JP2007176904A - Method for producing iodonium salt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably producing a diaryl iodonium salt having high purity and useful as an acid generator and a radical generator in high yield. <P>SOLUTION: The production method comprises the mixing of a compound having N-O group in the molecule with an iodoaryl compound and a peracid and thereafter the addition of an aromatic compound to the mixture. Preferably, an acid is added together with the aromatic compound. A compound having electron-donating substituent can be used as a substitute for the aromatic compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel method for producing an iodonium salt that is useful as a radical polymerization initiator, an acid generator, and a cationic polymerization initiator.

Conventionally, as a negative photosensitive lithographic printing plate, a PS plate having a configuration in which an oleophilic photosensitive resin composition is provided on a hydrophilic support is widely used, and the plate making method is usually through a lithographic film. After the mask exposure, the desired printing plate was obtained by dissolving and removing the non-image area with alkaline water or the like.
In recent years, digitization technology that electronically processes, stores, and outputs image information using a computer or the like has become widespread, and even in the plate making method of a lithographic printing plate, using laser light, without a lithographic film, A CTP technique for directly producing a printing plate is established, and a chemically amplified negative CTP printing plate that generates an acid by light or heat by exposure and causes the crosslinking reaction by using the acid as a catalyst (see, for example, Patent Document 1). ), Or negative CTP printing plates (see, for example, Patent Document 2) in which radicals are generated by heat or light and the radicals are used as a catalyst have been developed.
In recent years, in the development of the semiconductor field, the light source of the irradiation apparatus used for fine processing, especially lithography, has become shorter and shorter with the increase in the density of semiconductor elements. 2. Description of the Related Art Chemically amplified resist compositions that contain an acid generator in a product, generate an acid from the acid generator by exposure, and form an image with the acid have come to be used generally. As acid generators used in chemically amplified resist compositions, sulfonium salts, iodonium salts, diazodisulfone compounds and the like have been studied.
These onium salts useful as acid generators, such as sulfonium salts, iodonium salts, and diazonium salts, are also used as cationic polymerization initiators.

As described above, onium salts such as iodonium salts, diazonium salts, and sulfonium salts are widely used as acid generators for CTP, radical generators, and acid generators for resist compositions. Among these, as acid generators and radical generators, iodonium salts excellent in the balance between stability and reactivity, particularly diaryl iodonium salts, are preferred and have recently been attracting attention. The known methods are concerned with safety, such as using peracetic acid, using nitric acid or sulfuric acid in excess, or using a large amount as a solvent. In such a production method, although many synthesis examples such as alkyl-substituted diaryl iodonium salts are seen, the present inventors have focused on a synthesis method relating to electron donating iodonium salts and bis (alkoxyphenyl) iodonium salts. Have not been studied much, and as such a technique, a method using lead organostannate and dicyanoiodonium (see, for example, Non-Patent Document 1), acetic acid, acetic anhydride, sulfuric acid and sodium periodate are used. Only the method to be used (for example, see Non-Patent Document 2) is known. In addition, in the case of a synthesis reaction using peracetic acid, there was a problem in that during the synthesis of the intermediate iodoaryl diacetate, the purity of the diaryliodonium salt was reduced due to heat generation during the peracetic acid reaction and side reactions accompanying the heat generation. . In addition, the current situation is that little is known about a method for producing an iodonium salt having an electron-donating group in addition to a bis (alkoxyphenyl) iodonium salt.
Japanese Patent Laid-Open No. 7-20629 JP 2001-343742 A Tetrahedron Letter, (1992) P1419-1422. J. et al. A. C. S. (1953), P2705

  An object of the present invention made in consideration of the above problems is to provide a diaryl iodonium salt useful as an acid generator and a radical generator, which can be produced stably and in a high yield. It is providing the manufacturing method of an iodonium salt.

