JP2000247923A - Production of 3,3-dichloro-1,1,1-trifluoroacetone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convert the subject compound being a main product by using raw materials prepared as by-products in the fluorination reaction of pentachloroacetone with hydrogen fluoride and reacting the raw material in the presence of a specific catalyst and hydrogen fluoride. SOLUTION: A raw material mixture composed of (B) 3-chloro-1,1,1- trifluoroacetone and (C) 3,3,3-trichloro-1,1,1-trifluoroacetone is reacted in a vapor phase in the presence of (A) a solid catalyst and (D) hydrogen fluoride to give (E) 3,3-dichloro-1,1,1-trifluoroacetone. The component A is preferably a catalyst obtained by fluorinating alumina or a metal supported alumina. The components B and C are preferably by-products prepared in fluorinating pentachloroacetone in a vapor phase. The composition ratio of the component B/C (molar ratio) is preferably 1/9 to 9/1. The unreacted components B and C are recovered and can be reused as the raw materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing 3,3-dichloro-1,1,1-trifluoroacetone, which is useful as an intermediate for pharmaceuticals and agricultural chemicals and as a reagent for introducing a fluorine-containing group.

[0002]

2. Description of the Related Art Dokl. Chem. (Engl. Tra
nsl. ), 307, 241 (1989) include 3,
From 3,3-trichloro-1,1,1-trifluoro-propan-2-one via a mercury compound as a catalyst and aluminum enolate in an anhydrous solvent, 3,3-dichloro-
It is described that 1,1,1-trifluoroacetone can be synthesized.

[0003] However, this production process must be kept strictly anhydrous, and there is a problem in using this method industrially, for example, using mercury. Accordingly, the present applicant has proposed a method for producing 3,3-
As a method for producing dichloro-1,1,1-trifluoroacetone, 3,3-dichloro-1,1,1-trifluoroacetone can be obtained by gas-phase fluorination of pentachloroacetone with hydrogen fluoride. And filed an application (Japanese Patent Application No. 10-104507).

[0004]

However, in this production method using hydrogen fluoride, 3,3-dichloro-1,1,1,3
Although 1-trifluoroacetone can be obtained as the main product, significant amounts of 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,
It was revealed that 1,1-trifluoroacetone is by-produced.

[0005]

The present inventors have studied the above method and found that the by-produced 3-chloro-1,1,1-trifluoroacetone and 3,3,3
The trichloro-1,1,1-trifluoroacetone by-product, in the presence of certain catalysts and hydrogen fluoride,
They have found that they can be converted to 3,3-dichloro-1,1,1-trifluoroacetone, and have reached the present invention.

That is, the present invention relates to a method for preparing 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone in the gas phase in the presence of a solid catalyst. 3,3-dichloro-1, characterized in that the starting material mixture is reacted in the presence of hydrogen fluoride.
This is a method for producing 1,1-trifluoroacetone.

The 3-chloro-1,1,1 used in the present invention
-Trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone may be those obtained by any production method, but a preferred example is pentachloroacetone. Those obtained as by-products of 3,3-dichloro-1,1,1-trifluoroacetone when subjected to gas-phase fluorination. These by-products can be easily separated and obtained by purifying a gas phase fluorination reaction product by a known purification means such as distillation.

The raw material mixture 3-chloro-1,1,1-trifluoroacetone / 3,3,3-trichloro-1,
Although the composition ratio (molar ratio) of 1,1-trifluoroacetone is not particularly limited, it is 1/9 to 9/1 and 3/7 to 7
/ 3 is preferred, and in practice, it is more preferably 4/6 to 6/4.

The solid catalyst used in the present invention is fluorinated alumina obtained by fluorinating alumina or metal-carrying alumina or fluorinated alumina carrying a metal.

The alumina for preparing the fluorinated alumina according to the present invention is not particularly limited, but is usually alumina obtained by molding and dehydrating a precipitate formed from an aqueous solution of aluminum salt using ammonia or the like. Commercially available for catalyst carriers or for drying
-Alumina can be preferably used.

