JPH01226846A - Production of fluoroketone - Google Patents

Abstract

PURPOSE:To obtain the title compound under low pressure in high yield, by using a mixture of a nonfluorine and aprotic polar solvent and a fluorine- containing solvent and reacting a fluorocarboxylic acid fluoride wit a fluoroolefin in the presence of a catalyst. CONSTITUTION:A fluorocarboxylic acid fluoride (e.g. perfluoropropionic acid fluoride) is reacted with a fluoroolefin (e.g. tetrafluoroethylene) in the presence of a catalyst by using a mixture of a nonfluorine and aprotic polar solvent such diglyme, acetonitrile or dimethylformamide and a fluorine-containing solvent such as perfluoroethane or tetrafluoroethylene as an inert solvent to give a fluoroketone (e.g. perfluorotriethylcarbinol). The reaction can be carried out under low pressure of about 3-15kg/cm<2> and a small amount of by-products is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a fluoroketone, which involves reacting a fluorocarboxylic acid fluoride and a fluoroolefin in an inert solvent in the presence of a catalyst.

(Prior art) Fluorocarboxylic acid fluoride and fluoroolefin are prepared in an aprotic polar solvent such as noblime, triglyme, acetonitrile, etc. as CsF, KF.

It is known to produce fluoroketones and fluoroalcohols by reacting them in the presence of catalysts capable of generating fluorine anions, such as RbF and AgF. For example, Journal of the American Chemical Society 4-(J, Am, Chem, Soc,) No. 84
Vol. 4285-4288 (1968) describes the reaction of carbonyl fluoride, fluoroamyl fluoride such as trifluoroacetyl fluoride, hexafluoropropylene, and fCsF in acetonitrile as a catalyst to produce a fluoroketone having an inpropyl group. A method for synthesizing is shown. However, according to experimental examples, it is several tens of kiloliters? The desired product was obtained at a conversion rate of at most 60% under a high pressure of /c1PL2. Also, British Patent 1.1
No. 31.206 discloses that an alkoxide having a perfluoroalkyl group obtained from a perfluorocardene-arized fluoride and a metal fluoride, for example, cesium fluoroptoxide and tetrafluoroethylene, which is a fluoroolefin, is treated with acetonitrile. The reaction progressed further, instead of producing nosafe fluoroketone.
-Fluorodiethylbutyl carbinol is obtained.

Also, Journal of Organic Chemistry (
J, Org, Chem-) Volume 31, Nos. 955-95
7 (1966), a polymerization reaction of tetrafluoroethylene was carried out in diglyme in the presence of CsF to obtain a mixture consisting of tetrafluoroethylene oligomers. As can be seen from the above reported examples, the conventional method of synthesizing fluoroketones using a fluoroolefin and fluorocarmenic acid fluoride in an aprotic polar solvent using CsF, KF, RbF, AgF, etc. as a catalyst is extremely difficult. It requires high pressure, has a low yield, and produces many by-products.

(Problems to be Solved) In view of the above-mentioned problems of the prior art, the present invention aims to establish a method for synthesizing fluoroketones under as low a pressure as possible, in a high yield, and that suppresses the production of by-products as much as possible. purpose.

(Means for Solving the Problem) The present inventors have discovered that the above object can be achieved by using a specific mixed solvent when producing a fluoroketone by reacting fluorocarmenic acid fluoride with a fluoroolefin. This discovery led to the completion of the present invention.

That is, the present invention provides a method for producing a fluoroketone by reacting a fluorocarmenic acid fluoride and a fluoroolefin in an inert solvent in the presence of a catalyst, in which a non-fluorine and aprotic solvent is used as the inert solvent. This is a method for producing a fluoroketone, characterized by using a mixture of a polar solvent and a fluorine-containing solvent.

