Method for producing fluorine-containing sulfonic acid anhydride

Abstract

To provide a method for producing a fluorinated sulfonic acid anhydride (2) that is useful as pharmaceuticals, catalysts for organic synthesis and the like, or synthetic materials, the method capable of suppressing consolidation in a reaction between a fluorinated sulfonic acid and diphosphorus pentoxide, achieving a high yield.SOLUTION: A method for producing a fluorinated sulfonic acid anhydride (2) causes a fluorinated sulfonic acid (1) to react with diphosphorus pentoxide in coexistence with silica.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a fluorine-containing sulfonic acid anhydride. [Background technology]

[0002] Fluorine-containing sulfonic acid anhydrides have conventionally been useful as catalysts for pharmaceuticals and organic synthesis, or as synthetic raw materials. As a method for producing a fluorine-containing sulfonic anhydride, for example, a method is known in which diphosphorus pentoxide is added to trifluoromethanesulfonic acid, a dehydration condensation reaction is carried out to produce trifluoromethanesulfonic anhydride, and the produced trifluoromethanesulfonic anhydride is volatilized and recovered. However, metaphosphoric acid (a reaction product of diphosphorus pentoxide and water) produced as a by-product in the dehydration condensation reaction is glassy and has an extremely high viscosity, and a mixture containing trifluoromethanesulfonic acid and diphosphorus pentoxide becomes unstirable during the reaction (hereinafter, the phenomenon in which a mixture containing trifluoromethanesulfonic acid and diphosphorus pentoxide becomes unstirable during the reaction is referred to as "caking"). As a result, the reaction does not proceed, and the produced trifluoromethanesulfonic anhydride cannot be recovered by heating. As a result, it is known that the yield of trifluoromethanesulfonic anhydride is at most 60% or less on a trifluoromethanesulfonic acid basis (Patent Documents 1 to 7). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-268148 [Patent Document 2] Japanese Patent Application Publication No. 9-227498 [Patent Document 3] Japanese Patent Application Publication No. 10-114734 [Patent Document 4] JP 2007-145815 A [Patent Document 5] JP 2007-297359 A [Patent Document 6] JP 2013-112670 A [Patent Document 7] JP 2016-47861 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a production method in which water or phosphoric acid is added to a reaction product of solidified trifluoromethanesulfonic acid and diphosphorus pentoxide to dissolve metaphosphoric acid, and the reactor is allowed to be stirred, and then vacuum distillation is performed again to recover unreacted trifluoromethanesulfonic acid, thereby increasing the yield of trifluoromethanesulfonic anhydride based on the reacted trifluoromethanesulfonic acid. However, this method does not prevent the reaction product of trifluoromethanesulfonic acid and diphosphorus pentoxide from solidifying. In addition, this method requires the addition of water or phosphoric acid little by little to prevent a sudden temperature rise due to reaction heat, and stirring cannot be performed until it is dissolved. Therefore, it is necessary to wait a long time until metaphosphoric acid is completely dissolved in the added water or phosphoric acid, and from an industrial point of view, it is not necessarily a productive process.

[0005] Patent Documents 2 and 3 disclose a production method in which the reaction of trifluoromethanesulfonic acid with diphosphorus pentoxide is carried out in a fluorine-based solvent to suppress caking. However, since a large amount of solvent is required to suppress caking, it is not necessarily considered to be a highly productive process from an industrial point of view. From the same point of view, it is desirable to reuse the fluorine solvent used, but an additional step is required for reuse, which may make the process complicated.

[0006] Patent Document 4 discloses a production method in which caking is suppressed in the reaction between trifluoromethanesulfonic acid and diphosphorus pentoxide by using an excess amount of trifluoromethanesulfonic acid relative to diphosphorus pentoxide. However, although it is desirable to reuse the raw material trifluoromethanesulfonic acid from an industrial point of view, an additional step is required for reuse, which is considered to complicate the process.

[0007] Patent Documents 5 to 7 disclose a production method in which the reaction between trifluoromethanesulfonic acid and diphosphorus pentoxide is carried out using a kneader reactor equipped with a twin-shaft blade having a predetermined power per volume of the reaction vessel, thereby forcibly kneading even in a state of solidification caused by metaphosphoric acid. However, it is necessary to use a special device, a kneader reactor equipped with a twin-shaft blade having a predetermined power per volume of the reaction vessel, and a production method capable of suppressing solidification by a simpler method is required. [Means for solving the problem]

[0008] As a result of intensive investigations aimed at solving the above-mentioned problems, the present inventors have found that by reacting a fluorine-containing sulfonic acid (1) (hereinafter also referred to as "compound (1)") with diphosphorus pentoxide in the coexistence of silica, caking can be suppressed and a fluorine-containing sulfonic anhydride (2) (hereinafter also referred to as "compound (2)") can be produced, thereby completing the present invention.

[0009] That is, the present invention is as follows. [1] The following general formula (2): (R f SO 2 ) 2 O (2) (In the formula, R f teeth , saturated Saturated or unsaturated fats group A hydrocarbon group, is - CH 2 - to If so, -CH 2 -may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom, Among the hydrogen atoms of the hydrocarbon group, all except the hydrogen of -CH where the substitution has been made are substituted with fluorine atoms, 2 R f The carbon number is 1 to 20, and two R f They may be the same or different) The present invention relates to a method for producing a fluorine-containing sulfonic acid anhydride (2) represented by the following formula: The following general formula (1): R f SO 3 H (1) (In the formula, R f teeth , saturated Saturated or unsaturated fats group A hydrocarbon group, is - CH 2 - to If so, -CH 2 - may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom, Among the hydrogen atoms of the hydrocarbon group, all except the hydrogen of -CH where the substitution has been made are substituted with fluorine atoms, 2 ​ R f has 1 to 20 carbon atoms. A fluorine-containing sulfonic acid (1) represented by the formula: Diphosphorus pentaoxide and React in the presence of silica, the ratio (ε / (γ+δ)) of the mass (ε) of the silica to the total mass (γ+δ) of the mass (γ) of the fluorine-containing sulfonic acid (1) and the mass (δ) of the diphosphorus pentoxide is 0.1 to 100; A manufacturing method comprising: [2] The production method according to [1], wherein a ratio (β / α) of the amount of substance (β) of the diphosphorus pentoxide to the amount of substance (α) of the fluorine-containing sulfonic acid (1) is 0.1 to 100. [3] The production method according to [1] or [2], wherein the reaction temperature is −40 to 300° C. [4] The method according to any one of [1] to [3], wherein the silica has a silicon dioxide content of 50 mass% or more. Effect of the Invention

[0010] According to the present invention, solidification in the reaction between a fluorinated sulfonic acid (1) and diphosphorus pentoxide can be suppressed, and a fluorinated sulfonic anhydride (2) can be produced in good yield. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention (hereinafter, referred to as the present embodiment) will be described in detail. However, the present invention is not limited to the present embodiment, and can be modified in various ways within the scope of the present invention.

[0012] The manufacturing method of this embodiment is as follows: The following general formula (2): (R f SO 2 ) 2 O (2) (In the formula, R f represents a saturated or unsaturated aliphatic or aromatic hydrocarbon group in which at least one hydrogen atom is substituted with a fluorine atom, and the ethylene structure in the hydrocarbon group may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom; R f The carbon number is 1 to 20, and two R f They may be the same or different) The present invention relates to a method for producing a fluorine-containing sulfonic acid anhydride (2) represented by the following formula: The following general formula (1): R f SO 3 H (1) (In the formula, R f represents a saturated or unsaturated aliphatic or aromatic hydrocarbon group in which at least one hydrogen atom is substituted with a fluorine atom, and the ethylene structure in the hydrocarbon group may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom; R f has 1 to 20 carbon atoms. A fluorine-containing sulfonic acid (1) represented by the formula: Diphosphorus pentaoxide and React in the presence of silica It is characterized by:

[0013] The compound (1), diphosphorus pentoxide, and silica, as well as the reaction conditions for producing compound (2) from compound (1), will be described in detail below.

[0014] <Fluorine-containing sulfonic acid (1) (compound (1))> The fluorine-containing sulfonic acid (1) is represented by the following general formula (1): R f SO 3 H (1) (In the formula, R f represents a saturated or unsaturated aliphatic or aromatic hydrocarbon group in which at least one hydrogen atom is substituted with a fluorine atom, and the ethylene structure in the hydrocarbon group may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom; R f has 1 to 20 carbon atoms. It is expressed as: The fluorine-containing sulfonic acids (1) may be used alone or in combination of two or more kinds.

[0015] R f R is a saturated or unsaturated aliphatic or aromatic hydrocarbon group in which a hydrogen atom is substituted with a fluorine atom, as described below. f may be at least one hydrocarbon group selected from the group consisting of saturated aliphatic, unsaturated aliphatic, and aromatic groups in which a hydrogen atom is substituted with a fluorine atom, as described below. Saturated or unsaturated aliphatic hydrocarbons are preferred because they tend to be easily available or produced and economically advantageous.

[0016] R fThe substituent of the hydrogen atom of the hydrocarbon group is not particularly limited as long as it is a commonly used substituent, but specific examples include halogen atoms such as fluorine atom, chlorine atom, and bromine atom; aliphatic hydrocarbon groups such as nitrile group, methyl group, ethyl group, vinyl group, allyl group, 1-methylvinyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and fluoromethyl group; aromatic hydrocarbon groups such as benzyl group, phenyl group, nitrile-substituted phenyl group, and fluorinated phenyl group; groups having a structure in which the aliphatic hydrocarbon group and aromatic hydrocarbon group are fluorinated; amino group; nitro group; sulfo group; hydroxyl group; silyl group; phosphoric acid group; and thiol group. These substituents may be used alone or in combination of two or more types.

[0017] R f When the hydrocarbon group has an aliphatic portion, the ethylene structure (-CH 2 -) may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom, or may be substituted with a structure having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, and a silicon atom. R f The ethylene structure of the hydrocarbon group (-CH 2 The structure in which the - is substituted is not particularly limited as long as it is a commonly used structure, but may be a divalent structure. Specific examples include an ether group (-O-), a carbonate group (-OCO 2 -), ester group (-CO 2 -), carbonyl group (-CO-), sulfide group (-S-), sulfoxide group (-SO-), sulfone group (-SO 2 -), urethane group (-NHCO 2 These structures may be used alone or in combination of two or more.

