JPH1059930A - Production of bis(4-bromomethylphenyl)sulfide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compound useful as a raw material for optical materials such as plastic lenses for eyeglasses, a coating material, an adhesive, a sealant, etc., by reacting diphenyl sulfide with a formaldehyde derivative and an inorganic bromine compound in the presence of a mineral acid in a fatty acid solvent. SOLUTION: Diphenyl sulfide is reacted with a formaldehyde derivative such as paraformaldehyde, trioxane or dimethoxymethane and an inorganic bromine compound such as sodium bromide or potassium bromide in the presence of a mineral acid such as sulfuric acid in a fatty acid solvent such as a lower fatty acid, e.g. preferably acetic acid to thereby produce the objective compound useful as a raw material for optical materials such as a Fresnel lens, a lenticular lens, an optical disk substrate, a plastic optical fiber, a prism sheet for liquid crystal display(LCD), a light guide plate or a diffusing sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing bis (4-bromomethylphenyl) sulfide. More specifically, plastic lenses for spectacles, Fresnel lenses, lenticure lenses, optical disc substrates, plastic optical fibers, LCD prism sheets, light guide plates,
The present invention relates to a method for producing bis (4-bromomethylphenyl) sulfide, which is useful as a raw material for optical materials such as diffusion sheets, paints, adhesives, and sealing materials, and is particularly useful as a raw material for optical materials.

[0002]

2. Description of the Related Art Bis (4-bromomethylphenyl) sulfide is disclosed, for example, in JP-A-59-5240 as a component of a polymerizable compound in a radiation-polymerizable mixture used for a photoresist or the like. ing. However, there is no description about the production method itself, and it has been difficult to produce it industrially. on the other hand,
As a method for bischloromethylation of diphenyl sulfide, a method of reacting diphenyl sulfide with paraformaldehyde and hydrogen chloride (Izv. Akad. Nauk SSS
R, Ser. Khim., 12 , 2799-801, 1976).

However, there is no known method for producing bis (4-bromomethylphenyl) sulfide by bisbromomethylating diphenyl sulfide.

[0004]

The present inventors have tried to obtain bis (4-bromomethylphenyl) sulfide by using hydrogen bromide instead of hydrogen chloride in the above reaction. However, the target product is hardly produced,
Also, in a method in which hydrogen bromide gas is introduced into a reaction vessel to which zinc chloride is added as a catalyst, a large amount of by-products such as diarylmethane is generated, and the desired bis (4-bromomethylphenyl) sulfide is not obtained. could not. Even if sulfuric acid was used in place of zinc chloride in this reaction, a large amount of by-products such as diarylmethane was similarly produced, and bis (4-bromomethylphenyl) sulfide could not be obtained.

An object of the present invention is to provide an industrially advantageous method for producing bis (4-bromomethylphenyl) sulfide.

[0006]

Means for Solving the Problems In view of the above situation, the present inventors have conducted intensive studies to provide a method for producing bis (4-bromomethylphenyl) sulfide from diphenyl sulfide, and have found that inorganic bromine compounds and The present inventors have found that bis (4-bromomethylphenyl) sulfide can be produced by bromomethylating diphenyl sulfide in a fatty acid solvent in the presence of a mineral acid using a formaldehyde derivative, thereby completing the present invention. .

That is, the gist of the present invention is to provide (1) bis (4-bromomethyl) characterized in that a formaldehyde derivative and an inorganic bromine compound are reacted with diphenyl sulfide in a fatty acid solvent in the presence of a mineral acid. (2) The method according to the above (1), wherein the formaldehyde derivative is paraformaldehyde, trioxane or dimethoxymethane, and (3) the method wherein the inorganic bromine compound is sodium bromide or potassium bromide. (1) The production method according to (2), (4) the production method according to any one of (1) to (3), wherein the mineral acid is sulfuric acid, and (5) the fatty acid is a lower fatty acid having 2 to 4 carbon atoms. The present invention relates to the production method according to any one of the above (1) to (4), and (6) the production method according to the above (5), wherein the fatty acid is acetic acid.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, diphenyl sulfide is reacted with a formaldehyde derivative and an inorganic bromine compound in a fatty acid solvent in the presence of a mineral acid to form bis (4-
Bromomethylphenyl) sulfide can be produced. The diphenyl sulfide used in the present invention is not particularly limited, and a commercially available product (for example, manufactured by Sumitomo Seika Co., Ltd.) can be used.

