Method for producing aromatic compound having fluoroalkyl group

Abstract

Provided is a novel method with which it is possible to efficiently produce an aromatic compound having a fluoroalkyl group. Provided is a method for producing a compound represented by general formula (1), the method including a step for heating a compound represented by general formula (2), the heating step satisfying either (1) intermittent heating to 170 DEG C or higher or (2) continuous flow heating to 500 DEG C or higher. [In formula (1), R1 may be the same or different and each represents a fluoroalkyl group. And n represents an integer of 2-5. ] (In formula (2), R1 and n are as defined above. ].

Description

Technical Field

[0001] This invention relates to a method for manufacturing an aromatic compound having a fluorinated alkyl group. Background Technology

[0002] As a method for producing aromatic compounds having fluorinated alkyl groups, it is known to use phenyl trifluoroacetate or 4-fluorophenyl trifluoroacetate as raw materials, and to perform thermal deacidification by heating the raw materials to 650°C while allowing them to flow in a quartz glass tube, to obtain trifluorotoluene and 1-fluoro-4-fluorophenylbenzene, respectively (see, for example, Non-Patent Literature 1). As a result, the yield of the target compound is 15.5% when using phenyl trifluoroacetate as a raw material, and 2.0% when using 4-fluorophenyl trifluoroacetate as a raw material.

[0003] Existing technical documents Non-patent literature Non-patent literature 1: Journal of Fluorine Chemistry, 32 (1986) 467-470 Summary of the Invention

[0004] The problem that the invention aims to solve The purpose of this invention is to provide a novel method for efficiently manufacturing aromatic compounds having fluoroalkyl groups.

[0005] Technical solutions for solving the problem The present invention comprises the following components.

[0006] Item 1. A method for manufacturing a compound of general formula (1), the method comprising a step of heating a compound of general formula (2), In equation (1), R 1 Same or different indicates fluoroalkyl.

[0007] n represents an integer from 2 to 5. [In the formula, R] 1 The meanings of and n are the same as described above. The above heating process satisfies either (1) intermittent heating to above 170°C or (2) continuous gas-phase heating to above 500°C.

[0008] Item 2. The manufacturing method as described in Item 1, wherein the aforementioned R 1 It is a perfluoroalkyl group.

[0009] Item 3. The manufacturing method as described in Item 1 or 2, wherein n is 5.

[0010] Item 4. The manufacturing method as described in any one of items 1 to 3, wherein (1) is satisfied above, and the heating process is carried out under conditions of 0.05 to 1.00 MPa on a gauge pressure gauge.

[0011] Item 5. The manufacturing method as described in any one of items 1 to 4, wherein (2) is satisfied above, and in the heating step above, a thermally conductive container is used as the reaction vessel.

[0012] Item 6. A composition comprising a compound of general formula (1), a compound of general formula (3), and / or a compound of general formula (4), In equation (1), R 1 Same or different indicates fluoroalkyl.

[0013] n represents an integer from 2 to 5. [In equation (3), the meaning of n is the same as above.] [In equation (4), R] 1 The meanings of and n are the same as above.

[0014] Item 7. The composition as described in Item 6, wherein, relative to 1 mole of the compound represented by the above general formula (1), it contains a total of 30 moles or less of the compound represented by the above general formula (3) and / or the compound represented by the above general formula (4).

[0015] Item 8. The composition as described in Item 6 or 7, further comprising a compound represented by general formula (5), [In the formula, n has the same meaning as above.]

[0016] Item 9. The composition of any one of items 6 to 8, used as an etching gas, cleaning gas, or deposition gas.

[0017] Invention Effects Using this invention, a novel method for manufacturing aromatic compounds having fluoroalkyl groups can be provided. Detailed Implementation

[0018] In this specification, "containing" is a concept that includes "comprise", "consist essentially of", and "consist of".

[0019] In addition, in this specification, when “A~B” is used to represent a numerical range, it means above A and below B.

[0020] In this invention, "selectivity" refers to the ratio (in moles) of the total molar amount of the target compound contained in the reaction product (or the effluent gas from the reactor outlet in the case of a continuous gas-phase flow) to the total molar amount (in moles) of compounds other than the feed compound in the reaction product (or the effluent gas from the reactor outlet in the case of a continuous gas-phase flow).

