JP2020111520A - Production method of cyclobutane - Google Patents

Abstract

To provide a production method of a cyclobutane containing a fluorine atom with high selectivity.SOLUTION: In a production method of a cyclobutane represented by general formula (1) (in formula, X1-X6 are the same or different and respectively represent a hydrogen atom, a halogen atom, or a perfluoroalkyl group), a cyclobutene represented by general formula (2) (in formula, symbols are identical to those mentioned before) and hydrogen fluoride are made to react with each other in the presence of a catalyst in the gas phase.SELECTED DRAWING: None

Description

The present disclosure relates to a method of making cyclobutane.

Cyclobutane containing a halogen atom is a compound useful as a dry etching gas for semiconductors, various refrigerants, a foaming agent, a heat transfer medium, and the like.

In Non-Patent Document 1, from 3,3,4,4,-tetrafluorocyclobutene, CoF ₃ , MnF ₃ , AgF ₂ , CeF ₄ or KCoF ₄ using a fluorinating agent, by fluorination reaction, 1H- A method of making heptafluorocyclobutane is disclosed.

The method in Non-Patent Document 2, a hexafluoro cyclobutene (cC ₄ F _6), using a hydrogen bromide (HBr), by an addition reaction, to produce 1 Br, 2H-hexafluoro-cyclobutane and (cC ₄ F ₆ BrH) Is disclosed.

Journal of Fluorine Chemistry, 2006, Vol.127, 79-84, “Fluorination of fluoro-cyclobutene with high-valency metal fluoride” Journal of American Chemistry, 1949, Vol.71, 2339-2340, “The Addition of Hydrogen Bromide to Fluorinated Olefins”

The present disclosure aims to produce cyclobutane containing a halogen atom with high selectivity.

The present disclosure includes the following configurations.

Item 1.
General formula (1):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
A method for producing cyclobutane represented by
General formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same as above.)
A method for producing, comprising a step of reacting cyclobutene represented by and hydrogen fluoride in a gas phase in the presence of a catalyst.

Item 2.
Item 2. The production method according to Item 1, wherein 0.1 mol to 100 mol of hydrogen fluoride is supplied and reacted with respect to 1 mol of cyclobutene represented by the general formula (2).

Item 3.
3. The production method according to Item 1 or 2, wherein the catalyst is at least one catalyst selected from the group consisting of activated carbon and a chromium compound.

Item 4.
General formula (1):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
A composition containing cyclobutane represented by:
The composition, wherein the total amount of the composition is 100 mol %, the content of cyclobutane represented by the general formula (1) is 99 mol% or more.

Item 5.
Item 5. The composition according to Item 4, which is used as a cleaning gas, an etching gas, a deposit gas, or a building block for organic synthesis.

According to the present disclosure, cyclobutane containing a halogen atom can be produced with high selectivity.

As a result of earnest studies, the inventors of the present invention have shown that, in the presence of a catalyst, a step of adding a reaction with hydrogen fluoride to a raw material compound is carried out in the gas phase to give the compound represented by the general formula (1). It was found that cyclobutane containing a fluorine atom can be produced with high selectivity.

The present disclosure has been completed as a result of further research based on such findings.

The present disclosure includes the following embodiments.

General formula (1) of the present disclosure:

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
The method for producing cyclobutane represented by
General formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same as above.)
The step of reacting cyclobutene represented by and hydrogen fluoride is included.

In the present disclosure, the reaction is an addition reaction with hydrogen fluoride, and the step is performed in the gas phase in the presence of a catalyst.

In the present disclosure, by satisfying the above requirements, cyclobutane containing a fluorine atom can be produced with high selectivity.

In the present disclosure, the “selectivity” refers to the target compound (fluorine atom is included in the effluent gas with respect to the total molar amount of compounds other than the raw material compounds (cyclobutane containing a fluorine atom) in the effluent gas from the reactor outlet. It means the ratio (mol%) of the total molar amount of (including cyclobutane).

In the present disclosure, the "conversion rate" refers to a compound other than the raw material compound (such as cyclobutane containing a fluorine atom) contained in the outflow gas from the reactor outlet with respect to the molar amount of the raw material compound (cyclobutene) supplied to the reactor. Means the ratio (mol%) of the total molar amount of.

