JP6835060B2 - Cyclobutene manufacturing method - Google Patents

Description

The present disclosure relates to a method for producing cyclobutene.

Cyclobutene containing a halogen atom is a compound useful as a dry etching gas for semiconductors, various refrigerants, foaming agents, heat transfer media and the like.

Among cyclobutenes containing halogen atoms, a method for producing 1H-pentafluorocyclobutene from 1H, 2H-hexafluorocyclobutane by a hydrogen fluoride reaction is known (for example, for 1H-pentafluorocyclobutene). Non-patent documents 1 and 2). This technique synthesizes 1H-pentafluorocyclobutene in an open reaction system using glassware.

Buxton; Tatlow; Journal of the Chemical Society; (1954); p. 1177 --1179 Fuller, G .; Tatlow, J.C .; Journal of the Chemical Society; (1961); p. 3198 --3203

An object of the present disclosure is to produce cyclobutene containing a halogen atom with a high selectivity.

The present disclosure includes the following configurations.

Item 1.
General formula (1):

(In the formula, X ¹ , X ² , X ³ and X ⁴ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. Y represents the halogen atom.)
It is a method for producing cyclobutene represented by.
General formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ and Y are the same as above. X ⁵ and X ⁶ indicate the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. .)
Including the step of desorbing cyclobutane represented by
A production method in which the desorption reaction step is carried out in the gas phase.

Item 2.
Item 2. The production method according to Item 1, wherein X ⁵ is a hydrogen atom, X ⁶ is a halogen atom, and the elimination reaction is a dehydrohalogenation reaction.

Item 3.
General formula (1):

(In the formula, X ¹ , X ² , X ³ and X ⁴ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. Y represents the halogen atom.)
A composition containing cyclobutene represented by
A composition in which the total amount of the composition is 100 mol% and the content of cyclobutene represented by the general formula (1) is 95 mol% or more.

Item 4.
The content of 1H-perfluorocyclobutene (1H-cC ₄ F ₅ H) is 99 mol% or more, and the content of 3H-perfluorocyclobutene (3H-cC ₄ F ₅ H) is 1 mol% or less. The composition composition according to the above item 3.

Item 5.
Item 3. The composition according to Item 3 or 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, cyclobutene containing a halogen atom can be produced with a high selectivity.

As a result of diligent research, the present inventors performed the step of desorbing the raw material compound in the gas phase to obtain cyclobutene containing a halogen atom represented by the above general formula (1) with a high selectivity. We found that it could be manufactured.

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

The disclosure includes the following embodiments:

General formula (1) of the present disclosure:

(In the formula, X ¹ , X ² , X ³ and X ⁴ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. Y represents the halogen atom.)
The method for producing cyclobutene represented by is
General formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ and Y are the same as above. X ⁵ and X ⁶ indicate the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. .)
Includes a step of desorbing cyclobutane represented by.

In the present disclosure, the desorption reaction step is performed in the gas phase.

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

In the present disclosure, the "selectivity" refers to the target compound (halogen atom) contained in the effluent gas with respect to the total molar amount of the compound other than the raw material compound (cyclobutene containing a halogen atom, etc.) in the effluent gas from the reactor outlet. It means the ratio (mol%) of the total molar amount of cyclobutene (containing).

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

Further, since the method for producing cyclobutene of the present disclosure is not a batch reaction but a gas phase reaction of a distribution system, there is an advantage that it is not necessary to use a solvent and industrial waste does not occur.

(1) Raw Material Compound In the present disclosure, the raw material compound is referred to as the general formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. Y represents a halogen atom. )
It is cyclobutane represented by.

X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group.

Y represents a halogen atom.

Halogen atoms of X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ and Y include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

The ^{perfluoroalkyl groups of X 1} , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are alkyl groups in which all hydrogen atoms are substituted with 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 cyclobutane containing a halogen atom represented by the general formula (2), which is a raw material compound, X ¹ , X ² , X ³ and X ^{4 can be produced with a high selectivity of cyclobutene containing a halogen atom.} Is the same or different and represents a hydrogen atom, a halogen atom, or a perfluoroalkyl group, ^{more preferably X 5} is a hydrogen atom, X ⁶ is a fluorine atom, and Y is a fluorine atom.

