JPH085816B2 - Method for producing fluorinated hydrocarbons - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to reacting a halogenated hydrocarbon containing hydrogen with anhydrous hydrogen fluoride in a liquid phase to convert the halogen of the halogenated hydrocarbon containing hydrogen to fluorine. And a method for producing a fluorinated hydrocarbon.

(Prior Art) A halogenated hydrocarbon containing hydrogen and anhydrous hydrogen fluoride,
As a method for producing a fluorinated hydrocarbon by reacting in a liquid phase using stannic halide as a catalyst, USP 2,452,975, U can be used.
There are SP 2,495,407 and Japanese Patent Publication No. 47-39086.

In USP 2,452,975, unsaturated halogenated hydrocarbons containing hydrogen and hydrogen fluoride are reacted using stannic chloride as a catalyst. Further, in Japanese Examined Patent Publication No. 47-39086, vinylidene chloride is reacted with hydrogen fluoride in the presence of stannic chloride to produce 1,1-difluoro-1-chloroethane, which is polymerized as compared with an antimony pentachloride catalyst. It says that things will decrease significantly.

(Problems to be Solved by the Invention) When a halogenated hydrocarbon and anhydrous hydrogen fluoride are reacted in a liquid phase to obtain a fluorinated hydrocarbon, antimony halide such as antimony pentachloride has long been used as a catalyst. Well known (eg USP 2,005,708). However, when a halogenated hydrocarbon containing hydrogen, for example, 1,1,2-trichloroethane and anhydrous hydrogen fluoride are reacted in a liquid phase,
When antimony halide is used as a catalyst, high boiling point,
The by-products of oligomers and black precipitates are remarkable. The high boiling point here is a relatively low molecular weight compound produced by dimerization or trimerization of the raw material or the fluorine-substituted product of the raw material,
An oligomer is a polymer that has undergone further polymerization. The black precipitate is a brown to black carbide-like substance which is insoluble in the reaction solution after the reaction, nor in water or acetone.

According to the knowledge of the present inventors, those containing no hydrogen atom in the halogenated carbon, such as hexachloroethane and 1,
When 2-difluoro-1,1,2,2-tetrachloroethane is used as a raw material, even if antimony halide is used as a catalyst, high boiling substances, oligomers and black precipitates are not formed. However, as described above, in the case of a halogenated hydrocarbon containing a hydrogen atom, for example, 1,1,2-trichloroethane, high-boiling substances, oligomers and black precipitates are remarkably produced.
When the raw material halogenated hydrocarbon contains a hydrogen atom,
It is considered that dehydrohalogenation such as dehydrochlorination and deHF will occur during the reaction, so that dimerization and trimerization proceed to form a high boiling point product, and further polymerized oligomers and black precipitates are formed. To be

To overcome these drawbacks, USP 2,452,975 uses stannic chloride as a catalyst. According to the description, stannic chloride is a milder catalyst, and in the examples in which 1,1,2-trichloroethane and anhydrous hydrogen fluoride are reacted with stannic chloride as a catalyst, coke is used. It is stated that no tar is generated. From the results of the study conducted by the present inventors, by-products of high-boiling substances, oligomers and black precipitates are significantly reduced in the stannic chloride catalyst as compared with the antimony halide catalyst.

However, as a finding of the present inventors, when a tin catalyst such as stannic halide, for example, a stannic chloride catalyst is used,
Although it is liquid at the beginning of the reaction, there arises a problem that tar derived from tin begins to be generated as the reaction proceeds. The tar derived from tin is a tar-like substance in which a tin compound and a halogenated hydrocarbon are mixed.

Halogenated hydrocarbons and anhydrous hydrogen fluoride are almost insoluble in each other and form two liquid phases. Stannous chloride is a liquid and does not dissolve in anhydrous hydrogen fluoride, but it dissolves in halogenated hydrocarbons, so the reaction liquid is in a two-liquid phase before the start of the reaction. By the way, SnC in which stannic chloride (SnCl ₄ ) is fluorinated
L ₂ F ₂ and SnF ₄ are solids and are insoluble in anhydrous hydrogen fluoride and halogenated hydrocarbons. When the reaction is started, fluorination of stannic chloride also occurs, and these fluorine substitution products (SnCl ₂ F ₂ and S
nF ₄ etc.) is produced and, together with a certain amount of halogenated hydrocarbons, becomes a tar-like substance. This tar-like substance was dissolved in acetone, and only halogenated hydrocarbons as raw materials and products other than acetone were detected as organic substances in the gas chromatograph measurement.In addition, tar-like substances were determined by atomic absorption spectrophotometry and ion concentration measurement. It is known that more than half of these are Sn, Cl, and F, which is completely different from the high-boiling substances, oligomers, and black precipitates found in the antimony halide catalyst.

