JP2003238475A - Method for producing 1,1,1-trifluoroacetone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control heat generation on the surface of a catalyst and to prolong the life of the catalyst in a technique for producing 1,1,1-trifluoroacetone by hydrogenolysis of a halogenated trifluoroacetone in a vapor phase in the presence of the catalyst. <P>SOLUTION: A solid-phase catalyst obtained by bringing a carrier into contact with a solution containing palladium and an additive metal (at least one kind of a metal selected from silver, rhenium and gold) or bringing the carrier into contact with a solution containing palladium and a solution containing the additive metal and reducing the carrier with reducing gas is used as the catalyst. Preferably 1-100 g of the additive metal is contained in 100 g of palladium. Activated carbon, alumina, silica alumina or silica is preferable as the carrier. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is useful as an intermediate for pharmaceuticals and agricultural chemicals, and as a reagent for introducing a fluorine-containing group.
The present invention relates to a method for producing 1,1-trifluoroacetone. It also relates to a method for preparing a solid phase catalyst used in that case.

[0002]

As a method for industrially producing 1,1,1-trifluoroacetone which is a useful organic reagent, the present applicant has proposed that the halogenated trifluoroacetones represented by the general formula [1]

[0003]

[Chemical 2]

(Wherein, X represents chlorine, bromine or iodine, and n represents an integer of 1 to 3) as a raw material.
A method of reducing in a liquid phase in the presence of metallic zinc as a reducing agent and a protic solvent has been disclosed in JP-A-2000-336057.

Further, the applicant of the present invention, as a method which does not require metallic zinc as a reducing agent, vaporizes halogenated trifluoroacetone represented by the general formula [1] by using a solid phase catalyst composed of a specific transition metal. The method of hydrocracking in the phase is disclosed as Japanese Patent Laid-Open No. 2001-316322. The catalyst used in the present invention is ruthenium,
A transition metal such as palladium, iridium, rhodium, nickel, copper or iron is supported on a carrier such as activated carbon. By reacting the halogenated trifluoroacetone with hydrogen gas in the gas phase in the presence of this catalyst, the target compound 1,1,1-trifluoroacetone can be produced in high yield without producing a large amount of zinc waste. Acetone could be synthesized.

[0006]

Problems to be Solved by the Invention
As a main problem in the invention of Japanese Patent No. 322, there is a fact that strong heat is likely to occur on the surface of the solid-phase catalyst. If the heat generated on the surface of the solid-phase catalyst is too large, it becomes difficult to control the reaction, and the efficiency is deteriorated, for example, the feed rate of the raw material is reduced and the reaction tube needs to be thin to improve the heat removal effect. In addition, the system that generates a large amount of heat also shortens the life of the catalyst.

That is, in the technique of deriving halogenated trifluoroacetone into 1,1,1-trifluoroacetone by hydrogenolysis, if the heat generation on the catalyst surface can be suppressed to a smaller level, 1,1,1-trifluoroacetone can be obtained. It facilitates industrial production of acetone. It has been required to find a means for suppressing such heat generation.

[0008]

[Means for Solving the Problems] In view of the above problems, the present inventors have decided to use halogenated trifluoroacetone with 1,
The inventors have diligently studied a method for more effectively inducing 1,1-trifluoroacetone.

As a result, the halogenated trifluoroacetone is hydrolyzed in the gas phase with hydrogen gas to give 1,1,1-
In the technique of deriving into trifluoroacetone, the use of a solid-phase catalyst in which a metal selected from silver, rhenium, and gold (hereinafter referred to as an additive metal) is supported on the same carrier to solve the above problems. I found that. That is, contact the carrier with a solution containing a palladium compound, and a solution containing an added metal compound,
By using a solid phase catalyst obtained by subjecting the carrier to a solution containing a palladium compound and an added metal compound at the same time and then subjecting the solution to a reducing gas such as hydrogen for the reaction, the activity as a catalyst is substantially increased. It was found that the heat generation on the surface of the catalyst was significantly suppressed without being damaged. We also found that the use of these catalysts significantly increases the catalyst life.

