JPH09194404A - Production of 1-chloro-3,3,3-trifluoropropene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce 1-chloro-3,3,3-trifluoropropene useful for an intermediate for a medicine, a pesticide and a functional material from an easily available raw material. SOLUTION: The objective 1-chloro-3,3,3-trifluoropropene is obtained by reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride under the existence of a fluorinating catalyst in gas phase. The fluorinating catalyst used in the reaction is an oxide or a fluoride of one or more metals selected from aluminum, chromium, manganese, nickel and cobalt and is preferably a chromium catalyst supported on a alumina. The ratio of 1,1,1,3,3-pentachloropropane to hydrogen fluoride used for the reaction is preferably (1/3) to (1/10) and the supported metal ratio on the catalyst is 1-10wt.%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a process for producing 1-chloro-3,3,3-trifluoropropene which is useful as an intermediate for pharmaceuticals, agricultural chemicals and functional substances, and more specifically to a gas phase fluorination reaction. Is a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a method for producing 1-chloro-3,3,3-trifluoropropene, an addition reaction of 3,3,3-trifluoropropyne with hydrogen chloride (J. Chem.
Soc. , 1952, 3490. ) Or 3-chloro-
Dehydroiodination reaction of 1,1,1, -trifluoro-3-iodopropane with ethanolic KOH (J. Che
m. Soc. , 1953, 1199. ) Are known.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The production method mentioned in the prior art is to obtain the starting material 3,3,3-trifluoropropyne or 3-chloro-1,1,1,1-trifluoro-3-iodopropane. However, the latter is not a method suitable for industrial implementation.

Therefore, the present invention provides a method that is industrially feasible and employs a starting material that is relatively easily available as a raw material.

[0005]

[Means for Solving the Problems] The present inventor uses, as a raw material, a substance which is available on an industrial scale or which can be relatively easily produced from a raw material available on an industrial scale.
When a method for producing chloro-3,3,3-trifluoropropene was examined, 1,1,1,3,3-pentachloropropane was used as a raw material, and this was gas-phase fluorinated with hydrogen fluoride in the presence of a catalyst. The inventors have found that the objectives can be achieved by this, and completed the present invention.

That is, the present invention is characterized in that 1,1,1,3,3-pentachloropropane is reacted with hydrogen fluoride in the presence of a fluorination catalyst in a gas phase, 1-chloro-3,3,3. This is a method for producing 3-trifluoropropene.

The starting material of the present invention is 1,1,1,3
3-Pentachloropropane is a known substance and can be easily produced by a method described in a known document. The fluorination catalyst according to the present invention is one or two selected from aluminum, chromium, manganese, nickel and cobalt.
These include oxides, fluorides, chlorides, fluorinated chlorides, oxyfluorides, oxychlorides, and oxyfluorinated chlorides of one or more kinds of metals. These may also be supported on an appropriate carrier. As the carrier, aluminum oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride, oxyfluorinated chloride, etc., or activated carbon can be used.

The method for preparing these catalysts is not limited, but when the catalyst is prepared without using a carrier, it is prepared once from a metal hydroxide precipitated from a solution of the soluble compound of the above metal using a basic substance. It can be obtained by partially or completely modifying the formed metal oxide with hydrogen fluoride, hydrogen chloride, chlorinated fluorinated hydrocarbon or the like. When used as a supported catalyst, aluminum oxide such as γ-alumina or hydrogen fluoride, hydrogen chloride, or
Impregnating or spraying a solution in which a soluble compound of one or more metals selected from chromium, manganese, nickel and cobalt is dissolved in alumina modified with halogen such as chlorinated fluorinated hydrocarbon. Is prepared in.

The amount of supported metal is 0.1 to 20 wt%, preferably 1 to 10 wt%. In the catalyst according to the present invention, an alkaline earth element such as Mg and Ca and a lanthanoid element such as La and Ce can be added as subcomponents. These are added in order to suppress recrystallization of the oxyhalide which is the carrier or the supported metal and maintain the activity. The weight ratio of the accessory component element to the supported metal is 50:50 to 99.9: 0.1, preferably 70:30 to 99: 1.

As the soluble compound, water, ethanol,
Examples thereof include nitrates, chlorides, oxides, etc. of the corresponding metals which are soluble in a solvent such as acetone. Specifically, chromium nitrate, chromium trichloride, chromium trioxide, potassium dichromate, manganese nitrate, manganese chloride, manganese dioxide, nickel nitrate, nickel chloride, cobalt nitrate, cobalt chloride and the like can be used.

The catalyst prepared by any method is treated with a fluorinating agent such as hydrogen fluoride, fluorinated or chlorinated hydrocarbon at a temperature higher than a predetermined reaction temperature before use, and the It is effective to prevent compositional changes. Supplying oxygen, chlorine, fluorinated or chlorinated hydrocarbons, etc. into the reactor during the reaction is effective for extending the life of the catalyst, improving the reaction rate, and improving the reaction yield.

