JPH10287609A - Production of 3,3-dichloro-1,1,1-trifluoroacetone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compound useful as an intermediate for medicines and agrochemicals and a reagent for introducing fluorine-containing group by subjecting pentachloroacetone to liquid phase fluorination with hydrogen fluoride in the presence of an antimony catalyst. SOLUTION: Pentachloroacetone is subjected to liquid phase fluorination with hydrogen fluoride in a molar ratio of 3-50, especially preferably 5-10 based on pentachloroacetone by using an antimony compound (preferably a trivalent or pentavalent antimony halide or antimony metal, most preferably antimony pentachloride or antimony trichloride) in an amount of 0.1-50 mol%, preferably 1-20 mol% based on the pentachloroacetone as a catalyst, preferably at 50-150 deg.C and 1.0-100 Kg/cm<2> , more preferably at 80-120 deg.C and 5-30 Kg/cm<2> in a solvent, preferably 1,3-bistrifluooromethylbenzene or 2,4-dichloro-1-trifluoromethylbenzene to produce the objective compound.

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 method has problems in that it must be kept strictly anhydrous in the production process and that this method is industrially adopted, such as the use of mercury. Therefore, the present invention provides a method for producing 3,3-dichloro-1,1,1-trifluoroacetone suitable for production on an industrial scale.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present inventors have found that 3,3-dichloro-1,1,1-trifluoroacetone suitable for production on an industrial scale. After diligent studies on various manufacturing processes in order to establish a manufacturing method for chlorination, the use of antimony compounds as catalysts in the liquid-phase fluorination of the corresponding chlorinated products with hydrogen fluoride enables high yields to be achieved. It has been found that 3,3-dichloro-1,1,1-trifluoroacetone can be obtained, and the present invention has been achieved.

That is, the present invention is a method for producing 3,3-dichloro-1,1,1-trifluoroacetone by liquid-phase fluorination of pentachloroacetone with hydrogen fluoride, wherein an antimony compound is used as a catalyst. The method to use.

[0006] Pentachloroacetone used in the present invention can be synthesized by a known method. For example, a method is known in which acetone is chlorinated with chlorine using light, a metal chloride, an acid, a metal organic acid salt, or the like as a catalyst, and a method in which the corresponding chlorinated alcohol is oxidized.

The antimony catalyst in the liquid phase fluorination of halogenated hydrocarbons with hydrogen fluoride is generally SbF
aXb (X is a halogen, a and b are each 0 to 5
And a + b = 5. ), It is assumed that the antimony compound also adopts such a mixed halogen state regardless of the starting compound in the active state in the present invention. Also, antimony halide is chlorine, bromine, iodine,
Since fluorine is easily oxidized from its inactive trivalent state to its 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 objective can be achieved by using trivalent or pentavalent antimony halide or antimony metal as a starting material. Thus, specific examples of antimony compounds include antimony pentachloride, antimony pentabromide, antimony pentaiodide, antimony pentafluoride, antimony trichloride, antimony tribromide, antimony triiodide, and antimony trifluoride. Although possible, antimony pentachloride or antimony trichloride is most preferred.

In the method of the present invention, the number of moles of the catalyst is 0.1 to 50% by mole of pentachloroacetone,
20 mol% is preferable, and 5 to 10 mol% is more preferable. Below 0.1 mol%, the conversion of pentachloroacetone and the yield of 3,3-dichloro-1,1,1-trifluoroacetone both decrease, and above 50 mol%, the tar of high boiling compounds is reduced. It is not preferred because of increased production and / or increased overfluorinated products.

The reaction temperature is 30 to 200 ° C.,
150 ° C is preferred, and 80 to 120 ° C is more preferred.
Below 30 ° C, the reaction rate of pentachloroacetone is 3,3
-The yield of dichloro-1,1,1-trifluoroacetone is reduced, and at 200 ° C. or higher, the amount of production of tar composed of high-boiling compounds is increased and / or excessively fluorinated product is reduced. It is not preferable because it increases.

[0011] The molar ratio of hydrogen fluoride to pentachloroacetone is in the range of 3 to 50, preferably 2 to 20, particularly preferably 5 to 10. When the molar ratio is less than 3, the reaction rate of pentachloroacetone is not sufficiently high, while
Even if the molar ratio exceeds 50, no improvement in the reaction rate of pentachloroacetone is observed, and 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,
1.0-100 kg / cm ² is preferred, and 5-30 kg
/ Cm ² is more preferred.