When the tin-derived tar is intended to carry out the reaction continuously, it clogs the nozzles and pipes of the reactor, which is a great obstacle to the operation.

Even if the catalyst is a tin catalyst such as stannic halide other than stannic chloride, the same tar derived from tin is produced as the fluorination proceeds.

An object of the present invention is to provide an industrially useful method for producing a fluorinated hydrocarbon by suppressing the formation of tar derived from tin.

(Means for Solving Problems) In the method for producing a fluorinated hydrocarbon of the present invention, which solves the above problems, a halogenated hydrocarbon containing hydrogen and anhydrous hydrogen fluoride are used as a base in anhydrous hydrogen fluoride. In the presence of a product from a working compound, the tin compound shown below, and anhydrous hydrogen fluoride,
It is characterized by reacting in a liquid phase.

Tin compounds: stannic halide, stannic oxyhalide, organic tin However, the following oxygen-containing compounds and nitrogen-containing compounds are excluded from the compounds that act as a base in anhydrous hydrogen fluoride.

Oxygen-containing compounds: H ₂ O, H ₂ O ₂ , oxygen-containing organic substances Nitrogen-containing compounds: NH ₃ , nitrogen-containing organic substances Conventionally, when a fluorination reaction of a hydrocarbon using a metal halide is carried out in a liquid phase, Oxygen organic matter and water are said to be extremely harmful for the fluorination reaction, and these compounds are thoroughly and thoroughly removed from the raw materials before the reaction. For example, USP 2,005,708 P8 states that the presence of water in the raw material is not desirable, and it is preferable to use substantially anhydrous hydrogen fluoride. Also, Sakai, "Organic Fluorine Chemistry (1)" Technical Report 247 states that catalytic efficiency decreases rapidly if not done anhydrous. In fact, when the fluorination reaction is carried out using antimony pentachloride, titanium tetrachloride, etc. as a catalyst, it is shown from the results of the study conducted by the present inventors that the reaction is significantly inhibited by adding an oxygen-containing organic substance or water. Has been done.

However, surprisingly, when stannic halide is used as a catalyst, if oxygen-containing organic substances and water are mixed and anhydrous hydrogen fluoride and halogenated hydrocarbon are reacted in a liquid phase, the reaction is inhibited. Not only that, but also tar derived from tin is not generated.

When the stannic halide is stannic chloride, at the beginning of the reaction,
Since stannous chloride dissolves in halogenated hydrocarbons, the reaction liquid is a liquid phase consisting of an anhydrous hydrogen fluoride phase (hereinafter referred to as HF phase) and a halogenated hydrocarbon phase (hereinafter referred to as organic phase). is there. However, when the reaction progresses and stannic chloride is fluorinated into SnCl ₂ F ₂ or SnF ₄ , it becomes insoluble in both the HF phase and the organic phase, and together with a certain amount of halogenated hydrocarbons. It produces a tar-like material, that is, tin-derived tar. Tin-derived tar clogs the nozzles and pipes of the reactor, which is a major obstacle to continuous operation.

However, when the reaction is carried out by mixing oxygen-containing organic matter and water in stannic chloride, stannic chloride reacts with the oxygen-containing organic matter and water and anhydrous hydrogen fluoride, resulting in stannic chloride and SnCl 2. ₂ F ₂ , S
A completely new tin compound different from nF ₄ is formed, and this compound dissolves in anhydrous hydrogen fluoride, so even if the reaction proceeds, almost no tin-derived tar is generated in the reaction solution.

As a result of repeated experiments, a new tin compound soluble in this anhydrous hydrogen fluoride was formed from the oxygen-containing compound shown below and / or the nitrogen-containing compound shown below, and the tin compound shown below and anhydrous hydrogen fluoride. He found that he would do so and filed a patent application (Japanese Patent Application No. 60-940).