[0021] In this invention, "conversion rate" refers to the ratio (mol%) of the total molar amount of compounds other than the feed compounds contained in the reaction products (or the outflow gas from the reactor outlet in the case of continuous gas flow) to the molar amount of the feed compounds supplied to the reactor.

[0022] In this invention, "yield" refers to the ratio (mol%) of the total molar amount of the target compound contained in the reaction product (or the outflow gas from the reactor outlet in the case of a continuous gas-phase flow) to the molar amount of the feed compound supplied to the reactor.

[0023] 1. A method for manufacturing aromatic compounds containing fluorinated alkyl groups. The manufacturing method of the present invention is a method for manufacturing the compound represented by general formula (1), including a step of heating the compound represented by general formula (2). In equation (1), R 1 Same or different indicates fluoroalkyl.

[0024] n represents an integer from 2 to 5. [In formula (2), R] 1 The meanings of and n are the same as described above. The above heating process satisfies either (1) intermittent heating to above 170°C or (2) continuous gas-phase heating to above 500°C.

[0025] (1-1) Starting compound (general formula (2)) In the manufacturing method of the present invention, the compound represented by general formula (2) is the compound represented by the following general formula (2): [In the formula,] R 1 Same or different indicates fluoroalkyl.

[0026] n represents an integer from 2 to 5.

[0027] In general formula (2), R 1 The fluoroalkyl group shown refers to an alkyl group in which at least one hydrogen atom is replaced by a fluorine atom.

[0028] In this invention, the more electronegative fluorine atoms (unlike other halogen atoms), the easier it is to stably generate fluoroalkyl anions and the easier it is to break the bonds required for the thermal deacidification reaction. From the perspective of facilitating the thermal deacidification reaction, a higher number of fluorine atoms in the fluoroalkyl group is preferred. Therefore, perfluoroalkyl groups are preferred as fluoroalkyl groups. Perfluoroalkyl refers to an alkyl group in which all hydrogen atoms are replaced by fluorine atoms. On the other hand, when the bond between the carbon atom of the carbonyl group and the oxygen at the α-position is easily broken, ether compounds or alcohol compounds are easily generated as byproducts. Therefore, a higher number of fluorine atoms facilitates the stable generation of fluoroalkyl anions, facilitates the breaking of the bonds required for the thermal deacidification reaction, and thus helps to suppress the formation of these byproducts.

[0029] Fluoroalkyl groups can be of any type, including straight-chain, branched, and cyclic. Among these, straight-chain fluoroalkyl groups are preferred from the perspectives of conversion, yield, and selectivity.

[0030] There is no particular limitation on the number of carbon atoms in the fluoroalkyl group, but from the viewpoints of conversion, yield, and selectivity, 1 to 5 is preferred, 1 to 4 is more preferred, and 1 to 3 is even more preferred.

[0031] Examples of such fluoroalkyl groups include fluoromethyl, difluoromethyl, trifluoromethyl, fluoroethyl (1-fluoroethyl, 2-fluoroethyl, etc.), difluoroethyl (1,1-difluoroethyl, 2,2-difluoroethyl, etc.), trifluoroethyl (2,2,2-trifluoroethyl, etc.), tetrafluoroethyl (1,1,2,2-tetrafluoroethyl, 1,2,2,2-tetrafluoroethyl, etc.), and pentafluoroethyl.

[0032] In general formula (2), n refers to the number of fluorine atoms bonded to the benzene ring, which is an integer from 2 to 5. As shown in Non-Patent Document 1, the yield of the target product is significantly reduced when fluorine atoms bonded to the benzene ring are present. This tendency is more pronounced as the number of fluorine atoms increases. Therefore, according to Non-Patent Document 1, it is generally believed that the reaction hardly proceeds when there are two or more fluorine atoms bonded to the benzene ring. In this respect, in the present invention, even if there are two or more fluorine atoms bonded to the benzene ring, the target product can be generated by using specific conditions in the batch reaction (condition (1)) and the gas-phase continuous flow reaction (condition (2)). In other words, the present invention is useful from the perspective that the target product can be generated even when there are many fluorine atoms bonded to the benzene ring. n is preferably an integer from 3 to 5, more preferably 4 or 5, and even more preferably 5.

[0033] Compounds of general formula (2) that serve as starting materials satisfying the above conditions can be specifically listed. wait.

[0034] The compounds represented by the above general formula (2) can be known compounds or commercially available products. In addition, the compounds represented by the above general formula (2) can be used alone or in combination of two or more.