[0018] R fThe number of carbon atoms is 1 to 20, preferably 1 to 10, more preferably 1 to 7, and particularly preferably 1 to 5, since these tend to be easily available or produced and are economically advantageous.

[0019] R f The number of fluorine atoms resulting from the substitution of hydrogen atoms in the aliphatic or aromatic hydrocarbon group (the number of hydrogen atoms in the hydrocarbon group substituted with fluorine atoms) is not particularly limited as long as it is 1 or more, but is preferably 3 or more. Depending on the type of compound (1), it is more preferably 5 or more, and even more preferably 7 or more. When high durability of compound (1) and / or compound (2) is required, it is particularly preferable that all of the hydrogen atoms in the aliphatic or aromatic hydrocarbon group are fluorine atoms.

[0020] R f The number of substituted ethylene structures (the number of ethylene structures substituted with structures having oxygen atoms or the like) may be 0 to 10, more preferably 0 to 7, and further preferably 0 to 5.

[0021] In this embodiment, the compound (1) is represented by the following general formula (3): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). Particularly preferred is a fluorine-containing vinyl sulfonic acid (3) represented by the following formula:

[0022] As m, an integer of 0 to 1 is preferable, and 0 is more preferable, since it is easily available or produced and tends to be economical. As n, 1 to 4 is preferable, 2 to 4 is more preferable, and 2 is even more preferable, because n is easily available or produced and tends to be economical. As a combination of m and n, m=0 and n=2 are particularly preferable.

[0023] The structure of the compound (2) produced from the above-mentioned fluorine-containing vinyl sulfonic acid (3) is represented by the following general formula (4): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). It is expressed as:

[0024] m and n are the same as in compound (3), and m is preferably 0 to 1, and more preferably 0, since it is easily available or produced and tends to be economical. As n, 1 to 4 is preferable, 2 to 4 is more preferable, and 2 is even more preferable, because n is easily available or produced and tends to be economical. As a combination of m and n, m=0 and n=2 are particularly preferable.

[0025] The fluorine-containing sulfonic acid (1) can be produced by a conventional method or can be purchased commercially.

[0026] <Diphosphorus pentoxide> Diphosphorus pentoxide has the formula "P 2 O 5 " However, the actual structure is "P 4 O 10 It has the chemical formula: tetraphosphorus decaoxide. It is also known as phosphorus oxide, phosphorus pentoxide, and phosphoric anhydride.

[0027] The purity of diphosphorus pentoxide is not particularly limited as long as it is a generally available purity, but since side reactions can be suppressed and the yield of compound (2) tends to be improved, the purity is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 97% by mass or more, and particularly preferably 98% by mass or more.

[0028] Diphosphorus pentoxide having the desired purity can be purchased from Fujifilm Wako Pure Chemical Industries, Ltd., Tokyo Chemical Industry Co., Ltd., Aldrich, Nacalai Tesque, Inc., Kanto Chemical Co., Ltd., Nippon Chemical Industry Co., Ltd., Rasa Kogyo Co., Ltd., and the like.

[0029] <Silica> In this embodiment, silica refers to silicon dioxide (SiO 2 The content of silicon dioxide contained in silica is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 97% by mass or more, and particularly preferably 99% by mass or more, since side reactions can be suppressed and the yield of compound (2) tends to be improved. The silicon dioxide content in silica can be found from information provided by the manufacturer selling the silica, or can be found by common analytical methods such as X-ray fluorescence analysis, X-ray diffraction analysis, ICP atomic emission spectrometry, and ICP mass spectrometry.

[0030] Silica can be broadly divided into crystalline silica and amorphous silica. Crystalline silica is a compound of silica that has a unique X-ray diffraction pattern when analyzed by X-ray diffraction (X-ray diffraction patterns can be confirmed from the database owned by the International Diffraction Data Center, and the crystal structure of the silica used can be determined by the similarity between the X-ray diffraction pattern measured for the silica used and the X-ray diffraction pattern in the database). Crystalline silica is a compound with a crystal structure such as quartz, cristobalite, tridymite, keatite, coesite, and stishovite. In the present embodiment, the silica is preferably crystalline silica, since it can suppress side reactions and tends to improve the yield of compound (2). The content of crystalline silica is preferably 50% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, of the silicon dioxide contained in the silica. The content of crystalline silica is calculated by dividing the total mass of silicon dioxide having a crystal structure, such as the above-mentioned quartz, cristobalite, tridymite, etc., by the total mass of silicon dioxide contained in the silica.

[0031] The shape of silica is not particularly limited as long as it is a generally available shape, and may be any of spherical, spindle-shaped, rod-shaped, needle-shaped, cylindrical, columnar, scaly, thin, plate-shaped, and crushed. The mixture of compound (1), diphosphorus pentoxide, and silica, and the mixture during the reaction, tend to have improved fluidity, and the shape tends to be highly stable in a fluid state, so if this viewpoint is emphasized, spherical silica is preferred. It is easy to obtain and tends to be economically excellent, so if this viewpoint is emphasized, silica with various shapes mixed is preferred.

[0032] In this embodiment, the particle size refers to the cumulative average diameter measured by a particle size distribution measuring device (the particle size at the point where the cumulative curve is 50% when the total volume of the powder population to be analyzed is taken as 100%). The particle size of the silica is not particularly limited as long as it is a generally available particle size, but it is preferably 0.01 to 1000 μm. Since there is a tendency for caking to be suppressed, the particle size of silica is preferably 1000 μm or less, more preferably 150 μm or less, further preferably 60 μm or less, and particularly preferably 30 μm or less. The particle size of silica is preferably 0.01 μm or more, more preferably 0.1 μm or more, because it is easily available or produced and tends to be economical. The particle size of silica is further preferably 1 μm or more, particularly preferably 5 μm or more, because the bulk density of silica increases, the capacity of the apparatus used for producing compound (2) tends to be small, and the cost of the apparatus tends to be low.

[0033] In the present embodiment, the calculated specific surface area of ​​silica obtained by particle size analysis is not particularly limited as long as it is a calculated specific surface area of ​​commonly available silica. However, since there is a tendency that caking can be suppressed, it is preferred to use a calculated specific surface area of ​​0.01 m2 It is preferably at least 0.05 m 2 / mL, more preferably at least 0.20 m 2 / mL, even more preferably at least 0.50 m 2 / mL, and particularly preferably at least 100 m 2 / mL. Since it tends to be easy to obtain or manufacture and has excellent economy, and the bulk density of silica increases, the capacity of the apparatus used in producing compound (2) is small, and the cost of the apparatus tends to be low, it is preferably at most 20 m 2 / mL, more preferably at most 5.0 m 2 / mL, even more preferably at most 2.0 m 2 / mL, and particularly preferably at most. The calculated specific surface area is a value obtained by the following formula (1) using the area average diameter obtained by a particle size distribution apparatus. Calculated specific surface area (m 2 / mL) = 6 ÷ area average diameter (μm) (1)

[0034] The silica is not particularly limited as long as it is generally available or can be produced, but specific examples include Snow Brand Silica SiFOMN series, Snow Brand Silica Special Grade series, Snow Brand Silica CVG series, Snow Brand Silica SP series, and SiFOMN fused quartz series, all manufactured by Marukama Kamado Toryo Co., Ltd., Nikko silica sand, all manufactured by JFE Mineral Co., Ltd., Vietnam Silica Sand VT series, Vietnam Silica Sand TH series, Vietnam Silica Sand TH Powder series, Izu Tokufun, Izu Silica Granules, Yagusa Sand, Jinya Sand, Kashima Sand, and Takeori Co., Ltd. Shell mold silica sand, natural silica sand, silica sand MX, silica powder A-3, silica powder special powder, silica powder (special), silica powder (S), silica powder #300, silica powder CM silica flower M, Albany sand, Kemerton sand, ACI sand, ACI-G sand, Terengganu sand, Yunotsu silica sand, reclaimed sand, Utsumi silica sand, Enshu silica sand, Mikawa silica sand, Sarawak sand, Pearl sand, Hookah sand, Flattery sand, Fremantle sand, Mitsubishi Corporation Building Materials Co., Ltd. Mizunami silica sand, Mikawa silica sand, Seto silica sand, special silica powder, high purity silica powder manufactured by Maruto, high purity silica powder, special silica sand powder manufactured by Yamamoto Domoto Kogyosho, HIS grade, HIGH grade, OPTICAL grade, FILLER grade manufactured by Nichitsu, sea sand manufactured by Miyazaki Chemicals, sea sand manufactured by Fujifilm Wako Pure Chemical, sea sand (methanol washed), GB series, EGB series, EMB series, GP series, J series manufactured by Potters Barotini, L series manufactured by Unitika Ltd. Examples of such silica include the E series, SPL series, AEROSIL (registered trademark) manufactured by Nippon Aerosil Co., Ltd., the MU series fumed silica manufactured by Shin-Etsu Chemical Co., Ltd., Reoloseal (registered trademark) manufactured by Tokuyama Corporation, Toxil, Fineseal, and OSC series wet silica manufactured by Maruo Calcium Co., Ltd., and the HDK series fumed silica manufactured by Wacker Asahi Kasei Silicones Co., Ltd., Radiolite manufactured by Showa Chemical Industry Co., Ltd., Topco, Celite manufactured by Imerys, and Locahelp manufactured by Mitsui Mining and Smelting Co., Ltd.