As a result of intensive studies, the present inventor can suppress side reactions and heat generation by using a compound having an N—O bond in the molecule in a method for producing an iodonium salt in which a peracid is allowed to act on an iodoaryl compound. As a result, it was found that a high-purity diaryliodonium salt could be produced, and the present invention was completed.
That is, the method for producing a diaryl iodonium salt of the present invention is characterized in that a compound having an N—O bond in the molecule, an iodoaryl compound and a peracid are mixed, and then an aromatic compound is added.

In the general formula (I), R ¹ and R ² each independently represents an organic group.
R ¹ and R ² are preferably an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and R ¹ and R ² may be bonded to each other to form a ring.
R ¹ and R ² are preferably an alkyl group or a cyclic structure in which R ¹ and R ² are bonded from the viewpoint of the effect of stabilizing the reaction.

More specifically, as a production method of the present invention, an iodoaryl compound is allowed to act with a peracid in a solvent containing the compound having the N—O bond, and then an aromatic compound is added, and an acid or its It is preferable to carry out a step of adding a salt.
In addition, by using a compound having an electron-donating substituent as the starting aromatic compound, a symmetric or asymmetrical diaryliodonium salt compound having an electron-donating group at an arbitrary position can be obtained.

  In the production method of the present invention, when an iodoaryl compound is allowed to act with a peracid, introduction of a compound having an N—O bond in the molecule into the system suppresses generation of heat and the accompanying byproducts. Although the mechanism of action is not clear, when reacting a peracid with an iodoaryl compound, the compound traps excessive radicals generated by the decomposition of the peracid, thereby suppressing side reactions, and It is considered that exothermicity can be suppressed, and further, the promotion of side reactions caused by the exotherm is also suppressed, leading to further improvement in the purity of the resulting diaryliodonium salt.

  ADVANTAGE OF THE INVENTION According to this invention, the highly purified diaryliodonium salt useful as an acid generator and a radical generator can be manufactured stably and with a high yield. In addition, according to the production method of the present invention, it is possible to easily produce a symmetric or asymmetric diaryliodonium salt, a diaryliodonium salt having an electron donating group, and the like by selecting a raw material. .

Hereinafter, the present invention will be described in detail.
In the production method of the present invention, first, (1) a compound having an N—O bond, an iodoaryl compound, and a peracid are mixed to cause a peracid to act on the iodoaryl compound, whereby an iodoaryl that is an intermediate. A diacetate is obtained, then (2) an aromatic compound is added, and the iodoaryl diacetate and the aromatic compound are coupled to obtain a diaryl iodonium salt compound.
Therefore, a symmetric or asymmetric diaryl iodonium salt compound can be obtained by appropriately selecting an iodoaryl compound as a raw material and an aromatic compound to be coupled.
Further, in the present invention, (1) in the step of reacting the iodoaryl compound with a peracid, the compound having an amino group and a carboxylic acid group is allowed to coexist in the molecule to react the iodoaryl compound with the peracid. It is possible to suppress the side reaction and heat generation of this, and it is possible to produce a high-purity diaryliodonium salt.
In addition, it is also possible to introduce a desired anion into the diaryliodonium salt by adding an acid or a salt thereof during or after the coupling reaction of the diaryliodonium salt of the present invention.

<Compound with N—O bond in molecule>
The compound having an N—O bond in the molecule used in the present invention can be used as long as it is a compound having an N—O structure in the molecule. As the compound suitably used in the present invention, The compound represented by the following general formula (I) is mentioned.