Oxygen-containing compounds: H ₂ O, H ₂ O ₂ , oxygen-containing organic compounds Nitrogen-containing compounds: NH ₃ , nitrogen-containing organic compounds Tin compounds: stannous halide, stannic oxyhalide, organotin However, further experiments As a result, not only the oxygen-containing compounds and the nitrogen-containing compounds shown above, but also any compound that acts as a base in anhydrous hydrogen fluoride, the tin compound shown above, and anhydrous hydrogen fluoride Even from the above, it was found that a new tin compound which is soluble in this anhydrous hydrogen fluoride is produced, and the present invention has been completed. The new tin compound soluble in anhydrous hydrogen fluoride is referred to as a novel tin compound or a novel tin catalyst in the present invention.

A compound that acts as a base in anhydrous hydrogen fluoride (hereinafter simply abbreviated as a base) means a proton (H ⁺ ) from hydrogen fluoride (HF) in anhydrous hydrogen fluoride, as shown in formulas (1) to (4). by supplying, F ^- the receiving and / or HF to fluoride ion (F) ^- or bi fluoride ion _{^{(HF 2 -) H n F}} n + 1 , such as
^- (n is 0 or n> 0 comprising an integer) be anything that generates ions.

^{X + HF → XH + + F} - (1) X + 2HF → XH + + HF 2 - (2) YF → Y + + F - (3) YF + HF → Y + + HF 2 - (4) (X in the above formula, YF represents base However, the oxygen-containing compound shown below and the oxygen-containing compound shown below are not included in the base in the present invention.

Oxygen-containing compound: H ₂ O, H ₂ O ₂ , oxygen-containing organic substance Nitrogen-containing compound: NH ₃ , nitrogen-containing organic substance Examples of the base in the present invention include the following compounds. Alkali metal salts, alkaline earth metal salts, silver salts, thallium salts, ammonium salts, sulfuric acid or sulfate salts,
Nitric acid or nitrate, perchloric acid or perchlorate, iodic acid or iodate, aromatic hydrocarbon, oxide, azide,
Examples include cyanide, XeF ₆ , benzenesulfonic acid, Fe (CO) ₅ . AlF metal salts include NaF, NaCl, KF, KCl,
For alkaline earth metal salts such as LiF, PbF and CsF, Sr
F ₂ , BaF ₂ and so on. Aromatic hydrocarbons include benzene,
Examples include toluene, xylene, tetramethylbenzene and hexamethylbenzene. Examples of oxides include CrO ₃ and SiO ₂ . Some examples of the behavior of these bases in anhydrous hydrogen fluoride are as shown in formulas (5) to (18). [Lagowski, "The Chemistry o"
f Non−Aqueous Solvents ”, Academic Press, Vol.2) p4
3-93] ^{NaF + HF → Na + + HF} 2 - (5) Cl - + 2HF → HCl ↑ + HF 2 - (6) ^{_{HNO 3 + 4HF → NO 2 +}} + H 3 O + + 2HF 2 - (8) KNO 3 + 4HF → NO 2 + + H 3 O + + K + + 3HF 2 - (9) ^{Ar + 2HF → ArH + + HF} 2 - (11) ( provided that, Ar represents an aromatic _{hydrocarbon.) SiO 2 + 8HF → SiF} 4 + 2H 3 O + + 2HF 2 - (12) CrO 3 + 4HF → CrO 2 F 2 + H 3 O ^{_{+ + HF 2 - (13)}} Hg (N 3) 2 + 4HF → [Hg (N ₃ H) _{2] ^{2+ + 2HF 2 - (14)}} Hg (CN) 2 + 2HF → [Hg (CN) (CNH)] ⁺ + HF ^{_{2 - (15) XeF 6 +}} HF → XeF 5 + + HF 2 - (16) C 6 H 5 SO 3 H + 3HF → C 6 H 5 SO 2 F ++ H 3 O + + HF 2 - (17) Fe (CO) 5 + 2HF → [ Fe (CO) ₅ H] ^{+ +} HF ₂ ^- (18) However, where except for the above-mentioned oxygen-containing compound and the above-mentioned nitrogen-containing compound, any compound that acts as of anhydrous hydrogen fluoride bases, limited to the above example Not done.

