JPH1017502A - Production of 1,1,1,3,3-pentafluoropropane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing 1,1,1,3,3-pentafluoropropane suitable for the production in an industrial scale. SOLUTION: This method for producing 1,1,1,3,3-pentafluoropropane comprises performing an addition reaction of hydrogen fluoride to 1,3,3,3-tetrafluoropropene in the presence of a catalyst for a hydrogen halide addition, consisting of a halide of one or more kinds of metals selected from aluminum, tin, bismuth, antimony and iron.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 1,1,1,1 useful as a foaming agent such as polyurethane foam or a refrigerant.
The present invention relates to a method for producing 3,3-pentafluoropropane.

[0002]

_2. Description of the Related Art As a method for producing 1,1,1,3,3-pentafluoropropane, CF ₃ -CClX-CF ₂ C
1 (catalyst hydrogenation) (JP-A-6-256235)
No.), a method of hydrogenating 1,1,3,3,3-pentafluoro-1-propene with Pd-Al ₂ O ₃ (Izves
t. Akad. Nauk S.D. S. S. R. , Otde
l. Khim. Nauk. 1960, 1412-18;
CA 55,349f), a method for hydrogenating 1,2,2-trichloropentafluoropropane (USP 294)
2036), a method of fluorinating 1,1,1,3,3-pentachloropropane with hydrogen fluoride in the presence of a fluorination catalyst (WO96 / 01797, JP-A-8-10465)
No. 5) and a method of fluorinating 1,2,2-trihydrodichlorotrifluoropropane with hydrogen fluoride in the presence of a fluorination catalyst (JP-A-8-73385).

[0003]

SUMMARY OF THE INVENTION The above-mentioned JP-A-6-2
Although hydrogen replacement of chlorine atoms by hydrogenation described in US Pat. No. 56235 or US Pat. No. 2,942,366 is a method excellent in the reaction rate and the selectivity, the deterioration of the catalyst is remarkable.
Further, a fluorinated chlorinated product as a raw material must be prepared in advance, and there are many difficult points for industrial application. On the other hand, the method by hydrogenation to an olefin described above is an excellent method for producing 1,1,1,3,3-pentafluoropropane, but the 1,1,3,3,3-
It is difficult to obtain pentafluoro-1-propene, and there is a problem in industrially adopting it. 1,1,
The method for fluorinating 1,3,3-pentachloropropane is a simple method for obtaining the target 1,1,1,3,3-pentafluoropropane in one step, but the yield is relatively low. Further, the method of fluorinating 1,2,2-trihydrodichlorotrifluoropropane has a problem that it is necessary to prepare a raw material fluorinated chlorinated product in advance.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present inventors have prepared a method for producing 1,1,1,3,3-pentafluoropropane suitable for production on an industrial scale. After intensive studies on various production processes in order to establish a high yield, it was found that hydrogen fluoride was added in the liquid phase to a specific fluorinated olefin in the presence of a catalyst, so that the desired 1,1,1 , 3,3-Pentafluoropropane can be obtained, and have reached the present invention.

That is, the present invention provides a method for producing 1,1,1,3,3-pentafluoropropane by adding hydrogen fluoride to 1,3,3,3-tetrafluoropropene in the presence of a hydrogen halide addition catalyst. It is. In this case, a method of using one or more metal halides selected from aluminum, tin, antimony, bismuth and iron as a hydrogen halide addition catalyst. further,
The halogen of these metal halides is chlorine, bromine,
1,1,1,3,3 which is either iodine or fluorine
-A method for producing pentafluoropropane.

[0006] The 1,3,3,3-tetrafluoropropene used in the present invention is obtained by dehydroiodating 1,3,3,3-tetrafluoro-1-propane iodide with alcoholic potassium hydroxide. (R.N. Haszeldi
ne et al. Chem. Soc. 1953, 1199-
1206; CA 48 5787f) or 1,1,
A method of dehydrofluorinating 1,3,3-pentafluoropropane with potassium hydroxide in dibutyl ether (IL Kunyanants et al., Izvest. Ak
ad. Nauk S.D. S. S. R. , Otdel. Kh
im. Nauk. 1960, 1412-18; CA 5
5,349f) and the like are known. Further, the present applicant discloses in Japanese Patent Application No. 8-159998 a method for fluorinating 1-chloro-3,3,3-trifluoropropene in the gas phase.

