JP2007112783A - Method for producing diaryl iodonium salt and the resultant diaryl iodonium salt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for safely producing in high stability a diaryl iodonium salt useful as an acid generator and a radical generator, and to provide such a new diaryl iodonium salt. <P>SOLUTION: The method comprises the following process. An iodoaryl compound is made to react with an alkali metal perboronate in a carboxylic acid-containing solvent followed by adding an aromatic compound and an acid to the system, wherein, as the aromatic compound, a compound having electron-donating substituent(s) can be used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

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 such techniques include methods using organotin stannate and cyanoiodonium (see, for example, Non-Patent Document 1), acetic acid, acetic anhydride, sulfuric acid, and sodium periodate. There is only known a method of using (for example, see Non-Patent Document 2). However, these methods also use a reagent that is difficult to handle, such as peracetic acid, and there is concern about the production stability. 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, which has been made in view of the above problems, is to provide a safe and stable production method of diaryliodonium salts useful as acid generators and radical generators.
Another object of the present invention is to provide a novel diaryliodonium salt.

In the method for producing a diaryl iodonium salt according to claim 1 of the present invention, first, an iodoaryl compound is allowed to act with an alkali metal perborate in a solvent containing a carboxylic acid, and then an aromatic compound and an acid are reacted. It is characterized by adding.
By using a compound having an electron-donating substituent as the aromatic compound used here, a diaryliodonium salt having an electron-donating group excellent in stability and reactivity can be easily produced.
After reacting the iodoaryl compound with an alkali metal perborate in a solvent containing a carboxylic acid, a solvent may be further added before adding the aromatic compound and the acid.
As the carboxylic acid contained in the solvent, an alkyl carboxylic acid is preferably mentioned.

  In the method for producing a diaryl iodonium salt according to claim 5 of the present invention, an iodoaryl compound is allowed to react with an alkali metal perborate in a solvent containing a carboxylic acid, and then the aromatic compound is directly added to the solvent. The diaryliodonium salt is produced in one step by adding an acid and optionally adding a solvent.

  The iodonium salt compound according to claim 6 of the present invention has a structure represented by the following general formula (I).

In the general formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group, an alkenyl group or an alkynyl group, and X ⁻ represents a monovalent anion structure.
The iodonium salt compound according to claim 7 of the present invention has a structure represented by the following general formula (II).

In the general formula (II), R ⁴ represents an alkyl group, an alkenyl group, or an alkynyl group, and X ⁻ represents a sulfonate anion or an inorganic anion structure.

ADVANTAGE OF THE INVENTION According to this invention, the safe and excellent manufacturing method of the diaryl iodonium salt useful as an acid generator and a radical generator can be provided. Furthermore, according to the present invention, a diaryliodonium salt can be produced safely and stably in one step.
In addition, according to the present invention, a novel diaryliodonium salt having an electron donating group as a substituent can be provided.

Hereinafter, the present invention will be described in detail.
The method for producing a diaryl iodonium salt according to the present invention is characterized in that an iodoaryl compound is reacted with an alkali metal perborate in a solvent containing a carboxylic acid, and then an aromatic compound and an acid are added.
According to the method for producing a diaryl iodonium salt of the present invention, an iodoaryl compound is allowed to react with an alkali metal perborate in a solvent containing a carboxylic acid, and then the aromatic compound, an acid is further added to the solvent as it is. The diaryliodonium salt can be produced in one step by adding a solvent if desired.
Hereinafter, the production method of the present invention will be described in the order of steps.

(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.
Of these, an iodoaryl compound having one or more substituted alkoxy groups is preferred from the viewpoint of the stability of the iodonium salt.