As a tin compound for producing the novel tin compound,
There are stannic halides, stannic oxyhalides and organotins. The halogenated _{stannic, SnCl 4, SnF 4, SnBr} 4 and the like _{but, SnCl x F 4-x (} 0 , such as resulting from SnCl ₄ and HF <
It does not matter even if x <4). Examples of the stannic oxyhalide include SnCl ₂ O, SnF ₂ O and SnClFO. Organotin has a bond of Sn and C, and is, for example,
Examples include tetramethyltin, oxydiethyltin and dichlorodimethyltin.

In order to react a halogenated hydrocarbon containing hydrogen with anhydrous hydrogen fluoride using the novel tin catalyst, the above tin compound is reacted with the above base and anhydrous hydrogen fluoride in advance, and the novel tin catalyst is reacted. After the compound is formed, the halogenated hydrocarbon containing hydrogen may be reacted with anhydrous hydrogen fluoride in the presence of the compound, or the compound may contain the above-mentioned tin compound, the above-mentioned base with anhydrous hydrogen fluoride and hydrogen. A halogenated hydrocarbon may be simultaneously added and reacted. In the latter case, anhydrous hydrogen fluoride serves both as a fluorine source for forming the novel tin compound and as a fluorine source for fluorinating a halogenated hydrocarbon.

The novel tin compound and a stannic halide such as SnC
The characteristic difference with l ₄ , SnCl ₂ F ₂ and SnF ₄ is the difference in solubility in solvents and ¹¹⁹ Sn-NMR spectrum.

Regarding the solubility in a solvent, SnCl ₄ dissolves in a non-polar solvent such as 1,1,2-trichloroethane or chloroform, but SnCl ₂ F ₂ and SnF ₄ remain solid and do not dissolve. The novel tin compound is also insoluble in nonpolar solvents. For example, even if an anhydrous hydrogen fluoride solution of the novel tin compound is mixed with 1,1,2-trichloroethane or chloroform, two liquid phases are formed, and the novel tin compound contains 1,1,2-trichloroethane or chloroform. Not found in chloroform. Among polar solvents, SnCl ₄ , SnCl ₂ F ₂ , SnF ₄ and the novel tin compound are all soluble in methanol, acetone and the like. This is probably because methanol, acetone, etc. are dissolved by coordinating to the Sn atom. Of the polar solvents, SnCl ₄ , SnCl ₂ F ₂ and SnF ₄ are all insoluble in anhydrous hydrogen fluoride, whereas the novel tin compound is completely soluble. This difference in solubility appears in the presence or absence of the formation of tar derived from tin. That is, when a tin compound, for example, SnCl ₄ and anhydrous hydrogen fluoride or a halogenated hydrocarbon are added and reacted without the presence of a base, in the state where the reaction has proceeded, the non-fluorinated SnCl ₄ becomes an organic phase. Melted, fluorinated SnCl ₂ F ₂
And SnF ₄ are solid and insoluble in both the organic phase and the HF phase, causing tin-derived tar. The HF phase contains almost no Sn. However, when the reaction is carried out in the presence of a base, the new tin compound is produced, which is insoluble in halogenated hydrocarbons and soluble in anhydrous hydrogen fluoride, and is distributed to the organic phase.
Since Sn is small and most of it is dissolved in the HF phase, tin-derived tar is hardly generated.