The method for producing cyclobutane according to the present disclosure is suitable for production on an industrial level. The method for producing cyclobutane according to the present disclosure uses cyclobutene and hydrogen fluoride as raw materials, and these raw materials are available on an industrial level. The method for producing cyclobutane according to the present disclosure can achieve high selectivity when 1H-heptafluorocyclobutane is the target compound.

(1) Raw material compound
Cyclobutene represented by the general formula (2) In the present disclosure, the starting compound is the general formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
Are cyclobutene and hydrogen fluoride.

X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and each represents a hydrogen atom, a halogen atom or a perfluoroalkyl group.

Examples of the halogen atom of X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The perfluoroalkyl group of X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ is an alkyl group in which all hydrogen atoms are replaced by fluorine atoms. The perfluoroalkyl group has, for example, 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. It is preferably a fluoroalkyl group. The perfluoroalkyl group is preferably a linear or branched perfluoroalkyl group. The perfluoroalkyl group is preferably a trifluoromethyl group (CF ₃ -) and a pentafluoroethyl group (C ₂ F ₅ -).

As the cyclobutene represented by the general formula (2), which is a raw material compound, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and cyclobutane containing a fluorine atom can be produced with high selectivity. More preferably, X ⁶ are the same or different and each is a fluorine atom or a perfluoroalkyl group.

Examples of the cyclobutene represented by the general formula (2), which is a raw material compound, include the following:

And the like.

These cyclobutenes represented by the general formula (2) can be used alone or in combination of two or more kinds. As such cyclobutene, a known or commercially available product can be adopted.

In the cyclobutene represented by the general formula (2), cyclobutane containing a fluorine atom can be produced with high selectivity and high selectivity, and thus X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X More preferably, ⁶ is a fluorine atom.

The molar ratio of cyclobutene to hydrogen fluoride (HF) is usually preferably supplied to the reactor in a gas phase together with cyclobutene (raw material compound) represented by the general formula (2). It is preferable to supply hydrogen fluoride in an amount of about 0.1 mol to 100 mol per 1 mol of cyclobutene (raw material compound) represented by the general formula (2). The amount of hydrogen fluoride supplied is more preferably about 0.5 mol to 50 mol, still more preferably about 1 mol to 30 mol, relative to 1 mol of cyclobutene (raw material compound) represented by the general formula (2). About 20 to 20 mol is particularly preferable. By setting the supply amount of hydrogen fluoride in the above range, it is possible to favorably proceed the addition reaction with hydrogen fluoride and reduce the production of impurities, and the selectivity of cyclobutane containing a fluorine atom in the product is high, It can be recovered in high yield.

(2) Addition reaction The step of reacting cyclobutene and hydrogen fluoride in the present disclosure is an addition reaction with hydrogen fluoride, and is performed in the gas phase in the presence of a catalyst. The step (addition reaction) of reacting cyclobutene and hydrogen fluoride in the present disclosure is preferably carried out in a gas phase, particularly preferably in a gas phase continuous flow system using a fixed bed reactor. When the gas phase continuous flow system is used, the apparatus, operation and the like can be simplified, and it is economically advantageous.

In the step of reacting cyclobutene and hydrogen fluoride in the present disclosure, for example, as a raw material compound, in the cyclobutene represented by the general formula (2), X ¹ , X ² , X ³ , X ⁴ and X ⁶ are fluorine. More preferably, it is an atom.

According to the following reaction formula, the addition reaction with hydrogen fluoride is preferable.

Catalyst The step of reacting cyclobutene and hydrogen fluoride in the present disclosure is carried out in the gas phase in the presence of a catalyst in the addition reaction with hydrogen fluoride.

The catalyst used in this step is preferably activated carbon.

