JPH02172969A - Production of dithiol di(meth)acrylate - Google Patents

Abstract

PURPOSE:To obtain the subject compound useful as a raw material for acrylic resin, etc., in high yield and purity by reacting a dithiol with beta-chloro-alpha- methylpropionyl chloride in a polar organic solvent in the presence of sodium hydroxide, etc., under specific reaction condition. CONSTITUTION:The objective dithiol di(meth)acrylate of formula II (R is H or methyl) can be produced by (2) reacting 1mol of a dithiol of formula I (A is O or S; m is 1 or 2: n is 0 or 1) with 1.5-3.0mol of beta-chloro-alpha-methylpropionyl chloride in a polar organic solvent (e.g. acetone, methyl ethyl ketone or DMSO) at -10 to 40 deg.C in the presence of 1.5-3.0mol of an aqueous solution of sodium hydroxide or potassium hydroxide and (2) reacting the reaction product with 1.5-3.0mol (based on 1mol of the compound of formula I) of an aqueous solution of sodium hydroxide or potassium hydroxide or a tert-amine at -10 to +40 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing dithiol di(meth)acrylate useful as a raw material for acrylic resins or methacrylic resins.

[Conventional technology]

Ethylene glycol diacrylate, diethylene glycol dimethacrylate, and (meth)acrylates of ethylene oxide adducts of bisphenol A are utilized for modifying, ie, crosslinking, polymethacrylate resins.

[Problems to be Solved by the Invention] The present inventors have been researching the use of acrylic resins and methacrylic resins as resins for optical parts such as lenses. When using acrylate, diethylene glycol dimethacrylate, and (meth)acrylate of ethylene oxide adduct of bisphenol A, a high refractive index cannot be expected.

Therefore, the present inventors first proposed the general formula (It) (wherein A
represents oxygen or sulfur, R represents hydrogen or a methyl group, m
is 1 or 2, and n is an integer of 0 or 1. It was discovered that the resin obtained by radical polymerization of the compound shown in (Unexamined Japanese Patent Publication No. 63-188660
) These compounds can be synthesized by a conventionally known method of reacting a dithiol raw material with acrylic acid chloride or methacrylic acid chloride. However, in these methods, a reaction in which dithiol is added to the olefin group of acrylic acid chloride or methacrylic acid chloride as a by-product proceeds, so not only is the yield inferior, but the purification method is difficult, and these by-products There was a problem in that polymerization of monomers mixed with .

, (Means for Solving the Problems) In order to achieve the above-mentioned problems, the present inventors have developed a cheaper β β as a substitute for the industrially expensive acrylic acid chloride or methacrylic acid chloride that has been conventionally used as a raw material. A method for producing dithiol di(meth)acrylate represented by general formula (n) using -chloropropionyl chloride or β-chloro-α-methylpropionyl chloride as a raw material was intensively studied.

As a result, β-chloropropionyl chloride or β
-Even if chloro-α-methylpropionyl chloride is used as a raw material, esterification and dehydrochlorination (olefination) reactions can be carried out in the same reaction system by using a selected hydrochloric acid scavenger and specified reaction conditions. The present invention has been completed based on the discovery that not only it is possible to carry out the reaction, but also that the addition reaction of dithiol to olefin can be avoided.

That is, the present invention provides dithiol represented by the general formula (I) in a polar organic solvent at a temperature of -10 to 40°C in the presence of 1.5 to 3.0 mol of caustic soda or an aqueous solution of caustic potassium per 1 mol. , reacted with 1.5 to 3.0 mol of β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride, and further heated at -10 to 40°C.
At a temperature of ) A method for producing acrylate.

The polar organic solvent used in the method of the present invention has the general formula (
Any organic solvent can be used as long as it dissolves the dithiol represented by I) and is compatible with water, but ketones such as acetone and methyl ethyl ketone, N,N-dimethylformamide, dimethyl sulfoxide, etc. are preferably used. use

The amount of these polar organic solvents used is 1 to 30 times the weight of the dithiol represented by general formula (I).