In addition, structural differences are observed from ¹¹⁹ Sn-NMR measurement. ¹¹⁹ Sn- of SnCl ₄ and chloroform solution or acetone solution
NMR shows singlets. ¹¹⁹ Sn-NMR of an acetone or methanol solution of SnF ₄ has four equivalent F
There is a quintuple line that seems to have been coupled. Sn
Precipitation occurs when Cl ₄ reacts with HF, which is caused by SnCl ₂
It is said to have a composition of F ₂ or SnCl ₄ · SnF ₄ (“Inorganic Chemistry Complete Book XII-1-1 Tin” Maruzen P246), and also has a composition of SnCl ₂ F ₂ from the analysis results of the present inventors. It has been confirmed. ¹¹⁹ Sn-NMR spectrum of the precipitate methanol solution, SnCl ₃ F were mixed in methanol SnCl ₄ and SnF _4, S
¹¹⁹ Sn-NMR of the mixture solution such NCL ₂ F ₂ and SnClF ₃ was produced
It almost agrees with the spectrum. On the other hand, tin compounds containing Sn
For the novel tin compound produced using Cl ₄ and NaF as a base, after the reaction was completed, the HF phase of the reaction solution was measured as it was, and the multiplicity of peaks was found to be SnCl ₄ , SnCl ₂ F ₂ , SnF _4, etc. It is supported that it is another tin compound that is very different and quite different. That is, when the ¹¹⁹ Sn-NMR spectrum of the novel tin compound is investigated in detail, a quintet based on SnF ₆ ²⁻ ,
Peak considered two quintet based on SnClF ₅ ^2- are observed.

The halogenated hydrocarbon containing hydrogen may have any structure as long as hydrogen is present in the molecule. However, in the case where two carbons are bonded by a single bond, as shown below,
There are hydrogens on both carbons and at least one carbon has 2
It is better that more than one hydrogen bond, (X represents a halogen atom other than F, R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a hydrocarbon group or a halogenated hydrocarbon group.) For example, 1,1,2-trichloroethane. Of course, if hydrogen is included, halogenated hydrocarbons containing double bonds and C ₃
The above halogenated hydrocarbons may be used, and the halogen may be bromine or iodine.

Halogenated hydrocarbon containing hydrogen, for example, in the case of reacting 1,1,2-trichloroethane and anhydrous hydrogen fluoride to obtain a fluorinated hydrocarbon, compared to the case of using antimony pentachloride or titanium tetrachloride as a catalyst, As already mentioned, the use of stannic halides such as stannic chloride significantly reduces high boiling substances, oligomers and black precipitates. However, when a base is added to this and reacted, in addition to the effect that the tin-derived tar is not generated with almost no decrease in the reaction rate, high-boiling substances, oligomers and black precipitates are converted to stannic chloride alone. There is a secondary effect that it will decrease so much more than in comparison. Similar effects can be seen with other tin compounds, stannic oxyhalide and organic tin. On the other hand, when reacting with antimony pentachloride or titanium tetrachloride as a catalyst, if a base such as NaF is mixed in order to suppress the formation of high-boiling substances, oligomers and black precipitates, the catalytic activity will be lost. , The reactivity of halogenated hydrocarbon containing hydrogen becomes extremely small.

When a halogenated hydrocarbon containing hydrogen and anhydrous hydrogen fluoride are reacted using a novel tin catalyst, a base is reacted with a tin compound and anhydrous hydrogen fluoride to form the novel tin compound in advance. When reacting a halogenated hydrocarbon containing hydrogen with anhydrous hydrogen fluoride in the presence of the same, or when simultaneously reacting with a base, a tin compound, anhydrous hydrogen fluoride and a halogenated hydrocarbon containing hydrogen However, the amount of the base added is not more than 2 equivalents, preferably 0.5, per mol of tin.
~ 1.5 equivalents. If the amount exceeds 2 equivalents, the reaction will not proceed rapidly. The base 1 equivalent here, in anhydrous hydrogen fluoride, F ^- and HF ₂ ^- is the amount of base which anion is 1 mol generated as.

A halogenated hydrocarbon containing hydrogen and anhydrous hydrogen fluoride,
As the conditions for the reaction in the presence of the novel tin compound, the conditions currently known as the liquid phase fluorination reaction with anhydrous hydrogen fluoride may be applied. For example, when 1,1,2-trichloroethane is used as a raw material, the temperature is 50 to 200 ° C., the pressure is 3 to 30 kg / cm ² G, and hydrogen chloride produced as a by-product may be extracted if necessary.

The amount of anhydrous hydrogen fluoride in the reaction solution was 6 per mol of Sn.
It is desirable that the amount is at least mol, preferably at least 9 mol, and if the amount is less than this, the reaction rate becomes low.

The amount of Sn is 0.05 mol or more, preferably 0.07 mol or more, relative to 1 mol of the halogenated hydrocarbon containing hydrogen. If the amount of Sn is less than this, the reaction rate also decreases.