The catalyst used in this step is preferably a metal catalyst. As metal catalysts, chromium catalysts such as chromium oxide, chromium fluoride oxide, and chromium fluoride; aluminum catalysts such as aluminum oxide, aluminum fluoride oxide and aluminum fluoride; iron oxides, iron fluoride oxides, iron fluorides, etc. It is preferable to use a metal catalyst such as a catalyst, a nickel catalyst such as nickel oxide, nickel fluoride oxide or nickel fluoride, or a magnesium catalyst such as magnesium oxide, magnesium fluoride oxide or magnesium fluoride. The catalyst is preferably at least one selected from the group consisting of the above metal catalysts.

The catalyst used in this step is preferably at least one selected from the group consisting of activated carbon and the above metal catalyst. Among these catalysts, chromium catalysts such as activated carbon, chromium oxide, chromium fluoride oxide, and chromium fluoride are more preferable because the target compound can be obtained with higher selectivity. It is also possible to further improve the conversion rate of the raw material compound.

In this step, in contacting the raw material compound with the catalyst in the gas phase, it is preferable to contact the catalyst with the raw material compound in a solid state (solid phase).

In this step, the catalyst may be in a powder form, but a pellet form is preferable for a gas phase continuous flow reaction.

The specific surface area of the catalyst measured by the BET method (hereinafter, also referred to as BET specific surface area) is usually 10 to 3,000 m ² /g, preferably 10 to 2,500 m ² /g, more preferably 20 to 2,000m was ² / g, more preferably a 30~1,500m ² / g. When the BET specific surface area of the catalyst is in such a range, the density of the catalyst particles is not too small, and thus the target compound can be obtained with high selectivity. It is also possible to improve the conversion rate of the raw material compound. For example, as a catalyst, BET specific surface area is preferably used activated carbon a 800m ² / g~2,000m ² / g.

When activated carbon is used as the catalyst, it is preferable to use powdered activated carbon such as crushed carbon, shaped carbon, granular carbon, spherical carbon and the like. As the powdered activated carbon, it is preferable to use powdered activated carbon having a particle size of 4 mesh (4.76 mm) to 100 mesh (0.149 mm) in the JIS test. When activated carbon is used as the catalyst, it is possible to use activated carbon that has been treated by flowing nitrogen for a certain period of time at a temperature of 300 to 500° C. before use (heat-treated activated carbon).

When a metal catalyst is used as the catalyst, it is preferably supported on a carrier. Examples of the carrier include carbon, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), silica (SiO ₂ ), titania (TiO ₂ ), and the like. As carbon, activated carbon, amorphous carbon, graphite, diamond or the like can be used.

As an example of the catalyst in the present disclosure, chromium oxide and fluorinated chromium oxide will be described. For chromium oxide, for example, when chromium oxide is represented by Cr ₂ O ₃ .nH ₂ O, the value of n is preferably 3 or less, and more preferably 1 to 1.5. In the composition formula: CrO _m , the chromium oxide is preferably one in which m is usually in the range of 1.5<m<3. As a catalyst, fluorinated chromium oxide can be prepared by fluorinating chromium oxide. Examples of the fluorination include fluorination with hydrogen fluoride (HF) and fluorination with fluorocarbon and the like.

The fluorinated chromium oxide as a catalyst can be obtained, for example, according to the method described in Japanese Patent No. 3412165. By fluorinating chromium oxide with hydrogen fluoride (HF treatment), fluorinated chromium oxide can be obtained. The fluorination temperature is preferably 100 to 460°C, for example. The pressure for fluorination is preferably the pressure at which it is subjected to a catalytic reaction. In the present disclosure, it is particularly preferable to use a highly fluorinated chromium oxide catalyst having a high fluorine content. The highly fluorinated-chromium oxide catalyst can be obtained by fluorinating chromium oxide at a higher temperature than usual for a long time.

The highly fluorinated-chromium oxide catalyst preferably has a fluorine content of 30% by mass or more, more preferably 30 to 45% by mass. The fluorine content can be measured by a mass change of the catalyst or a general quantitative analysis method of chromium oxide.

Gas phase reaction temperature In the step of reacting cyclobutene and hydrogen fluoride in the present disclosure, the lower limit of the reaction temperature is to allow the addition reaction with hydrogen fluoride to proceed more efficiently and obtain the target compound with higher selectivity. From the viewpoint of being able to do so and suppressing the decrease in conversion, it is usually 50° C., preferably 200° C., more preferably 250° C., and further preferably 300° C.