Fluorocarmenic acid fluoride i used in the present invention
/:t, a known compound having a fluorine atom bonded to a carbon atom to which a small number of synergistic rubinyl groups are bonded in the molecule in addition to the fluorine atom of the fluorocarbunyl group may be employed without any restriction. Depending on the number of fluorocarbyl groups, monocarboxylic acid fluoride, dicarboxylic acid fluoride, tricarmenic acid fluoride, tetracarboxylic acid fluoride, etc. may be mentioned, all of which can be used in the present invention.

Among these, monocarboxylic acid fluoride and dicarboxylic acid fluoride are preferably used because the effects of the present invention are remarkable.

The fluorocarboxylic acid fluoride used in the present invention is preferably a j-fluoro compound bonded to a carbon atom and having all fluorine atoms substituted with fluorine atoms. Further, the following compounds in which a halogen atom other than a fluorine atom or a hydrogen atom is bonded to a carbon atom other than the next carbon atom adjacent to the fluorocarbunyl group can also be suitably used.

The fluorocarboxylic acid fluoride that can be suitably used in the present invention is a compound represented by the following general formula.

XCF2(CF2)nCOF'.

FOC(CF2)nCOF or F'0CCF'Y(,OCF'2-CFY'0)x(C
F2), (OCF'2・CFY'), CFY#COF'
Specifically, the following compounds can be mentioned.

CF, COF, CF3CF2C0F, CF3(C
F2) 2COF, CF3(CF2)4COF.

0F3(CF2)5COF, CF3(CF2)6COF
', CF, (CF2), COF.

FICF2CF2COF, C1CF2CF2C0F, I
CF2CF2CF2C0F.

H(CF2CF2)2COF, H(CF2CF2)
3COF'.

FOCCOF, FOCCF2COF, FOC(
CF2)2COF.

FOC(CF2)3COF, FOC(CF2)4COF
,FOC(CF2)5COFFOCCF 0CF2CF
It is a compound such as 0CF20F20CF COF.

Next, as the fluoroolefin, known compounds can be employed without any restrictions. Specifically, fluoro compounds having 2 to 5 carbon atoms such as tetrafluoroethylene and hexafluoropropylene are preferred, but compounds in which a part of the fluorine atoms are substituted with other halo atoms, such as chloro Trifluoroethylene and the like can also be used.

Next, as the catalyst, any known catalyst used in the reaction between a fluorocarbon monofluoride and a fluoroolefin can be employed without any limitations. Commonly used catalysts are compounds that generate fluorine anions under reaction conditions. Specifically, such compounds include K
F, CsF, RbF.

Examples include AgF and NH2F (where Rfl is a hydrogen atom or an alkyl group). The amount of catalyst to be used can be selected from a wide range, and is usually used in a molar ratio of 0.1 or more to the fluorocarboxylic acid fluoride. In order to obtain a high reaction rate, it is preferable to select from the range of 0.5 to 2.0.

The most important feature of the present invention is that the reaction between the fluorocarboxylic acid fluoride and the fluoroolefin is carried out in a mixture of a fluorine-free and aprotic polar solvent and a fluorine-containing solvent.

As the fluorine-free and aprotic polar solvent, any known solvent can be used without any restriction as long as it does not contain a fluorine atom in its molecule and does not act as a proton donor in the reaction system. For example, ethers such as diglyme, triglyme, and tetraglyme, niacetonitrile; dialkylformamides such as dimethylformamide, and the like are preferably used.

Further, as one of the fluorine-containing solvents, a solvent having a fluorine atom in the molecule can be used with no limitations. In particular, fluorine-containing solvents that are substantially insoluble in the above-mentioned fluorine-free and aprotic polar solvents are preferred. Specific examples of fluorine-containing solvents that can be suitably used in the present invention include:
For example, perfluorohbutane, 9-fluorooctane, perfluorononane, and/or? - monofluoronofluorinated fins having 7 or more carbon atoms such as fluorodecane; monofluorotrialkylamines such as nonfluorotripropylamine, monofluorotributylamine, and monofluorotriamylamine; Oils consisting of oligomers of tetrafluoroethylene or hachlorotrifluoroethylene, such as guifuroyl (trade name: Daikin Industries, Ltd.); perfluoropolyether oils obtained from epoxides of tetrafluoroethylene or hahexafluorodelopyrene; For example, Krytox (trade name: manufactured by DuPont), Fontlin oil (trade name: Montefloss Corporation), etc. can be used.