(Solvent containing carboxylic acid)
In the production method of the present invention, first, the iodoaryl compound is charged into a solvent containing a carboxylic acid, but the solvent herein may be a solvent composed of a carboxylic acid, and the carboxylic acid is water, It may be a solvent dissolved and dispersed in a suitable solvent such as an organic solvent.
The carboxylic acid contained in the solvent is not particularly limited as long as it is an acid compound having a carboxy group, and can be arbitrarily selected from the group consisting of alkyl carboxylic acid, aryl carboxylic acid, alkenyl carboxylic acid and the like. In view of the fact that it is used as a reaction solvent by itself or mixed, dissolved and dispersed uniformly with other solvents, it can be converted into a liquid at 20 to 100 ° C. preferable.

Specific examples of the carboxylic acid that can be used include alkyl, aryl, and alkenyl carboxylic acids such as acetic acid, propionic acid, butanoic acid, valeric acid, lauric acid, methacrylic acid, cyclopentanecarboxylic acid, and cyclohexanecarboxylic acid. Is mentioned. Of these, alkylcarboxylic acids such as acetic acid and propionic acid are preferable from the viewpoint of the production suitability of the diaryl iodonium salt obtained.
These carboxylic acids may have a substituent such as a halogen atom, a hydroxyl group, an alkoxy group, an alkyl group, an alkenyl group, or an alkynyl group.
When a liquid carboxylic acid is used and the solvent is composed of carboxylic acid alone, the solvent may contain only one carboxylic acid, or two or more carboxylic acids may be used in combination.

Any solvent that can be mixed with carboxylic acid can be used as a solvent used when carboxylic acid is mixed with another solvent to form a solvent. Examples of the solvent that can be 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-dimethyltetrahydrofuran, 2,2,5,5, -tetramethyltetrahydrofuran, tetrahydropyran, 3-methyltetrahydropyran, dioxa , Ethyl acetate, butyl acetate, acetic acid, propionic acid, toluene, methanol, ethanol, and water.
Of these, acetonitrile, dichloromethane, and the like are preferable from the viewpoint of easy reaction and subsequent salt removal.
Two or more kinds of solvents used in a mixture with carboxylic acid can be used in combination as long as they do not inhibit the reaction.
When mixing a carboxylic acid and the said solvent to make a solvent, the density | concentration of the carboxylic acid in a solvent becomes like this. Preferably it is 30-99 mass%.
Further, the content of the carboxylic acid in the solvent is preferably 200 mol% or more, more preferably 200 to 20000 mol%, more preferably 500 to 15000, based on the iodoaryl compound. Most preferably, it is mol%.

(Alkali metal perborate)
In the production method of the present invention, an iodoaryl compound and an alkali metal perborate are allowed to act by adding an iodoaryl compound into the solvent and adding an alkali metal perborate thereto. The alkali metal perborate that can be used in the present invention can be used as long as it is an alkali metal salt, but a sodium salt is preferred from the viewpoint of availability and handling.
In the present invention, sodium perborate or a hydrate thereof can be used. From the viewpoint of safety, monohydrate is preferable, and tetrahydrate is more preferable.

In the present invention, the alkali metal perborate is preferably used in an amount of 2 equivalents or more with respect to the iodoaryl compound, more preferably 3 equivalents to 30 equivalents, and even more preferably 4 equivalents to 20 equivalents.
The reaction temperature when the iodoaryl compound is allowed to react with the alkali metal perborate may be equal to or higher than the melting point of the solvent used, but is preferably 0 ° C. to 80 ° C., more preferably from the viewpoint of reactivity and suppression of side reactions. Is in the range of 25 ° C to 60 ° C, more preferably 35 ° C to 55 ° C.

(acid)
Next, an aromatic compound and an acid are further added and reacted in this solvent. The acid that can be used at this time includes at least one alkylsulfonic acid, arylsulfonic acid, phosphoric acid, and acid group. Phosphate ester, sulfinic acid, sulfuric acid, monosulfate ester, nitric acid, hydrogen halide, periodic acid, perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, halogen-substituted carboxylic acid, hexafluoroantimony, or salts thereof Can be used. 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 500 mol%, and 100 to 200 mol%. Most preferred.