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

And other compounds.

These cyclobutanes represented by the general formula (2) can be used alone or in combination of two or more. Commercially available products can be adopted as such cyclobutane.

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

(2) Elimination reaction In the step of the elimination reaction in the present disclosure, the elimination reaction is carried out in the gas phase. The step of the desorption reaction in the present disclosure is preferably carried out in the gas phase, and particularly preferably in the gas phase continuous flow system using a fixed bed reactor. When the gas phase continuous flow system is used, the equipment, operation, etc. can be simplified and it is economically advantageous.

In the step of the elimination reaction in the present disclosure, it is preferable that X ⁵ is a hydrogen atom, X ⁶ is a halogen atom, and the elimination reaction is a dehydrohalogenated hydrogen reaction. In the step of the elimination reaction in the present disclosure, it is preferable that X ⁵ is a hydrogen atom, X ⁶ is a fluorine atom, and the elimination reaction is a defluorinated hydrogen reaction.

For example, in cyclobutane containing a halogen atom represented by the general formula (2) as a raw material compound, X ¹ , X ² , X ³ , X ⁴ and X ⁶ are fluorine atoms, and X ⁵ is a hydrogen atom. , Y is preferably a fluorine atom.

According to the following reaction formula, the elimination reaction is preferably a defluorinated hydrogen reaction.

Catalyst In the step of desorption reaction in the present disclosure, it is preferable to carry out the desorption reaction in the presence of a catalyst and in the gas phase.

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 oxide, chromium fluoride oxide, chromium fluoride, aluminum oxide, aluminum fluoride oxide, aluminum fluoride, iron oxide, iron fluoride oxide, iron fluoride, nickel oxide, nickel fluoride oxide, fluoride It is preferably at least one selected from the group consisting of nickel, magnesium oxide, magnesium fluoride oxide and magnesium fluoride.

Of these catalysts, activated carbon, chromium oxide, chromium fluoride oxide, aluminum oxide, and aluminum fluoride oxide are more preferable because the target compound can be obtained with a higher selectivity. It is also possible to further improve the conversion rate of the raw material compound.

In this step, when the raw material compound and the catalyst are brought into contact with each other in the gas phase, it is preferable to bring the catalyst into contact with the raw material compound in a solid state (solid phase).

In this step, the catalyst may be in the form of powder, but the form of pellets is preferable for the gas phase continuous flow type 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 400 m ² / g, and more preferably 20 to 375 m. ^{It is 2} / g, more preferably 30 to 350 m ² / g. When the BET specific surface area of the catalyst is in such a range, the target compound can be obtained with a high selectivity because the density of the catalyst particles is not too small. It is also possible to improve the conversion rate of the raw material compound.

When activated carbon is used as a catalyst, it is preferable to use powdered activated carbon such as crushed carbon, briquette, granular charcoal, and spherical charcoal. 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 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 the carbon, activated carbon, amorphous carbon, graphite, diamond and the like can be used.

As an example of the catalyst in the present disclosure, chromium oxide and fluorinated chromium oxide will be described. As 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. Further, the chromium oxide preferably has a composition formula: CrO _m 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 fluorination include fluorination with hydrogen fluoride (HF) and fluorination with fluorocarbons and the like.

Fluorinated chromium oxide as a catalyst can be obtained, for example, according to the method described in Japanese Patent No. 3412165. Fluorinated chromium oxide can be obtained by fluorinating (HF treatment) the chromium oxide with hydrogen fluoride. The fluorination temperature is preferably 100 to 460 ° C, for example. The fluorination pressure 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 hyperfluorinated-chromium oxide catalyst can be obtained by fluorinating chromium oxide at a higher temperature than usual for a long period of time.