The fluorine-containing solvent that is substantially insoluble in the non-fluorine-containing and aprotic polar solvent mentioned above depends on the combination of solvents used, but for example, it is suitable for ethers such as diglyme, triglyme, and tetragram. For acetonitrile, guifuroyl can be suitably used.

Needless to say, these non-fluorine-based aprotic polar solvents and fluorine-containing solvents must be inert to the reaction between the fluorocarboxylic acid fluoride and the fluoroolefin.

Although the mixing ratio of the non-fluorine-based aprotic polar solvent and the fluorine-containing solvent is not particularly limited, in order to fully exhibit the effects of the present invention, the volume ratio of one of these two solvents to the other must be adjusted. 0.1~0.9, further 0.3~
The range is preferably 0.7.

Next, the present invention will be specifically explained in detail. As mentioned above, since the non-fluorine and aprotic polar solvent is polar,
Usually contains a small amount of water. Since water inhibits this reaction, it is preferable to exclude it as much as possible. The dehydration method may be adsorption or chemical, but methods include passing it through a Molecular Sheep column or adding Molecular Sheep to the solvent to be dehydrated, and then separating the solvent by FA or decantation. It is convenient and preferable. On the other hand, fluorine-containing solvents have almost no water absorption,
Commercially available products can be used as they are.

Since catalysts are generally highly hygroscopic, it is desirable to dehydrate them by heating or other means before use.

The inert solvent and catalyst described above are added to a pressure-resistant reaction vessel equipped with a stirrer, and then the fluorocarboxylic acid fluoride is added. The addition ratio is generally preferably 0.1 to 0.6 in terms of volume ratio to the inert solvent. Of course, more may be added to increase the f# produced per reaction. After that, after thoroughly replacing the inside of the reaction vessel with fluoroolefin,
Raising the temperature to a predetermined temperature and pressure of a predetermined fluoroolefin,
Boost the pressure. The reaction temperature is 50°C to 150°C, and the fluoroolefin pressure is lower than that of the conventional method, and the reaction proceeds at a pressure of 3 kg/cm2 to 15 kl? /cm2 is also sufficient. Although the reaction proceeds at higher pressures, the reaction equipment may become expensive, and the amount of by-products produced may increase, as in conventional methods. If the molar ratio of the fluoroolefin absorption number C to the fluorocarboxylic acid fluoride is 1 to 1.5, the desired fluoroketone is sufficiently produced.

Although the reaction time cannot be absolutely determined depending on the degree of reaction, catalyst pressure, pressure of fluoroolefin, etc., the present invention can be achieved in several hours to several tens of hours. In addition, a small amount of a crown ether or polyether surfactant may be added as a co-catalyst to promote the reaction.

(Effects) According to the method of the present invention, the desired fluoroketone can be obtained in high yield at low pressure and by suppressing the formation of by-products in the reaction between fluorocarzenic acid fluoride and fluoroolefin.

(Examples) Examples and comparative examples are listed below to specifically explain the present invention, but the present invention is not limited to these examples.

Example 1 100 ml of diglyme dehydrated with a molecular sieve was placed in a pressure-resistant glass container with a capacity of 500,111 J and equipped with a stirrer.
As a fluorine-containing solvent! - Fluorotriamylamine 10 (11/ and CsF dried under reduced pressure at 300°C)
229 and a nonionic surfactant H3210 (NOF > 29) were added. After that, the contents were cooled with dry ice methanol, and after degassing the gas phase with a total vacuum pump, 319's .g-fluorozolopionic acid fluoride was added. introduced.