As the solid catalyst according to the present invention, fluorinated alumina obtained by partially or completely fluorinating alumina with a fluorine-containing substance such as hydrogen fluoride or chlorinated fluorinated hydrocarbon is preferably used. As the fluorinating agent, inorganic fluorinating agents, for example, hydrogen fluoride, ammonium fluoride,
Fluorine, chlorine monofluoride, chlorine trifluoride, sulfur hexafluoride,
Organic fluorine compounds such as nitrogen trifluoride, for example, chlorodifluoromethane, difluoromethane, trifluoromethane, carbon tetrafluoride, hexafluoroethane, 1,1,
Examples thereof include 1,2-tetrafluoroethane and pentafluoroethane.

The fluorinated alumina according to the present invention is prepared, for example, by immersing alumina in a hydrogen fluoride solution, for example, an aqueous solution of hydrogen fluoride, or by spraying a hydrogen fluoride solution on the alumina and then drying it. Alternatively, a method in which alumina filled in a container is heated and the above-mentioned fluorinating agent is allowed to flow therethrough in a gaseous state can be used.
Regardless of which method is employed, it is preferable that hydrogen fluoride be passed at a temperature equal to or higher than the reaction temperature of the fluorination reaction in the final stage of the preparation of the fluorinated alumina. Therefore,
Usually, the treatment is performed at 200 to 500 ° C or 250 to 450 ° C.

The solid catalyst according to the present invention includes aluminum, chromium, manganese, nickel, cobalt,
Oxides, fluorides, chlorides, fluorides, oxyfluorides, oxychlorides, oxyfluorides, and the like of one or more metals selected from iron can be used. If a plurality of metals are used, it is preferred that one of them is aluminum, chromium or iron. They may also be supported on alumina or fluorinated alumina. The fluorinated alumina refers to aluminum fluoride, fluoride fluoride, oxyfluoride, oxyfluoride chloride, or the like obtained by partially or completely fluorinating aluminum oxide.

When these metals are used by being supported on a carrier, the supported metal is 0.1 to 100 parts by weight based on 100 parts by weight of the carrier.
Parts by weight, preferably 1 to 50 parts by weight.

The method for preparing these catalysts is not limited, but when the catalyst is prepared without using a carrier, the catalyst is prepared once from a metal hydroxide precipitated from a solution of the above-mentioned soluble compound of a metal using a basic substance. It can be obtained by partially or completely modifying the metal oxide thus obtained with halogen with hydrogen fluoride, hydrogen chloride, chlorinated fluorinated hydrocarbon or the like. When used as a supported catalyst, a solution obtained by dissolving a soluble compound of one or more metals selected from chromium, manganese, nickel, cobalt, and iron in the above-mentioned γ-alumina or fluorinated alumina is used. Impregnate or
The fluorination catalyst is prepared by spraying, then drying, and then converting the support to a fluorinated alumina partially or completely with a fluorinating agent in the same manner as for the alumina described above.

The soluble compounds include water, ethanol,
There is no particular limitation as long as it is an oxide or salt of the relevant metal dissolved in a solvent such as acetone, and examples thereof include nitrates, chlorides, sulfates, carbonates, and acetates. Specifically, use chromium nitrate, chromium trichloride, chromium trioxide, potassium dichromate, manganese nitrate, manganese chloride, manganese dioxide, nickel nitrate, nickel chloride, cobalt nitrate, cobalt chloride, iron nitrate, iron chloride, etc. Is preferred. These compounds may be hydrates, and the valence of the metal may be any valence.

Before use, the catalyst prepared by any of the above methods is treated with a fluorinating agent such as hydrogen fluoride, fluorinated or fluorinated chlorinated hydrocarbon at a predetermined reaction temperature or higher before use. It is effective to prevent a change in the composition of the catalyst. 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.

When the fluorination catalyst according to the present invention loses its activity due to the reaction, it can be easily reactivated. That is, the deactivated catalyst can be reactivated by contact with an oxidizing substance at an elevated temperature, such as oxygen, air, ozone, chlorine, or the like. The processing temperature at that time is 200 to 550 ° C, preferably 300 to 500 ° C. If the temperature is lower than 200 ° C., the catalyst remains unreacted.

The reaction temperature of the process according to the invention is between 100 and 500.
° C, preferably 130 to 400 ° C, more preferably 160 to 300 ° C. If the reaction temperature is lower than 100 ° C., the reaction is slow and not practical. If the reaction temperature is increased, the reaction proceeds faster, but 3,3,3-trichloro-
A compound in which the chlorine atom of 1,1,1-trifluoroacetone has been replaced by fluorine is formed, and 3,3-dichloro-1,1,1 is formed.
It is not preferable because the selectivity of 1-trifluoroacetone is lowered.