The present inventors further prefer that the amount of the added metal supported in these solid-phase catalysts is 1 to 100 g in total per 100 g of palladium, and the carrier is selected from activated carbon, alumina, silica-alumina, or silica. I have found that what is provided is preferable.

The inventors of the present invention also prepared a catalyst, in which palladium and silver are supported on the same carrier, which is one of the catalysts used in this way, by using a carrier containing a solution containing palladium nitrate and silver nitrate. It has been found that it is particularly preferable to bring the carrier into contact with a solution containing Pd, or to bring the carrier into contact with a solution containing palladium nitrate and silver nitrate at the same time, and then carry out a reduction treatment with a reducing gas, thus completing the present invention.

The "catalyst in which palladium and the added metal are carried on the same carrier" in the present invention is called "composite catalyst". On the other hand, a physical mixture of a carrier supporting only palladium and a carrier supporting only an added metal does not correspond to the “composite catalyst” in the present invention.

That is, the present invention provides a method for hydrolyzing a halogenated trifluoroacetone represented by the general formula [1] with hydrogen gas in a gas phase to obtain 1,1,1-trifluoroacetone. The catalyst is characterized by using a solid-phase catalyst in which palladium and at least one additional metal selected from silver, rhenium, and gold are supported on the same carrier. Further, in particular, the solid-phase catalyst is characterized by being obtained by contacting a carrier with a solution containing a palladium compound and a solution containing an added metal compound, and then reducing this with a reducing gas. . Further, the solid phase catalyst is characterized by being prepared by bringing a carrier into contact with a solution containing a palladium compound and an added metal compound at the same time, and then reducing the solution with a reducing gas. In addition, in the solid-phase catalyst, the amount of the added metal supported is 1 to 100 g in total per 100 g of palladium. Further, it is characterized in that a carrier selected from activated carbon, alumina, silica alumina or silica is used as the carrier. The present invention further provides that the carrier is contacted with a solution containing palladium nitrate and a solution containing silver nitrate,
A catalyst for use in the above reaction, wherein palladium and silver are supported on the same carrier, characterized in that the carrier is brought into contact with a solution containing palladium nitrate and silver nitrate at the same time and then subjected to reduction treatment with a reducing gas. Provide the means to do.

The present invention will be described in more detail below. The method of the present invention can be carried out in a gas phase in a flow type gas phase reactor. The structural formula of the halogenated trifluoroacetone represented by the general formula [1], which is a raw material in the method of the present invention, is listed below.

[0015]

[Chemical 3]

In the present invention, of these halogenated trifluoroacetones, only one kind may be used, or a mixture of a plurality of halogenated trifluoroacetones may be used. Converted to 1,1-trifluoroacetone.

As the carrier, activated carbon, alumina, silica alumina or silica can be used. Examples of the supporting method include a method of immersing a solution containing the above metal compound in a carrier and spraying the solution on the carrier. At this time, as the solution containing the palladium compound and the added metal compound,
A chloride, bromide, fluoride, oxide, hydroxide, nitrate, sulfate, carbonate, aco complex, halogeno complex or the like of these metals dissolved in water or alcohol can be used.

The order of bringing the carrier into contact with the metal compound is such that the carrier is brought into contact with the solution containing the palladium compound and then brought into contact with the solution containing the added metal compound, and the carrier is brought into contact with the solution containing the added metal compound. Then, either a method of contacting with a solution containing a palladium compound or a method of contacting with both solutions simultaneously may be used. It is also possible to prepare a solution containing both the palladium compound and the added metal compound, and contact this solution with the carrier at one time,
Usually, it is preferable because it is easier to operate.

After impregnating the carrier with palladium and the added metal by these methods, the carrier is dried and calcined at about 150 to 350 ° C. in the presence of an inert gas, and then a reducing gas such as hydrogen gas is circulated. By applying the reduction process,
A composite catalyst is prepared.