[0035] By crushing available silica, silica having a desired particle size can be produced. The crushing method is not particularly limited as long as it is a commonly used method, and may be wet or dry, and examples of the apparatus include jaw crusher, gyration crusher, cone crusher, impact crusher, rod mill, hammer crusher, roll crusher, cutter mill, autogenous crusher, stamp mill, stone mill, crusher, ring mill, roller mill, jet mill, pin mill, rotary mill, vibration mill, planetary mill, attritor, and bead mill. These apparatuses may be used alone or in combination of multiple types. More specific examples of grinding equipment include Nibbler, Feather Mill, Farma Mill, Hammer Mill, Hammer Blade, Disintegrator, Rubber Chopper, Rotoplex, Compact Line, ACM Pulverizer, Glacis, Fine Impact Mill, Victory Mill, Contraplex, Linrex Mill, Micro Pulverizer, Counter Jet Mill, Micron Jet, Super Micron Mill, Innomizer, Pulvis, Spiral Jet Mill, Disper Mill, and Hydro Mill manufactured by Hosokawa Micron Corporation, and Automatic Pulverizer manufactured by Nara Machinery Co., Ltd. Manufactured by Kurimoto Iron Works Co., Ltd.: New Cosmomizer, Micros, Super Clean Mill, Sample Mill, Super Free Mill, Mill Box, Cosmo Box, Hammer Mill, Goblin, Baryonyx, Briodon, Polvogene, and Gina; Kurimoto Iron Works Co., Ltd.: Cross Jet Mill, Pocket Jet, Gadget, Hi-G, Agitator Mill, VX Mill, Roller Mill, Ball Mill, Rod Mill, K-VIX Mill, and Granulator; Sugiyama Heavy Industries Co., Ltd.: Jaw Crusher, Ratchet Roll Crusher, Corrugated Roll Crusher, Roll Crusher, Tan Dem roll crusher, Oniha roll crusher, S-shaped crusher, 4-axis crusher, fiber mill, bevel impactor, radical impactor, ball mill, attrition mill, and cube rotor mill, Super Powder Mill, Fairy Powder Mill, Stamp Mill, High-speed Crusher, Hammer Crusher, Sloot Mill, Seryuner, Shredder, and Cutter Mill manufactured by Nishimura Machinery Works, Inc., Vertical Roller Mill, Kryptron Zepros, Kryptron Venti, Kryptron, Kryptron Eddy, Kryptron Prime, Jedi, Converge Mill, Oshlobit, Conibit, and Hammer Mill, Super Jet Mill, Super Rotor, and Blade Mill manufactured by Nisshin Engineering Inc., Dry Star, Sigma Dry, Lab Star, Nano Getter, Mugen Flow, and Delta Vita manufactured by Ashizawa Finetech Co., Ltd., Single Track Jet Mill, Sk Jet O Mill, Cojet System α-mkV, Sanitary JOM Series, AO Jet Mill, Impeller Mill, Planetary Mill, Orient Crusher,Atomizers, pin mills, and spiral mills; Makino Sangyo Co., Ltd. frame breakers, Oniha crushers, tearing crushers, hammer crushers, Makino-type crushers, Exceed mills, disc-type crushers, Coroplex-type crushers, Contraplex-type crushers, and Ultraplex-type crushers; Tsukasa Kogyo Co., Ltd.'s Powcutter, Powcrusher, Line mills, Wave mills, and Powjet; Imex Co., Ltd.'s Easy Nano, Ready mills, Neo-Alpha mills, low-temperature and freezing grinding bead mills, Visco mills, and sand grinders; Hiroshima Metal & Machinery Co., Ltd.'s Apex mills, Ul Examples of such mills include Tora Apex Mill, Wide Separator Apex Mill, Dual Apex Mill, Ultra Apex Mill Advance, Apex Disperser ZERO, and Apex LABO; Nippon Coke Engineering Co., Ltd.'s MSC Mill, SC Mill, SC Mill Long, MY Mill, Attritor, Trigonal, Fine Mill, Dynamic Mill, Alchemy, Stream Mill, and Centri Cutter; and Inoue Seisakusho Co., Ltd.'s Mighty Mill Mark II, Spike Mill, Key Mill, MP Mill, MF Mill, Mighty Mill, Nano Sonic Mill, Three Roll Mill Ceramic Roll, and Three Roll Mill Chilled Roll.

[0036] Silica may be surface-modified as necessary. The surface-modified silica may be generally available or may be subjected to a surface-modification treatment. The compound used for the surface modification is not particularly limited as long as it is a generally used compound, but since it tends to have excellent adsorption ability to silica, organic acids such as organic sulfonic acid, organic phosphoric acid, organic phosphate ester, carboxylic acid, and alkoxysilane compounds (compounds also called silane coupling agents under another name) can be exemplified.More specific examples of organic acids include methanesulfonic acid, ethanesulfonic acid, octane sulfonic acid, dodecanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, dimethylbenzenesulfonic acid, biphenylsulfonic acid, styrenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tridecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, naphthalenedisulfonic acid, anthracenesulfonic acid, phenanthrenesulfonic acid, tributyl phosphate, diethyl phosphate, methyl phosphate, butoxyethyl phosphate, bis(butoxyethyl)phosphate, dibutyl phosphate, dihexyl phosphate, triphenyl phosphate, phenyl phosphate, dimethylphenyl phosphate, naphthyl phosphate, dimethylphosphonate ... dibutyl phosphate, dihexyl phosphate, triphenyl phosphate, phenyl phosphate, dimethylphenyl phosphate, naphthyl phosphate, dimethylphosphonate, tributyl phosphate, diethyl phosphate, methyl phosphate, butoxyethyl phosphate, dibutyl phosphate, dihexyl phosphate, triphenyl phosphate, phenyl phosphate, dimethylphenyl phosphate, naphthyl phosphate, dimethylphosphonate, tributyl phosphate, diethyl phosphate, methyl phosphate, diethyl Examples of the phosphonic acids include tributyl phosphite, triphenyl phosphite, triphenylphosphine oxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, methyl phosphonic acid, ethyl phosphonic acid, octyl phosphonic acid, dodecyl phosphonic acid, phenyl phosphonic acid, octyl phenyl phosphonic acid, dodecyl phenyl phosphonic acid, naphthalene phosphonic acid, anthracene phosphonic acid, and phenanthrene phosphonic acid; methyl phosphinic acid, ethyl phosphinic acid, phenyl phosphinic acid, diphenyl phosphinic acid, acetic acid, caproic acid, caprylic acid, capric acid, lauric acid, and stearic acid; benzoic acid, toluic acid, dodecyl benzoic acid, methoxybenzoic acid, phenoxybenzoic acid, naphthalene carboxylic acid, phthalic acid, salicylic acid, dodecyl benzoic acid, anthracene carboxylic acid, phenanthrene carboxylic acid, lactic acid, malic acid, and adipic acid. Examples of alkoxysilane compounds include: Examples of the compound include alkylalkoxysilanes such as methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, and octyltrimethoxysilane, epoxyalkoxysilanes such as γ-glycidoxypropyltriethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, aminoalkoxysilanes such as aminopropyltriethoxysilane and N-phenylaminopropyltrimethoxysilane, vinylalkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane, and acrylicalkoxysilanes such as acryloxytrimethoxysilane and acrylomethoxytriethoxysilane. The compound used for surface modification may be used alone or in combination of two or more kinds.

[0037] The silica may be used alone or in combination of two or more kinds.

[0038] When compound (1) is reacted with diphosphorus pentoxide in the presence of silica, additives such as ether compounds, nitrile compounds, amide compounds, sulfo compounds, saturated hydrocarbon compounds, aromatic hydrocarbon compounds, halogenated hydrocarbon compounds, ketone compounds, ester compounds, and fluorine compounds can be used as needed. The additives may be used alone or in combination.

[0039] The additive is not particularly limited as long as it is a commonly used compound. Specific examples of the additive include tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, cyclopentyl methyl ether, diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol dibutyl ether, 1,2-dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol diisopropyl ether. ether compounds such as diethyl glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, and dipropylene glycol dimethyl ether; nitrile compounds such as acetonitrile, propionitrile, butyronitrile, isobutyronitrile, 2-methylbutyronitrile, cyclohexanecarbonitrile, benzonitrile, and adiponitrile; N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, tetramethylurea, and 1,Amide compounds such as 3-dimethyl-2-imidazolidinone; sulfo compounds such as dimethyl sulfoxide, dibutyl sulfoxide, ethyl methyl sulfone, ethyl isopropyl sulfone, sulfolane, and 3-methyl sulfolane; saturated hydrocarbon compounds such as n-pentane, n-hexane, isohexane, n-heptane, n-octane, isooctane, n-nonane, n-decane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; aromatic hydrocarbon compounds such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, naphthalene, tetralin, and biphenyl; methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, trichloroethane, tetrachloroethane, pentachloroethane, hexachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, and dichloropropane. halogenated hydrocarbon compounds such as trichloropropane, isopropyl chloride, butyl chloride, hexyl chloride, chlorobenzene, dichlorobenzene, trichlorobenzene, chlorotoluene, and chloronaphthalene; ketone compounds such as acetone, methylacetone, ethyl methyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl hexyl ketone, diethyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, and cyclohexanone; ester compounds such as ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, hexyl acetate, octyl acetate, cyclohexyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, and benzyl benzoate; fluoroalkylsulfonic anhydrides (C, m F 2m+1 SO 2 ) 2 O(m=1-10), fluoroalkylsulfonic acid ester C m F 2m+1 SO 2 O.C. n F 2n+1 (m=1-10, n=1-10), Perfluoroalkane C m F 2m+2 (m=4-20), perfluoroalkylamines (C mF 2m+1 ) 3 Examples of such fluorine compounds include N (m=2 to 10) perfluoropolyethers.

[0040] The additives may have a reduced water content, if necessary. Additives with low water content can be purchased, or a method for reducing the water content of the additive can be used. The method for reducing the water content of the additive is not particularly limited as long as it is a commonly available method, and examples thereof include a method using a dehydrating agent and a distillation method. The dehydrating agent is not particularly limited as long as it is a commonly used dehydrating agent, and examples thereof include sodium hydride, magnesium sulfate, sodium sulfate, calcium sulfate, calcium chloride, zinc chloride, calcium oxide, magnesium oxide, diphosphorus pentoxide, activated alumina, silica gel, and molecular sieves. When a dehydrating agent is used, an additive containing a dehydrating agent may be used as long as it does not affect the reaction between compound (1) and diphosphorus pentoxide, or an additive that does not contain a dehydrating agent after filtration or the like may be used. The dehydrating agent may be used alone or in combination of two or more types.