In the present invention, the molar ratio of the organic substance / hydrogen fluoride to be supplied to the reaction zone can be changed depending on the conditions.
0.1 to 1/50, preferably 1 / 0.1 to 1/20, more preferably 1 / 0.2 to 1/5. In this reaction, it is not necessary to fluorinate the organic matter with hydrogen fluoride, so an excess of hydrogen fluoride is not a problem from the viewpoint of the reaction, but a large amount of hydrogen fluoride hinders the separation from the product. It is not preferable because it is cold.

The reaction pressure is not particularly limited, but 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 1 to 60 seconds.
Seconds, more preferably 10 to 30 seconds.

The reactor may be made of a material having heat resistance and corrosion resistance to hydrogen fluoride, hydrogen chloride and the like, and is preferably stainless steel, Inconel, Hastelloy, Monel, platinum or the like. It can also be made of materials lined with these metals.

The 3,3-dichloro-1,1,1-trifluoroacetone produced by the method of the present invention is purified by applying a known method to the fluorination reaction product. For example, after being taken out of the reactor together with unreacted hydrogen fluoride in a liquid or gaseous state, excess hydrogen fluoride is removed by an operation such as distillation or liquid phase separation, and then the remaining acidic components are removed from a basic substance or the like. And purifying distillation to obtain the desired high-purity 3,3-dichloro-1,1,1-trifluoroacetone. The unreacted raw materials 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1
1-trifluoroacetone can be returned to the reaction system and used as a reaction raw material.

[0024]

EXAMPLES [Preparation Example 1] Activated alumina (KH manufactured by Sumitomo Chemical Co., Ltd.)
S-46: Particle size 4-6 mm, 400 g was weighed, and the powder adhering to the surface was washed off with water. 153 g of hydrogen fluoride (hydrofluoric anhydride) was dissolved in 1380 g of water to prepare a 10% aqueous hydrogen fluoride solution. A 10% aqueous hydrogen fluoride solution was gradually added to the washed activated alumina, stirred, left standing for 3 hours, washed with water, filtered, and then dried at 200 ° C. for 2 hours in an electric furnace. 3. Dry activated alumina with inner diameter of 4.
400cc into a 2cm long 60cm stainless steel reaction tube
The temperature of the electric furnace was raised to 200 ° C. while flowing nitrogen, and a hydrogen fluoride treatment was performed while hydrogen fluoride was accompanied by nitrogen. The temperature was increased as the treatment was performed, but the flow rates of nitrogen and hydrogen fluoride were adjusted so as not to exceed 400 ° C. When the heat generation was stopped, the setting of the electric furnace was further maintained at 400 ° C. for 2 hours, and the catalyst preparation was completed.

[Preparation Example 2] 1336 g of a special-grade reagent ferric nitrate hexahydrate (Fe (NO ₃ ) ₂ .6H ₂ O) was dissolved in pure water to make 4 kg. 4.5 kg of fluorinated alumina prepared in the same manner as in Preparation Example 1 was immersed in this solution, and allowed to stand overnight. Next, alumina was removed by filtration, kept at 100 ° C. in a hot air circulation type drier, and further dried overnight. The obtained iron-supported fluorinated alumina was converted to a 5.4 mm-diameter equipped with an electric furnace.
A 200 cm long cylindrical SUS316L reaction tube was filled, and the temperature was raised to 300 ° C. while flowing nitrogen gas. When water flow was no longer observed, nitrogen gas was accompanied by hydrogen fluoride to reduce the concentration. Gradually increased. After a hot spot due to fluorination of the filled iron-supported fluorinated alumina reached the outlet end of the reaction tube, the state was maintained for 1 hour to prepare a catalyst.

