JPH05286927A - Synthesis of sulfonium salts - Google Patents

Abstract

PURPOSE:To easily synthesize a sulfonium sulfonate useful as a curing catalyst for a one-pack thermosetting resin composition stably storable at ordinary temperature. CONSTITUTION:The objective sulfonium sulfonate compound is produced by reacting (A) a benzyl alcohol compound optionally having a substituent inert to the reaction on the benzene ring and/or alpha-site, preferably a compound of formula (R1 to R5 are H, halogen or alkyl; R2 and R3 may be OH, alkoxy, NO2, NH2, alkylamino, acyl, CN, alkoxycarbonyl or CONH2) with (B) a thioether, preferably tetrahydrothiophene and (C) an organic sulfonic acid chloride, preferably a benzene- or naphthalenesulfonic acid chloride which may be substituted with alkyl group preferably in the presence of (D) an acid acceptor, especially dicyclohexylamine or a metal alcoholate. Salts other than the above compound can be synthesized by the interchange reaction with a salt of the formula MX (M is alkali metal; X is anion such as AsF<->6).

Description

Detailed Description of the Invention

BACKGROUND ART JP-A-58-37003 and JP-A-58-37004 disclose a benzylsulfonium salt. These compounds are thermally cleaved to generate an acid and are useful as a curing catalyst for the one-component thermosetting resin composition.

In the cited patent documents, these compounds are two-step reaction in which the corresponding thioether is reacted with the corresponding benzyl halide and the anion of the resulting sulfonium halide is exchanged with a desired anion according to a conventional method of sulfonium salt synthesis. Was synthesized by.

[0003] DISCLOSURE inventors of the present invention is more convenient synthesis results explored the these compounds, and thioether should Suruoniumu of the corresponding benzyl alcohol, by reacting at once organic sulfonic acid chloride, We have successfully synthesized the desired sulfonium sulfonate compounds.

The benzyl alcohol which can be used in this synthetic method is represented by the formula:

[Chemical 2] (In the formula, R ₁ , R ₂ and R ₃ are independently a hydrogen atom, hydroxy, halogen, alkyl, alkoxy, nitro,
Amino, alkylamino, acyl, cyano, alkoxycarbonyl or carbamoyl, R ₄ and R ₅
Are independently hydrogen atom, halogen or alkyl. )
Alcohols are preferred.

Tetrahydrothiophene is preferred as the thioether.

As the organic sulfonic acid chloride, benzene- or naphthalene sulfonic acid chloride optionally substituted with an alkyl group is preferable.

The reaction includes benzene, toluene, ethyl acetate, butyl acetate, acetone, methyl isobutyl ketone,
In an aprotic solvent such as dichloromethane, dichloroethane, tetrahydrofuran, dioxane, nitromethane, nitrobenzene, acetonitrile or in a protic solvent such as isopropanol or t-butyl alcohol, the corresponding cyclic thioether, benzyl alcohol, and organic sulfonic acid chloride are added. May be reacted at 0 ° C to the boiling point of the solvent. In order to remove by-product hydrogen chloride, a secondary amine or a tertiary amine, particularly preferably dicyclohexylamine, may be added to the reaction system as an acid binder.

Salts other than sulfonate salts, such as AsF _{6
^{-, SbF 6 -, BF 4}} -, PF 6 -, ClO 4 -, F
When a salt with eCl ₄ ⁻ or CF ₃ SO ₃ ⁻ ion is desired, it can be synthesized by an exchange reaction between an alkali metal salt such as sodium salt of these anions and a sulfonate salt.