[0041] <The ratio (β / α) of the amount of diphosphorus pentoxide (β) to the amount of compound (1) (α)> In this embodiment, the amount of diphosphorus pentoxide is 141.94 g / mol. The ratio (β / α) of the molar amount (β) of diphosphorus pentoxide to the molar amount (α) of compound (1) is preferably 0.1 or more, more preferably 0.5 or more, since this tends to prevent unreacted compound (1) from remaining. Depending on the type of compound (1), it is even more preferably 1 or more, and particularly preferably 2 or more. The upper limit of the ratio (β / α) of the amount of substance (β) of phosphorus pentoxide to the amount of substance (α) of compound (1) is not particularly limited. However, since the amount of phosphorus pentoxide used tends to be reduced and the economics of the method for producing compound (2) are excellent, it is preferably β / α is 100 or less, more preferably 20 or less. Since the yield of compound (2) tends to increase and the economics of the method for producing compound (2) are excellent, it is even more preferably β / α is 10 or less, and particularly preferably 5 or less.

[0042] <Ratio (ε / (γ + δ)) of the mass (ε) of silica to the total mass (γ + δ) of the mass (γ) of compound (1) and the mass (δ) of phosphorus pentoxide> The ratio (ε / (γ + δ)) of the mass (ε) of silica to the total mass (γ + δ) of the mass (γ) of compound (1) and the mass (δ) of phosphorus pentoxide is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 0.75 or more, and particularly preferably 1.0 or more, since it tends to suppress caking in the reaction of compound (1) and phosphorus pentoxide. The upper limit of the ratio (ε / (γ + δ)) of the mass (ε) of silica to the total mass (γ + δ) of the mass (γ) of compound (1) and the mass (δ) of phosphorus pentoxide is not particularly limited. However, since the amount of silica used tends to be reduced and the economics of the method for producing compound (2) are excellent, it is preferably (ε / (γ + δ)) is 100 or less, more preferably 10 or less. Since the yield of compound (2) tends to increase and the economics of the method for producing compound (2) are excellent, it is even more preferably (ε / (γ + δ)) is 7 or less, and particularly preferably 5 or less.

[0043] <Reaction of compound (1) and phosphorus pentoxide> The reaction temperature of compound (1) with diphosphorus pentoxide is not particularly limited as long as it is a reaction temperature that is generally used, but since the reactivity of compound (1) with diphosphorus pentoxide tends to be high, the reaction temperature is preferably −40° C. or higher, and more preferably −20° C. or higher. From the same viewpoint and because the reaction temperature tends to be economical when adjusting the temperature industrially, the reaction temperature is further preferably 0° C. or higher, and particularly preferably 10° C. or higher. The upper limit of the reaction temperature between compound (1) and diphosphorus pentoxide is not particularly limited, but since volatilization of compound (1) can be suppressed and the yield of compound (2) tends to be more stable, the upper limit is preferably 300° C. or lower, and more preferably 250° C. or lower. Since deterioration of compound (2) can be suppressed and the method for producing compound (2) tends to be more economical, the upper limit is further preferably 200° C. or lower, and particularly preferably 180° C. or lower. The reaction temperature of compound (1) and diphosphorus pentoxide does not have to be constant so long as it is within the above range, and may be changed during the reaction.

[0044] When compound (2) is produced by the reaction of compound (1) with diphosphorus pentoxide, it is presumed that compound (1) reacts with diphosphorus pentoxide to form a reactant, and then compound (2) is produced from the reactant. Therefore, the reaction temperature for forming the reactant and the reaction temperature for producing compound (2) from the reactant may be the same or different. The reaction temperature when forming the reactant is preferably −40° C. or higher, more preferably −20° C. or higher, since the reactivity of compound (1) with diphosphorus pentoxide tends to be high. From the same viewpoint and because it tends to be economically advantageous when adjusting the temperature industrially, it is more preferably 0° C. or higher, particularly preferably 10° C. or higher. Since suppressing the reaction between compound (1) and diphosphorus pentoxide tends to suppress deterioration of compound (1) due to reaction heat, the reaction temperature is preferably 180° C. or lower, more preferably 150° C. or lower, and even more preferably 120° C. or lower. The reaction temperature for producing compound (2) from the reactant is preferably 80° C. or higher, more preferably 100° C. or higher, and even more preferably 120° C. or higher, since the production of compound (2) tends to be promoted. The reaction temperature is preferably 300° C. or lower, and more preferably 250° C. or lower, since the yield of compound (2) tends to be stable. The reaction temperature is more preferably 200° C. or lower, and particularly preferably 180° C. or lower, since deterioration of compound (2) can be suppressed and the economic efficiency of the method for producing compound (2) tends to be improved.

[0045] The reaction time of compound (1) with diphosphorus pentoxide is not particularly limited as long as it is within a range generally used, but since the stability of the yield of compound (2) is further increased, it is preferably 0.5 hours or more, and more preferably 1 hour or more. Since an excessive reaction time tends to result in a more economical production method, it is preferably 100 hours or less, and from the same viewpoint, it is more preferably 50 hours or less, and even more preferably 20 hours or less.

[0046] The reaction pressure between compound (1) and diphosphorus pentoxide is not particularly limited as long as it is within a range that is usually used, and may be any of pressurized, normal, and reduced pressure. Depending on the type of compound (1), the vapor pressure at the reaction temperature is high, so that reaction under pressurized pressure may be preferable since volatilization of compound (1) can be suppressed. Depending on the type of compound (1), the vapor pressure at the reaction temperature is low, so that reaction under normal pressure may be preferable since it tends to be more economical. Depending on the type of compound (2), the vapor pressure at the reaction temperature is low, so that when compound (2) is volatilized and recovered, reduced pressure may be preferable. Depending on the type of compound (2), the vapor pressure at the reaction temperature is low, so that reaction under normal pressure may be preferable since it tends to be more economical. The upper limit of the pressure when applying pressure is not particularly limited as long as it is within a range that is commonly used, but since this tends to reduce the complexity of the pressurizing device, the pressure is preferably 100 MPaG or less, more preferably 1 MPaG or less, even more preferably 0.4 MPaG or less, and particularly preferably 0.2 MPaG or less. The lower limit of the pressure when reducing the pressure is not particularly limited as long as it is within a range that is commonly used. However, since this tends to reduce the complexity of the device for reducing the pressure, the lower limit is preferably 0.01 PaA or more, more preferably 1 PaA or more, even more preferably 100 PaA or more, and particularly preferably 500 PaA or more. The pressure in the reaction of compound (1) with diphosphorus pentoxide does not need to be constant so long as it is within the above range, and may be changed during the reaction.

[0047] The atmosphere for the reaction of compound (1) with diphosphorus pentoxide is not particularly limited as long as it is a commonly used atmosphere, and typically includes air, nitrogen, and argon atmospheres. Among these, nitrogen and argon atmospheres are preferred because they tend to produce compound (2) more safely. In addition, nitrogen atmosphere is more preferred because it tends to be a more economical production method. The atmospheric dew point of the reaction atmosphere is preferably -10°C or lower, more preferably -30°C or lower, and even more preferably -50°C or lower, since this tends to suppress deterioration of diphosphorus pentoxide. The reaction atmosphere may be used alone or in combination of a plurality of reaction atmospheres.

[0048] As described above, in the reaction between compound (1) and diphosphorus pentoxide, compound (1) reacts with diphosphorus pentoxide to form a reactant, and then compound (2) is produced from the reactant. As a result of detailed observation of this reaction, the present inventors found that the reactant solidifies when it becomes a reactant, and even if the solidified reactant is pulverized, it solidifies again when compound (2) is produced from the reactant. Therefore, by reacting compound (1) with diphosphorus pentoxide to produce a reactant using an apparatus capable of suppressing solidification when it becomes a reactant, and then adding silica, it is also possible to suppress solidification when compound (2) is produced from the reactant. That is, silica may be added when compound (1) is reacted with diphosphorus pentoxide to form a reactant, silica may be added after compound (1) is reacted with diphosphorus pentoxide to form a reactant, or silica may be added when compound (1) is reacted with diphosphorus pentoxide to form a reactant, and further silica may be added after the reactant is formed. Among these, the method of adding silica when compound (1) is reacted with diphosphorus pentoxide to form a reactant is preferred because it tends to always suppress solidification in the reaction in which compound (1) reacts with diphosphorus pentoxide to produce compound (2) and tends to reduce the complexity of operations during the reaction. In the method of adding silica when reacting compound (1) with diphosphorus pentoxide to form a reaction product, the order in which compound (1), diphosphorus pentoxide, and silica are added is not particularly limited. However, because there is a tendency to further suppress solidification due to the reaction between compound (1) and diphosphorus pentoxide, preferred examples of the method include a method of adding a mixture of compound (1) and silica to diphosphorus pentoxide, a method of adding diphosphorus pentoxide to a mixture of compound (1) and silica, a method of adding a mixture of diphosphorus pentoxide and silica to compound (1), and a method of adding compound (1) to a mixture of diphosphorus pentoxide and silica.