[0035] (1-2) reaction In the reaction of the present invention, in the compound represented by the above general formula (2), the group -OCOR 1 Thermal deacidification occurs, and through a decarbonation reaction, the -OCO- group is released to form the -R group. 1 .

[0036] At this time, R 1 The hydrogen and fluorine atoms on the benzene ring will not change or remain even after the reaction of this invention. In other words, the -OCOR group... 1 Thermal deacidification is performed, and the -OCO- group is removed to form the -R group. 1 However, the structures other than these are maintained.

[0037] As a result, compounds of general formula (1) can be obtained.

[0038] Regarding the reaction of this invention, either a batch reaction in which the starting material is added to the reaction vessel all at once, or a continuous gas-phase flow reaction in which the starting material is continuously supplied to the reaction vessel while the product is extracted from the reaction vessel, can be used. The conditions vary depending on the method used, and will be described in detail later. A batch reaction is preferred as it reduces the likelihood of generating difficult-to-separate byproducts.

[0039] In addition, the above reaction can be carried out in the liquid phase or in the gas phase.

[0040] (1-3) Intermittent (condition (1)) In the manufacturing method of the present invention, when a batch reaction is used, there are no particular limitations on the reaction vessel used, as long as it can withstand the reaction, and there are no particular limitations on its shape and structure. From the viewpoint that the reaction can be carried out at low temperatures and the compound represented by the general formula (1) as the target object can be easily obtained, a pressure-resistant reaction vessel is preferred.

[0041] In the manufacturing method of the present invention, there are no restrictions on the reaction vessel. Preferably, the compound of general formula (2) as the raw material is added to a pressure vessel such as an autoclave, and the temperature is raised to 170°C or above using a heater, and the reaction is carried out for a certain period of time. At this time, either a gas-phase reaction or a liquid-phase reaction can be used. In addition, in the case of using a liquid-phase reaction, it is preferable to carry out the reaction in a solvent under stirring. Non-Patent Document 1 describes the recovery of the raw material at a reaction temperature of 500°C or below, so the ability to carry out the decarbonation reaction at a relatively extremely low temperature is an unexpected result.

[0042] Materials that can be used as reaction vessels include, for example, glass, stainless steel, iron, nickel, and iron-nickel alloys.

[0043] In the manufacturing method of the present invention, when a batch liquid-phase reaction is used, there are no particular limitations on the solvent that can be used; both non-polar and polar solvents can be used. From the viewpoints of conversion, yield, and selectivity, a non-polar solvent is preferred. Furthermore, a solvent that does not undergo thermal decomposition at the reaction temperature is preferred. Since the reaction temperature is 170°C or higher, a solvent that does not undergo thermal decomposition, or a solvent with a thermal decomposition temperature of 175°C or higher, is preferred. Specifically, examples of solvents that can be used include: aliphatic organic solvents such as hexane, cyclohexane, and heptane; aromatic organic solvents such as benzene, toluene, xylene, mesitylene, trifluorotoluene, and chlorobenzene; aliphatic halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform; lactam compounds such as N-methylpyrrolidone; ether compounds such as tetrahydrofuran and diethyl ether; and ketone compounds such as acetone. These solvents can be used alone or in combination of two or more.

[0044] When the amount of nonpolar solvent used is the solvent amount, there is no particular restriction and it can be set as an excess. From the viewpoint of conversion rate, yield, selectivity, etc., it is preferred to be 80 to 10,000 parts by mass relative to 100 parts by mass of the compound shown in general formula (2), and more preferably 100 to 1,000 parts by mass.

[0045] The manufacturing method of the present invention preferably uses an intermittent reaction vessel (such as an autoclave) and a closed reaction system to carry out the reaction. As the reaction atmosphere, it is preferably carried out in an inert gas atmosphere such as nitrogen, argon, or helium.

[0046] In the manufacturing method of the present invention, from the viewpoint of easily suppressing the formation of high-boiling-point compounds as byproducts and easily and efficiently carrying out the thermal deacidification reaction, the reaction temperature in the batch process is 170°C or higher, preferably 180–300°C, and more preferably 190–240°C. When the reaction temperature is less than 170°C, only the side reaction occurs, and the thermal deacidification reaction does not occur, so the target product cannot be generated, resulting in poor yield and selectivity.