[Example 1] A gas phase reaction apparatus (made of SUS316L, having a diameter of 4.2) comprising a cylindrical reaction tube equipped with an electric furnace.
328 g of the catalyst prepared in Preparation Example 1 as a gas-phase fluorination catalyst was packed into the column. The temperature of the reaction tube was raised to 250 ° C. while flowing nitrogen gas at a flow rate of about 30 ml / min.
And hydrogen fluoride was entrained in the nitrogen gas at a rate of about 0.3 g / min. 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-
The trifluoroacetone mixture (47:43) was vaporized in advance and started feeding to the reactor at a rate of 2.5 g / min. 3
100 g of a mixture of chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone is supplied to the reactor, and the product gas flowing out of the reactor is dried ice. Collected with an acetone-trap. When 101 g of the obtained organic substance was analyzed by gas chromatography, 3,3-dichloro-1,1,1 was obtained.
17.2% of 1-trifluoroacetone, 3-chloro-
1,1,1-trifluoroacetone 24.4% and 3,3,3-trichloro-1,1,1-trifluoroacetone 13.8%.

Example 2 A gas phase reaction apparatus (made of SUS316L, having a diameter of 4.2) comprising a cylindrical reaction tube equipped with an electric furnace.
328 g of the catalyst prepared in Preparation Example 1 as a gas-phase fluorination catalyst was packed into the column. The temperature of the reaction tube was raised to 200 ° C. while flowing nitrogen gas at a flow rate of about 30 ml / min.
And hydrogen fluoride was entrained in the nitrogen gas at a rate of about 0.3 g / min. 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-
The trifluoroacetone mixture (47:43) was vaporized in advance and started feeding to the reactor at a rate of 2.5 g / min. 3
100 g of a mixture of chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone is supplied to the reactor, and the product gas flowing out of the reactor is dried ice. Collected with an acetone-trap. When 111 g of the obtained organic substance was analyzed by gas chromatography, 3,3-dichloro-1,1,1 was obtained.
1-trifluoroacetone 29.4%, 3-chloro-
It was 35.8% of 1,1,1-trifluoroacetone and 28.2% of 3,3,3-trichloro-1,1,1-trifluoroacetone.

Example 3 A gas phase reactor (made of SUS316L, having a diameter of 4.2) comprising a cylindrical reaction tube equipped with an electric furnace.
328 g of the catalyst prepared in Preparation Example 1 as a gas-phase fluorination catalyst was packed into the column. The temperature of the reaction tube was raised to 300 ° C. while flowing nitrogen gas at a flow rate of about 30 ml / min.
And hydrogen fluoride was entrained in the nitrogen gas at a rate of about 0.3 g / min. 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-
The trifluoroacetone mixture (47:43) was vaporized in advance and started feeding to the reactor at a rate of 2.2 g / min. 3
100 g of a mixture of chloro-1,1,1-trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone is supplied to the reactor, and the product gas flowing out of the reactor is dried ice. Collected with an acetone-trap. When 92 g of the obtained organic substance was analyzed by gas chromatography, 3,3-dichloro-1,1,1 was determined.
-Trifluoroacetone 46.1%, 3-chloro-1,
23.7% of 1,1-trifluoroacetone and 3,
3,3-trichloro-1,1,1-trifluoroacetone was 3.9%.

Example 4 A gas phase reactor (made of SUS316L, having a diameter of 4.2) comprising a cylindrical reaction tube equipped with an electric furnace.
328 g of the catalyst prepared in Preparation Example 1 as a gas-phase fluorination catalyst was packed into the column. The temperature of the reaction tube was raised to 250 ° C. while flowing nitrogen gas at a flow rate of about 30 ml / min.
And hydrogen fluoride was entrained in the nitrogen gas at a rate of about 0.2 g / min. 1. While controlling the outlet valve of the reactor
The pressure was increased to 3 kg / cm ² . 3-chloro-1,1,1
-Trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone mixture (47: 4
3) was vaporized in advance, and supply to the reactor was started at a rate of 2.5 g / min. 2.3 while controlling the outlet valve of the reactor
The reaction gas was extracted at kg / cm ² . 3-chloro-1,1,1-trifluoroacetone and 3,
100 g of the 3,3-trichloro-1,1,1-trifluoroacetone mixture was supplied to the reactor, and the product gas flowing out of the reactor was collected by a dry ice-acetone trap. When 103 g of the obtained organic substance was analyzed by gas chromatography, 3,3-dichloro-1,1,1-
Trifluoroacetone 53.8%, 3-chloro-1,
22.9% of 1,1-trifluoroacetone and 3,
3,3-Trichloro-1,1,1-trifluoroacetone was 7.9%.