R ¹ and R ² represent an organic group independent of each other.
R ¹ and R ² preferably include an alkyl group, an alkenyl group, an alkynyl group, and an aryl group, and R ¹ and R ² may be bonded to each other to form a ring.
Also, if the R ^1, R ² has a substituent group, respectively, it is possible to introduce a substituent having 1 or more functional groups shown below. Substitutable functional groups include alkyl groups, cycloalkyl groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, aryl groups, alkoxy groups, aryloxy groups, halogen atoms, hydroxyl groups, amide groups, sulfo groups, haloalkyl groups, amino groups, A thiol group, a carboxyl group, an alkoxycarbonyl group, a urethane group, a urea group, a thioalkoxy group, an alkylcarbonyl group, an arylcarbonyl group, and a nitro group.
Preferred substituents include a hydroxyl group and an alkyl group.
R ¹ and R ² are preferably alkyl groups from the viewpoint of the effect of stabilizing the reaction, and R ¹ and R ² are alkyl groups, which are 5-membered or 6-membered hydrocarbons bonded to each other. An embodiment in which a cyclic structure is formed is also preferred.
Further, it is also preferable to introduce a substituent such as an alkyl group, a cycloalkyl group, a hydroxyl group, an amide group, a sulfo group, an amino group, a carboxyl group, or a heterocyclic group into such a cyclic structure.
In addition, when R ¹ and R ² are bonded to form a ring, it is possible to form a ring containing a heteroatom such as N, S, or O as a component of the ring. The heteroatom can also have an ionic structure.

  Preferred specific examples of the compound having an N—O bond in the molecule that can be used in the present invention are shown below, but the present invention is not limited thereto.

  Compounds having an N—O bond that can be suitably used in the present invention are commercially available from, for example, Aldrich, Wako Pure Chemical Industries, Tokyo Chemical Industry, and the like.

  The preferable addition amount of the compound having an N—O bond in the production method of the present invention is 0.001 mol% or more, preferably 0.01 mol% to 1000 mol% with respect to the iodoaryl compound as a starting material. More preferably, it is in the range of 0.05 mol% to 100 mol%.

<Iodoaryl compound>
In the present invention, an iodoaryl compound that can be used as a starting material when producing a diaryliodonium salt includes iodobenzene; an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom. , Iodobenzene substituted with 1 to 5 substituents selected from a hydroxyl group, an amide group, a sulfo group, a haloalkyl group, and an amino group. When the iodobenzene having the substituent has a plurality of substituents, the substituents may be the same or different from each other.
Further, as other iodoaryl compounds, compounds such as iodonaphthalene, iodoanthracene, iodophenanthrene, and derivatives thereof, specifically, compounds in which the above-described substituents are introduced into these compounds can be used. Examples of such compounds.

<Peracid>
As the peracid that can be used in the present invention, any peracid having an —O—O— bond can be used. However, peracetic acid, perbenzoic acid, performic acid, monoperphthalic acid, permaleic acid, peroxanic acid, peroxyacid, Examples thereof include succinic acid, perglutaric acid, peradipic acid, pertrifluoroacetic acid, perchloroacetic acid, and hydrogen peroxide.
From the viewpoint of availability and handling, hydrogen peroxide water and peracetic acid are preferable.
In the present invention, first, the iodoaryl compound and peracid are mixed to produce an intermediate iodoaryl diacetate. From the viewpoint of reactivity and safety, the amount of peracid added is iodoaryl. It is preferable that it is about 10 mol%-10000 mol% with respect to a compound, More preferably, it is about 100 mol%-about 1000 mol%.

<Solvent>
As the solvent that can be suitably used in the present invention, any aryliodide compound and peracid can be used without particular limitation as long as it can dissolve the peracid, but the carboxylic acid can be dissolved or mixed with the carboxylic acid to form a uniform solvent. It is preferable to select one. Examples of the solvent that can be suitably used in the present invention include dichloromethane, dichloroethane, chloroform, acetonitrile, acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, dimethylacetamide, N-methylpyrrolidone, diethyl ether, tetrahydrofuran, 1,2- Dimethoxyethane, diisopropyl ether, butyl methyl ether, sec-butyl methyl ether, butyl ethyl ether, t-butyl methyl ether, 2-methoxyethyl ether, diethylene glycol diethyl ether, diethoxymethane, 2-methyltetrahydrofuran, 2,5-dimethyl Tetrahydrofuran, 2,2,5,5, -tetramethyltetrahydrofuran, tetrahydropyran, 3-methyltetrahydropyran, di Hexane, ethyl acetate, butyl acetate, acetic acid, propionic acid, acetic anhydride, toluene, anisole and xylene.
Preferably, a combination of acetic acid is preferable when peracetic acid is used, and a combination of acetic anhydride is preferable when hydrogen peroxide is used, but a combination of peracetic acid / acetic acid is preferable from the viewpoint of safety.