Among these, when silver is used as the additive metal, the halide of silver is hardly soluble and is not preferable as a raw material, and it is preferable to use other silver compounds such as silver nitrate. When silver is used as the additive metal, if the counter anion of palladium is a halide ion or if a halide ion is present in the liquid phase, a sparingly soluble silver halide is formed with silver, and the carrier It is not preferable because it may hinder the dipping in water. That is, it is preferable to use other than the halide ion as the counter anion of palladium.

As described above, in order to prepare a solid-phase catalyst in which palladium and silver are supported on the same carrier, the carrier is brought into contact with a solution containing palladium nitrate and silver nitrate, or the carrier is mixed with a solution containing palladium nitrate and In a preferred embodiment, the solution is brought into contact with a solution containing silver nitrate to impregnate the metal, and then reduction treatment with a reducing gas is performed. In this case, it is preferable that the halide ion does not exist even in the solvent in which the metal compound is dissolved, and pure water or nitric acid aqueous solution can be preferably used.

When such a composite catalyst is used, there is virtually no change in the selectivity and yield of 1,1,1-trifluoroacetone as compared with the case of using a conventional catalyst in which only palladium is supported. Nevertheless, the temperature rise on the catalyst surface is greatly suppressed, making it much easier to control the reaction,
Moreover, the catalyst life is significantly increased. On the other hand, even if only the added metal is supported on the carrier, the catalytic activity is very low and the hydrogenolysis hardly progresses. In addition, even if the normal catalyst supporting only palladium and the carrier supporting only the added metal are physically mixed, the reaction proceeds, but the temperature rise on the catalyst surface is not sufficiently suppressed and the catalyst life is also increased. do not do. That is, the effect of advancing the reaction of synthesizing 1,1,1-trifluoroacetone by hydrogenolysis of halogenated trifluoroacetone advantageously uses a catalyst in which palladium and the added metal are supported on the same carrier. In some cases, it is specifically expressed.

Although silver, rhenium, and gold all have the same effect as the additive metal, both the effect of suppressing heat generation and the effect of extending the catalyst life are generally silver> rhenium, The order is gold.

In the method of the present invention, the amount of palladium supported on the carrier (weight converted to metal atoms) is not particularly limited, but is preferably 0.1 g to 10 g, and particularly preferably 0.2 to 5 g per 100 g of the carrier. . If it is less than 0.1 g, the yield of 1,1,1-trifluoroacetone will decrease, and if it exceeds 5 g, it is economically unfavorable.

The amount of the added metal supported in the composite catalyst is not particularly limited, but the total amount of the added metal is preferably 1 to 100 g with respect to 100 g of palladium, and 5 to 50 is preferable.
Particularly preferably g. If the added metal is less than 1 g, it is difficult to obtain the effect of intentionally using it.
If it exceeds g, the palladium content is relatively decreased and the activity as a catalyst is decreased, which is not preferable.

The hydrogenolysis of halogenated trifluoroacetone may be carried out without a solvent or with a solvent. When using a solution, an aqueous solution or an alcohol solution (methanol solution, ethanol solution, etc.) is preferable, and an aqueous solution is particularly preferable. When alcohol is used, the carbon number is 1 to
An alcohol in which the alkyl group of 20 is bonded to a hydroxyl group is preferable. In the case of an aqueous solution or an alcohol solution, the halogenated trifluoroacetone may have a structure such as a hydrate represented by the following formulas [2] to [4], an alcohol adduct, gem-diol, hemiacetal, or acetal. It does not matter even if the structure is.

[0027]

[Chemical 4]

[0028]

[Chemical 5]

[0029]

[Chemical 6]

(In each formula, X and n have the same meanings as in formula [1]. M is an integer, R ₁ is an alkyl group, and R ₂ and R ₃ are each independently a hydrogen atom or an alkyl group. When a solvent is used, the amount thereof is not particularly limited, but it is 10 per 100 g of halogenated trifluoroacetone.
It is preferably 0 g or less, particularly preferably 50 g or less. If the amount of the solvent is larger than the above amount, problems such as the need for an excessively large reaction device may occur, which is not economically preferable.