[0049] The method for mixing compound (1), diphosphorus pentoxide, and silica is not particularly limited as long as it is a commonly used method, and examples of such methods include a mixing tank type (horizontal type, vertical type), the number of stirring shafts (two shafts, three shafts, four shafts), the shape of the stirring blade (for example, fan, propeller, cross, butterfly, dragonfly, turbine, disc turbine, disperse, paddle, inclined paddle, helical, double helical, ribbon, straight blade, 45° twist blade, 90° twist blade, etc.), and the installation of a baffle in the mixing tank. More specifically, examples of mixing equipment include the pressure kneader, Wonder Kneader, Mix Lab, kneading test equipment, small-volume pressure kneader, MS-type small pressure kneader, twin-arm kneader, valve kneader, kneader ruder, special pressure kneader, reduced pressure kneader, twin-screw taper extruder, twin-screw single-screw extruder, and feeder ruder manufactured by Nihon Spindle Mfg. Co., Ltd., the KRC kneader, batch kneader, pressure kneader, extruder, CD dryer, SC processor, and CD dryer manufactured by Kurimoto Iron Works, Ltd., and the I BDM twin-shaft mixer, butterfly mixer, CDM concentric twin-shaft mixer, pony mixer, trimix, planetary mixer, PD mixer, kneader, flushing kneader, salt milling kneader, pressure kneader, and KX kneader manufactured by Kamiseisakusho Co., Ltd.; Pam Apex mixer, super double mixer manufactured by Pacific Machinery Co., Ltd.; vertical mixer, ribbon mixer, high-speed paddle mixer, and paddle mixer manufactured by Nishimura Machinery Co., Ltd.; Byte mix, Nauta mixer, solid air, micron thermo processor, and torus disk manufactured by Hosokawa Micron Co., Ltd.; paddle dryer, single paddle dryer, Buno cooler, multi-fin processor, extruder, and high-speed mixing and granulating machine manufactured by Nara Machinery Co., Ltd.; PV mixer and SV mixer manufactured by Kobelco Eco-Solutions Co., Ltd.; Ribocone and flow jet granulator manufactured by Okawara Manufacturing Co., Ltd.; twin-shaft kneading extruder manufactured by The Japan Steel Works, Ltd.; Hivismix, Hivisdispermix, and Combimix manufactured by Primix Corporation. , the ACM series manufactured by Aikosha Seisakusho Co., Ltd., the mixer, twin servo mixer, S kneader, spherical kneader, spherical beveled axis kneader, and high-speed kneading granulator manufactured by Shinagawa Kogyosho Co., Ltd., the intensive mixer and Evactherm manufactured by Nippon Eirich Co., Ltd., the axial mixer and Hemisphere mixer manufactured by Sugiyama Heavy Industries Co., Ltd., the vacuum mixer dryer manufactured by Katsuragi Kogyo Co., Ltd., the vacuum mixer dryer manufactured by Yasujima Co., Ltd., the mixer, semi-pressure kneader, kneader ruder, and vacuum extruder manufactured by MIG Co., Ltd., etc. In the case where a large amount of silica is used or where silica is added to a pulverized reaction product to produce compound (2), in addition to the above-mentioned apparatuses, examples of the apparatus include KID dryer, rotoluba dryer, rotary dryer, and rotary kiln manufactured by Kurimoto Iron Works, Ltd., conical dryer manufactured by Kobelco Eco-Solutions Co., Ltd., electrically heated rotary kiln, gas heated rotary kiln, batch type rotary kiln, desktop rotary kiln, vacuum desktop rotary kiln, and special atmosphere + vacuum rotary kiln manufactured by Takasago Industrial Co., Ltd., super rotary dryer and eco dryer manufactured by Okawara Manufacturing Co., Ltd., rotary kiln and double cone mixer manufactured by Sugiyama Heavy Industries Co., Ltd., double cone dryer manufactured by Katsuragi Kogyo Co., Ltd., and rotary kiln manufactured by Yasujima Corporation. The above mixing device may be used alone or in combination of a plurality of mixing devices.

[0050] In the case where compound (1), diphosphorus pentoxide, and silica are not mixed at the same time, but any of the combinations of compound (1) and diphosphorus pentoxide, compound (1) and silica, and diphosphorus pentoxide and silica is mixed before being supplied to an apparatus for mixing compound (1), diphosphorus pentoxide, and silica, in addition to the above-mentioned apparatus, a Nibbler, Feather Mill, Farma Mill, Hammer Mill, Hammer Blade, Disintegrator, Rubber Chopper, Rotoplex, Compact Line, ACM Perverizer, Glacis, and Phi Impact Mill, Victory Mill, Contraplex, Linrex Mill, Micro Pulverizer, Counter Jet Mill, Micron Jet, Super Micron Mill, Innomizer, Pulvis, Spiral Jet Mill, Disper Mill, and Hydro Mill manufactured by Nara Machinery Co., Ltd. Jiyu Mill, New Cosmomizer, Micros, Super Clean Mill, Sample Mill, Super Jiyu Mill, Mill Box, Cosmo Box, Hammer Mill, Goblin, Baryonyx, Briodon, Polvogene, and Gina manufactured by Kurimoto Iron Works Co., Ltd. Cross Jet Mill , Pocket Jet, Gadget, Hi-G, Agitator Mill, VX Mill, Roller Mill, Ball Mill, Rod Mill, K-VIX Mill, and Granulator, Jaw Crusher, Ratchet Roll Crusher, Corrugated Roll Crusher, Roll Crusher, Tandem Roll Crusher, Oniha Roll Crusher, S-Shaped Crusher, 4-Axis Crusher, Fiber Mill, Bevel Impactor, Radical Impactor, Ball Mill, Attrition Mill, and Cube Rotor Mill manufactured by Sugiyama Heavy Industries Co., Ltd., Super Powder Mill, Fairy manufactured by Nishimura Machinery Co., Ltd. Powder mills, stamp mills, high-speed grinders, hammer crushers, sloot mills, Seryuners, shredders, and cutter mills; vertical roller mills, Kryptron Zepros, Kryptron Venti, Kryptron, Kryptron Eddy, Kryptron Prime, Jedi, Converge Mill, Oshlobit, Conibit, and hammer mills manufactured by EarthTechnica Corporation; Super Jet Mills, Super Rotors, and Blade Mills manufactured by Nisshin Engineering Inc.; Dry Star, Sigma Dry, and Lab Star manufactured by Ashizawa Finetech Co., Ltd.Nano Getter, Mugen Flow, and Delta Vita, Seishin Enterprise Co., Ltd.'s Single Track Jet Mill, Sk Jet O Mill, Cojet System α-mkV, Sanitary JOM Series, AO Jet Mill, Impeller Mill, Planetary Mill, Orient Crusher, Atomizer, Pin Mill, and Spiral Mill, Makino Sangyo Co., Ltd.'s Frame Dismantler, Oniha Crusher, Tear Crusher, Hammer Crusher, Makino Crusher, Exceed Mill, Disc Type Crusher, Coroplex Crusher, Contraplex Crusher, and Ultraplex Crusher, Tsukasa Kogyo Co., Ltd.'s Pow Cutter, Pow Crusher, Line Mill, Wave Mill, and Pow Jet, Imex Co., Ltd.'s Easy Nano, Ready Mill, Neo-A Examples of such mills include Luffa Mill, low-temperature / freeze grinding bead mill, Visco Mill, and sand grinder; Apex Mill, Ultra Apex Mill, Wide Separator Apex Mill, Dual Apex Mill, Ultra Apex Mill Advance, Apex Disperser ZERO, and Apex LABO manufactured by Hiroshima Metal & Machinery Co., Ltd.; MSC Mill, SC Mill, SC Mill Long, MY Mill, Attritor, Trigonal, Fine Mill, Dynamic Mill, Alchemy, Stream Mill, and Centri Cutter manufactured by Nippon Coke & Engineering Co., Ltd.; Mighty Mill Mark II, Spike Mill, Key Mill, MP Mill, MF Mill, Mighty Mill, Nano Sonic Mill, 3-roll mill ceramic roll, and 3-roll mill chilled roll manufactured by Inoue Seisakusho Co., Ltd. The above mixing device may be used alone or in combination of a plurality of mixing devices.

[0051] Examples of the method of adding compound (1) to an apparatus for mixing compound (1), diphosphorus pentoxide, and silica include a method of adding compound (1) by utilizing its own weight, a method of adding compound (1) under pressure, a method of adding compound (1) by using a liquid delivery pump (e.g., a smooth flow pump, a motor-driven metering pump, a solenoid-driven metering pump, an air-driven pump, a dynamic vacuum pump, a tube pump, a slurry pump, a magnet pump, an air-driven bellows pump, an electromagnetically-driven metering pump, a rotary volumetric pump, etc.), etc. The method of using a liquid delivery pump is preferred because it tends to have excellent controllability of the rate at which compound (1) is added.

[0052] Examples of the method of adding diphosphorus pentoxide and / or silica to an apparatus for mixing compound (1), diphosphorus pentoxide, and silica include a method of adding by utilizing its own weight, a method of adding by passing an air current (e.g., suction-type pneumatic transport, low-pressure pressure-fed pneumatic transport, high-pressure pressure-fed pneumatic transport, etc., and the pneumatic transport may be transport in a different atmosphere such as dry air transport, nitrogen transport, and argon transport), and a method of adding by using a powder feeder (e.g., a screw feeder, a vibration feeder, a circle feeder, a conveyor-type feeder, an auger-type powder filling machine, a weighing-type powder feeder, a volumetric-type powder feeder, etc.). The method of using a powder feeder is preferred because it tends to have excellent controllability of the speed at which diphosphorus pentoxide and / or silica is added.

[0053] Regarding the above-mentioned respective devices, adding means, containers, etc. (for example, a device used when reacting compound (1) with diphosphorus pentoxide, a container containing compound (1), diphosphorus pentoxide, and silica, a liquid delivery pump used when adding compound (1), a powder feeder used when adding compound (2) and / or silica, etc.), and piping etc. connecting each of them, materials used in places that come into contact with compound (1), compound (2), and silica are not particularly limited as long as they are commonly used materials, and examples thereof include metals, metal alloys, resins, composites of metals and resins, ceramics, etc. More specific examples include titanium, nickel, zirconia, platinum, carbon steel, alloy steel, cast iron, stainless steel (SUS304, SUS304L, SUS430, SUS410, SUS316, SUS316L, SUS329J1, SUS329J4L, etc.), nickel-titanium alloys, nickel-chromium-molybdenum alloys (Inconel (registered trademark) 600, 625, 718, X750, etc., Hastelloy (registered trademark) C-22, C276, etc.), nickel-copper alloys (Monel (registered trademark) 400, K, S, H, Nickelvac (registered trademark) 400, Nikoros (registered trademark) 400, etc.), nickel-cobalt-chromium-molybdenum alloys, nickel-molybdenum alloys (Hastelloy (registered trademark) ALLOY B2, B, etc.), nickel-cobalt alloys, nickel-iron alloys, nickel-tungsten alloys, cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (ELGILOY, PHYNOX (registered trademark), etc.), platinum-enriched stainless steel, fluorine-based resins (Teflon (registered trademark), copolymers of tetrafluoroethylene and perfluoroalkoxyethylene, perfluoroethylene propene copolymers, ethylene tetrafluoroethylene copolymers, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene chlorotrifluoroethylene copolymers, etc.), polyether ether ketone, polypropylene, polyphenylene ether, polyamide 6, polyamide 66, aromatic polyamide, polyphenylene sulfide, polysulfone, polyether sulfone, polyether imide, polyamide imide, etc. The above materials may be used alone or in combination of two or more.