Example 5 A gas phase reactor (Inconel 600) comprising a cylindrical reaction tube provided with a heating medium circulation jacket
5.4 cm in diameter and 150 cm in length) were charged with 3.2 kg of the catalyst prepared in Preparation Example 2 as a gas phase fluorination catalyst. The temperature of the reaction tube was raised to 250 ° C. while flowing nitrogen gas at a flow rate of about 100 ml / min, and hydrogen fluoride was entrained in the nitrogen gas at a rate of about 3 g / min and chlorine gas at a rate of about 3.3 ml / min. Was. The temperature of the reaction tube was lowered to 195 ° C. as it was, and hydrogen fluoride was accompanied by nitrogen gas at a rate of about 3 g / min and chlorine gas at a rate of about 3.3 ml / min. 3-
Chloro-1,1,1-trifluoroacetone and 3,
The 3,3-trichloro-1,1,1-trifluoroacetone mixture (42:44) was vaporized in advance and started to be supplied to the reactor at a rate of 30 g / min. 3-chloro-1,1,1
1 kg of a mixture of trifluoroacetone and 3,3,3-trichloro-1,1,1-trifluoroacetone was supplied to the reactor, and a product gas flowing out of the reactor was collected by a dry ice-acetone trap. 978 obtained
g of the organic substance was analyzed by gas chromatography. As a result, 64.7% of 3,3-dichloro-1,1,1-trifluoroacetone, 14.5% of 3-chloro-1,1,1-trifluoroacetone and 3 , 3,3-trichloro-1,
1,1-trifluoroacetone was 9.5%.

REFERENCE EXAMPLE A gas phase reactor (made of SUS316L, having a diameter of 4.2 c) comprising a cylindrical reaction tube equipped with an electric furnace.
Preparation example 2 as gas-phase fluorination catalyst
400 g of the catalyst prepared in the same manner as described above was charged. The temperature of the reaction tube was raised to 250 ° C. while flowing nitrogen gas at a flow rate of about 1.2 l / hour, and hydrogen fluoride was entrained in the nitrogen gas at a rate of about 36 g / hour. Keep the temperature of the reaction tube at 30
The temperature was raised to 0 ° C and kept for 1 hour. Next, the temperature of the reaction tube was raised to 21.
The temperature was lowered to 5 ° C., the flow rate of nitrogen gas was set to 1.2 l / h, the supply rate of hydrogen fluoride was set to 36 g / hour, and the supply rate of chlorine was set to 0.33 g / hour.
Feeding to the reactor was started at a rate of g / h.

After supplying 230 g of pentachloroacetone to the reactor, the product gas flowing out of the reactor was dried with ice.
Collected with an acetone-trap. When 125 g of the obtained organic substance was analyzed by gas chromatography,
3-dichloro-1,1,1-trifluoroacetone 6
8.6%, 3,3,3-trichloro-1,1,1-trifluoroacetone 10.9%, 3-chloro-1,1,1
Trifluoroacetone 10.2%.

[0033]

The 3,3-dichloro-1,1,1 of the present invention
-The method for producing trifluoroacetone is useful as an industrial production method because it uses a raw material that is produced by the fluorination reaction of pentachloroacetone with hydrogen fluoride, which is easily adopted industrially.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Sakaya 2805 Imafukunakadai, Kawagoe-shi, Saitama Central Research Institute of Glass Co., Ltd. (72) Inventor Ryo Nada 2805 Imafukunakadai, Kawagoe-shi, Saitama Central 4H006 AA02 AC30 BA09 BA28 BA30 BA37 BC10 BE01 BE30 BE53 BM10 BM71 BM72 BR10 FE71 FE74 FE75 4H039 CA51 CA52 CD10 CD20

Claims (2)

[Claims] (1) 3-chloro-1,1,1-trifluoroacetone and 3,3,3-trifluoroacetone in a gas phase in the presence of a solid catalyst.
A method for producing 3,3-dichloro-1,1,1-trifluoroacetone, comprising reacting a raw material mixture composed of trichloro-1,1,1-trifluoroacetone in the presence of hydrogen fluoride. 2. The catalyst according to claim 1, wherein the solid catalyst is alumina or a catalyst obtained by fluorinating metal-supported alumina.
A method for producing the 3,3-dichloro-1,1,1-trifluoroacetone described.