When carrying out the reaction, the above-mentioned raw material or a solution thereof may be gasified by a vaporizer, then introduced into a reactor, and reacted with hydrogen gas in the presence of a catalyst.
At this time, for the purpose of controlling the reaction and preventing the deterioration of the catalyst,
Nitrogen gas can coexist in the reactor.

The set temperature of the reactor in hydrocracking is 5
0 degreeC-300 degreeC is preferable, and 80 degreeC-230 degreeC is especially preferable. If it is lower than 50 ° C, the reaction rate is not sufficient, which is not preferable. On the other hand, when the temperature exceeds 300 ° C, heat generation on the catalyst surface is large, the catalyst life is shortened, and hydrogenolysis of trifluoromethyl group and / or hydrogenation to carbonyl group proceeds to promote 1,1,1-trifluoro. It is not preferable because the yield of acetone is reduced and the by-product makes purification difficult.

The number of moles of hydrogen which acts on 1 mole of the halogenated trifluoroacetone as the starting material depends on the number (n) of the halogen atoms of the halogenated methyl group (—CH _{2 —n} X _n ) of the starting compound, .5 to 50, and 2
-10 is preferable and 2.5-5 is especially preferable.
If the number of moles is less than 1.5, the reaction rate of the halogenated trifluoroacetone as a raw material is not sufficiently high, while if the molar ratio exceeds 50, almost no improvement in the reaction rate is observed, which is economical from the viewpoint of unreacted hydrogen recovery. All of them are not preferable because they are not advantageous.

The reactor for carrying out the reaction of the present invention is a tetrafluoroethylene resin, chlorotrifluoroethylene resin, PFA.
It is preferable to use a material with resin, carbon, etc. lined inside. If the reaction is performed in the absence of water, in addition to these materials, use iron, stainless steel, nickel, or Hastelloy (TM). You can also use the ones. The method for carrying out the method of the present invention is not limited, but specific examples of typical embodiments will be described. A flow-through reactor that can withstand the reaction conditions is filled with the composite catalyst supported on activated carbon. It is heated from the outside of the reactor and hydrogen is circulated, or hydrogen and nitrogen are simultaneously circulated. When the inside of the reaction tube reaches a predetermined temperature, the raw material mixture containing the raw material halogenated trifluoroacetone is introduced into the vaporizer, vaporized and mixed with hydrogen, and after that, it is introduced into the reaction tube and circulated. The mixture of gas and liquid flowing out from the reaction tube is absorbed in water, cooled and recovered as a liquid. The halogenated trifluoroacetone may be introduced into the reactor separately from hydrogen.

The 1,1,1-trifluoroacetone produced by the method of the present invention is purified by applying a known method for a hydrogenolysis reaction product of a fluorinated compound. The product containing 1,1,1-trifluoroacetone flowing out in a liquid or gas state together with hydrogen chloride was cooled and taken out, and then hydrogen chloride was removed by an operation such as distillation or liquid phase separation, and then remained. The desired highly pure 1,1,1-trifluoroacetone can be obtained by removing the acidic component with a basic substance and then subjecting it to purification distillation.

[0036]

EXAMPLES The embodiments of the present invention in the vapor phase method will be described below with reference to examples, but the present invention is not limited to these examples. In the examples, “%” in the gas chromatographic analysis composition represents “area%”.

[Catalyst Preparation Example 1] Preparation of "palladium-silver / activated carbon" catalyst (composite catalyst).