[0054] <Fluorine-containing sulfonic acid anhydride (2) (compound (2))> The following general formula (2): (R f SO 2 ) 2 O (2) (In the formula, R f represents a saturated or unsaturated aliphatic or aromatic hydrocarbon group in which at least one hydrogen atom is substituted with a fluorine atom, and the ethylene structure in the hydrocarbon group may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom; R f The carbon number is 1 to 20, and two R f They may be the same or different) It is expressed as: The fluorine-containing sulfonic acid anhydride (2) may be one type alone or a combination of two or more types.

[0055] In the formula, R f The details of R in the general formula (1) representing the fluorine-containing sulfonic acid (1) are as follows: f may be considered the same as

[0056] INDUSTRIAL APPLICABILITY As described above, the present invention can suppress caking in the reaction of a fluorinated sulfonic acid (1) with diphosphorus pentoxide, and can produce a fluorinated sulfonic anhydride (2) useful as a catalyst for medicines, organic synthesis, etc., or as a synthetic raw material with good yield. EXAMPLES

[0057] The present invention is not limited to the following examples, so long as they do not depart from the gist of the present invention.

[0058] The analytical methods used in the examples and comparative examples are as follows.

[0059] <Particle size analysis> Particle size was measured using a particle size distribution analyzer (MT-3300II manufactured by Microtrack Bell Co., Ltd.). Water was used as the solvent. The amount of sample was adjusted so that it was within the optimal concentration range displayed by the device (usually 0.05 to 2 g).

[0060] <Nuclear magnetic resonance analysis (NMR): 19 Molecular structure analysis using F-NMR> Regarding the products obtained in the examples and comparative examples, 19 Molecular structure analysis was carried out using F-NMR under the following measurement conditions. [Measurement conditions] Measurement equipment: JNM-ECZ400S nuclear magnetic resonance equipment (manufactured by JEOL Ltd.) Observation kernel: 19 F Solvent: deuterated chloroform Reference substance: tetramethylsilane (0.00 ppm) Observation frequency: 400MHz ( 1 H) Pulse width: 6.5μsec Wait time: 2 seconds Number of times: 16

[0061] <Nuclear magnetic resonance analysis (NMR): 1 Molecular structure analysis using H-NMR> Regarding the products obtained in the examples and comparative examples, 1 Molecular structure analysis was carried out using H-NMR under the following measurement conditions. [Measurement conditions] Measurement equipment: JNM-ECZ400S nuclear magnetic resonance equipment (manufactured by JEOL Ltd.) Observation kernel: 1 H Solvent: deuterated chloroform Reference substance: tetramethylsilane (0.00 ppm) Observation frequency: 400MHz ( 1 H) Pulse width: 7.3 μsec Wait time: 5 seconds Number of times: 8

[0062] <Analysis by X-ray diffraction method (XRD): Crystal structure analysis of silica> For the silica used in the examples, crystal structure analysis was performed using the X-ray diffraction method (XRD) under the following measurement conditions. [Measurement conditions] X-ray diffractometer (XRD): RINT2500 type powder X-ray diffractometer (manufactured by Rigaku Corporation) X-ray source: Cu tube (40 kV, 200 mA) Measurement range: 5 - 60° (0.02° / step) Measurement speed: 0.2° / min Slit width (scattering, divergence, light receiving): 1°, 1°, 0.15 mm

[0063] The raw materials used in the examples and comparative examples are shown below.

[0064] [Production Example 1] (Fluorine-containing sulfonic acid (1) (Compound (1)) According to JP-A-2019-156782, Compound (5) represented by the following formula (5) was produced. CF 2 =CFOCF 2 CF 2 SO 3 Na (5) Using the obtained compound of the above formula (5) and referring to WO 2020 / 012913, fluorine-containing sulfonic acid (6) (Compound (6)) was produced by the following method. Compound (5) (800 g, 2.67 mol), 23 mass% sulfuric acid (prepared from sulfuric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) and distilled water (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)) (1.71 kg, the amount of sulfuric acid contained is 4.00 mol) was added to a 6 L separable flask, stirred, and then cyclopentyl methyl ether (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) (1.20 kg) was added, stirred for 1 hour, and then allowed to stand for 2 hours. The upper cyclopentyl methyl ether phase was collected in a flask, placed in an evaporator set at 45 ° C., and rotated at 120 rpm. The pressure was gradually reduced, and finally reduced to 3.0 kPaA, and then volatile components were distilled off for 4 hours. Distilled water (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (600 g) was added to the flask, placed in an evaporator set at 45 ° C., and rotated at 120 rpm. The pressure was gradually reduced, and finally reduced to 3.0 kPaA, after which the volatile components were distilled off for 2 hours. Furthermore, distilled water (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (600 g) was added to the flask, which was then placed in an evaporator set at 45°C and rotated at 120 rpm. The pressure was gradually reduced, and finally reduced to 3.0 kPaA, after which the volatile components were distilled off for 1 hour. 0.30 g of the resulting concentrate was taken out, 1As a result of the H-NMR analysis, no peak of cyclopentyl methyl ether was detected. 397.0 g of the concentrate was transferred to a flask equipped with a stirrer and a Liebig condenser with a receiver, and the atmosphere was replaced with nitrogen three times. Cooling water set at -5°C was passed through the Liebig condenser, the flask was placed in an oil bath set at 90°C, stirred, and the pressure was reduced to 0.7 kPaA. After confirming the distillation of the volatile components, the oil bath was gradually heated to 130°C, and one hour after confirming the distillation, the pressure was returned to normal pressure with nitrogen, and the flask was removed from the oil bath. After the flask reached room temperature, the mass of the contents was measured and found to be 325.7 g. To the resulting content (0.30 g), 1,2-dimethoxyethane (Fujifilm Wako Pure Chemical Industries, Ltd., Wako special grade, dried molecular sieve 4A 1 / 16 (Fujifilm Wako Pure Chemical Industries, Ltd.) was added, dehydrated, and the water content was adjusted by removing the molecular sieve 4A 1 / 16) (1.0 g) and benzotrifluoride (Tokyo Chemical Industry Co., Ltd.) (0.10 g) were added for analysis, and the mixture was stirred. 19 F-NMR analysis revealed that 306.0 g (1.10 mol) of fluorine-containing sulfonic acid (6) represented by the following formula (6) was obtained. CF 2 =CFOCF 2 CF 2 SO 3 H (6) For analysis, 1,2-dimethoxyethane (Fujifilm Wako Pure Chemical Industries, Ltd., Wako special grade, dried molecular sieve 4A 1 / 16 (Fujifilm Wako Pure Chemical Industries, Ltd.) was added, dehydrated, and the molecular sieve 4A 1 / 16 was removed to adjust the moisture content) (2.0 g) was added to the content (0.20 g) and stirred, and the moisture content was analyzed using a Karl Fischer moisture meter (Kyoto Electronics Manufacturing Co., Ltd., MKC-710D). As a result, it was found that the content contained 18.1 g of water. The moisture content of the 1,2-dimethoxyethane used was also measured, and the moisture content of the content was calculated excluding the moisture content contained in the 1,2-dimethoxyethane used. The product obtained as described above will be referred to as "fluorine-containing compound (6) obtained in Production Example 1" or "compound (6) obtained in Production Example 1" in the following examples, comparative examples, etc.

[0065] (Diphosphorus pentoxide) Phosphorus(V) oxide (Wako Pure Chemical Industries, Fujifilm, Wako special grade)

[0066] (silica) Silica A (manufactured by Tokai Kogyo Co., Ltd., Izutokufun, particle size 12 μm, calculated specific surface area obtained by particle size analysis is 1.1 m 2 / mL, silicon dioxide content 95% by mass, XRD analysis showed that the quartz crystal structure was predominant, and silica A was determined to be crystalline silica. Silica B (Takeori Kogyosho Co., Ltd., silica powder #300, particle size 6.1 μm, calculated specific surface area obtained by particle size analysis is 1.6 m 2 / mL, silicon dioxide content 89% by mass, and XRD analysis showed that the quartz crystal structure was predominant, determining that Silica B was crystalline silica. Silica C (manufactured by Takeori Kogyosho Co., Ltd., silica powder CM, silica flower M, particle size 22 μm, calculated specific surface area obtained by particle size analysis is 0.53 m 2 / mL, silicon dioxide content 99% by mass, XRD analysis showed that the quartz crystal structure was predominant, and silica C was determined to be crystalline silica) Silica D (Takeori Kogyosho Co., Ltd., silica powder A-3, particle size 53 μm, calculated specific surface area obtained by particle size analysis is 0.22 m 2 / mL, silicon dioxide content 96% by mass, XRD analysis showed that the quartz crystal structure was predominant, and silica D was determined to be crystalline silica. Silica E (JFE Mineral Co., Ltd., Nikko silica sand No. 8, particle size 113 μm, calculated specific surface area obtained by particle size analysis is 0.06 m 2 / mL, silicon dioxide content 89% by mass, and XRD analysis showed that the quartz crystal structure was predominant, determining that silica E was crystalline silica.

[0067] (others) Benzotrifluoride (Tokyo Chemical Industry Co., Ltd.) Hexafluorobenzene (Tokyo Chemical Industry Co., Ltd.)

[0068] [Example 1] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (30.7 g, 216 mmol) and silica A (74.2 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 20.0 g (containing 18.8 g (67.6 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 15.0 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19The product was analyzed by F-NMR. As a result of the analysis, it was found that 14.5 g (26.9 mmol, yield 79.5%) of fluorine-containing sulfonic anhydride (7) represented by the following general formula (7) was obtained. It was also found that 0.39 g (1.4 mmol) of fluorine-containing sulfonic acid (6) was contained. In the analysis, the mass of benzotrifluoride, the CF 3 , fluorine-containing sulfonic anhydride (7), and fluorine-containing sulfonic acid (6) CF 2 From the integral value of the above, the masses of the fluorine-containing sulfonic anhydride (7) and the fluorine-containing sulfonic acid (6) were calculated. (CF 2 =CFOCF 2 CF 2 SO 2 ) 2 O (7) 19 F-NMR: δ(ppm) -85.3(4F), -112.0(4F), -116.4(2F), -123.6(2F), -139.0(2F) The yield of the fluorine-containing sulfonic acid anhydride (7) was calculated according to the following formula (1). Yield (%) of fluorine-containing sulfonic anhydride (7) = amount of fluorine-containing sulfonic anhydride (7) / (amount of fluorine-containing sulfonic acid (6) used as raw material × 0.5) × 100 (1) For example, the yield (%) of the fluorine-containing sulfonic acid anhydride (7) in this example is 26.9 (mmol) / (67.6 (mmol)×0.5)×100=79.5. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 3.2 and ε / (γ+δ) was 1.5.