(Aromatic compounds)
Since the aromatic compound is used for iodonium chloride, any aromatic compound having at least one hydrogen atom on the aromatic group can be used. Aromatic compounds that can be used for this reaction include benzene, naphthalene, anthracene, phenanthrene, and the like. The aromatic compound is substituted with 1 to 5 substituents selected from an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, a hydroxyl group, an amide group, a sulfo group, a haloalkyl group, and an amino group. It may be. When the aromatic compound has a plurality of substituents, these substituents may be the same or different from each other.

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%.

  Here, the reaction temperature in the case of reacting the acid and the aromatic compound is not particularly limited as long as the reaction system can be stirred, but from the viewpoint of stability of the iodonium salt to be produced and control of the reaction, -20. It is preferable to make it react at -100 degreeC, More preferably, it is the range of -10 degreeC-50 degreeC.

In addition, before adding an aromatic compound and an acid and making these act, or when adding these, a solvent can be further added if desired. The solvent added here may be the same as the solvent used in the reaction, or may be different. From the viewpoint of side reaction inhibiting effect and take-out property, the solvent added here is preferably acetonitrile, dichloromethane, alcohol or the like. Thus, there is an advantage that the reaction can be controlled more easily by adding a solvent before the aromatic compound and acid are allowed to act.
The amount of the solvent added is preferably about 0 to 200% by weight with respect to the solvent containing carboxylic acid.

The production method of the present invention can be applied to the synthesis of an electron-donating iodonium salt, for which there are few reports on synthesis examples so far.
In the production method of the present invention, an iodoaryl compound is allowed to react with perboric acid in a solvent containing a carboxylic acid to form an iodo complex, and an aromatic compound and an acid are added thereto. An aryl compound and an aryl compound are coupled to obtain a diaryl iodonium salt in one step.
In the preferred form of this reaction, from the viewpoint of practicality, the reaction for reacting the iodoaryl compound with perboric acid is preferably carried out in acetic acid or propionic acid. In the subsequent iodonium chlorination reaction, sulfonic acid or hexafluorophosphoric acid is used. It is preferable to use it.

  The iodonium salt obtained by the production method of the present invention can be converted to a desired salt structure by performing salt exchange by a known method such as the method described in WO 02/081439.

According to the method for producing an iodonium salt of the present invention, a diaryl iodonium salt having an electron donating group as a substituent, which has been difficult to synthesize in a high yield by a conventionally known production method, can be easily produced.
Next, diaryliodonium salts to which the production method of the present invention can be suitably applied will be described.
The following iodonium salts [Exemplary compounds (I-1) to (I-35)] can be synthesized by the production method of the present invention and subsequent known salt exchange. However, the production method of the present invention is not limited to the synthesis of the following iodonium salts.

  According to the production method of the present invention, a diaryliodonium salt useful as an acid generator and a radical generator, particularly an electron-donating diaryliodonium salt that has not been studied in the past, an organic solvent having a safety problem in particular. Without being used, it can be produced using a general-purpose solvent or acid compound, and this method has the advantage of excellent production stability.

  As a result of investigations, the present inventors have found a novel compound in a diaryliodonium salt to which the production method of the present invention can be suitably applied. That is, the invention described in claims 6 to 7 of the present application relates to a novel diaryliodonium salt having a structure represented by the following general formula (I), more preferably the general formula (II).

In the general formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represents an alkyl group, an alkenyl group or an alkynyl group.
As the alkyl group when R ¹ , R ² , R ³ , or R ⁴ represents an alkyl group, the alkyl group having 1 to 20 carbon atoms, for example, a methyl group, an n-butyl group, a t-butyl group, an n- An octyl group, a cyclohexyl group, a dodecyl group, etc. are mentioned.
Examples of the alkenyl group in the case where R ¹ , R ² , R ³ , or R ⁴ represents an alkenyl group include alkenyl groups having 1 to 20 carbon atoms, such as an allyl group, a 3-butene group, and a 5-hexene group. It is done.
Examples of the alkynyl group in the case where R ¹ , R ² , R ³ , or R ⁴ represents an alkynyl group include an alkynyl group having 1 to 20 carbon atoms, such as a 2-butyne group and a 2-propyne group.
Among these, R ¹ , R ² , R ³ , or R ⁴ is preferably an alkyl group, more preferably R ¹ , R ² , and R ³ are methyl from the viewpoint of production suitability, stability, purification, and the like. It is preferable that R ⁴ is an alkyl group having 1 to 15 carbon atoms.