After dissolving 0.5 g of palladium nitrate in terms of metal weight and 0.1 g of silver nitrate in terms of metal weight in 250 g of water, 100 g of palm shell activated carbon (granular, diameter 4 mm)
Was added and the mixture was immersed for 18 hours. The water was removed under reduced pressure, the glass tube (30 mm in diameter) was filled, heated to 120 ° C., and dried while flowing nitrogen. After sufficiently drying, hydrogen was passed at 100 ml / min, and 2 at a rate of 50 ° C / hour.
The temperature was raised to 50 ° C., and hydrogen flow was continued at that temperature for another 2 hours to prepare a “palladium-silver / activated carbon” catalyst. The obtained catalyst had a palladium content of 0.5% by weight and a silver content of 0.1% by weight per activated carbon. The catalyst obtained is called catalyst 1. [Catalyst Preparation Example 2] Preparation of "palladium-rhenium / activated carbon" catalyst (composite catalyst).

0.5 g of palladium chloride in terms of metal weight and 0.2 g of rhenium oxide (Re ₂ O ₇ ) in terms of metal weight
Was dissolved in 250 g of a 10% aqueous hydrochloric acid solution, and then a "palladium-rhenium / activated carbon" catalyst was prepared in the same manner as in Catalyst Preparation Example 1. The obtained catalyst had a palladium content of 0.5% by weight and a rhenium content of 0.2% by weight per activated carbon. The catalyst obtained is called catalyst 2. [Catalyst Preparation Example 3] Preparation of "palladium-gold / activated carbon" catalyst (composite catalyst).

0.5 g of palladium chloride in terms of metal weight and 0.3 g of tetrachlorogold (III) in terms of metal weight
After dissolving the acid (HAuCl ₄ ) in 250 g of a 10% aqueous hydrochloric acid solution, a “palladium-gold / activated carbon” catalyst was prepared in the same manner as in Catalyst Preparation Example 1. The obtained catalyst had a palladium content per activated carbon of 0.5% by weight and a gold content of 0.3% by weight.
Is. The catalyst obtained is called catalyst 3.

[Catalyst Preparation Example 4] Preparation of "palladium-silver / activated carbon" catalyst (composite catalyst).

After dissolving 0.5 g of palladium nitrate in terms of metal weight and 0.3 g of silver nitrate in terms of metal weight in 250 g of water, a "palladium-silver / activated carbon" catalyst was prepared in the same manner as in Catalyst Preparation Example 1. . The obtained catalyst had a palladium content per activated carbon of 0.5% by weight and a silver content of 0.3% by weight. The catalyst obtained is called catalyst 4.

[Catalyst Preparation Example 5] "Palladium-silver-gold /
Preparation of "activated carbon" catalyst (composite catalyst).

0.5 g of palladium nitrate in terms of metal weight
And 0.1 g of metal nitrate in terms of metal weight, and metal weight
Converted to 0.1 g of tetrachloroauric (III) acid (HAu
Cl _Four) Was dissolved in 250 g of water, and
Similarly, a "palladium-silver-gold / activated carbon" catalyst was prepared.
It was The palladium content per activated carbon of the obtained catalyst was
0.5% by weight, silver content 0.1% by weight, gold content
It is 0.1% by weight. The catalyst obtained is called catalyst 5.

[Catalyst Preparation Example 6] "Palladium / activated carbon"
Preparation of catalyst.

After dissolving 0.5 g of palladium chloride in terms of metal weight in 250 g of a 10% hydrochloric acid aqueous solution, a "palladium / activated carbon" catalyst was prepared in the same manner as in Catalyst Preparation Example 1. The palladium content of the obtained catalyst per activated carbon was 0.5% by weight. The catalyst obtained is called catalyst 6.

[Catalyst Preparation Example 7] Preparation of "silver / activated carbon" catalyst.

250 g of silver nitrate in terms of metal weight of 250
After dissolving in g water, a "silver / activated carbon" catalyst was prepared as in Catalyst Preparation Example 1. The silver content of the resulting catalyst per activated carbon is 0.5% by weight. The catalyst obtained is called catalyst 7.