[0069] [Example 2] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (23.9 g, 168 mmol) and silica A (65.1 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 19.9 g (containing 18.7 g (67.2 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 13.2 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 12.2 g (22.6 mmol, yield 67.2%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.90 g (3.2 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 2.5 and ε / (γ+δ) was 1.5.

[0070] [Example 3] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (42.1 g, 296 mmol) and silica A (94.2 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 19.5 g (containing 18.3 g (65.9 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 13.2 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 12.9 g (23.9 mmol, 72.7% yield) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.22 g (0.8 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 4.5 and ε / (γ+δ) was 1.6.

[0071] [Example 4] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (28.5 g, 201 mmol) and silica A (51.2 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 19.2 g (containing 18.0 g (64.9 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had stopped, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 14.2 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19The product was analyzed by F-NMR. As a result of the analysis, it was found that 13.8 g (25.6 mmol, 79.0% yield) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.29 g (1.0 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings. As a result, 5.93 g remained on the sieve and 78.8 g of material passed through the sieve. In this example, β / α was 3.1 and ε / (γ+δ) was 1.1.

[0072] [Example 5] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (15.5 g, 109 mmol) and silica A (112 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 10.1 g (containing 9.49 g (34.1 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 7.05 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 6.62 g (12.3 mmol, 72.1% yield) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.37 g (1.3 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 3.2 and ε / (γ+δ) was 4.5.

[0073] [Example 6] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (31.8 g, 224 mmol) and silica A (77.1 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 20.1 g (containing 18.9 g (67.9 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When 140° C. and 10 kPaA were maintained, the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 14.8 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 14.2 g (26.5 mmol, 77.9% yield) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.43 g (1.6 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 3.3 and ε / (γ+δ) was 1.5.

[0074] [Example 7] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (30.1 g, 212 mmol) and silica B (71.8 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 19.6 g (containing 18.4 g (66.2 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 15.1 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19The product was analyzed by F-NMR. As a result of the analysis, it was found that 14.6 g (27.1 mmol, yield 81.9%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.41 g (1.5 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 3.2 and ε / (γ+δ) was 1.5.

[0075] [Example 8] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (31.0 g, 219 mmol) and silica C (75.1 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 19.6 g (containing 18.4 g (66.2 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 14.6 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 14.0 g (26.1 mmol, 78.8% yield) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.44 g (1.6 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 3.3 and ε / (γ+δ) was 1.5.

[0076] [Example 9] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (29.9 g, 211 mmol) and silica D (74.6 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 20.1 g (containing 18.9 g (67.9 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 14.6 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 14.0 g (26.1 mmol, yield 76.8%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.40 g (1.4 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, leaving 14.3 g on the sieve and 95.6 g of material passing through the sieve. In this example, β / α was 3.1 and ε / (γ+δ) was 1.5.

[0077] [Example 10] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (31.8 g, 224 mmol) and silica E (77.3 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 20.7 g (containing 19.4 g (69.9 mmol) of fluorine-containing sulfonic acid (6)). The oil bath was set to 90° C. and the mixture was stirred for 1 hour, and then stirred for 20 minutes at 140° C. and 10 kPaA. When the oil bath was set to 160° C., the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had ceased, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 15.2 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19The product was analyzed by F-NMR. As a result of the analysis, it was found that 14.6 g (27.1 mmol, yield 77.5%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.49 g (1.7 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings. As a result, 35.5 g remained on the sieve and 79.0 g of material passed through the sieve. In this example, β / α was 3.2 and ε / (γ+δ) was 1.5.

[0078] [Example 11] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (29.8 g, 210 mmol) and silica A (48.0 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 19.4 g (containing 18.2 g (65.5 mmol) of fluorine-containing sulfonic acid (6)). After stirring for 1 hour with the oil bath set to 90°C, the flask was removed from the oil bath and cooled to room temperature. Stirring in the flask was stopped, and silica A (24.0 g) measured in the space under a nitrogen atmosphere was added to the flask. Stirring was resumed, the flask was placed in an oil bath, the oil bath was set to 90°C, and stirring was continued for 10 minutes, and then the pressure was increased to 140°C and 10 kPaA and stirring was continued for 20 minutes. When the oil bath was set to 160°C, the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. After confirming that distillation had ceased, stirring was stopped. After replacing the air in the flask with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, and the receiver was removed from the ethanol cooled with dry ice and returned to room temperature. The Liebig condenser was removed from the flask, and the flask was then sealed with a glass stopper and moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 14.5 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, and 19The product was analyzed by F-NMR. As a result of the analysis, it was found that 13.9 g (25.9 mmol, yield 79.0%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.40 g (1.4 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 3.2 and ε / (γ+δ) was 1.5.

[0079] [Comparative Example 1] In a space with a nitrogen atmosphere dried by a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (31.2 g, 219 mmol) was placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 20.3 g (containing 19.1 g (68.6 mmol) of fluorine-containing sulfonic acid (6)). When the oil bath was set to 90° C. and stirring was performed for 1 hour, it was confirmed that the contents of the flask were attached to the stirring rod and the inner surface of the flask, and stirring was not possible. From this, it was determined that solidification occurred in this comparative example. In this comparative example, β / α was 3.2.

[0080] [Comparative Example 2] In a space with a nitrogen atmosphere dried by a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (28.2 g, 199 mmol) was placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing the fluorine-containing compound (6) obtained in Production Example 1 were attached, and the flask was taken out of the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and the fluorine-containing compound (6) was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of the fluorine-containing compound (6) obtained in Production Example 1 introduced into the flask was 12.0 g (containing 11.3 g (40.5 mmol) of fluorine-containing sulfonic acid (6)). When the oil bath was set to 90° C. and stirring was performed for 1 hour, it was confirmed that the contents of the flask were attached to the stirring rod and the inner surface of the flask, and stirring was not possible. From this, it was determined that solidification occurred in this comparative example. In this comparative example, β / α was 4.9.

[0081] [Reference example 1] In a space with an air atmosphere dried by a membrane dryer (IDG100SAV4-03, manufactured by SMC Corporation) and a dry column (DC-L4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (343 g, 2.42 mol) was placed in a semi-pressurized kneader (ND-025, manufactured by MIG Co., Ltd.) at room temperature, and two shafts were rotated in the same direction (one shaft was set at 90 rpm, the other at 60 rpm). Fluorine-containing sulfonic acid (6) (221 g) (containing 208 g (747 mmol) of fluorine-containing sulfonic acid (6)) produced by the same method as in Production Example 1 was gradually added, and kneaded for 2 hours. When the rotation of the apparatus was stopped and the contents were taken out, a kneaded product of fluorine-containing sulfonic acid (6) and diphosphorus pentoxide was obtained as a powder. In this reference example, β / α was 3.2.

[0082] [Reference example 2] In a space of an air atmosphere dried with a membrane dryer (IDG100SAV4-03, manufactured by SMC Corporation) and a dry column (DC-L4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (170 g, 1.20 mol) and fluorine-containing sulfonic acid (6) (106 g) (containing 99.6 g (358 mmol) of fluorine-containing sulfonic acid (6)) produced by the same method as in Production Example 1 were placed in a kneader (2P-03, manufactured by Primix Corporation) at room temperature, and kneaded for 10 minutes at a revolution setting of 50 rpm and for 50 minutes at a revolution setting of 100 rpm. When the rotation of the apparatus was stopped and the contents were removed, a kneaded product of fluorine-containing sulfonic acid (6) and diphosphorus pentoxide was obtained as a powder. In this reference example, β / α was 3.3.

[0083] [Reference example 3] In a space of an air atmosphere dried by a membrane dryer (IDG100SAV4-03, manufactured by SMC Corporation) and a dry column (DC-L4, manufactured by Nikka Seiko Co., Ltd.), a continuous twin-screw kneader (S1KRC, manufactured by Kurimoto Iron Works Co., Ltd.) was operated at a rotation speed of 200 rpm, diphosphorus pentoxide (378 g / h, 2.66 mol / h) was supplied using a powder micro-quantitative supplying device (FeedCommu M-030F, manufactured by Nisshin Engineering Inc.), and fluorine-containing sulfonic acid (6) (225 g / h) (fluorine-containing sulfonic acid (6) was 211 g / h (760 mmol / h)) produced by the same method as in Production Example 1 was supplied using a macro tube pump (MP-1000, manufactured by Tokyo Rikakikai Co., Ltd.) and kneaded. As a result, a kneaded product of fluorine-containing sulfonic acid (6) and diphosphorus pentoxide was obtained as a powder. In this reference example, β / α was 3.6.

[0084] [Example 12] In a space with a nitrogen atmosphere dried with a dry column (manufactured by Nikka Seiko Co., Ltd., DC-A4), the kneaded product (39.8 g) produced in Reference Example 1 (containing 14.7 g (52.8 mmol) of fluorine-containing sulfonic acid (6) and 24.3 g (171 mmol) of diphosphorus pentoxide) and silica B (31.1 g) were placed in a flask, a half-moon-shaped stirring rod with a stirring seal and a Liebig condenser with a receiver were attached, and the flask was removed from the space with a nitrogen atmosphere. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (manufactured by Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 40°C, stirred, the oil bath was set to 90°C and stirred for 1 hour, and then stirred at 140°C·10 kPaA for 20 minutes. When the oil bath was set to 160°C, the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that distillation had ceased, the stirring was stopped. After replacing the atmosphere in the flask with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 12.0 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, and 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 11.7 g (21.7 mmol, yield 82.2%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.26 g (0.9 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, ε / (γ+δ) was 0.80.