In the general formula (I), X ^- represents a monovalent anion structure. The anion structure here refers to the final anion structure after completion of salt exchange, which is carried out as desired.
The anion structure in the general formula (I) includes inorganic anion structures such as halogen ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion and sulfate anion, or paratoluenesulfonate anion and trifluoromethanesulfonate anion. Sulfonate anions such as nonafluorobutane sulfonate anion, naphthalene sulfonate anion, pentafluorobenzene sulfonate anion, 3,5-dimethoxycarbonylbenzene sulfonate anion, acetate anion, benzoate anion, trifluoroacetate anion, etc. Examples thereof include carboxylic acid anions, sulfate anions such as monomethyl sulfate anions, and sulfinate anions such as benzenesulfinic acid.
Among them, reactive, from the viewpoint of stability, X ^- is a sulfonate anion is preferably an inorganic anion.

In the general formula (II), R ⁴ represents an alkyl group, an alkenyl group, or an alkynyl group, and this is synonymous with R ⁴ in the general formula (I). Preferably, R ⁴ is a carbon atom. It is a C1-C15 alkyl group, More preferably, it is a C4-C12 alkyl group.
X ⁻ in the general formula (II) represents a sulfonate anion or an inorganic anion structure, and from the viewpoint of reactivity and stability, specifically, a hexafluorophosphate ion, a sulfonate anion having a fluoroalkyl group, an aromatic A sulfonate anion in which a sulfonate group is bonded to a group is preferred.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
[Example 1]
3.32 g of octyloxyiodobenzene is dissolved in 45 ml of acetic acid as a solvent, and heated and stirred at 40 ° C. To this, 15.4 g of perboric acid tetrahydrate was slowly added in 20 minutes, stirred at 40 ° C. to 45 ° C. for 6 hours, then allowed to stand at room temperature for 12 hours, and 30 ml of acetonitrile was added dropwise to reduce the internal temperature to 5 ° C. or less. Then, 1.60 g of 1,3,5-trimethoxybenzene which is an aromatic compound was added, and 1.81 g of paratoluenesulfonic acid was dissolved in 30 ml of acetonitrile and added dropwise.
Thereafter, the mixture was stirred at 5 ° C. or lower for 2 hours, then poured into 300 ml of ice water, extracted with 250 ml of dichloromethane, and the aqueous layer was further extracted with 100 ml of dichloromethane. The organic phase is washed with an aqueous solution in which 37.8 g of sodium sulfite is dissolved in 300 ml of water, and the organic phase is further washed twice with 300 ml of water. The organic phase was concentrated until the amount of the solvent became 1/10, 50 ml of ethyl acetate was added, the mixture was concentrated again, and allowed to stand to obtain 3.20 g (yield: 48%) of the following iodonium salt.

The structure of the obtained diaryl iodonium salt 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)

[Example 2]
Except that the starting material was iodobutoxybenzene, the aromatic compound was changed to butoxybenzene, and the acid was changed to methofluorobutanesulfonic acid, the following iodonium salt was obtained in the same scheme as in Example 1, and 2.97 g (yield) : 41%). The structure is shown together with the NMR results.

NMR 400 MHz CDCl ₃ 0.956 (t, 6H, J = 7.6); 1.559 (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)

Example 3
The following iodonium salt 2.44 g (yield: 45%) was obtained in the same scheme as in Example 1 except that the starting material was changed to iodobenzene. The structure is shown together with the NMR results.

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 ( 7.460 (t, 1H, J = 7.6); 7.727 (d, 2H, J = 8.0); 7.870 (m, 2H)

Example 4
The following iodonium salt (3.07 g, yield: 50%) was obtained in the same scheme as in Example 1 except that the starting material was changed to p-butoxyiodobenzene. The structure is shown together with the NMR results.