[0047] Furthermore, in the manufacturing method of the present invention, the reaction temperature can be raised to the maximum temperature in one heating operation, or it can be raised to the maximum temperature in stages through multiple heating operations.

[0048] In the manufacturing method of the present invention, the intermittent reaction pressure refers to the pressure inside the reaction vessel used. In the manufacturing method of the present invention, there are no particular limitations, but from the viewpoint that it is easy to improve the conversion rate, yield, and selectivity even when the reaction temperature is lowered, pressurization is preferred. Specifically, the reaction pressure is preferably 0.05 to 1.00 MPa, more preferably 0.1 to 0.5 MPa. In this specification, the reaction pressure generally refers to gauge pressure. During pressurization, the reaction vessel is sealed, and inert gases such as nitrogen, argon, and helium are blown into the reaction system, thereby increasing the pressure inside the reaction system. Thus, by pressurizing the sealed reaction vessel, the fluoroalkyl group detached from the starting material and the group -OCOR detached from general formula (2) react... 1 Some aromatic compounds collide, thereby easily generating compounds of the general formula (1) that are the target.

[0049] In addition, there is no particular limitation on the reaction time; it can be set to a time that allows the reaction to proceed fully. Specifically, it can be set to a time that allows the reaction to proceed until the composition of the reaction system no longer changes.

[0050] In the manufacturing method of the present invention, when a liquid phase reaction is used, the reaction can also be carried out in a continuous and pressurized manner by means of connecting a back pressure valve to a continuous phase trough reactor (CSTR), or by extracting liquid while vaporizing and extracting the product.

[0051] After the reaction is complete, the compound can be purified using common methods as needed to obtain the compound shown in general formula (1).

[0052] (1-4) Gas-phase continuous flow type (condition (2)) In this invention, the temperature is raised to 500°C or higher when a gas-phase continuous flow reaction is employed, in which raw materials are continuously added into the reactor and the target material is continuously extracted from the reactor.

[0053] In the case of a continuous gas-phase flow, the reaction vessel (reaction tube), as described in Non-Patent Document 1, is usually made of quartz or similar material that can suppress side reactions. However, in the manufacturing method of the present invention, a raw material with n of 2 or more in general formula (2) and high stability is used, which facilitates heat transfer, thereby allowing the fluoroalkyl group detached from the starting material to react with the group -OCOR detached from general formula (2). 1 Some aromatic compounds collide and readily generate compounds of the general formula (1) that are the target substances. Therefore, although there are concerns about side reactions, thermally conductive containers (thermal tubes) are preferred as reaction vessels (reaction tubes).

[0054] There are no particular restrictions on the materials that can be used for reaction vessels, but considering the likelihood of side reactions, Hastelloy (nickel-based alloy), iron, stainless steel, copper, nickel, etc. are preferred.

[0055] Furthermore, there are no particular limitations on the shape and structure of the reaction vessel (reaction tube). Examples of reaction vessels (reaction tubes) include vertical reactors, horizontal reactors, and multi-tube reactors.

[0056] In the manufacturing method of the present invention, when a continuous gas-phase flow is adopted, the reaction atmosphere is preferably, for example, an inert gas atmosphere such as nitrogen, argon, or helium.

[0057] In the manufacturing method of the present invention, the reaction temperature when using a continuous gas-phase flow is 500°C or higher, preferably 550–750°C, and more preferably 600–700°C. When the reaction temperature is below 500°C, the reaction hardly occurs, only side reactions take place, and the thermal deacidification reaction does not occur, therefore the target product cannot be generated.

[0058] In the manufacturing method of the present invention, when a continuous gas-phase flow is adopted, there is no particular limitation on the reaction pressure; it can be used under reduced pressure, normal pressure, or increased pressure.

[0059] In the manufacturing method of the present invention, when a continuous gas-phase flow is adopted, the reaction time is not particularly limited. From the viewpoints of conversion rate, yield, selectivity, etc., the flow time of the raw material is preferably 1 to 10 minutes, more preferably 1 to 5 minutes, and even more preferably 1 to 2 minutes.

[0060] In the manufacturing method of the present invention, when a continuous gas-phase flow is adopted, there is no particular limitation on the flow rate of the starting compound. From the viewpoints of conversion rate, yield, selectivity, etc., it is preferably 1 to 100 mL / min, more preferably 2 to 50 mL / min, and even more preferably 5 to 20 mL / min.