When activated carbon is used as the catalyst, the reaction temperature is preferably 50°C to 400°C, more preferably 100°C to 350°C, still more preferably 150°C to 300°C.

When a chromium catalyst is used as the catalyst, the reaction temperature is preferably 50° C. or higher, more preferably 250° C. or higher, even more preferably 300° C. or higher.

The upper limit of the reaction temperature for reacting cyclobutene with hydrogen fluoride is such that the addition reaction with hydrogen fluoride can proceed more efficiently and the target compound can be obtained with a higher selectivity, and the reaction product decomposes. Or, from the viewpoint of suppressing a decrease in selectivity due to polymerization, it is usually 500°C, preferably 450°C, and more preferably 400°C.

Gas phase reaction time The reaction time for reacting cyclobutene with hydrogen fluoride is the contact time of the starting compound with the catalyst (W/F ₀ )[W: weight of metal catalyst (g), F ₀ : flow rate of starting compound (cc /Sec)], the conversion rate of the raw material compounds can be increased, but the amount of catalyst increases and the equipment becomes large, which is inefficient.

Therefore, the reaction time for reacting cyclobutene and hydrogen fluoride is the contact time (W/F ₀ ) of the raw material compound to the catalyst from the viewpoint of improving the conversion rate of the raw material compound and suppressing the equipment cost. It is preferably 1 g·sec/cc to 30 g·sec/cc, more preferably 1.5 g·sec/cc to 10 g·sec/cc, and 2.0 g·sec/cc to 5.0 g·sec/cc. More preferably,

The contact time of the raw material compound with the catalyst means the time of contact between the raw material compound and the catalyst.

The molar ratio of cyclobutene and hydrogen fluoride The supply amount of hydrogen fluoride, when using activated carbon as a catalyst, and a chromium catalyst, from the viewpoint of reaction cost and productivity, cyclobutene represented by the general formula (2) (raw material The compound is preferably reacted in an amount of about 0.1 mol to 100 mol, more preferably about 0.5 mol to 75 mol, still more preferably about 1 mol to 50 mol, per 1 mol of the compound).

Gas phase reaction pressure The reaction pressure for reacting cyclobutene and hydrogen fluoride is preferably −0.05 MPa to 2 MPa, from the viewpoint of advancing the addition reaction with hydrogen fluoride more efficiently, and −0.01 MPa to 1 MPa. It is more preferable that the pressure is from normal pressure to 0.5 MPa. In the present disclosure, the pressure is a gauge pressure unless otherwise noted.

In the reaction of cyclobutene and hydrogen fluoride, as a reactor for reacting a raw material compound and a catalyst (activated carbon, chromium catalyst, etc.) by contacting, if the temperature and pressure can withstand the above, the shape and structure are particularly Not limited. Examples of the reactor include a vertical reactor, a horizontal reactor, a multitubular reactor, and the like. Examples of the material of the reactor include glass, stainless steel, iron, nickel, iron-nickel alloy and the like.

Exemplification of gas phase reaction The reaction between cyclobutene and hydrogen fluoride (addition reaction with hydrogen fluoride) is a flow system or batch system in which the starting compound is continuously charged into the reactor and the target compound is continuously withdrawn from the reactor. It can be implemented by either method. If the target compound stays in the reactor, the elimination reaction can proceed further, so that it is preferable to carry out the process in a flow system. The step of reacting cyclobutene and hydrogen fluoride in the present disclosure is preferably performed in a gas phase, and particularly preferably performed in a gas phase continuous flow system using a fixed bed reactor. When the gas phase continuous flow system is used, the apparatus, operation and the like can be simplified, and it is economically advantageous.

The atmosphere for the reaction between cyclobutene and hydrogen fluoride is preferably in the presence of an inert gas and/or in the presence of hydrogen fluoride from the viewpoint of suppressing the deterioration of the catalyst (activated carbon, chromium catalyst, etc.). .. The inert gas is preferably at least one selected from the group consisting of nitrogen, helium, argon and carbon dioxide. Among these inert gases, nitrogen is more preferable from the viewpoint of cost reduction. The concentration of the inert gas is preferably 0 to 50 mol% of the gas component introduced into the reactor.