[Catalyst Preparation Example 8] Preparation of "rhenium / activated carbon" catalyst.

After dissolving 0.5 g of rhenium oxide (Re ₂ O ₇ ) in terms of metal weight in 250 g of a 10% hydrochloric acid aqueous solution, a “rhenium / activated carbon” catalyst was prepared in the same manner as in Catalyst Preparation Example 1. The content of rhenium per activated carbon of the obtained catalyst is 0.5% by weight. The catalyst obtained is called catalyst 8.

[Catalyst Preparation Example 9] Preparation of "gold / activated carbon" catalyst.

After dissolving 0.5 g of tetrachloroauric (III) acid (HAuCl ₄ ) in terms of metal weight in 250 g of water, a "palladium-gold / activated carbon" catalyst was prepared in the same manner as in Catalyst Preparation Example 1. The gold content per activated carbon of the obtained catalyst is 0.5% by weight. The catalyst obtained is called catalyst 9.

[Catalyst Preparation Example 10] Preparation of a catalyst in which a "palladium / activated carbon" catalyst and a "silver / activated carbon" catalyst were mixed.

The catalyst 6 obtained in Preparation Example 6 and the catalyst 7 obtained in Preparation Example 7 were mixed in a weight ratio of 5: 1. The solid obtained is called catalyst 10.

Table 1 summarizes the catalysts 1 to 10 prepared as described above.

[0056]

[Table 1]

[Examples 1 to 6] Synthesis of 1,1,1-trifluoroacetone using a composite catalyst.

The following operations were carried out in common with each experiment of Examples 1 to 5. Stainless steel tubular reactor (diameter 18m
m, a cylinder with a height of 500 mm, and a protection tube with a diameter of 8 mm and a height of 500 mm (a cylinder for inserting a thermocouple) is present in the center of the inside of the protection tube except the inside. Any one of the catalysts 1 to 5 was filled (the filling amount was 100 ml (50 g) in each case). While flowing hydrogen gas at a flow rate of 0.1 liter / minute from the upper part of the tube to the lower part of the tube, the outside of the reactor was heated to 100 ° C. by a heat medium (external set temperature of reactor: 100 ° C.). After the internal temperature of the reactor (the temperature indicated by the thermocouple inserted in the protective tube) became stable at 100 ° C, a mixture of halogenated trifluoroacetone (gas chromatograph composition: 1-chloro-3,3,3-
Trifluoroacetone 3.8%, 1,1-dichloro-
3,3,3-trifluoroacetone 84.0%, 1,
1,1-trichloro-3,3,3-trifluoroacetone (9.9%, other ingredients 2.3%) 180 g,
It was introduced at a rate of 3 g / min into a vaporizer set at 100 ° C. This vaporized organic substance was mixed with hydrogen gas (flow rate of 0.1 liter / min), this mixed gas was introduced into the reactor, and continuously flowed from the upper part of the tube to the lower part of the tube.

When the introduction of the sample was started, the internal temperature of the reactor (the temperature of the thermocouple inserted in the protective tube) increased. The highest temperature was shown near the entrance of the sample (upper part of the tube). The maximum value of the temperature in the reactor (hereinafter referred to as "maximum temperature") was measured by moving the thermocouple in the protective tube. This maximum temperature showed an almost constant value during continuous introduction.

The flow was continued for 10 hours until all the samples were introduced. Then, instead of hydrogen gas, nitrogen gas was passed at the same speed for 1 hour. The liquid and gas flowing out from the reactor were introduced into 700 g of water at 0 ° C. and collected. The amount of organic matter recovered was determined by subtracting the weight of water calculated from water measurement (Karl Fischer method) from the total weight. Composition of organic components is gas chromatograph (FID)
Sought by.