In the present invention, it is desirable to remove water contained in 1,3,3,3-tetrafluoropropene, hydrogen fluoride, a hydrogen halide addition catalyst and the like and water in the reaction system as much as possible.

[0008] Taking the action of antimony halide as an example of a preferred hydrogen halide addition catalyst to be used in the present invention, pentavalent generally has strong catalytic activity but chlorine, bromine,
Since iodine and fluorine easily oxidize from the inactive trivalent state to the active pentavalent state, it is not necessary to use pentavalent antimony from the time of introduction into the reaction system. Therefore, when an antimony catalyst is used in the present invention, the object can be achieved by using trivalent or pentavalent antimony halide or antimony metal as a starting material. Therefore, when specifically citing antimony compounds,
Examples include antimony pentachloride, antimony pentabromide, antimony pentaiodide, antimony pentafluoride, antimony trichloride, antimony tribromide, antimony triiodide, and antimony trifluoride, with antimony pentachloride being most preferred. Similarly, aluminum halides include aluminum trichloride, aluminum tribromide, aluminum triiodide, and aluminum trifluoride, with aluminum trichloride being most preferred. Examples of the tin halide include tin tetrachloride, tin tetrabromide, tin tetraiodide, and tin tetrafluoride, with tin tetrachloride being most preferred. Among bismuth halides, bismuth trichloride is most preferable among various bismuth halides. Among the iron halides, ferric chloride is most preferable among various iron halides.

The process of the present invention can be carried out in a batch mode, a semi-batch mode or a flow mode reactor in which only the product is removed from the reactor. Hereinafter, in describing the reaction conditions of the present invention, conditions in a batch-type reaction will be described.However, when the method of the present invention is performed in a flow-through manner, those skilled in the art having ordinary knowledge may appropriately change the conditions. Is possible.

In the method of the present invention, the catalyst concentration is 1,
0.1 to 3,3,3-tetrafluoropropene
20 mol% is preferable, and 1 to 10 mol% is more preferable. If it is 0.1 mol% or less, both the conversion of 1,3,3,3-tetrafluoropropene and the yield of 1,1,1,3,3-pentafluoropropane decrease, and if it is 20 mol% or more, it increases. The production of tar consisting of a boiling point compound increases,
It is not preferable because catalyst deterioration is remarkable.

The reaction temperature is preferably from 0 to 150.degree.
-100 ° C is more preferred. 1, 3, 3, below 0 ° C
Conversion of 3-tetrafluoropropene, 1,1,1,
If the yield of 3,3-pentafluoropropane decreases, and if the temperature is higher than 150 ° C., the pressure in the reaction system increases, and the reaction operation is difficult.

The molar ratio of hydrogen fluoride to 1,3,3,3-tetrafluoropropene may be at least a stoichiometric amount, particularly preferably 1 to 10. When the molar ratio is less than 1, the conversion of 1,3,3,3-tetrafluoropropene is not sufficiently high, and when the molar ratio exceeds 10, no improvement in the conversion of 1,3,3,3-tetrafluoropropene is observed. It is not economically advantageous from the viewpoint of recovering unreacted hydrogen fluoride.

The pressure required for the reaction depends on the reaction temperature.
What is necessary is just to keep the reaction mixture in a liquid phase in the reactor.
-20 kg / cm ² is preferable, and 1-10 kg / cm ² is more preferable.

In the present invention, a solvent can coexist in the reaction system for the purpose of controlling the reaction and preventing catalyst deterioration. Examples of the solvent include 1,4-bistrifluoromethylbenzene, 2,4-dichlorobenzotrifluoride and the like.
Alternatively, 1,1,1,3,3-pentafluoropropane, which is the target substance, may be used.