After completion of the reaction between cyclobutene and hydrogen fluoride (addition reaction with hydrogen fluoride), if necessary, perform purification treatment according to a conventional method to obtain cyclobutane containing a fluorine atom represented by the general formula (1). You can

(3) Target Compound The target compound in the present disclosure has the general formula (1):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
Is cyclobutane containing a fluorine atom.

Cyclobutane containing a fluorine atom represented by the general formula (1) to be produced is, for example,

And the like.

In the cyclobutane containing a fluorine atom represented by the general formula (1), X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and are a hydrogen atom, a halogen atom or a perfluoroalkyl. Indicates a group.

In the method for producing cyclobutane according to the present disclosure, the raw material compound is subjected to an addition reaction with hydrogen fluoride in the step of reacting the cyclobutene represented by the general formula (2) with hydrogen fluoride. In the cyclobutene represented by the formula (2), X ¹ , X ² , X ³ , X ⁴ and X ⁶ are more preferably fluorine atoms.

According to the following reaction formula, the addition reaction with hydrogen fluoride is preferable.

As the target compound, as the cyclobutane containing a fluorine atom represented by the general formula (1), it is more preferable that X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are fluorine atoms.

According to the production method of the present disclosure, cyclobutane containing a fluorine atom represented by the general formula (1) can be favorably produced at an industrial level with high selectivity.

(4) A composition containing a cyclobutane containing a fluorine atom As described above, a cyclobutane containing a fluorine atom represented by the general formula (1) can be obtained. It may be obtained in the form of a composition containing the cyclobutane containing a fluorine atom represented by the formula and the cyclobutene represented by the general formula (2).

As the cyclobutane containing a fluorine atom represented by the general formula (1) contained in the composition, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are preferably fluorine atoms.

In the composition containing the cyclobutane containing a fluorine atom represented by the general formula (1) of the present disclosure, the content of the cyclobutane containing a fluorine atom represented by the general formula (1), with the total amount of the composition being 100 mol %. Is preferably 99 mol% or more.

In the composition containing the cyclobutane containing a fluorine atom represented by the general formula (1) of the present disclosure, the content of the cyclobutane containing a fluorine atom represented by the general formula (1), with the total amount of the composition being 100 mol %. Is preferably 1 mol% to 99.9 mol%, more preferably 5 mol% to 99.9 mol%, still more preferably 10 mol% to 99.9 mol%.

According to the production method of the present disclosure, even when obtained as a composition containing cyclobutane containing a fluorine atom represented by the general formula (1), the fluorine atom represented by the general formula (1) is contained. Cyclobutane can be obtained with a particularly high selectivity, and as a result, it is possible to reduce the components other than cyclobutane containing a fluorine atom represented by the general formula (1) in the composition. According to the production method of the present disclosure, the labor of purification for obtaining a cyclobutane containing a fluorine atom represented by the general formula (1) can be reduced.

The composition containing the cyclobutane containing a fluorine atom represented by the general formula (1) of the present disclosure is the same as the case of cyclobutane containing a fluorine atom represented by the general formula (1) alone. In addition to the etching gas for forming the fine structure at the tip, it can be effectively used for various purposes such as a deposit gas, a building block for organic synthesis, and a cleaning gas.

The deposit gas is a gas that deposits an etch resistant polymer layer.

The building block for organic synthesis means a substance that can be a precursor of a compound having a highly reactive skeleton. For example, when cyclobutane containing a fluorine atom represented by the general formula (1) of the present disclosure and a composition containing the same are reacted with a fluorine-containing organosilicon compound such as CF ₃ Si(CH ₃ ) ₃ , CF ₃ It is possible to introduce a fluoroalkyl group such as a group into a substance that can be a detergent or a fluorine-containing pharmaceutical intermediate.

Although the embodiments of the present disclosure have been described above, various modifications of the forms and details can be made without departing from the spirit and scope of the claims.