In Example 6, water was allowed to coexist in the reaction system to carry out the same reaction. Mixtures of halogenated trifluoroacetones described in Examples 1-5 (gas chromatographic composition: 1-chloro-3,3,3-trifluoroacetone 3.8%, 1,1-dichloro-3,3,3- Trifluoroacetone 84.0%, 1,1,1-trichloro-3,
90 g of 3,3-trifluoroacetone (9.9%, other components 2.3%) and 90 g of water were mixed to prepare 180 g of an aqueous solution of halogenated trifluoroacetone. Using 180 g of this halogenated trifluoroacetone aqueous solution as a raw material, introduced into a reactor through a vaporizer, and using catalyst 1 (palladium-silver / activated carbon catalyst), the same equipment, operation, and conditions as in Examples 1 to 5 were used. The reaction was carried out.

The results obtained for Examples 1-6 are summarized in Table 2 below.

[0063]

[Table 2]

From Table 2, it can be seen that the halogenated trifluoroacetone was converted to 1,1,1-trifluoroacetone with good selectivity in any of the composite catalyst systems in the reaction for 10 hours. This is equivalent to the palladium / activated carbon catalyst system shown below (Comparative Example 1). On the other hand, the maximum temperature is 120 to 145 ° C. in the system containing no water (difference from the external temperature; +20 to + 45 ° C.) (Examples 1 and 4) and 114 ° C. in the system containing water (compared with the external temperature). Difference; + 14 ° C) (Example 6), palladium / activated carbon catalyst system (Comparative Example 1,
Compared to 6), heat generation is significantly suppressed. [Comparative Examples 1 to 6] Synthesis of 1,1,1-trifluoroacetone without using a composite catalyst.

In Comparative Examples 1 to 5, catalysts 6 to 10 (all of which are ordinary transition metal catalysts) were used, and Examples 1 to 5 were used.
Mixture of halogenated trifluoroacetone described in (gas chromatographic composition: 1-chloro-3,3,3-trifluoroacetone 3.8%, 1,1-dichloro-3,
3,3-trifluoroacetone 84.0%, 1,1,1
-Trichloro-3,3,3-trifluoroacetone 9.
9%, other ingredients 2.3%) as raw materials,
The hydrogenation reaction was carried out under the same equipment, operation, and conditions as in 5.

Comparative Example 6 is a reaction carried out in the presence of water in the reaction system. As the catalyst, catalyst 6 (silver / activated carbon catalyst) was used, and the reaction was carried out in the same manner as in Example 6 using 180 g of the aqueous solution of the halogenated trifluoroacetone described in Example 6 as a raw material.

The results obtained for Comparative Examples 1 to 6 are shown in Table 3.
Put together.

[0068]

[Table 3]

From Table 3, when the silver / activated carbon catalyst is used, heat generation is larger than that when the composite catalyst is used.
It shows that it is difficult to control the reaction (Comparative Examples 1 and 6). It was also confirmed that the catalyst in which only the added metal was supported on the activated carbon had almost no activity as a catalyst (Comparative Examples 2 to 4). Further, it can be seen that heat generation is large only by physically mixing the palladium / activated carbon catalyst and the silver / activated carbon catalyst, and the heat generation suppressing effect as when using the composite catalyst is not exhibited (Comparative Example 5).

[Examples 7 to 9 and Comparative Example 7] Comparison of the activity of the catalysts when the reaction was carried out for a long time.

The halogenated trifluoroacetone mixture described in Examples 1 to 5 (gas chromatographic composition: 1-chloro-3,3,3-trifluoroacetone 3.8%,
1,1-dichloro-3,3,3-trifluoroacetone 84.0%, 1,1,1-trichloro-3,3,3-trifluoroacetone 9.9%, other ingredients 2.3%)
Using the above as a raw material and using the same reactor as above, a hydrocracking reaction was performed. However, in these experiments, the halogen trifluoroacetone feed rate was 0.25 g / min,
The hydrogen supply rate was 0.13 g / min, the preset temperature outside the reactor was 120 ° C., and the raw material supply (reaction) was continued for 500 hours. In Example 7, the catalyst 1 (palladium-
Silver / activated carbon), catalyst 2 (palladium-rhenium / activated carbon) in Example 8, catalyst 3 (palladium-gold / activated carbon) in Example 9, and catalyst 6 (palladium / activated carbon) in Comparative Example 7.