[0061] Alternatively, the manufacturing method of the present invention can be carried out in the presence of a catalyst such as CaCl2, but since the reaction efficiency does not change significantly and considering concerns about side reactions, it is preferable to carry out the reaction in the absence of a catalyst.

[0062] After the reaction is complete, the compound can be purified using common methods as needed to obtain the compound shown in general formula (1).

[0063] (1-5) Target compounds (general formula (1)) The target compound thus generated is the compound shown in general formula (1): [In the formula,] R 1 Same or different indicates fluoroalkyl.

[0064] n represents an integer from 2 to 5.

[0065] In general formula (1), R 1 And n as described above.

[0066] In other words, the target compounds generated in this invention, namely the compounds represented by general formula (1), can be specifically listed. wait.

[0067] 2. Composition As described above, compounds of general formula (1) can be obtained, but compounds of general formula (1) are usually obtained in the form of compositions containing compounds of general formula (1), compounds of general formula (3), and / or compounds of general formula (4). In equation (1), R 1 Same or different indicates fluoroalkyl.

[0068] n represents an integer from 2 to 5. [In equation (3), the meaning of n is the same as above.] [In equation (4), R] 1 The meanings of and n are the same as described above. Regarding the compound represented by general formula (1), as described above.

[0069] In addition, in general formula (3), n can take the example above.

[0070] Therefore, as compounds represented by general formula (3), examples can be listed, for instance. wait.

[0071] In addition, in general formula (4), R 1 The examples above can be used for n. The preferred specific examples are also the same.

[0072] Therefore, as compounds represented by general formula (4), examples can be listed, for instance. wait.

[0073] In the manufacturing method of the present invention, the total content of the compound shown in general formula (3) and / or the compound shown in general formula (4) is not particularly limited, and can be set to 30 moles or less, particularly 0.001 to 20 moles, relative to 1 mole of the compound shown in general formula (1).

[0074] The composition of the present invention can be obtained using the manufacturing method of the present invention. When the manufacturing method of the present invention is carried out in an intermittent manner, a composition containing the compound shown in general formula (1) and the compound shown in general formula (3) can be readily obtained as the composition of the present invention. In this case, the content of the compound shown in general formula (3) is not particularly limited, and can be set to 0.10 moles or less, particularly 0.001 to 0.10 moles, relative to 1 mole of the compound shown in general formula (1).

[0075] Furthermore, when a gas-phase continuous flow method is used in the manufacturing method of the present invention, compositions containing the compound shown in general formula (1), the compound shown in general formula (3), and the compound shown in general formula (4) can be readily obtained as the compositions of the present invention. In this case, the content of the compound shown in general formula (3) is not particularly limited, and can be set to 1.0 to 3.0 moles, particularly 1.5 to 2.0 moles, relative to 1 mole of the compound shown in general formula (1). In addition, the content of the compound shown in general formula (4) is not particularly limited, and can be set to 10.0 to 27.0 moles, particularly 15.0 to 18.0 moles, relative to 1 mole of the compound shown in general formula (1).

[0076] The compositions of the present invention may also contain compounds represented by general formula (5): [In the formula, n has the same meaning as above.]

[0077] In general formula (5), n can take the example above.

[0078] Therefore, as compounds represented by general formula (5), examples can be listed, for instance. wait.

[0079] When the composition of the present invention contains a compound of general formula (5), the content of the compound of general formula (5) is not particularly limited, and can be set to 5 to 80 moles, particularly 7 to 50 moles, relative to 1 mole of the compound of general formula (1).

[0080] In addition, the compounds shown in general formula (3), general formula (4), and general formula (5) have similar retention times in gas chromatography as the compounds shown in general formula (1), so even with purification, they are difficult to completely remove.

[0081] Therefore, the compositions of the present invention include any one of compositions that have undergone purification treatment and compositions that have not undergone purification treatment.

[0082] When the intermittent method is used as the manufacturing method of the present invention, In the purified composition, when the total amount of the composition of the present invention is set to 100 vol%, the content of the compound represented by general formula (1) can be set to 90.00 to 99.99 vol% (especially 95.00 to 99.98 vol%), the content of the compound represented by general formula (3) can be set to 0.01 to 10.00 vol% (especially 0.02 to 5.00 vol%), and the content of the compound represented by general formula (5) can be set to 0 to 5.00 vol% (especially 0.01 to 3.00 vol%). In compositions that have not undergone purification, when the total amount of the compositions of the present invention is set to 100 mol%, the content of the compound represented by general formula (1) can be set to 1.50 to 10.00 mol% (especially 2.00 to 8.00 mol%), the content of the compound represented by general formula (3) can be set to 0.01 to 0.30 mol% (especially 0.02 to 0.20 mol%), and the content of the compound represented by general formula (5) can be set to 45.00 to 98.00 mol% (especially 50.00 to 95.00 mol%).