Tetrafluoroethylene was then introduced to atmospheric pressure. The temperature of the reactor was raised to 100°C. Furthermore, the pressure of tetrafluoroethylene was set to 7.0 kg/cm2,
The reaction continued for 20 hours. Thereafter, the temperature was lowered to room temperature and the pressure inside the reactor was released. Next, the temperature of the reactor was set to 80°C, and the i4-fluorodiethyl ketone and diglyme distilled out under reduced pressure were collected. Approximately 39.
Almost pure perfluorosoethyl ketone of 9 was obtained in 80% yield. Furthermore, the temperature of the reactor was raised to distill off most of the remaining diglyme and fluorotriamylamine, and the contents of the reactor were dried. The dried product was placed in another flask, concentrated sulfuric acid was added to sufficiently soak the dried product, and distillation was performed.

Approximately 3 g of liquid was distilled out and was found to be 1,000-fluorotriethyl carbinol based on F-nuclear magnetic resonance spectrum and infrared absorption spectrum analysis.

Comparative Example 1] Experiment 2 was conducted using the same apparatus, composition, and conditions as in Example 1, except that fluorotriamylamine was not added. 20
Even after the passage of time, the absorption layer of tetrafluoroethylene was about 1/15 of that of Example 1, and even if the reaction time was 100 hours, the absorption layer of tetrafluoroethylene was only about 1/4 of that of Example 1.

The reaction was stopped at this time and the same treatment as in Example 1 was carried out, resulting in approximately 49 -safe fluorodiethyl ketones and approximately 1
g of .-monofluorotriethylcarbinol were obtained.

Example 2 The following experiment 2 was conducted on trifluoroacetyl fluoride using the reactor 1 of Example 1.

Acetonitrile 150cc as a polar solvent Gui 70yl ◆1 (Daikin ■!y3) 50eC as a fluorine-containing solvent
-i was used. In the same manner as in Example 1, 23 g of trifluoroacetyl fluoride and 209.18 KF as a catalyst were added.
-Crown-629 all added. When the reaction temperature was set to 80° C. and the pressure of tetrafluoroethylene was adjusted to 10:9/Crn for 30 hours, 30 g of .g-fluoromethylethyl ketone was obtained (yield: 70 examples). In addition, 29 fluoromethyl diethyl carbinol was obtained.

Example 3 Using the reactor of Example 1, the following injection was carried out for ω-H-dodecafluorobutanoyl fluoride.

The reaction vessel and operation were the same as in Experiment 1.

Tetraglyme 150ee and 7-onpurine YOI (trade name: Z-fluoropolyether) 5Qcc (trade name, manufactured by Monteflos) were used as a mixed solvent. In this case, the mixed solvent was mixed uniformly. ω-H-dodecafluoroheptanoyl fluoride 359 and AgF 159? The mixture was reacted for 15 hours at a reaction temperature of 100° C. and a pressure of 6 cm2/cm2. When the ketone was distilled in the same manner as in Example 1, ω-
H-dodecafluorohexafluoroisopropyl ketone was obtained.

Example 4 Using the reactor of Example 1, .g-fluorobutanoyl fluoride 259. KF'lOp and triglyme 80ml as solvent, octadecafluorooctane 60ml
The pressure of tetrafluoroethylene was increased to 10! '
, 9/σ2, and the reaction was carried out at 90° C. for 15 hours. As a result, 249 (yield: 65%) of .g-fluoroethyl derovir ketone was obtained.

Claims (1)

[Claims] (1) In a method for producing a fluoroketone by reacting a fluorocarboxylic acid fluoride and a fluoroolefin in an inert solvent in the presence of a catalyst, a non-fluorine-based and aprotic polar solvent is used as the inert solvent. A method for producing a fluoroketone, the method comprising using a mixture of a fluorine-containing solvent and a fluorine-containing solvent.