NMR 400 MHz CDCl ₃ 0.950 (t, 3H, J = 7.2); 1.450 (m, 2H); 1.727 (m, 2H); 2.315 (s, 3H); 3.846 ( 3.887 (s, 6H); 3.898 (m, 2H); 6.151 (s, 2H); 6.778 (d, 2H, J = 8.8); 7.077 (D, 2H, J = 8.0); 7.669 (d, 2H, J = 8.0); 7.766 (d, 2H, J = 8.8)

Example 5
Except that the starting material was iodobenzene, the aromatic compound was benzene, and the acid was removed and replaced with fluoromethanesulfonic acid, in the same scheme as in Example 1, 2.11 g of the following iodonium salt (yield: 49%). The structure is shown together with the NMR results.

  NMR 400 MHz DMSO 7.536 (t, 4H, J = 8.0); 7.671 (t, 2H, J = 7.6); 8.254 (d, 2H, J = 7.2)

Example 6
3.32 g of octyloxyiodobenzene is dissolved in 45 ml of acetic acid, heated and stirred at 40 ° C. To this, 15.4 g of perboric acid tetrahydrate was slowly added in 20 minutes, stirred at 40 ° C. to 45 ° C. for 6 hours, and then allowed to stand at room temperature for 12 hours so that the internal temperature became 25 ° C. 1.60 g of 1,5-trimethoxybenzene was slowly added, and 1.81 g of paratoluenesulfonic acid was slowly added, followed by stirring at 5 ° C. or lower for 2 hours, and then poured into 300 ml of ice water and extracted with 250 ml of dichloromethane. Further, the aqueous layer was extracted with 100 ml of dichloromethane.
The organic phase is washed with an aqueous solution in which 37.8 g of sodium sulfite is dissolved in 300 ml of water, and the organic phase is further washed twice with 300 ml of water. The organic phase was concentrated until the amount of the solvent became 1/10, 50 ml of ethyl acetate was added, the mixture was concentrated again, and allowed to stand, whereby 3.00 g of the same iodonium salt as obtained in Example 1 (yield: 45%).

Example 7
1.5 g of the iodonium salt 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 1.3 g of the following iodonium salt (yield: 90). 0.0%).

  As described above, according to the production method of the present invention, a diaryliodonium salt having an electron donating group as a substituent, which has been difficult to synthesize in a high yield, can be easily produced in a high yield. it can. Moreover, the diaryliodonium salt which has arbitrary anion structures can be manufactured by applying well-known salt exchange.

Claims (7)

  A method for producing a diaryl iodonium salt, comprising reacting an iodoaryl compound with an alkali metal perborate in a solvent containing a carboxylic acid, and then adding an aromatic compound and an acid.   The method for producing a diaryliodonium salt according to claim 1, wherein the aromatic compound is a compound having an electron-donating substituent.   The solvent is further added before the aromatic compound and the acid are added after the iodoaryl compound is allowed to act on the alkali metal perborate in a solvent containing a carboxylic acid. Item 3. A method for producing a diaryliodonium salt according to Item 2.   The method for producing a diaryliodonium salt according to any one of claims 1 to 3, wherein the carboxylic acid contained in the solvent is an alkyl carboxylic acid.   A diaryl iodonium salt in which a diaryl iodonium salt is produced in one step by reacting an iodoaryl compound with an alkali metal perborate in a solvent containing a carboxylic acid and then adding the aromatic compound and the acid as it is. Production method. An iodonium salt compound having a structure represented by the following general formula (I).

In the general formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group, an alkenyl group or an alkynyl group, and X ⁻ represents a monovalent anion structure. An iodonium salt compound having a structure represented by the following general formula (II).

In the above general formula, R ⁴ represents an alkyl group, an alkenyl group, or an alkynyl group, and X ⁻ represents a sulfonate anion or an inorganic anion structure.