Examples of the formaldehyde derivative used in the present invention include paraformaldehyde, trioxane, dimethoxymethane, diethoxymethane and the like, with paraformaldehyde, trioxane and dimethoxymethane being particularly preferred. The amount of the formaldehyde derivative to be used is 1.6 to 3.2 times, preferably 1.8 to 2.5 times, the molar amount of diphenyl sulfide in terms of pure formaldehyde. If the amount of the formaldehyde derivative used is less than 1.6 moles, the monobromomethyl compound increases and the yield decreases, and if it is more than 3.2 moles, the tribromomethyl compound increases and the yield decreases.

The inorganic bromine compound used in the present invention includes:
Examples thereof include sodium bromide, potassium bromide, and ammonium bromide, and preferred are sodium bromide and potassium bromide. The amount of the inorganic bromine compound to be used is 1.7 to 6.0 times mol, preferably 1.9 mol, relative to diphenyl sulfide.
４4.0 times mol. The amount of the inorganic bromine compound used is 1.
If the amount is less than 7 times the amount of by-products such as monobromomethyl compound increases, the yield decreases, and if it is more than 6.0 times, the corresponding improvement in the yield cannot be expected. Not a target.

The mineral acid used in the present invention includes sulfuric acid, nitric acid and the like, but sulfuric acid is preferred. The amount of the mineral acid used is 1.0 to 20.0 moles, preferably 1.5 to 14.0 moles, relative to diphenyl sulfide. If the amount of the mineral acid is less than 1.0 mole, the reaction is not completed and the yield decreases, and if it is more than 20.0 mole, the corresponding increase in yield cannot be expected and it is not economical.

The fatty acids used in the present invention include lower fatty acids having 2 to 4 carbon atoms, such as acetic acid, propionic acid, isobutyric acid and butyric acid, and acetic acid is preferred. The amount of the fatty acid used is 1 to 15 with respect to 1 part by weight of diphenyl sulfide.
Parts by weight, preferably 1.2 to 10 parts by weight. If the amount of the fatty acid is less than 1 part by weight, stirring becomes difficult,
If the amount is more than 15 parts by weight, a corresponding increase in yield cannot be expected and it is not economical.

The reaction temperature is 50 to 120 ° C., preferably 6
5 to 110 ° C. If the reaction temperature is lower than 50 ° C., the progress of the reaction is slow, and by-products are also produced. The reaction time varies depending on the reaction temperature and the like, but is 1 to 15 hours, preferably 2 to 1 hour.
2 hours. If the reaction time is shorter than 1 hour, the reaction is not completed, and if the reaction time is longer than 15 hours, a corresponding improvement in yield cannot be expected and it is not economical.

After completion of the reaction, the reaction solution is poured into water and extracted with an organic solvent such as toluene or methylene chloride. Alternatively, water and an organic solvent are sequentially added to the reaction solution to form an organic solvent such as toluene or methylene chloride. An organic layer containing bis (4-bromomethylphenyl) sulfide, an isomer, a tribromomethyl form, a monobromomethyl form and the like is obtained by extraction with a solvent.
The obtained organic layer is washed with water, and then concentrated to obtain a crude product. This crude product can be purified by recrystallization from a solvent such as cyclohexane or toluene.

The bis (4) obtained by the production method of the present invention
-Bromomethylphenyl) sulfide has two bromomethyl groups that can be easily converted to other functional groups, and the diphenyl sulfide skeleton has a high refractive index.
Raw materials for optical materials such as plastic lenses for glasses, Fresnel lenses, lenticure lenses, optical disk substrates, plastic optical fibers, prism sheets for LCDs, light guide plates, diffusion sheets, etc., paints, adhesives, and sealing materials, especially raw materials for optical materials It is a very useful sulfur-containing compound used as.

[0016]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples and the like.