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

Desorption reaction temperature In the step of desorption reaction in the present disclosure, the lower limit of the reaction temperature is a viewpoint that the desorption reaction can proceed more efficiently and the target compound can be obtained with a higher selectivity, and the conversion rate is lowered. From the viewpoint of suppressing the temperature, the temperature is usually 50 ° C., preferably 200 ° C., more preferably 250 ° C., still more preferably 300 ° C., and particularly preferably 350 ° C.

The upper limit of the reaction temperature in the desorption reaction is selected from the viewpoint that the defluorinated hydrogen reaction can proceed more efficiently and the target compound can be obtained with a higher selectivity, and the reaction product is decomposed or polymerized. From the viewpoint of suppressing the decrease in the rate, it is usually 500 ° C., preferably 450 ° C., and more preferably 400 ° C.

Elimination reaction time The reaction time of the elimination reaction is the contact time of the raw material compound with the catalyst (W / F ₀ ) [W: weight of the metal catalyst (g), F ₀ : flow rate of the raw material compound (cc / sec)]. If it is lengthened, the conversion rate of the raw material compound can be increased, but the amount of catalyst increases and the equipment becomes large, which is inefficient.

Therefore, the reaction time of the defluorinated hydrogen reaction is such that the contact time (W / F ₀ ) of the raw material compound with the catalyst is 5 g · sec from the viewpoint of improving the conversion rate of the raw material compound and suppressing the equipment cost. It is preferably / cc to 300 g · sec / cc, more preferably 10 g · sec / cc to 200 g · sec / cc, further preferably 15 g · sec / cc to 150 g · sec / cc. It is particularly preferably 20 g · sec / cc to 100 g · sec / cc.

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

In the elimination reaction in the present disclosure, when the reaction is carried out in the gas phase in the presence of a catalyst, the reaction temperature and the reaction time (contact time) are appropriately adjusted according to the catalyst, whereby the target compound can be selected at a higher selectivity. Obtainable.

When chromium oxide is used as the catalyst, the reaction temperature is preferably 300 ° C. or higher, more preferably 350 ° C. or higher. The contact time is preferably 10 g · sec / cc or more, more preferably 20 g · sec / cc or more, and even more preferably 40 g · sec / cc or more.

When alumina is used as the catalyst, the reaction temperature is preferably 300 ° C. or higher, and the contact time is preferably 5 g · sec / cc or higher.

When activated carbon is used as the catalyst, the reaction temperature is preferably 300 ° C. or higher, more preferably 350 ° C. or higher, and even more preferably 400 ° C. or higher. The contact time is preferably 5 g / sec / cc to 55 g / sec / cc, more preferably 5 g / sec / cc to 50 g / sec / cc, and 5 g / sec / cc to 40 g / sec /. It is more preferably cc.

Desorption reaction pressure The reaction pressure of the desorption reaction is preferably -0.05MPa to 2MPa, more preferably -0.01MPa to 1MPa, and the normal pressure from the viewpoint of promoting the desorption reaction more efficiently. It is more preferably ~ 0.5 MPa. In this disclosure, the pressure is a gauge pressure unless otherwise specified.

In the desorption reaction, the shape and structure of the reactor in which the raw material compound and the catalyst (metal catalyst or the like) are brought into contact with each other to react are not particularly limited as long as they can withstand the above temperature and pressure. Examples of the reactor include a vertical reactor, a horizontal reactor, a multi-tube reactor and the like. Examples of the material of the reactor include glass, stainless steel, iron, nickel, iron-nickel alloy and the like.

Illustrative Desorption Reaction The desorption reaction can be carried out by either a distribution method or a batch method in which the raw material compound is continuously charged into the reactor and the target compound is continuously extracted from the reactor. When the target compound stays in the reactor, the elimination reaction can proceed further, so it is preferable to carry out by a distribution method. The step of the desorption reaction in the present disclosure is preferably carried out in the gas phase, and particularly preferably in the gas phase continuous flow system using a fixed bed reactor. When the gas phase continuous flow system is used, the equipment, operation, etc. can be simplified and it is economically advantageous.