[0085] [Example 13] In a nitrogen atmosphere space dried in a dry column (manufactured by Nippon Seiko K.K., DC-A4), into a flask were placed the kneaded product (40.1 g) produced in Reference Example 2 (containing 14.5 g (52.2 mmol) of fluorosulfonic acid (6) and 24.7 g (174 mmol) of diphosphorus pentoxide), and silica B (31.0 g). A semi-circular stirring rod having a stirring seal and a Liebig condenser having a receiver were attached, and it was taken out from the nitrogen atmosphere space. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled by dry ice. The flask was placed in an oil bath (manufactured by Tokyo Rika Kikai Co., Ltd., OHB-3100S) set at 40°C, stirred, and after stirring for 1 hour with the oil bath set at 90°C, it was stirred at 140°C and 10 kPaA for 20 minutes. When the oil bath was set at 160°C, distillates were gradually recovered in the receiver. The pressure was gradually reduced from the time when the distillation slowed down to 2 kPaA. When it was confirmed that the distillation had stopped, the stirring was stopped. After replacing the flask with nitrogen, it was removed from the oil bath, the circulation of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled by dry ice, and it was returned to room temperature. The Liebig condenser was removed from the flask, the flask was stoppered with a glass stopper, and then the flask was transferred to a dry nitrogen atmosphere space. As a result of measuring the mass of the content of the receiver, it was 11.7 g. The content of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, 19 and analyzed by F-NMR. As a result of the analysis, it was found that 11.3 g (20.9 mmol, yield 80.3%) of fluorosulfonic acid anhydride (7) was obtained. It was also found that 0.33 g (1.2 mmol) of fluorosulfonic acid (6) was contained. The content of the flask transferred to a dry nitrogen atmosphere was sieved through a sieve with an opening of 11.2 mm. As a result, there was no substance remaining on the sieve. In this example, ε / (γ + δ) was 0.79.

[0086] [Example 14] In a space with a nitrogen atmosphere dried with a dry column (manufactured by Nikka Seiko Co., Ltd., DC-A4), the kneaded product (40.2 g) produced in Reference Example 3 (containing 14.1 g (50.8 mmol) of fluorine-containing sulfonic acid (6) and 25.2 g (178 mmol) of diphosphorus pentoxide) and silica B (31.9 g) were placed in a flask, a half-moon-shaped stirring rod with a stirring seal and a Liebig condenser with a receiver were attached, and the flask was removed from the space with a nitrogen atmosphere. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (manufactured by Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 40°C, stirred, the oil bath was set to 90°C and stirred for 1 hour, and then stirred at 140°C·10 kPaA for 20 minutes. When the oil bath was set to 160°C, the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that distillation had ceased, the stirring was stopped. After replacing the atmosphere with nitrogen, the flask was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 11.4 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, and 19 The product was analyzed by F-NMR. As a result of the analysis, it was found that 11.0 g (20.4 mmol, yield 80.2%) of fluorine-containing sulfonic anhydride (7) was obtained. It was also found that 0.30 g (1.1 mmol) of fluorine-containing sulfonic acid (6) was contained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, ε / (γ+δ) was 0.81.

[0087] [Comparative Example 3] In a space with a nitrogen atmosphere dried by a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), the kneaded product (38.6 g) manufactured in Reference Example 1 was put into a flask, a half-moon-shaped stirring rod with a stirring seal and a Liebig condenser with a receiver were attached, and the flask was taken out of the space with a nitrogen atmosphere. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, stirred, and the oil bath was set to 90°C and stirred for 1 hour, and it was confirmed that the contents of the flask were attached to the stirring rod and the inner surface of the flask, and stirring was not possible. From this, it was determined that solidification occurred in this comparative example.

[0088] [Comparative Example 4] In a space with a nitrogen atmosphere dried by a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), the kneaded material (39.2 g) produced in Reference Example 2 was put into a flask, a half-moon-shaped stirring rod with a stirring seal and a Liebig condenser with a receiver were attached, and the flask was taken out of the space with a nitrogen atmosphere. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, stirred, and the oil bath was set to 90°C and stirred for 1 hour, and it was confirmed that the contents of the flask were attached to the stirring rod and the inner surface of the flask, and stirring was not possible. From this, it was determined that solidification occurred in this comparative example.

[0089] [Comparative Example 5] In a space with a nitrogen atmosphere dried by a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), the kneaded product (41.0 g) produced in Reference Example 3 was placed in a flask, a half-moon-shaped stirring rod with a stirring seal and a Liebig condenser with a receiver were attached, and the flask was taken out of the space with a nitrogen atmosphere. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, stirred, and the oil bath was set to 90°C and stirred for 1 hour, and it was confirmed that the contents of the flask were attached to the stirring rod and the inner surface of the flask, and stirring was not possible. From this, it was determined that solidification occurred in this comparative example.

[0090] [Example 15] In a space with a nitrogen atmosphere dried with a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (13.8 g, 97.5 mmol) and silica B (61.4 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing trifluoromethanesulfonic acid (Wako Special Grade, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were attached, and the flask was removed from the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and trifluoromethanesulfonic acid was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of trifluoromethanesulfonic acid introduced into the flask was 27.1 g (181 mmol). The oil bath was set to 90°C, and the mixture was stirred at 90 kPaA, during which the distillate was gradually collected in the receiver. After confirming that no more distillate was being removed, the stirring was stopped. After the flask was purged with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, and the receiver was removed from the ethanol cooled with dry ice and allowed to return to room temperature. The Liebig condenser was removed from the flask, and the flask was then sealed with a glass stopper, after which it was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 21.3 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, 19 The reaction mixture was analyzed by F-NMR, and it was found that 20.5 g (72.7 mmol, yield 80.5%) of fluorine-containing sulfonic acid anhydride (2) was obtained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 0.54 and ε / (γ+δ) was 1.5.

[0091] [Example 16] In a space with a nitrogen atmosphere dried by a dry column (DC-A4, manufactured by Nikka Seiko Co., Ltd.), diphosphorus pentoxide (15.1 g, 106 mmol) and silica B (70.5 g) were placed in a flask, and a crescent-shaped stirring rod with a stirring seal, a Liebig condenser with a receiver, a three-way cock, and a dropping funnel containing nonafluoro-1-butanesulfonic acid (manufactured by Tokyo Kasei Kogyo Co., Ltd.) were attached, and the flask was removed from the space with a nitrogen atmosphere. Dry nitrogen was introduced from the three-way cock, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.) set at 40°C, and nonafluoro-1-butanesulfonic acid was gradually dropped while stirring. After the dropping was completed, the dropping funnel and the three-way cock were removed, and a glass stopper was attached. At this time, the amount of nonafluoro-1-butanesulfonic acid introduced into the flask was 31.0 g (103 mmol). The oil bath was set to 90°C and the mixture was stirred for 1 hour, then the mixture was stirred for 20 minutes at 140°C and 10 kPaA. When the oil bath was set to 160°C, the distillate was gradually collected in the receiver. When the distillation slowed down, the pressure was gradually reduced to 2 kPaA. When it was confirmed that the distillation had stopped, the stirring was stopped. After replacing the flask with nitrogen, it was removed from the oil bath, the flow of the refrigerant in the Liebig condenser was stopped, the receiver was removed from the ethanol cooled with dry ice, and the temperature was returned to room temperature. The Liebig condenser was removed from the flask, the flask was sealed with a glass stopper, and the flask was moved to a space with a dry nitrogen atmosphere. The mass of the contents of the receiver was measured and found to be 24.9 g. The contents of the receiver (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed. 19 F-NMR analysis revealed that 23.8 g (40.9 mmol, yield 79.2%) of fluorine-containing sulfonic acid anhydride (2) was obtained. The contents of the flask were transferred to a dry nitrogen atmosphere and passed through a sieve with 11.2 mm openings, resulting in no material remaining on the sieve. In this example, β / α was 1.0 and ε / (γ+δ) was 1.5. [Industrial Applicability]

[0092] According to the production process of the present invention, solidification in the reaction of fluorinated sulfonic acid (1) with diphosphorus pentoxide can be suppressed and fluorinated sulfonic anhydride (2) can be produced in good yield, and therefore the process can be suitably used in the production of raw materials that are useful as catalysts for medicines, organic synthesis, etc., or synthetic raw materials.

Claims

1. The following general formula (2): (R ｆ SO ２ ) ２ O (2) (In the formula, R ｆ is a saturated or unsaturated aliphatic hydrocarbon group, the hydrocarbon group being -CH ２ When the -CH 2 - has a structure, the -CH 2 - may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom, and all of the hydrogen atoms of the hydrocarbon group other than the hydrogen atoms of the -CH 2 - that has been substituted are substituted with fluorine atoms, and R ｆ has 1 to 20 carbon atoms, and two R ｆ They may be the same or different) The present invention relates to a method for producing a fluorine-containing sulfonic acid anhydride (2) represented by the following formula: The following general formula (1): R ｆ SO ３ H (1) (In the formula, R ｆ is a saturated or unsaturated aliphatic hydrocarbon group, the hydrocarbon group being -CH ２ When the -CH 2 - has a structure, the -CH 2 - may be substituted with a structure having an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom, and all of the hydrogen atoms of the hydrocarbon group other than the hydrogen atoms of the -CH 2 - that has been substituted are substituted with fluorine atoms, and R ｆ has 1 to 20 carbon atoms. A fluorine-containing sulfonic acid (1) represented by the formula: Diphosphorus pentaoxide and React in the presence of silica, the ratio (ε / (γ+δ)) of the mass (ε) of the silica to the total mass (γ+δ) of the mass (γ) of the fluorine-containing sulfonic acid (1) and the mass (δ) of the diphosphorus pentoxide is 0.1 to 100; A manufacturing method comprising:

2. 2. The process according to claim 1, wherein a ratio (β / α) of the amount of substance (β) of said diphosphorus pentoxide to the amount of substance (α) of said fluorine-containing sulfonic acid (1) is 0.1 to 100.

3. The method according to claim 1 or 2, wherein the reaction temperature is from -40 to 300°C.

4. The method according to any one of claims 1 to 3, wherein the silica has a silicon dioxide content of 50 mass% or more.

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