The reaction temperature is 100 to 450 ° C., preferably 150 to 300 ° C. When the reaction temperature is low, the reaction is slow and not practical. If the reaction temperature is raised, the life of the catalyst will be shortened, and the reaction will proceed rapidly, but high fluorinated compounds will be formed.
It is not preferable because the selectivity of -chloro-3,3,3-trifluoropropene decreases.

In the method of the present invention, the ratio of 1,1,1,3,3-pentachloropropane / hydrogen fluoride supplied to the reaction zone may vary depending on the reaction temperature, but is 1/3 to 1 /.
30, preferably 1/3 to 1/10. If the amount of hydrogen fluoride is excessive, the yield of the target product will decrease due to the increase in the amount of highly fluorinated products, and if the amount of hydrogen fluoride is small, the reaction rate will decrease and the yield of the target product will also decrease. descend. However, over- or under-fluorination is not critical in large-scale production, since the low fluorinated, unreacted, or hydrogen fluoride normally associated with the product is separated from the product and recycled.

The reaction pressure is not particularly limited, but it is preferably ¹ to 10 kg / cm ² from the viewpoint of the apparatus. It is desirable to select conditions so that the raw material organic substances, intermediate substances and hydrogen fluoride present in the system are not liquefied in the reaction system.
The contact time is usually 0.1 to 300 seconds, preferably 5 to 1
00 seconds.

The reactor may be made of a material having heat resistance and corrosion resistance to hydrogen fluoride, hydrogen chloride and the like, and stainless steel, hastelloy, monel, platinum and the like are preferable.
It can also be made of materials lined with these metals.

The product containing 1-chloro-3,3,3-trifluoropropene treated by the method of the present invention and discharged from the reactor is purified by a known method to give a product. The purification method is not limited. For example, the product is first washed with water or / and an alkaline solution to remove acidic substances such as hydrogen chloride and hydrogen fluoride, and after drying,
It can be carried out by subjecting it to distillation to remove organic impurities.

[0017]

[Preparation Example 1] 336 g of a special grade reagent CrCl ₃ .6H ₂ O was dissolved in pure water to make 1 L. 250 cc of granular [gamma] -alumina having a diameter of 5 mm and a surface area of 340 m < ² > / g was immersed in this solution and allowed to stand overnight. Next, γ-alumina was removed by filtration, kept at 100 ° C. in a hot air circulating dryer, and further dried overnight. The obtained chrome-supported alumina was equipped with an electric furnace to form a cylindrical SUS316 having a diameter of 5 cm and a length of 30 cm.
It was filled in a reaction tube made of L and heated to 300 ° C. while flowing nitrogen gas, and when the outflow of water was no longer observed, hydrogen gas was entrained in the nitrogen gas and the concentration thereof was gradually increased. The hot spot due to the fluorination of the filled chromium-supported alumina reached the outlet end of the reaction tube, and the reactor temperature was set to 3
The temperature was raised to 50 ° C., and the state was maintained for 1 hour to prepare a catalyst.

Example 1 Preparation Example 1 as a gas phase fluorination catalyst in a gas phase reactor (made of SUS316L, diameter 1 inch, length 30 cm) consisting of a cylindrical reaction tube equipped with an electric furnace.
50 cc of the catalyst prepared in (1) was filled. The temperature of the reaction tube is 300 ° C while flowing nitrogen gas at a flow rate of about 190 cc / min.
And hydrogen fluoride was entrained in the nitrogen gas at a rate of about 0.25 g / min. The temperature of the reaction tube was raised to 350 ° C. and kept for 1 hour. Next, the temperature of the reaction tube was lowered to 220 ° C., hydrogen fluoride was supplied at a feed rate of 0.29 g / min, and
1,1,3,3-Pentachloropropane was vaporized in advance and the supply to the reactor was started at a rate of 0.35 g / min.

After 1 hour from the start of the reaction, the reaction was stable. Therefore, the produced gas flowing out from the reactor was blown into water to remove the acidic gas, and then it was collected with a dry ice-acetone trap. The results of analyzing the collected organic matter by gas chromatography are shown in Table 1.

[0020]

[Table 1]

[Embodiments 2 to 4] After the preparatory steps similar to those in Example 1, the same reaction operation, recovery operation and analysis as in Example 1 were carried out under the conditions shown in Table 1. The results are shown in Table 1.

[0022]

The process for producing 1-chloro-3,3,3-trifluoropropene of the present invention is easy to obtain for 1,1,1.
1,3,3-pentachloropropane as raw material, high 1
Since it has a -chloro-3,3,3-trifluoropropene yield, it is useful as an industrial production method.

Claims (2)

[Claims] 1. The method according to claim 1, wherein 1, 1
1-chloro-3,3,3-characterizing that 1,1,3,3-pentachloropropane is reacted with hydrogen fluoride.
Method for producing trifluoropropene. 2. The 1-chloro-3 according to claim 1, wherein the fluorination catalyst is a chromium-supported alumina catalyst.
A method for producing 3,3-trifluoropropene.