The catalyst of the present invention can be easily activated to a pentavalent activated state when degraded or when a metal halide other than pentavalent is used as a catalyst raw material. This method comprises introducing chlorine at 10 ° C. to 100 ° C., optionally in the presence of a solvent such as 1,1,1,3,3-pentafluoropropane. Stirring can be performed if necessary. The amount of chlorine used is 1 to 100 times the number of moles of the catalyst. If the temperature is lower than 10 ° C., it takes a long time to activate. If the temperature is higher than 100 ° C., chlorination of a coexisting solvent such as 1,1,1,3,3-pentafluoropropane occurs, which is not preferable.

The reactor for carrying out the reaction of the present invention contains Hastelloy, stainless steel, Monel, nickel, or the like, or a metal such as these, or tetrafluoroethylene resin, chlorotrifluoroethylene resin, vinylidene fluoride resin, PFA resin, or the like. It is preferable to use a member made of a material lined with the above.

The 1,1,1, produced by the method of the present invention
The 3,3-pentafluoropropane is purified by applying a known method to the fluorination reaction product. For example, after being removed from the reactor in a liquid or gas state together with unreacted hydrogen fluoride, excess Hydrogen fluoride is removed by an operation such as liquid phase separation, and then acidic components are removed with water or a basic aqueous solution, and then the desired high-purity 1,1,1,3,3-pentane is distilled off. It is called fluoropropane.

[0018]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these embodiments.

Example 1 500 ml of SUS3 equipped with a stirrer, a reflux condenser maintained at -30 ° C. and a pressure regulating valve
In a 0.4 autoclave, 6.0 g (0.02 mol) of antimony pentachloride and 100 g of hydrogen fluoride (5.
(0 mol) was stirred for 30 minutes to activate the catalyst. The generated hydrogen chloride was discharged from a pressure regulating valve provided at the rear of the reflux condenser, and after returning the pressure to normal pressure, the pressure regulating valve was closed,
The autoclave was cooled with dry ice-methanol and 1,3,3,3-tetrafluoropropene 114 g
(1.0 mol), and the reaction temperature was increased to 50 ° C. while stirring.
3.5 hours after the start of the reaction, the reactor was cooled to room temperature, the pressure was reduced to normal pressure, and the gas distilled out of the reactor was passed through an aqueous layer and a concentrated sulfuric acid layer, and then dried with ice. -Collected in a trap cooled with methanol. The weight of the recovered organic matter was 123 g, and the product composition analyzed by gas chromatography was 1,1,1,3,3.
3-pentafluoropropane (HFC-245fa) 9
8.5%, 1,3,3,3-tetrafluoropropene (HCFC-1234) 0.4% and 1-chloro-
3,3,3-trifluoropropene (HCFC-123
3) It was 0.1%. Table 1 shows the results.

Examples 2, 3, 4, and 5 The reaction was carried out in the same manner as in Example 1 under the conditions shown in Table 1. Table 1 shows the results.

[0021]

[Table 1]

[0022]

The method of the present invention provides 1,1,1,1 with a high yield.
The effect is that 3,3-pentafluoropropane can be produced.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C07C 17/087 7106-4H C07C 17/087 // C07B 61/00 300 C07B 61/00 300

Claims (3)

[Claims] 1. Production of 1,1,1,3,3-pentafluoropropane, characterized in that hydrogen fluoride is added to 1,3,3,3-tetrafluoropropene in the presence of a hydrogen halide addition catalyst. Method. 2. The hydrogen halide addition catalyst is selected from the group consisting of aluminum, tin, bismuth, antimony and iron.
The method for producing 1,1,1,3,3-pentafluoropropane according to claim 1, which is a halide of one or more kinds of metals. 3. The method for producing 1,1,1,3,3-pentafluoropropane according to claim 1, wherein the halogen of the hydrogen halide addition catalyst is chlorine, bromine, iodine or fluorine.