The reaction temperature when the iodoaryl compound and peracid are reacted in the presence of a compound having an N—O bond in the molecule may be equal to or higher than the melting point of the solvent used, but from the viewpoint of reactivity and safety. The reaction time is preferably in the range from 0 ° C. to 200 hours, more preferably after the completion of the reactant mixing. (0 hours) to 50 hours.
In the production method of the present invention, first, a compound having an N—O bond in the molecule, an aryliodonium compound, and a peracid are mixed and reacted to form an iodoaryl diacetate. An aromatic compound is coupled to the body to obtain the desired diaryliodonium salt.

<Aromatic compounds>
Since the aromatic compound that can be used in the present invention is used for iodonium chlorination, it can be used as long as it has at least one hydrogen atom on the aromatic group, more specifically, aromatic. Substitutable aromatic hydrocarbons such as benzene, naphthalene, anthracene, phenanthrene, etc. having one hydrogen atom on the group, or substituting indole, thiazole, tetrazole, thiophene, benzophenone, benzothiophene, pyridine, pyrimidine, triazine, etc. An aromatic compound having a hetero atom can be mentioned. Here, the functional groups that can be substituted include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkoxy groups, aryloxy groups, halogen atoms, hydroxyl groups, amide groups, sulfo groups, haloalkyl groups, amino groups, thiol groups, carboxyls. Group, an alkoxycarbonyl group, a urethane group, a urea group, a thioalkoxy group, an alkylcarbonyl group, an arylcarbonyl group, and a nitro group, and may be substituted by 1 to 5 by these substituents. When the aromatic compound has a plurality of substituents, these substituents may be the same or different from each other.
Among these, a benzene compound having a substituent is preferable from the viewpoint of stability and production suitability of the coupling body, and an aromatic compound substituted with an alkoxy group is particularly preferable from the viewpoint of stability.

As such an aromatic compound, it is preferable to use a compound into which an electron-donating substituent is introduced from the viewpoint of improving characteristics as a radical initiator and an acid generator of the resulting diaryl iodonium salt. That is, by introducing an electron donating group into the iodonium salt, decomposition of the iodonium salt with water or anion, or decomposition over time due to nucleophilic species is suppressed, discoloration over time associated with decomposition, dark polymerization, etc. Is thought to be suppressed.
The electron donating group that can be introduced into the aromatic compound is preferably an alkyl group, an alkoxy group, an amino group, a urea group, an alkoxyalkyl group, an acyloxyamino group, a cycloalkyl group, or an allyl group. A substituent such as an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, a thiol group, a thioalkoxy group, an amino group, or a halogen atom may be included as long as the electron donating property is not lost.
Among these, particularly preferable electron donating groups include an alkyl group and an alkoxy group, and the most preferable substituent is an alkoxy group.
Preferable specific examples of the electron donating group include an alkyl group having 1 to 20 carbon atoms, such as a methyl group, an n-butyl group, a t-butyl group, an n-octyl group, and a dodecyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a butoxy group, a heteroxy group, an octyloxy group, a dodecyloxy group, and a cyclohexyl group.

When the aromatic compound has a plurality of electron donating groups, they may be the same or different from each other.
As the number of electron-donating groups substituted, the resulting diaryl iodonium salt preferably has 2 or more electron-donating groups, more preferably 3 or more, and most preferably 4 substituted.
The electron donating group introduced into the aromatic compound is introduced into the aryl group of the iodonium salt that is the target substance, and preferred substitution positions include the para position and the ortho position. One or more electron-donating groups may be introduced into both of the two aryl groups in the iodonium salt, or two or more electron-donating groups may be introduced into only one of them.
If the standard as a physical property value in introducing the electron donating group is given, it is preferable that the sum of Hammett values of substituents (electron donating groups introduced into the aryl group) is −0.27 or less, -0.54 or less is more preferable, and -0.84 or less is most preferable.
The Hammett value represents the degree of electron withdrawing of the substituent in the diaryliodonium salt obtained by the production method of the present invention. As the Hammett value in the present invention, the Chemical Society of Japan, Chemical Handbook, Basic II ( 1984, published by Maruzen Co., Ltd.). Note that the Hammett value is usually calculated based on the substitution position at the m-th and p-th values, but as an electronic effect, the o-th value may be calculated as the same value as the p-th value.