[0083] When a continuous gas-phase flow method is used as the manufacturing method of the present invention, In the purified composition, when the total amount of the composition of the present invention is set to 100 vol%, the content of the compound represented by general formula (1) can be set to 85.00 to 99.98 vol% (especially 90.00 to 99.95 vol%), the content of the compound represented by general formula (3) can be set to 0.01 to 10.00 vol% (especially 0.02 to 5.00 vol%), the content of the compound represented by general formula (4) can be set to 0.01 to 10.00 vol% (especially 0.02 to 5.00 vol%), and the content of the compound represented by general formula (5) can be set to 0 to 5.00 vol% (especially 0.01 to 3.00 vol%). In compositions that have not undergone purification, when the total amount of the compositions of the present invention is set to 100 mol%, the content of the compound represented by general formula (1) can be set to 1.0 to 3.0 mol% (especially 1.5 to 2.0 mol%), the content of the compound represented by general formula (3) can be set to 2.0 to 5.0 mol% (especially 2.5 to 4.0 mol%), the content of the compound represented by general formula (4) can be set to 25.0 to 30.0 mol% (especially 26.0 to 29.0 mol%), and the content of the compound represented by general formula (5) can be set to 45.0 to 65.0 mol% (especially 50.0 to 60.0 mol%).

[0084] Such compositions of the present invention can be effectively utilized in various applications such as etching gas, cleaning gas, and deposition gas.

[0085] The embodiments of the present invention have been described above, but various changes can be made to the manner and details without departing from the spirit and scope of the claims.

[0086] Example The following examples illustrate the features of the present invention. The present invention is not limited to these examples.

[0087] In the examples and comparative examples, R in general formula (2) is used as the matrix. 1 It is a trifluoromethyl, n=5 pentafluorophenyl trifluoroacetate.

[0088] Examples 1-3 and Comparative Example 1 (Intermittent) A stir bar was added to a stainless steel (SUS) autoclave, which served as the reaction vessel, and pentafluorophenyl trifluoroacetate was added in the amounts shown in Table 1. For the gas-phase reactions of Examples 1-2 and Comparative Example 1, no changes were made. For the liquid-phase reactions of Examples 3 and Comparative Examples 1-2, chlorobenzene was added to bring the solution concentration to 1 mol / L. The reaction vessel was then sealed, and the temperature was raised to the temperatures shown in Table 1, and the heating time was shown in Table 1. For Examples 1 and Comparative Example 1, the temperature was increased in stages as shown in Table 1. As a result, heating and pressurization were performed; the pressure in the reaction system was 0.13 MPa in Examples 1-2, 0.31 MPa in Example 3, and 0.20 MPa in Comparative Example 1.

[0089] After the reaction was completed, the product was identified by mass analysis using gas chromatography (GC-2014, manufactured by Shimadzu Corporation, trade name "GC-2014") and gas chromatography / mass spectrometry (GC / MS).

[0090] The results of the quality analysis confirmed that octafluorotoluene, the target substance, was generated in Examples 1-3.

[0091] The results are shown in Table 1. In Table 1, “C7F8” refers to octafluorotoluene, “F5PhOH” refers to pentafluorophenol, “HB” refers to a high-boiling-point compound with unknown structure, and “5Fbenzene” refers to pentafluorobenzene.

[0092] [Table 1] .

[0093] Example 4 and Comparative Examples 2-6 (Gas-phase continuous flow) In Comparative Example 8, 0.75 g of CaCl2 as a catalyst was added to a Hastelloy tube (outer diameter 1.5 cm) serving as the reaction tube. In Examples 4 and Comparative Examples 2-5, no catalyst was used, and the Hastelloy tube was used directly. After drying at 25°C for 24 hours under a nitrogen atmosphere, the pressure was brought to atmospheric pressure, and pentafluorophenyl trifluoroacetate was allowed to flow only at the amounts shown in Table 1. In Comparative Example 6, the contact time (w / f) between pentafluorophenyl trifluoroacetate and the CaCl2 catalyst was adjusted to 5.00 g·sec / cc.