The atmosphere during the desorption reaction is preferably in the presence of an inert gas and / or in the presence of hydrogen fluoride from the viewpoint of suppressing deterioration of the catalyst (metal catalyst or the like). 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 reducing costs. The concentration of the inert gas is preferably 0 to 50 mol% of the gas component introduced into the reactor.

After completion of the elimination reaction, if necessary, purification treatment is carried out according to a conventional method to obtain cyclobutene containing a halogen atom represented by the general formula (1).

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

(In the formula, X ¹ , X ² , X ³ and X ⁴ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. Y represents the halogen atom.)
It is a cyclobutene containing a halogen atom represented by.

X ¹ , X ² , X ³ and X ⁴ , and Y are the same as above.

The cyclobutene represented by the general formula (1) to be produced is, for example, the following.

And other compounds.

In cyclobutene containing a halogen atom represented by the general formula (1), X ¹ , X ² , X ³ and X ⁴ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group, and Y is , Fluorine atom is preferable. In the cyclobutene containing a halogen atom represented by the general formula (1), ^{it is more preferable that X 1} , X ² , X ³ and X ⁴ are fluorine atoms and Y is a fluorine atom.

In the method for producing cyclobutene containing a halogen atom in the present disclosure, the starting compound is cyclobutene containing a halogen atom represented by the general formula (2), and X ¹ , X ² , X ³ , X ⁴ and X ⁶ are fluorine. ^{It is preferable that X 5} is an atom, X 5 is a hydrogen atom, and Y is an elimination reaction when it is a fluorine atom.

According to the following reaction formula, the elimination reaction is preferably a defluorinated hydrogen reaction.

The target compound is preferably a cyclobutene containing a halogen atom represented by the general formula (1), where X ¹ , X ² , X ³ and X ⁴ are fluorine atoms and Y is a fluorine atom.

(4) Composition containing cyclobutene containing a halogen atom As described above, cyclobutene containing a halogen atom represented by the general formula (1) can be obtained, but as described above, the general formula (1) can be used. It may also be obtained in the form of a composition containing cyclobutene containing a halogen atom represented by it and cyclobutane containing a halogen atom represented by the general formula (2).

As the cyclobutene containing a halogen atom represented by the general formula (1) contained in the composition, X ¹ , X ² , X ³ and X ⁴ are preferably fluorine atoms, and Y is preferably a fluorine atom.

In the composition containing cyclobutene containing a halogen atom represented by the general formula (1) of the present disclosure, the content of cyclobutene containing a halogen atom represented by the general formula (1) is taken as 100 mol% of the total amount of the composition. Is preferably 95 mol% or more, and more preferably 99 mol% or more.

In the composition containing cyclobutene containing a halogen atom represented by the general formula (1) of the present disclosure, the content of cyclobutene containing a halogen atom represented by the general formula (1) is taken as 100 mol% of the total amount of the composition. 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%.

In the method for producing cyclobutene containing a halogen atom in the present disclosure, the following compounds can be produced as impurities in the elimination reaction.

In the composition containing cyclobutene containing a halogen atom represented by the general formula (1) of the present disclosure, 1H-perfluorocyclobutene (1H-cC ₄ F ₅ H) is contained, assuming that the total amount of the composition is 100 mol%. The amount is 99 mol% or more, and _{the content of 3H-perfluorocyclobutene (3H-cC 4} F ₅ H) is preferably 1 mol% or less.

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

The composition containing cyclobutene containing a halogen atom represented by the general formula (1) of the present disclosure is the same as that of cyclobutene alone containing a halogen atom represented by the general formula (1), such as a semiconductor or a liquid crystal. In addition to etching gas for forming the fine structure at the tip, it can be effectively used for various purposes such as deposit gas, building blocks for organic synthesis, and cleaning gas.