  The addition amount of the aromatic compound is preferably 50 mol% or more with respect to the iodoaryl compound from the viewpoint of production suitability and yield, more preferably 100 to 1000 mol%, and more preferably 100 to 500 mol%. Most preferably, it is mol%.

<Acid>
In the method of the present invention, an iodoaryl compound is allowed to act with a peracid in a solvent containing a compound having an N—O bond in the molecule, and then an acid or a salt thereof is added together with the aromatic compound. it can.
Examples of the acid that can be used in this step include alkylsulfonic acid, arylsulfonic acid, phosphoric acid, phosphate ester having at least one acid group, sulfinic acid, sulfuric acid, monosulfate ester, nitric acid, hydrogen halide, periodate Examples include acids, perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, halogen-substituted carboxylic acids, hexafluoroantimony, and salts thereof. Other acids include organoboron compounds such as tetraarylborate, phosphorus compounds, silyl compounds, and the like.

As preferred acids that can be used in the present invention, arylsulfonic acid such as para-toluenesulfonic acid, perfluoroalkanesulfonic acid such as trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid, etc., from the viewpoint of reactivity and iodonium salt removability , Tetrafluoroboric acid, hexafluorophosphoric acid and the like.
The addition amount of the acid is preferably 100 mol% or more with respect to the iodoaryl compound from the viewpoint of production suitability, more preferably 100 to 1000 mol%, and preferably 100 to 200 mol%. Most preferred.

In this step, when the intermediate and the aromatic compound are subjected to a coupling reaction, it is possible to react by adding a solvent so that the reaction can be easily controlled.
The solvent that can be added is preferably a solvent that can be mixed with the solvent used in the reaction of the iodoaryl compound and peracid, and is dichloromethane, dichloroethane, chloroform, acetonitrile, acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, dimethyl. Acetamide, N-methylpyrrolidone, diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane, diisopropyl ether, butyl methyl ether, sec-butyl methyl ether, butyl ethyl ether, t-butyl methyl ether, 2-methoxyethyl ether, diethylene glycol diethyl Ether, diethoxymethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 2,2,5,5, -tetramethyltetrahydro Orchids, tetrahydropyran, 3-methyltetrahydropyran, dioxane, ethyl acetate, butyl acetate, acetic acid, propionic acid, acetic anhydride, toluene, anisole and xylene. From the viewpoint of suppressing side reactions, non-aromatic solvents are preferable, and among them, acetonitrile is preferable from the viewpoint of handling and taking out products after the reaction.

  The reaction temperature for obtaining the desired diaryliodonium salt by coupling an aromatic compound to this intermediate may be at least the melting point of the solvent to be used, but from the viewpoint of reactivity-safety, preferably -78. The reaction time is preferably immediately after mixing (0 hour) to 100 hours, more preferably from (0 hour) to 48 hours from the viewpoint of productivity. It is a range.

The iodonium salt obtained by the method of the present invention can be converted to a desired salt structure by performing salt exchange by the method described in WO02 / 081439.
Specific examples of iodonium salts (diaryl iodonium salts) that can be obtained by the production method of the present invention and subsequent known salt exchange formulations are given below, but the compounds obtained by the production method of the present invention are limited to the following iodonium salts. I don't mean.