Furthermore, when this reaction is carried out continuously, various methods are conceivable. For example, the HF phase containing the novel tin compound and the organic phase containing the product are utilized by utilizing the characteristic that the novel tin compound dissolves in anhydrous hydrogen fluoride but hardly dissolves in halogenated hydrocarbon containing hydrogen. By utilizing the liquid separation process of separating the product into the organic phase and extracting the product from the organic phase, and the fact that substantially no tin-derived tar is formed, the product is converted to steam without extracting the catalyst or high-boiling substances. A steam withdrawal process, etc. may be considered.

The two continuous reaction processes will be described in more detail.

FIG. 1 shows a flow of the liquid draining process. Reactor 1
At a halogenated hydrocarbon containing hydrogen and anhydrous hydrogen fluoride,
The reaction is carried out in the presence of the novel tin compound. Hydrogen chloride, which is a by-product of the reaction, is condensed and removed in a condenser (or a distillation column) 2 and then taken out in a gaseous state. The condensed hydrogen fluoride and hydrocarbons are recycled to the reactor.

The inside of the reactor is a two liquid phase consisting of an organic phase and an HF phase.
The liquid is extracted as it is and separated by the decanter 3. Since the new tin compound mainly distributes to the HF phase, the HF phase is recycled to the reactor. The specific gravity of the HF phase changes depending on the Sn concentration in the HF phase. When the Sn concentration is high, the specific gravity is higher than in the organic phase, and it is in the lower layer in the decanter, but in Figure 1 the Sn concentration is so high. Instead, the HF phase is in the upper layer.

Since the organic phase separated by the decanter still contains a small amount of the new tin compound,
Recover with anhydrous hydrogen fluoride. The organic phase substantially free of the novel tin compound exiting the extraction column is subjected to a normal distillation operation in which a low boiling point compound is removed from the reaction product in the distillation column 5 and a high boiling point compound is removed from the reaction product in the distillation column 6. Be refined. At this time, the halogenated hydrocarbon containing hydrogen, which is the raw material separated from the product, is recycled to the reactor.

In this drainage process, if the novel tin compound in the organic phase is not sufficiently recovered with anhydrous hydrogen fluoride, tar containing Sn is produced in the kettle of the distillation column, which causes trouble. However, in a reactor, a decanter, an extraction tower, or the like where anhydrous hydrogen fluoride is present, the novel tin compound dissolves in anhydrous hydrogen fluoride, so that tar containing Sn is hardly generated.

FIG. 2 shows the flow of the steam extraction process.
In the steam extraction process, hydrogen chloride gas produced as a by-product is extracted together with hydrogen chloride gas produced as a by-product, and separated by a decanter 3 into an HF phase and an organic phase. At this time, if a halogenated hydrocarbon containing hydrogen as a raw material is also accompanied, it is separated from the product in the distillation column 2 immediately above the reactor and recycled to the reactor. The HF phase separated by the decanter is also recycled to the reactor, but this HF phase is substantially free of the novel tin compound. Since the organic phase separated by the decanter mainly consists of the product, it is purified by a usual distillation operation. At this time, the halogenated hydrocarbon containing hydrogen, which is the raw material separated by distillation, is recycled to the reactor.

In this vapor extraction process, since liquid is not extracted from the reactor, if tin-derived tar is produced, separate liquid is continuously or batchwise extracted from the reactor to treat them. There must be. But,
When the reaction is carried out in the presence of the novel tin compound, almost no tin-derived tar is produced, so that long-term continuous operation is possible without draining the liquid from the reactor.

(Function) The structure and reaction mechanism of the novel tin compound are not yet clear and are only estimates, but are considered as follows.

The base abstracts protons from hydrogen fluoride in anhydrous hydrogen fluoride to form HF ₂ ⁻ ions. Here 1 mol of base to HF
_It is assumed that 1 mol of ₂ ^- ions is produced [Equation (19)].

Base + 2HFBase−H ⁺ + HF ₂ ⁻ (19) For ease of thinking, if the starting tin compound is stannic fluoride (SnF ₄ ), SnF ₄ abstracts F ⁻ from HF ₂ ⁻ to anion. If the HF ₂ ⁻ ion is more than twice the total number of moles of SnF ₄ , all SnF ₄ will be converted to SnF ₆ ²⁻ via formula (21) via SnF ₅ ⁻ .