[0094] The reaction proceeds in a continuous gas-phase flow.

[0095] The reaction tube was heated to 200–650°C to begin the reaction.

[0096] 1.5 hours after the reaction begins, the fraction passing through the purging tower is collected.

[0097] After the reaction was completed, the product was identified by gas chromatography-mass analysis (GC / MS) using gas chromatography-mass analysis (GC-2014, manufactured by Shimadzu Corporation).

[0098] The results of the quality analysis confirmed that octafluorotoluene, the target compound, was generated in Example 4.

[0099] The results are shown in Table 2. In Table 2, “C7F8” refers to octafluorotoluene, “F5PhOH” refers to pentafluorophenol, “5Fbenzene” refers to pentafluorobenzene, and “ether” refers to octafluoroanisole.

[0100] [Table 2] .

[0101] Examples 5-6 and Comparative Example 7 The mixtures obtained in Examples 3 and 4 were purified using common methods to obtain compositions with the flow ratios (volume ratios) shown in Table 3, which were used as the compositions for Examples 5 and 6. Specifically, the composition obtained by purifying the mixture obtained in Example 3 was the composition of Example 5, and the composition obtained by purifying the mixture obtained in Example 4 was the composition of Example 6. In Comparative Example 7, commercially available octafluorotoluene was used directly. In Table 3, "C7F8" refers to octafluorotoluene, "F5PhOH" refers to pentafluorophenol, "5Fbenzene" refers to pentafluorobenzene, and "ether" refers to octafluoroanisole.

[0102] For the obtained composition, under ICP (Inductively Coupled Plasma), discharge power of 1000W, bias power of 300W, pressure of 10mTorr, and electron density of 8×10⁻⁶, the following conditions were met: 10 ~2×10 11 cm -3 The etching rates of a 1000 μm thick silicon oxide (SiO2) film and a 5000 μm thick amorphous carbon film (ACL) film formed on a silicon substrate were measured under etching conditions of 5–7 eV electronic temperature. The ratio of the etching rates of the SiO2 film to the ACL film (etching rate of SiO2 film / etching rate of ACL film) was used as the selectivity ratio relative to ACL. The SiO2 film was formed using a common method, and the ACL film was formed according to the previously reported method (Producer (registered trademark) APF™ PECVD - Applied Materials). The results and the selectivity ratio relative to ACL (etching rate of SiO2 film / etching rate of ACL film) are shown in Table 3.

[0103] [Table 3] .

Claims

1. A method for manufacturing a compound represented by general formula (1), characterized in that: This includes the process of heating the compound represented by general formula (2). In equation (1), R 1 Same or different indicates fluoroalkyl. n represents an integer from 2 to 5. In equation (2), R 1 The meanings of and n are the same as those described above. The heating process satisfies either (1) or (2) below. Condition (1) Use intermittent heating to reach above 170℃. Condition (2) Use gas phase continuous flow heating to above 500℃.

2. The manufacturing method as described in claim 1, characterized in that: The R 1 It is a perfluoroalkyl group.

3. The manufacturing method as described in claim 1, characterized in that: The value of n is 5.

4. The manufacturing method as described in claim 1, characterized in that: The condition (1) is met, and the heating process is carried out under the condition that the gauge pressure is 0.05 to 1.00 MPa.

5. The manufacturing method as described in claim 1, characterized in that: The condition (2) is met, and in the heating process, a thermally conductive container is used as the reaction vessel.

6. A composition, characterized in that: Contains compounds of general formula (1), compounds of general formula (3), and / or compounds of general formula (4). In equation (1), R 1 Same or different indicates fluoroalkyl. n represents an integer from 2 to 5. In equation (3), the meaning of n is the same as above. In equation (4), R 1 The meanings of and n are the same as those described above.

7. The composition according to claim 6, characterized in that: The total amount contained, relative to 1 mole of the compound represented by general formula (1), was less than 30 moles of the compound represented by general formula (3) and / or the compound represented by general formula (4).

8. The composition according to claim 6, characterized in that: It also contains compounds represented by general formula (5), In equation (5), the meaning of n is the same as above.

9. The composition according to any one of claims 6 to 8, characterized in that: Used as an etching gas, cleaning gas, or deposition gas.

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