  According to the production method of the present invention, a diaryliodonium salt useful as an acid generator and a radical generator, in particular, an electron-donating diaryliodonium salt that has not been studied in the past can be produced in a high yield. And it has the advantage that it is excellent in manufacturing stability. Moreover, since side reactions are effectively suppressed, a diaryliodonium salt having an arbitrary structure can be easily produced by selecting raw materials.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
<Example 1>
6.62 g of octyloxyiodobenzene (iodoaryl compound) is dissolved in 20 ml of acetic acid and stirred. The temperature is maintained at 30 ° C., 0.20 g of the following compound (A) [compound having an N—O group in the molecule] is added thereto, and the mixture is stirred at room temperature for 10 minutes. Adjust the temperature to 30 ° C, slowly add 8.0 g of 38-39% peracetic acid / acetic acid solution over 1 hour, stir at 30 ° C-35 ° C for 6 hours, leave at room temperature for 12 hours, add 30 ml of acetonitrile dropwise. Cool to ice so that the internal temperature becomes 5 ° C. or less, add 3.20 g of 1,3,5-trimethoxybenzene (aromatic compound), and dissolve 3.62 g of paratoluenesulfonic acid in 50 ml of acetonitrile. And dropped.

  Thereafter, the mixture was stirred at 5 ° C. or lower for 2 hours, then poured into 500 ml of ice water, extracted with 500 ml of dichloromethane, and the aqueous layer was further extracted with 200 ml of dichloromethane. The organic layer is washed with an aqueous solution in which 75.6 g of sodium sulfite is dissolved in 500 ml of water, and the organic layer is further washed twice with 300 ml of water. The organic layer was concentrated until the solvent amount became 1/10, 100 ml of ethyl acetate was added, the mixture was concentrated again, and allowed to stand to give 6.98 g of the following iodonium salt [Compound (I-35)] (yield: 52 %). The HPLC purity was 98.5%.

The structure of the obtained diaryl iodonium salt (I-35) was confirmed by NMR.
NMR 400 MHz CDCl ₃ 0.879 (m, 3H); 1.275-1.299 (m, 8H); 1.350-1.420 (m, 2H); 1.777 (m, 2H); 321 (s, 3H); 3.853 (s, 3H); 3.880 (s, 3H); 3.900 (q, 2H); 6.146 (s, 2H); 6.780 (d, 2H) , J = 8.8); 7.093 (d, 2H, J = 8.0); 7.701 (d, 2H, J = 8.0); 7.785 (d, 2H, J = 8. 8)

<Comparative Example 1>
In Example 1, when the reaction was carried out without adding the compound (A), which is a compound having an N—O group in the molecule, the same iodonium salt (I-35) as in Example 1 was found to be 6. Obtained in 10 g (yield: 46%). The HPLC purity was 90.7%.

<Example 2>
In Example 1, the compound (A) is a compound having 4-octoxyoxyiodobenzene in 4-butoxyiodobenzene, 1,3,5-trimethoxybenzene in butoxyiodobenzene, and an N—O group in the molecule. ) Was changed to 1.00 g of the following compound (B) and p-toluenesulfonic acid was changed to nonafluorobutanesulfonic acid, and the following iodonium salt (I-32) was obtained in a yield of 60%. The HPLC purity was 97.0%.

The structure of the obtained diaryl iodonium salt (I-32) was confirmed by NMR.
NMR 400 MHz CDCl ₃ 0.956 (t, 6H, J = 7.6); 1.659 (m, 4H); 1.756 (m, 4H); 3.941 (t, 4H, J = 6.8) ); 6.890 (d, 4H, J = 5.2); 7.879 (d, 4H, J = 5.2)

<Comparative example 2>
In Example 2, the reaction was carried out without adding the compound (B), which is a compound having an N—O group in the molecule. As a result, the same iodonium salt (I-32) as in Example 2 was collected. Obtained at a rate of 53%. The HPLC purity was 89.9%.

<Example 3>
In Example 1, the reaction was carried out by changing 4-octyloxyiodobenzene to iodobenzene and changing the compound (A), which is a compound having an N—O group in the molecule, to the following compound (C). The iodonium salt (I-25) was obtained with a yield of 58%. The HPLC purity was 98.2%.