^{_{SnF 4 + HF 2 - SnF 5}} - + HF (20) SnF 5 - + HF 2 - SnF 6 2- + HF (21) However, HF ₂ ^- 2 moles of ions with respect to the number of moles of SnF ₄
When it is less than twice, for example, 1, SnF ₅ ⁻ becomes SnF ₆ ²⁻ by extracting F ⁻ from the neutral HF molecule as shown in formula (22). As described above, SnF ₄ is ionized and dissolved in HF, and it is considered that tin-derived tar is not generated.

SnF ₅ ⁻ ＋ 2HFSnF ₆ ² ＋ H ₂ F ⁺ (22) It is considered that H ₂ F ⁺ generated in the formula (22) becomes an active species and the fluorination reaction of halogenated hydrocarbon proceeds. (2
In the formula 3), H ₂ F ⁺ is R-X which is a halogenated hydrocarbon as a raw material.
The fluorinated hydrocarbon R-F is generated by the formula (24), and at the same time, SnF ₅ ^- is regenerated and the formula (22) is restored. (2
Although the formulas (3) and (24) are described to generate a carbonium ion (R ⁺ ) for convenience, the details are completely unknown.

R−X + H ₂ F ⁺ → R ⁺ + HF + HCl (23) R ⁺ + SnF ₆ ^2- → R −F + SnF ₅ ⁻ (24) As seen in equations (21) and (22), SnF ₅ ⁻ is HF, HF ₂
⁺ From both F ^- but may pull the, from the electrically neutral HF, HF ₂ is an anion ^- is considered to be easier to pull out towards the. This means that 2 moles of base per 1 mole of Sn
The fact that the fluorination reaction of a halogenated hydrocarbon will not proceed if it is present in an amount equal to or greater than the equivalent will be explained. That is, when the base is present 2 or more equivalents relative to Sn 1 mole, (HF ₂ ^- / S
n) The molar ratio becomes 2 or more, and in this case, the reaction is completed by the formula (21), so that H ₂ F ⁺ is not generated, and the fluorination reaction of R—X (23), (24) The formula does not happen. However, when the amount of the base is less than 2 equivalents per mol of Sn, that is,
When the (HF ₂ ⁺ / Sn) molar ratio is less than 2, the following formula (22) occurs and the fluorination reaction of R—X proceeds.

Even if tin compounds of the starting material of stannic chloride (SnCl _4), the process proceeds fluorinated and ionization of SnCl _4, SnF ₆ ^- is presumed that ions are generated, ¹¹⁹ Sn-NMR suggests its presence
The spectrum has been obtained by the inventors. However, since this anion precipitates in anhydrous hydrogen fluoride at a certain concentration or more, in that case, the supernatant liquid may be used.

Here, it is considered that if no base is present, SnF ₄ hardly extracts F ⁻ from HF, so that ionization does not proceed and it does not dissolve in HF.

In the case of an antimony compound, for example, antimony pentafluoride, it dissolves in HF and H ₂ F ⁺ is generated as shown in the formula (25), which is said to be an active species [Lagowski's “The Chemical Of Non-Aqueous Solvent ((Lagowski, "The Chemistry of Non Aqueous So
lvents ”, Academic Press, vol.2, P61, 79 and Tabe and Noyori,“ Superacids / bases ”, Kodansha, P11-12]. When a base enters, SbF ₅ reacts with HF ₂ ⁻ generated in formula (19) and abstracts F ⁻ [formula (26)].

^{_{SbF 5 + 2HF → SbF 6 -}} + H 2 F + (25) SbF 5 + HF 2 - → SbF 6 - + HF (26) Even in this case, SbF ₅ is than HF molecules neutral HF ₂ ^- Write from the F ^It is considered that -can be easily extracted, and when a base is present, Eq. (26) occurs and H ₂ F ⁺ is not generated, and therefore the catalytic activity is considered to be lost.

 It is clearly stated that the above is an estimate.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

The analysis method and apparatus used in the examples are as follows.