After 60 hours and 150 hours from the start of the reaction,
After 300 hours and after 500 hours the mixture of gas and liquid leaving the reactor was taken up in cold water,
The composition of organic components was measured by gas chromatography.

Table 4 shows the gas chromatographic measurement results (purity of 1,1,1-trifluoroacetone) for each time in these experiments.

[0074]

[Table 4]

From Table 4, no significant difference in activity was observed between the catalyst systems at the stage 60 hours after the start of the reaction, but thereafter, the activity of the palladium / activated carbon catalyst (Comparative Example 7) was significantly reduced. In contrast, the composite catalyst (Example 7)
It is recognized that the activity of ~ 9) is hardly impaired and the catalyst life is increased.

[0076]

INDUSTRIAL APPLICABILITY The present invention is a technique for synthesizing 1,1,1-trifluoroacetone by hydrogenolysis of halogenated trifluoroacetone in the presence of a catalyst to suppress heat generation on the surface of the catalyst and to reduce catalyst life. Has the effect of being extended.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07C 49/167 C07B 61/00 300 // C07B 61/00 300 B01J 23/64 104Z (72) Inventor Goto Yoshihiko, Saitama Prefecture 2805, Imafuku Nakadai, Central Institute of Chemical Research, Central Glass Co., Ltd. (72) Inventor, Junji Negishi 2805, Imafuku Nakadai, Kawagoe, Saitama Prefecture, Central Glass Co., Ltd. Chemical Research Laboratory F-term (reference) 4G069 AA03 AA08 BA01A BA02A BA03A BA08A BA08B BB02A BB02B BB12C BC32A BC32B BC32C BC33A BC33B BC64A BC64B BC72A BC72B BC72C CB35 CB69 DA05 EA02Y EB18Y FA02 BA20 BC61 BA20 BA61 BA20 BA61 BA20 BA61 BA20 BA61 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA16 BA20

Claims (6)

[Claims] 1. A halogenated trifluoroacetone represented by the general formula [1]: (In the formula, X represents chlorine, bromine, or iodine, and n is 1 to 1.
Represents an integer of 3. ) Is hydrolyzed with hydrogen gas in a gas phase to synthesize 1,1,1-trifluoroacetone, palladium and other on the same carrier,
A solid-phase catalyst supporting at least one metal selected from silver, rhenium, and gold is used.
A method for producing 1,1,1-trifluoroacetone. 2. A solid phase catalyst is brought into contact with a solution containing a palladium compound and a solution containing a compound of at least one metal selected from silver, rhenium or gold, and then subjected to reduction treatment with a reducing gas. The method for producing 1,1,1-trifluoroacetone according to claim 1, which is prepared by 3. A solid phase catalyst is brought into contact with a solution simultaneously containing a palladium compound and a compound of at least one metal selected from silver, rhenium and gold, and then reduced with a reducing gas. The method for producing 1,1,1-trifluoroacetone according to claim 1, which is prepared by processing. 4. The amount of at least one metal selected from silver, rhenium and gold supported on a solid phase catalyst is
The method for producing 1,1,1-trifluoroacetone according to any one of claims 1 to 3, wherein the total amount is 1 to 100 g per 100 g of palladium. 5. The carrier according to claim 1, wherein the carrier is selected from activated carbon, alumina, silica alumina, or silica.
Method for producing 1-trifluoroacetone. 6. A method comprising contacting a carrier with a solution containing palladium nitrate and a solution containing silver nitrate, or by bringing the carrier into contact with a solution containing both palladium nitrate and silver nitrate at the same time and then performing a reduction treatment with a reducing gas. The method for preparing a solid-phase catalyst used in the method according to claim 1, wherein palladium and silver are supported on the same carrier.