The deposit gas is a gas for depositing an etching 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 cyclobutene containing a halogen atom represented by the general formula (1) of the present disclosure and a composition containing the cyclobutene 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 to convert it into a substance that can be a cleaning agent or a fluorine-containing pharmaceutical intermediate.

Although the embodiments of the present disclosure have been described above, various changes in the forms and details are possible without departing from the spirit and scope of the claims.

The present disclosure will be specifically described with reference to Examples below, but the present disclosure is not limited to these Examples.

Examples In the method for producing a cyclobutene containing a halogen atom in Examples, the starting compound is a cyclobutane containing a halogen atom represented by the general formula (2), in which X ¹ , X ² , X ³ , X ⁴ and X ⁶ are used. , Fluorine atom, X ⁵ is a hydrogen atom, and Y is a fluorine atom.

According to the following reaction formula, the elimination reaction was a defluorinated hydrogen reaction.

The target compound was cyclobutene containing a halogen atom represented by the general formula (1), where X ¹ , X ² , X ³ and X ⁴ were fluorine atoms and Y was a fluorine atom.

In addition, the following compounds can be produced as impurities in the elimination reaction.

Examples 1 to 3 (chromium oxide catalyst)
A SUS pipe (outer diameter: 1/2 inch) was used as a reaction tube, _{and 10 g of chromium oxide containing Cr 2} O ₃ as a main component was filled as a catalyst. As a pretreatment for using the catalyst for a desorption reaction (hydrogen fluoride reaction), anhydrous hydrogen fluoride was circulated 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 defluorinated hydrogen reaction. The BET specific surface area of fluorinated chromium oxide was 75 m ² / g.

To the SUS pipe (outer diameter: 1/2 inch), which is a reactor, 10 g of fluorinated chromium oxide (chromium fluoride oxide) was added as a catalyst. After drying at 200 ° C for 2 hours in a nitrogen atmosphere, the pressure is normal, _{and the contact time (W / F 0 ) between cC 4} F ₆ H ₂ (raw material compound) and fluorinated chromium oxide (catalyst) is 20 g. _{The raw material compound (cC 4} F ₆ H ₂ ) was circulated in the reactor so as to be sec / cc or 40 g · sec / cc.

The reaction proceeded in a gas phase continuous flow system.

The reactor was heated at 250 ° C. or 350 ° C. to initiate the hydrogen fluoride reaction.

One hour after the start of the defluorinated hydrogen reaction, the distillate that passed through the abatement tower was collected.

After that, mass spectrometry was performed by gas chromatography / mass spectrometry (GC / MS) using gas chromatography (manufactured by Shimadzu Corporation, trade name "GC-2014"), and NMR (manufactured by JEOL Ltd., trade name "400YH") was performed. ”) Was used to perform structural analysis by NMR spectrum.

From the results of mass spectrometry and structural analysis, it was confirmed that _{cC 4} F _{5 H was produced as the target compound.} In Example 1, _{the conversion rate from cC 4} F ₆ H ₂ (raw material compound) was 3.34 mol%, and _{the selectivity (yield) of cC 4} F ₅ H (target compound) was 45.9 mol%. In Example 2, the conversion rate was 29.1 mol% and the selectivity was 98.6 mol%. In Example 3, the conversion rate was 26.1 mol% and the selectivity was 97.2 mol%.

Examples 4 and 5 (alumina catalyst)
Following the experimental method of Example 1, _{alumina containing Al 2} O ₃ as a main component was used as a catalyst. Following the experimental method of Example 1, _{the contact time (W / F 0 ) between cC 4} F ₆ H ₂ (raw material compound) and alumina (catalyst) should be 10 g · sec / cc or 40 g · sec / cc. The raw material compound was distributed to the reactor. Following the experimental method of Example 1, the reactor was heated at 400 ° C. to start the defluorinated hydrogen reaction. Except for the above conditions, the hydrogen fluoride reaction, mass spectrometry and structural analysis were carried out in the same manner as in Example 1.