In the present invention, a solvent can coexist in the reaction system for the purpose of controlling the reaction and preventing catalyst deterioration. As the solvent, it is preferable to use a solvent which is hardly subjected to fluorination and chlorination, such as 1,3-bistrifluoromethylbenzene and 2,4-dichloro-1-trifluoromethylbenzene.

The catalyst of the present invention can be easily activated to a pentavalent activated state when it has deteriorated or when a compound other than pentavalent is used as a catalyst raw material. This method comprises pentachloroacetone, 3,3-dichloro-
It comprises introducing chlorine at 10 ° C. to 150 ° C. in the presence of 1,1,1-trifluoroacetone or any of the above-mentioned solvents. Further, chlorine can be continuously or intermittently added to the reaction system during the fluorination reaction. During the activation of the catalyst, it is possible to carry out stirring, if necessary. The amount of chlorine is 1 to 10 times the number of moles of the catalyst.
Use 0 times the number of moles. At 10 ° C or lower, it takes a long time to activate. At 150 ° C or higher, chlorination of coexisting pentachloroacetone, 3,3-dichloro-1,1,1-trifluoroacetone or the above-mentioned solvent may occur. There is.

The process of the present invention can be carried out in a batch system, a semi-batch system or a flow reactor in which only the product is removed from the reactor. It does not prevent the reaction conditions from being changed to an adjustable degree.

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 3,3-dichloro-1,1,1-trifluoroacetone produced by the method of the present invention is purified by applying a known method to a fluorination reaction product.
For example, after being taken out of the reactor together with hydrogen chloride and unreacted hydrogen fluoride in a liquid or gaseous state, hydrogen chloride,
Excess hydrogen fluoride is removed by an operation such as distillation or liquid phase separation, and the remaining acidic components are removed with a basic substance or the like.
Dichloro-1,1,1-trifluoroacetone can be obtained.

[0018]

The present invention will be described below in detail with reference to examples. Example 1 420 g of antimony pentachloride was used as a catalyst in a 10-liter autoclave made of SUS316L equipped with a reflux condenser and a stirrer.
3,500 g of hydrogen fluoride was charged, and stirring was started at room temperature (about 15 ° C.). Thirty minutes later, when the pressure in the reactor increased to 3 kg / cm ² due to generation of hydrogen chloride, 5400 g of pentachloroacetone was injected. Thereafter, when the temperature of the heating medium for heating the reactor was raised, the internal temperature reached about 80 ° C., and the generation of hydrogen chloride became active, and the pressure reached 13 kg / cm ^2. The reaction was continued while maintaining the reaction pressure at 13 kg / cm ² . 6
After a period of time, when the generation of hydrogen chloride stopped and the pressure in the reactor began to decrease, the pressure was reduced to normal pressure while cooling the reactor. After cooling the reactor, the temperature of the reflux condenser was set to 20 ° C, the temperature of the reactor was raised again to 50 ° C, and hydrogen fluoride was distilled off. Thereafter, the heat medium in the reactor was raised to 120 ° C., and flash distillation was performed without passing through a reflux condenser to obtain 2650 g.
Of organic matter were obtained. When the obtained organic matter was analyzed by gas chromatography, 3,3-dichloro-1,1,1,1 was obtained.
70.2% trifluoroacetone, 1-chloro-1,
8.5% of 3,3,3-tetrafluoroacetone, 1,3
Dichloro-1,1,3-trifluoroacetone, 1,
1,3-trichloro-1,1-difluoroacetone 1
0.4%, others were included.

[0019]

According to the process of the present invention, the desired organic chlorinated compound is reacted in a one-step reaction to obtain the desired 3,3-dichloro-
There is an effect that 1,1,1-trifluoroacetone can be produced.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Goto 2805 Imafukunakadai, Kawagoe-shi, Saitama Central Chemical Glass Co., Ltd.

Claims (3)

[Claims] 1. A process for producing 3,3-dichloro-1,1,1-trifluoroacetone, wherein pentachloroacetone is liquid-phase fluorinated with hydrogen fluoride in the presence of an antimony catalyst. 2. The antimony catalyst according to claim 1, wherein the antimony catalyst is antimony pentahalide, and the halogen is any of chlorine, bromine, iodine or fluorine.
A method for producing 1,1-trifluoroacetone. 3. The 3,3-dichloro-1,1,1 according to claim 1, wherein the reaction temperature is 30 to 200 ° C. and the reaction pressure is 1.0 to 100.0 kg / cm ² .
A method for producing 1-trifluoroacetone.