentafluoropropane, a reductive reaction with hydrogen wherein 1,2,2-trichloropentafluoropropane is used as a raw material is known (U.S. Pat. No. 2,942,036).
However, this reaction is not suitable for industrial use due to low yield and generation of 2-chloropentafluoropropene and 1,1,3,3,3-pentafluoropropene which are not reduced enough.
On the other hand, 1,1,1,3,3-pentafluoro-2-halogeno-3-chloropropane is useful by itself as an intermediate of medicines or agricultural chemicals and is a useful compound for the industrial use which can be conducted to hydrofluorocarbon as a substitute for HCFC and CFC which are used as various cooling mediums, blowing agents or cleaning agents, by fluorination or reduction and which can be conducted to monomers of various kinds of resins by dehydrochlorination. Especially, 3,1,1,3,3-pentafluoro-2,3-dichloropropane can be useful as a raw material of 1,1,1,3,3-pentafluoropropane.
Until now, a method of fluorinating propene halogenide with HF in a liquid phase under the presence of a antimony halogenide is known. For example, E. T. McBee et al. obtained 1,1,1,3,3-pentafluoro-2,3--dichloropropane by fluorinating 1,1,1-trifluoro-2,3,3-trichloropropene with HF under the presence of antimony catalyst (J. Am. Chem. Soc. 70, 2023, (1948)).
However, because 1,1,1-trifluoro-2,3,3-trichloropropene, HF and antimony catalyst as raw materials are supplied at once to a reactor before reaction, not only this reaction needs high reaction temperature of 250.degree. C., but also the yield of 1,1,1,3,3-pentafluoro-2,3-dichloropropane is so low as to be 50%, thus this reaction cannot be used industrially.
Besides, 1,1,1,2,3,3-hexaohloropropene is useful as an intermediate of various medicines or agricultural chemicals and is a useful raw material by which an intermediate of various fluorine compounds can be synthesized by fluorinating chlorine of this propene with HF. Especially, it is useful as a raw material of 1,1,1,3,3-pentafluoro-2,3-dichloropropane (HCFC 225da).
Generally, 1,1,1,2,3,3-hexaohloropropene can be synthesized by dehydrochlorination of 1,1,1,2,2,3,3-heptachloropropane. 1,1,1,2,2,3,3-heptachloropropane being a raw material is an economical industrial raw material which can be easily synthesized from chloroform and tetrachloroethylene as economical industrial raw materials.
Hitherto, there is known a method of synthesizing 1,1,1,2,3,3-hexachloropropene by dehydrochlorination of 1,1,1,2,2,3,3-heptachloropropane with alkali metal hydroxide like KOH in alcohol solvent (J. Am. Chem. Soc., 63,1438 (1941)).
However, because of using alcohol as the reaction solvent, this meth6d needs to filtrate the alkali metal chloride produced after the reaction and then separate the product from alcohol by the use of the operation such as distillation.
And, it is also known that by passing through a reaction tube heated around 400.degree. C., it can be obtained from 1,1,1,2,2,3,3-heptachloropropane, but this reaction requires high temperature and use of expensive metal for the material of the reaction tube because of the generation of HCl in the reaction.
OBJECT OF THE INVENTION
The first object of this invention is to provide a method being able to produce 1,1,1,3,3-pentafluoropropane (HFC 245fa) enough in high selectivity in which any problems as mentioned above do not occur.
The second object of
REFERENCES:
patent: 2637747 (1953-05-01), McBee
patent: 2724004 (1955-11-01), Frederick
patent: 2942036 (1960-06-01), Smith et al.
patent: 3639493 (1972-02-01), Campbell
patent: 4980324 (1990-12-01), Kellner et al.
patent: 5447896 (1995-09-01), Rao
Aoyama Hirokazu
Nakada Tatsuo
Takubo Seiji
Daikin Industries Ltd.
Ivy C. Warren
Smith Lyman H.
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