From the results of mass spectrometry and structural analysis, it was confirmed that _{cC 4} F _{5 H was produced as the target compound.} In Example 4, _{the conversion rate from cC 4} F ₆ H ₂ (raw material compound) was 7.92 mol%, and _{the selectivity of cC 4} F ₅ H (target compound) was 45.1 mol%. In Example 5, the conversion rate was 4.11 mol% and the selectivity was 35.0 mol%.

Examples 6 to 10 (activated carbon catalyst)
Activated carbon was used as a catalyst in accordance with the experimental method of Example 1. Following the experimental method of Example 1, _{the contact time (W / F 0 ) between cC 4} F ₆ H ₂ (raw material compound) and activated carbon (catalyst) is 10 g · sec / cc, 27 g · sec / cc or 47 g ·. The raw material compound was circulated through the reactor so as to be sec / cc. Following the experimental method of Example 1, the reactor was heated at 300 ° C., 350 ° C. or 400 ° C. to start the defluorinated hydrogen reaction. Except for the above conditions, the hydrogen fluoride reaction, mass spectrometry and structural analysis were carried out in the same manner as in Example 1.

From the results of mass spectrometry and structural analysis, it was confirmed that _{cC 4} F _{5 H was produced as the target compound.} In Example 6, _{the conversion rate from cC 4} F ₆ H ₂ (raw material compound) was 57.6 mol%, and _{the selectivity of cC 4} F ₅ H (target compound) was 95.3 mol%. In Example 7, the conversion rate was 97.7 mol% and the selectivity was 68.3 mol%. In Example 8, the conversion rate was 84.1 mol% and the selectivity was 83.8 mol%. In Example 9, the conversion rate was 72.3 mol% and the selectivity was 94.6 mol%. In Example 10, the conversion rate was 84.7 mol% and the selectivity was 95.7 mol%.

The results of each example are shown in Table 1 below. In Table 1, the contact time (W / F ₀ ) means the speed at which the flowing raw material gas flows, that is, the time during which the catalyst and the raw material gas come into contact with each other.

Claims (3)

General formula (1):

(In the formula, X ¹ , X ² , X ³ and X ⁴ represent the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. Y represents the halogen atom.)
It is a method for producing cyclobutene represented by.
General formula (2):

(In the formula, X ¹ , X ² , X ³ , X ⁴ and Y are the same as above. X ⁵ and X ⁶ indicate the same or different hydrogen atom, halogen atom, or perfluoroalkyl group. .)
Including the step of desorbing cyclobutane represented by
A step of the to elimination reaction in the presence of a catalyst, are performed by the gas phase,
The catalyst is
(I) Activated carbon;
(Ii) A group consisting of chromium oxide, chromium fluoride oxide, chromium fluoride, aluminum oxide, aluminum fluoride oxide, iron oxide, iron fluoride oxide, nickel oxide, nickel fluoride oxide, magnesium oxide, and magnesium fluoride oxide. At least one metal catalyst of choice;
(Iii) A metal catalyst supported on a carrier, which is a metal catalyst.
The carrier is at least one carrier selected from the group consisting of activated carbon, amorphous carbon, graphite, and diamond; at least one carrier selected from the group consisting of alumina; zirconia; silica; and titania.
The metal catalyst supported on the carrier is chromium oxide, chromium fluoride oxide, chromium fluoride, aluminum oxide, aluminum fluoride oxide, aluminum fluoride, iron oxide, iron fluoride oxide, iron fluoride, nickel oxide, and the like. A combination of at least one metal catalyst selected from the group consisting of nickel fluoride, nickel fluoride, magnesium oxide, magnesium fluoride and magnesium fluoride (provided that the metal catalyst is aluminum oxide when the carrier is alumina). except for);
At least one catalyst selected from the group consisting of,
Production method. The production method according to claim 1, wherein X ⁵ is a hydrogen atom, X ⁶ is a halogen atom, and the elimination reaction is a dehydrohalogenation reaction. The production method according to claim 1 or 2, wherein the step of the desorption reaction is carried out by a gas phase continuous flow system.