Elemental analysis Sn: Atomic absorption spectrophotometer (Hitachi 170-10) F: Ion electrode (Toa radio F-125) Ion meter (Toa radio 1M20E) Cl: Ion electrode (Toa radio CL-135) Ion meter (Toa radio) 1M1E) Gas chromatograph Shimadzu GC-3BT Filler: Apiezon Grease Shimadzu GC-3BF Filler: Squalane NMR JEOL GX-400 Example 1,1,2-trichloroethane 133,4 g (1.0 mol), anhydrous fluorinated 40 g of hydrogen (2.0 mol), 15.63 g (0.06 mol) of stannic chloride and 2.52 g (0.06 mol) of sodium fluoride were charged into a 200 cc Hastelloy C reactor. The reactor is equipped with a stirrer, condenser, thermometer and pressure gauge,
A valve for regulating the pressure is provided at the outlet of the condenser. Further, a nozzle and a valve were provided at the bottom of the reactor so that the reaction solution could be withdrawn after cooling after the reaction was completed. A 500 W mantle heater was attached to this reactor to start heating. Reactor internal pressure is 10 kg / cm ² G
At that point, the withdrawal of by-product hydrogen chloride was started, and this pressure was maintained throughout the reaction. The reaction was allowed to proceed, but was almost constant at 90-98 ℃.

The reaction was stopped 3 hours after the start of the temperature rise, the reactor was cooled, and the reaction liquid was taken out from the bottom nozzle. The reaction solution is
The HF phase (upper layer) and the organic phase (lower layer) were separated into two liquid phases, and no tar derived from tin was observed. The Sn concentration in both phases was measured and found to be 0.9% by weight in the organic phase and 13.1% by weight in the HF phase. The weight% of Sn in the HF phase based on the total amount of recovered Sn was 75.3% by weight, and most of the Sn was HF.
It was melting in the phase. No dimer was detected in the organic phase. A dimer is a dimer of 1,1,2-trichloroethane as a raw material and 1,2-dichloro-1-fluoroethane as a product.
CH ₂ Cl-CHCl-CHCl-CHCl ₂ and CH ₂ Cl-CHCl-CHCl-C
It is HClF. If the concentration of this dimer is high, the amount of oligomers and black precipitates that have undergone further polymerization will also increase.

The charging amount, reaction conditions and results of the above examples are shown in the table below.

(Effect) When a halogenated hydrocarbon containing hydrogen, for example, 1,1,2-trichloroethane is reacted with anhydrous hydrogen fluoride in a liquid phase using a catalyst to obtain a fluorinated hydrocarbon, if an antimony compound is used as a catalyst, The formation of high boiling substances, oligomers and black precipitates is remarkable. If a tin compound such as stannic chloride is used to suppress the formation of these compounds, the formation of high-boiling substances, oligomers and black precipitates will be significantly reduced, but the tin-derived compound due to the fluorine substitution product of stannic chloride will be used. Tar is generated. This is a major obstacle to the operation because it clogs the nozzles and piping of the reactor when the reaction is operated continuously.

However, when the novel tin compound produced in the presence of a base is used as a catalyst, it is dissolved in anhydrous hydrogen fluoride, so that tin-derived tar is not substantially produced and the reaction can be continuously operated.

Furthermore, as a secondary effect, when the novel tin compound is used as a catalyst, it is more likely to have a high boiling point, an oligomer, or a black precipitate than when a tin compound such as stannic chloride is used as a catalyst. Production is reduced.

[Brief description of drawings]

FIG. 1 shows the flow of the liquid extraction process of the present invention, and FIG. 2 shows the flow of the vapor extraction process.

Claims (1)

[Claims] 1. A compound acting as a base in anhydrous hydrogen fluoride,
Production of a fluorinated hydrocarbon characterized by reacting a halogenated hydrocarbon containing hydrogen with anhydrous hydrogen fluoride in a liquid phase in the presence of a product from a tin compound shown below and anhydrous hydrogen fluoride. Law. Tin compound: stannic halide, stannic oxyhalide, organic tin However, among the compounds that act as a base in anhydrous hydrogen fluoride,
The following oxygen-containing compounds and nitrogen-containing compounds are excluded. Oxygen-containing compounds: H ₂ O, H ₂ O ₂ , oxygen-containing organic substances Nitrogen-containing compounds: NH ₃ , nitrogen-containing organic substances