Example 1- (4-chlorobenzyl)-
Synthesis of tetrahydrothiophenium tosylate Tosyl chloride 19.0 was added to 60 g of tetrahydrofuran.
7 g (0.1 mol), tetrahydrothiophene 8.8
g (0.1 mol) and triethylamine 10.1 g
After dissolving (0.1 mol) and cooling to 10 ° C., 14.26 g (0.1 mol) of 4-chlorobenzyl alcohol was added. The reaction was carried out for 5 hours while suppressing the generation of heat. After completion of the reaction, the mixture was concentrated, and the precipitated white solid was washed with ether,
Dry to give the title compound. Yield 65%

Example 2. 1- (2-methylbenzyl)-
Synthesis of tetrahydrothiophenium tosylate 60 g of 1,4-dioxane tosyl chloride 19.0
7 g (0.1 mol), tetrahydrothiophene 8.8
g (0.1 mol) and dicyclohexylamine 27.
After dissolving 20 g (0.15 mol) and cooling to 10 ° C,
12.21 g of 2-methylbenzyl alcohol (0.1 m
ol) was added. The reaction was carried out for 5 hours while suppressing the generation of heat. After completion of the reaction, the mixture was concentrated, and the precipitated white solid was washed with ether and dried to obtain the title compound. 60% yield

Example 3.1 1- (4-chlorobenzyl)-
Synthesis of tetrahydrothiophenium hexafluoroantimonate 38.48 g of 1- (4-chlorobenzyl) -tetrahydrothiophenium tosylate obtained in Example 1 (0.
1 mol) was dissolved in 100 g of water, and 25.88 g (0.1 mol) of sodium hexafluoroantimonate was added. The white solid precipitated was filtered, washed with ether and dried to obtain the title compound. 60% yield

Example 4.1 1- (2-methylbenzyl)-
Synthesis of tetrahydrothiophenium tetrafluoroborate 1- (2 obtained in Example 2 in the same manner as in Example 3
The title compound was obtained from -methylbenzyl) -tetrahydrothiophenium tosylate and sodium tetrafluoroborate. 55% yield

Example 5.1 1- (4-methylbenzyl)-
Synthesis of tetrahydrothiophenium tosylate 12.21 g (0.1 mol) of 4-methylbenzyl alcohol was dissolved in 60 g of 1,4-dioxane, and 11.22 g (0.1 mo) of potassium tertiary butoxide.
l) was added with cooling. This solution was added dropwise to a solution of 19.07 g (0.1 mol) of tosyl chloride in 1,4-dioxane over 1 hour. Then, 8.8 g (0.1 mol) of tetrahydrothiophene was added, and the mixture was stirred at room temperature for 16 hours. After completion of the reaction, the solid thus precipitated was washed with ether and dried to obtain the title compound. Yield 53%

Claims (7)

[Claims] 1. A method for synthesizing a sulfonium sulfonate compound, which comprises reacting a benzyl alcohol optionally having a substituent that does not participate in the reaction at a benzene ring and / or an α-position, a thioether, and an organic sulfonic acid chloride. 2. The synthetic method according to claim 1, wherein the reaction is carried out in the presence of an acid binder. 3. The method according to claim 2, wherein the acid binder is dicyclohexylamine or a metal alcoholate. 4. A benzyl alcohol optionally having a substituent which does not participate in the reaction at the benzene ring and / or the α-position is represented by the formula: (In the formula, R ₁ , R ₂ and R ₃ are independently a hydrogen atom, hydroxy, halogen, alkyl, alkoxy, nitro,
Amino, alkylamino, acyl, cyano, alkoxycarbonyl or carbamoyl, R ₄ and R ₅
Are independently hydrogen atom, halogen or alkyl. )
The method according to any one of claims 1 to 3, wherein the alcohol is alcohol. 5. The synthetic method according to claim 1, wherein the thioether is tetrahydrothiophene. 6. The method according to claim 1, wherein the organic sulfonic acid chloride is benzene- or naphthalene sulfonic acid chloride optionally substituted with an alkyl group. 7. A sulfonium sulfonate compound obtained by the method according to any one of claims 1 to 6 having the formula MX
(Wherein, M is an alkali metal, X is AsF ₆ ^-, S
bF ₆ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , FeCl
₄ ⁻ or CF ₃ SO ₃ ⁻ ion. ), The sulfonate anion is converted to the above-mentioned X ^−.
A method for synthesizing a sulfonium salt, characterized by exchanging with anion.