The structure of the obtained diaryl iodonium salt (I-25) was confirmed by NMR.
NMR 400 MHz CDCl ₃ 2.327 (s, 3H); 3.873 (s, 9H); 6.712 (s, 2H); 7.108 (d, 2H, J = 8.0); 7.313 ( m, 2H); 7.460 (t, 1H, J = 7.6); 7.727 (d, 2H, J = 8.0); 7.870 (m, 2H)

<Comparative Example 3>
When the reaction was carried out without adding the compound (C), which is a compound having an N—O group in the molecule, in Example 3, the same iodonium salt (I-25) as in Example 3 was used. Was obtained in a yield of 57%. The HPLC purity was 91.1%.

<Example 4>
6.62 g of octyloxyiodobenzene (iodoaryl compound) is dissolved in 20 ml of acetic acid and stirred. The temperature is maintained at 30 ° C., and 0.20 g of the compound (A) which is a compound having an N—O group in the molecule is added thereto, followed by stirring at room temperature for 10 minutes. Adjust the temperature to 30 ° C, slowly add 8.0g of 38-39% peracetic acid / acetic acid solution over 1 hour, stir at 30 ° C-35 ° C for 6 hours, then leave at room temperature for 12 hours, internal temperature is 25 ° C Then, 3.20 g of 1,3,5-trimethoxybenzene, which is an aromatic compound, was slowly added, and further 3.62 g of paratoluenesulfonic acid was slowly added. Thereafter, the mixture was stirred at 20 ° C. or lower for 2 hours, then poured into 500 ml of ice water, extracted with 500 ml of dichloromethane, and the aqueous layer was further extracted with 200 ml of dichloromethane. The organic layer is washed with an aqueous solution in which 75.6 g of sodium sulfite is dissolved in 500 ml of water, and the organic layer is further washed twice with 300 ml of water. The organic layer was concentrated until the amount of the solvent became 1/10, 100 ml of ethyl acetate was added, the mixture was concentrated again, and allowed to stand to obtain 6.91 g (yield: 52%) of the following iodonium salt (I-33). It was. The HPLC purity was 98.3%.

  As is clear from the above examples, the production method of the present invention shows that the desired diaryliodonium salt can be obtained with high purity and high yield. Further, in contrast to Examples 1 to 4 and Comparative Examples 1 to 3 which differ only in that no compound having an N—O compound was used, this compound was allowed to coexist during the reaction of the iodoaryl compound and the peracid. Thus, it was confirmed that the purity and yield of the obtained target substance were improved.

<Example 5>
Keep 20 ml of acetic anhydride at 30 ° C., add 5 g of 30% hydrogen peroxide solution dropwise, stir at 30 ° C. to 35 ° C. for 5 hours, and add the compound (A) which is a compound having an N—O group in the molecule. 0.25 g is added, the temperature is adjusted to 10 ° C., and 6.62 g of octyloxyiodobenzene (iodoaryl compound) is added dropwise. After stirring at 10-15 ° C. for 6 hours, left at room temperature for 12 hours, 30 ml of acetonitrile was added dropwise, and the mixture was cooled with ice so that the internal temperature was 5 ° C. or less, and 1,3,5-trimethoxybenzene (aromatic compound) 3.20 g was added, and 3.62 g of paratoluenesulfonic acid was dissolved in 50 ml of acetonitrile and added dropwise. Thereafter, the mixture was stirred at 5 ° C. or lower for 2 hours, then poured into 500 ml of ice water, extracted with 500 ml of dichloromethane, and the aqueous layer was further extracted with 200 ml of dichloromethane.
The organic layer is washed with an aqueous solution in which 75.6 g of sodium sulfite is dissolved in 500 ml of water, and the organic layer is further washed twice with 300 ml of water. The organic layer was concentrated until the amount of the solvent became 1/10, 100 ml of ethyl acetate was added, and the mixture was concentrated again and allowed to stand, whereby the same iodonium salt (I-35) as obtained in Example 1 was obtained. Obtained in 7.01 g (yield: 53%). The HPLC purity was 98.4%.