Hereinafter, the present disclosure will be specifically described with reference to examples, but the present disclosure is not limited to these examples.

Examples In the method for producing a cyclobutane containing a fluorine atom of Examples, the starting compound was a cyclobutene represented by the general formula (2), wherein X ¹ , X ² , X ³ and X ⁴ were fluorine atoms.

According to the following reaction formula, an addition reaction of cyclobutene with hydrogen fluoride was performed.

The target compound was a cyclobutane containing a fluorine atom represented by the general formula (1), and X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ were fluorine atoms.

Example 1 (1-1 to 1-5), catalyst: A SUS pipe (outer diameter: 1/2 inch) was used as an activated carbon reaction tube, and 10 g of activated carbon was charged as a catalyst. The catalyst was used for the addition reaction with hydrogen fluoride. The BET specific surface area of the activated carbon was 850 m ² /g. 10 g of activated carbon as a catalyst was added to a SUS pipe (outer diameter: 1/2 inch) which is a reactor.

After drying for 2 hours at 200°C in a nitrogen atmosphere, the pressure was normal pressure and the contact time (W/F ₀ ) between cyclobutene cC ₄ F ₆ (raw material compound) and activated carbon (catalyst) was 2.0 gsec/cc. The raw material compound (cC ₄ F ₆ ) was passed through the reactor so that

The supply amount of hydrogen fluoride was 1 mol or 15 mol with respect to 1 mol of cyclobutene cC ₄ F ₆ (raw material compound).

The reaction proceeded in a gas phase continuous flow system.

The reactor was heated at 150°C, 200°C, 250°C or 300°C to start the addition reaction with hydrogen fluoride. One hour after starting the addition reaction with hydrogen fluoride, the distillate that passed through the detoxification tower was collected.

After that, mass spectrometry is performed by gas chromatography/mass spectrometry (GC/MS) using gas chromatography (manufactured by Shimadzu Corporation, trade name “GC-2014”), and NMR (manufactured by JEOL, trade name “400YH”). ]) was used for structural analysis by NMR spectrum.

From the results of mass spectrometry and structural analysis, it was confirmed that cC ₄ F ₇ H was produced as the target compound. In Example 1-1, the conversion rate from cC ₄ F ₆ (raw material compound) was 0.364 mol%, and the selectivity (yield) for cC ₄ F ₇ H (target compound) was 18.6 mol%.

In Example 1-2, the conversion was 11.6 mol% and the selectivity was 96.2 mol%.

In Example 1-3, the conversion was 4.57 mol% and the selectivity was 84.9 mol%.

In Examples 1-4, the conversion was 2.30 mol% and the selectivity was 38.8 mol%.

In Example 1-5, the conversion rate was 0.6 mol% and the selectivity was 94.2 mol%.

Example 2 (2-1 to 2-8), catalyst: SUS piping (outer diameter: 1/2 inch) was used as a chromium catalyst reaction tube, and 10 g of chromium oxide containing Cr ₂ O ₃ as a main component was filled as a catalyst. did. As a pretreatment for using the catalyst in the desorption reaction (dehydrofluorination reaction), anhydrous hydrogen fluoride was passed through the reactor, and the fluorination treatment was performed at a reactor temperature of 200°C to 300°C. The fluorinated chromium oxide was taken out and used for the dehydrofluorination reaction. The BET specific surface area of the fluorinated chromium oxide was 75 m ² /g. 10 g of fluorinated chromium oxide (chromium fluoride oxide) was added as a catalyst to a SUS pipe (outer diameter: 1/2 inch) which is a reactor.

After drying at 200°C for 2 hours in a nitrogen atmosphere, the pressure is normal pressure and the contact time (W/F ₀ ) between cyclobutene cC ₄ F ₆ (raw material compound) and fluorinated chromium oxide (catalyst) is 3.0 g. The raw material compound (cC ₄ F ₆ H ₂ ) was passed through the reactor so as to be sec/cc, 4.0 g·sec/cc or 5.0 g·sec/cc.

The amount of hydrogen fluoride supplied was 1 mol, 5 mol, or 20 mol with respect to 1 mol of cyclobutene cC ₄ F ₆ (raw material compound).