Example 1 A 2-liter four-necked flask equipped with a stirrer, a thermometer, a dropping funnel and a condenser was charged with diphenyl sulfide 18
6.3 g (1.0 mol), 63.2 g (2.0 mol) of 95% paraformaldehyde, sodium bromide 242.8
g (2.36 mol), 300 g of acetic acid, and then
388 g of 96% sulfuric acid prepared in advance (3.8 g)
Mol) and 200 g of acetic acid at a reaction temperature of 80-9.
The solution was added dropwise over 3 hours while maintaining the temperature at 0 ° C. After dropping,
Further, the mixture was stirred at the same temperature for 3.5 hours. Thereafter, the reaction solution was poured into 2000 g of water and extracted with 2200 g of methylene chloride. After liquid separation, the organic layer was washed with 1600 g of water for 3 hours.
After washing twice and concentrating, 354 g of a crude product was obtained. The crude product was recrystallized from 850 g of cyclohexane to give 242 g of bis (4-bromomethylphenyl) sulfide white crystals (melting point: 135.3-13).
6.3 ° C.). The yield based on diphenyl sulfide was 65%.

Example 2 Example 1 except that 60.1 g (0.667 mol) of trioxane was used instead of 95% paraformaldehyde.
The reaction and purification were carried out in the same manner as described above to obtain 238.5 g of bis (4-bromomethylphenyl) sulfide. The yield based on diphenyl sulfide was 64.1%.

EXAMPLE 3 238 g of potassium bromide instead of sodium bromide
(2.0 mol) and the amount of 96% sulfuric acid used was 204 g.
(2.0 mol), and the reaction and purification were carried out in the same manner as in Example 1 to obtain 215.8 g of bis (4-bromomethylphenyl) sulfide. The yield based on diphenyl sulfide was 58%.

Example 4 Bis (4-bromomethylphenyl) sulfide was obtained by conducting the reaction and purification in the same manner as in Example 1 except that 182.6 g (2.4 mol) of dimethoxymethane was used instead of 95% paraformaldehyde. 201 g were obtained. The yield based on diphenyl sulfide was 54%.

Comparative Example 1 93.1 g (0.5 mol) of diphenyl sulfide and 31.6 g of 95% paraformaldehyde were placed in a 1-liter four-necked flask equipped with a stirrer, a thermometer, a gas injection tube, and a cooling tube. 1.0 mol), 200 g of acetic acid and 10.2 g (0.1 mol) of 96% sulfuric acid.
Hydrogen bromide gas 162 over 3 hours while maintaining
g (2.0 mol), and the mixture was stirred at the same temperature for 3 hours. As a result, bis (4-bromomethylphenyl) sulfide could not be obtained only by giving by-products such as diarylmethane.

Comparative Example 2 In Comparative Example 1, zinc chloride 34 was used instead of 96% sulfuric acid.
When the reaction was carried out in the same manner as in Comparative Example 1 except that g (0.25 mol) was used, bis (4-bromomethylphenyl) sulfide was obtained only by giving by-products such as diarylmethane. Did not.

Comparative Example 3 Capacity 30 equipped with a stirrer, thermometer, dropping funnel and cooling pipe
In a 0 ml four-necked flask, add diphenyl sulfide 1
8.6 g (0.1 mol), 6.3 g (0.2 mol) of 95% paraformaldehyde, 24.3 g of sodium bromide
(0.24 mol), 100 g of chloroform was charged in place of the lower fatty acid as a solvent, and the reaction temperature was 50 to 60 ° C.
The reaction was carried out by dropwise addition of 96% sulfuric acid over 2 hours while keeping the temperature of the reaction system at room temperature, but only a polymer insoluble in water and the organic solvent was produced.

[0024]

According to the present invention, bis (4) which is a very useful sulfur-containing compound used as a raw material for optical materials and the like is provided.
(Bromomethylphenyl) sulfide can be industrially and advantageously produced easily from diphenyl sulfide, formaldehyde derivatives and inorganic bromine compounds in good yields.

Claims (6)

[Claims] 1. A process for producing bis (4-bromomethylphenyl) sulfide, comprising reacting a diphenyl sulfide with a formaldehyde derivative and an inorganic bromine compound in a fatty acid solvent in the presence of a mineral acid. 2. The method according to claim 1, wherein the formaldehyde derivative is paraformaldehyde, trioxane, or dimethoxymethane. 3. The method according to claim 1, wherein the inorganic bromine compound is sodium bromide or potassium bromide. 4. The method according to claim 1, wherein the mineral acid is sulfuric acid. 5. The method according to claim 1, wherein the fatty acid is a lower fatty acid having 2 to 4 carbon atoms. 6. The method according to claim 5, wherein the fatty acid is acetic acid.