<Comparative example 4>
In Example 5, the reaction was carried out without adding the compound (A), which is a compound having an N—O group in the molecule. 6.85 g (yield 52%) of iodonium salt (I-35) similar to that obtained in Example 1 was obtained. The HPLC purity was 89.6%.

<Example 6>
In Example 5, when the reaction was carried out by changing the compound (A), which is a compound having an N—O group in the molecule, to the following compound (D), the same iodonium salt as obtained in Example 1 was used. (I-35) was obtained in a yield of 7.45 g (57%). The HPLC purity was 98.6%.

<Example 7>
6.62 g of octyloxyiodobenzene (iodoaryl compound) is dissolved in 20 ml of acetic acid and stirred. The temperature is maintained at 20 ° C., and 0.25 g of the compound (A) is added thereto, followed by stirring at room temperature for 10 minutes. The temperature was adjusted to 20 ° C., 6.90 g of mCPBA (3-chloroperoxybenzoic acid) was slowly added, stirred at 25 ° C. to 30 ° C. for 6 hours, allowed to stand at room temperature for 12 hours, and 30 ml of acetonitrile was dropped. Cool to ice so that the internal temperature is 5 ° C. or less, add 3.20 g of 1,3,5-trimethoxybenzene (aromatic compound), and dissolve 3.62 g of paratoluenesulfonic acid in 50 ml of acetonitrile. It was dripped. Thereafter, the mixture was stirred at 5 ° C. or lower for 2 hours, then poured into 500 ml of ice water, extracted with 500 ml of dichloromethane, and the aqueous layer was further extracted with 200 ml of dichloromethane. The organic layer is washed with an aqueous solution in which 75.6 g of sodium sulfite is dissolved in 500 ml of water, and the organic layer is further washed twice with 300 ml of water. The organic layer was concentrated until the amount of the solvent became 1/10, 100 ml of ethyl acetate was added, the mixture was concentrated again, and the mixture was allowed to stand to give the following iodonium salt (I-35) similar to that obtained in Example 1. 6.86 g (yield: 51%) was obtained. The HPLC purity was 98.3%.

<Example 8>
In the production method of the present invention, anions can be exchanged as necessary.
1.5 g of the iodonium salt (I-35) obtained in Example 1 was dissolved in 8 ml of methanol, added dropwise to 50 ml of 0.5N KPF ₆ water, the resulting solid was filtered and dried, and the following iodonium salt (I- 36) 1.3 g (yield: 90.0%) was obtained.

Thus, it can be seen that the excellent effects of the present invention can be obtained even when the compound having an N—O group, a peracid, or an aromatic compound is changed in the molecule to be used.
Further, in the comparison between Example 1 and Example 5, when a compound having an N—O group in the molecule was previously dissolved in a solvent, and then an iodoaryl compound and a peracid were added, and an iodoaryl compound It can be seen that the effects of the present invention can be obtained in any case where a compound having an N—O group in the molecule is added dropwise after mixing the peroxyacid and the peracid.
Furthermore, in Example 8, it can be seen that the iodonium salt obtained by the production method of the present invention is subjected to salt exchange, and an iodonium salt compound having a desired anion structure can be obtained in high yield.

Claims (4)

  A method for producing a diaryl iodonium salt, comprising mixing a compound having an N—O group in a molecule, an iodoaryl compound and a peracid, and then adding an aromatic compound. The method for producing a diaryliodonium salt according to claim 1, wherein the compound having an N-O group in the molecule has a structure represented by the following general formula (I).

R ¹ and R ² each independently represents an organic group. R ¹ and R ² may be bonded to each other to form a ring.   2. An aromatic compound is added after an iodoaryl compound is allowed to act with a peracid in a solvent containing a compound having an N—O group in the molecule, and an acid or a salt thereof is further added. Or the manufacturing method of the diaryl iodonium salt of Claim 2.   The manufacturing method according to any one of claims 1 to 3, wherein the aromatic compound is a compound having an electron-donating substituent.