The reaction proceeded in a gas phase continuous flow system.

The reactor was heated at 50°C, 200°C, 250°C, 300°C or 350°C to start the addition reaction with hydrogen fluoride. One hour after starting the addition reaction with hydrogen fluoride, the distillate that passed through the detoxification tower was collected.

After that, mass spectrometry is performed by gas chromatography/mass spectrometry (GC/MS) using gas chromatography (manufactured by Shimadzu Corporation, trade name “GC-2014”), and NMR (manufactured by JEOL, trade name “400YH”). ]) was used for structural analysis by NMR spectrum.

From the results of mass spectrometry and structural analysis, it was confirmed that cC ₄ F ₇ H was produced as the target compound. In Example 2-1, the conversion rate from cC ₄ F ₆ (raw material compound) was 0.942 mol %, and the selectivity (yield) for cC ₄ F ₇ H (target compound) was 0.7 mol %.

In Example 2-2, the conversion rate was 0.183 mol% and the selectivity rate was 1.6 mol%.

In Example 2-3, the conversion was 0.506 mol% and the selectivity was 2.4 mol%.

In Example 2-4, the conversion rate was 0.396 mol% and the selectivity was 0.7 mol%.

In Example 2-5, the conversion rate was 0.924 mol% and the selectivity was 4.2 mol%.

In Example 2-6, the conversion rate was 1.37 mol% and the selectivity was 3.0 mol%.

In Example 2-7, the conversion rate was 1.62 mol% and the selectivity was 2.0 mol%.

In Example 2-8, the conversion rate was 2.87 mol% and the selectivity was 0.2 mol%.

Comparative Examples 1 and 2
According to the experimental method of the above-mentioned example, hydrogen fluoride was supplied to cyclobutene cC ₄ F ₆ (raw material compound) and a reaction was performed without using a catalyst.

The supply amount of hydrogen fluoride was 20 mol per 1 mol of cyclobutene cC ₄ F ₆ (raw material compound).

The reaction proceeded in a gas phase continuous flow system.

The reactor was heated at 200°C or 350°C to start the addition reaction with hydrogen fluoride. One hour after starting the addition reaction with hydrogen fluoride, the distillate that passed through the detoxification tower was collected.

Then, mass spectrometry is performed by gas chromatography/mass spectrometry (GC/MS) using gas chromatography (manufactured by Shimadzu Corporation, trade name “GC-2014”), and NMR (manufactured by JEOL, trade name “400YH”). ]) was used for structural analysis by NMR spectrum.

From the results of mass spectrometry and structural analysis, the conversion from cC ₄ F ₆ (raw material compound) was 0.801 mol% (Comparative Example 1) or 0.695 mol% (Comparative Example 2), but cC ₄ F ₇ H ( The formation of the target compound) was not confirmed.

The results of each example are shown in Table 1 below. In Table 1, the contact time (W/F ₀ ) indicates the flow rate of the flowing raw material gas, that is, the time for which the catalyst and the raw material gas are in contact with each other. The molar ratio HF / cC ₄ F _6, an amount of HF to cC ₄ F ₆ 1 mole (mol).

Claims (5)

General formula (1):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
A method for producing cyclobutane represented by
General formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same as above.)
A method for producing, comprising a step of reacting cyclobutene represented by and hydrogen fluoride in a gas phase in the presence of a catalyst. 2. The production method according to claim 1, wherein 0.1 mol to 100 mol of hydrogen fluoride is supplied and reacted with respect to 1 mol of cyclobutene represented by the general formula (2). 3. The production method according to claim 1 or 2, wherein the catalyst is at least one catalyst selected from the group consisting of activated carbon and a chromium compound. General formula (1):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are the same or different and represent a hydrogen atom, a halogen atom or a perfluoroalkyl group.)
A composition containing cyclobutane represented by:
The composition, wherein the total amount of the composition is 100 mol %, the content of cyclobutane represented by the general formula (1) is 99 mol% or more. The composition according to claim 4, which is used as a cleaning gas, an etching gas, a deposit gas or a building block for organic synthesis.