There is no limit to the concentration of the caustic soda or caustic potash aqueous solution used in the esterification reaction, but it is preferably 50% by weight or less, which is stable as an aqueous solution, and the amount of caustic soda or caustic potash used is represented by general formula (I). The molar ratio is 1.5 to 3.0 relative to dithiol. If the molar ratio of caustic soda or caustic potassium is less than 1.5, unreacted β-
Chloropropionyl chloride or β-chloro-α-
The hydrolysis reaction of methylpropionyl chloride becomes more likely to occur. As a result, during the olefination reaction, oxidation of unreacted dithiol represented by the general formula (I) and addition reaction between the unreacted dithiol represented by the general formula (I) and the generated dithiol di(meth)acrylate are likely to occur. , the yield of dithiol di(meth)acrylate represented by general formula (II) decreases.On the other hand, when the molar ratio exceeds 3.0, β-chloropropionyl chloride or β-
The hydrolysis reaction of chloro-α-methylpropionyl chloride tends to occur, and the yield of dithiol di(meth)acrylate represented by general formula (II) decreases.

In addition, the amount of β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride used is 1.5 per dithiol represented by general formula (I).
~3.0 molar ratio. When the molar ratio of β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride is less than 1.5, the unreacted dithiol represented by the general formula (r) is added to the dithiol di(meth)acrylate produced during the olefination reaction. cause a reaction, −
The yield of dithiol di(meth)acrylate represented by the general formula (n) decreases. In addition, if the molar ratio exceeds 3.0, the remaining β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride may cause a pungent odor, resulting in the production of dithiol di(meth)acrylate represented by the general formula (II) in the crude product. The purification process becomes complicated.

Next, the concentration of the caustic soda or caustic potash aqueous solution used in the olefinization reaction is not limited as in the esterification reaction, but it is preferably 50% by weight or less, which is stable as an aqueous solution, and the amount of caustic soda or caustic potash used is: 1.5 for the dithiol substituted in general formula (I)
The molar ratio is mol-3.0. Moreover, the third
Examples of class amines include trimethylamine, trimethylamine, triethylenediamine, etc., but even when these are used, the amount used is 1.5 mol to 3.0 mol ratio with respect to the dithiol represented by general formula (I). be. Caustic soda or caustic potash or tertiary amine is 1
．． If the molar ratio is less than 5, the olefination reaction will not be completed, making it difficult to extract the highly pure dithiol di(meth)acrylate represented by the general formula (I[). Also, if the molar ratio of caustic soda or caustic potassium exceeds 3.0, the general formula (
The hydrolysis reaction of dithiol di(meth)acrylate represented by II) becomes intense. Also, tertiary amine is 3.0
Exceeding the molar ratio not only causes a pungent odor to remain in the dithiol di(meth)acrylate represented by the general formula (II), but also tends to cause coloring of the product.

Next, the reaction temperature in the method of the present invention is -10 to 40°C for both the esterification reaction and the olefination reaction,
Particularly preferred is 0 to 10°C. If it is too low, the esterification from the dithiol represented by the general formula (I) and the olefinization reaction after the esterification reaction will be difficult to proceed,
If the temperature is too high, hydrolysis of β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride or the generated ester is likely to occur in the esterification reaction, and in the olefination reaction, the dithiol di(meth) represented by the general formula (It) is likely to occur. ) The hydrolysis reaction of acrylate is likely to occur, resulting in a decrease in yield.

Thus, in a general embodiment of the method of the present invention, a solution in which a dithiol represented by the general formula (r) is dissolved in a polar organic solvent is stirred, and the internal temperature is maintained at -10 to 40°C. After adding the entire amount of 1.5 to 3.0 mol of caustic soda or caustic potassium aqueous solution to 1 mol of dithiol represented by general formula (I) while cooling, 1.5 to 3.0 mol of β-chlorobuty, Lobionyl chloride or β-chloro-α-methylpropionyl chloride is added dropwise from the dropping funnel over 1 to 8 hours, and then 1.5 to 3.0 mol of caustic soda, caustic potassium aqueous solution, or tertiary amine is added over 1 to 8 hours. Alternatively, add 1.5 to 3.0 mol of caustic soda or caustic potassium aqueous solution and 1.5 to 3.0 mol of β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride from separate dropping funnels. At the same time, it took 1 to 8 hours to get down to Ura, and then another 1.5 hours.
This is a method in which ~3.0 mol of caustic soda, caustic potassium aqueous solution, or tertiary amine is added dropwise over 1 to 8 hours. It can be produced in high yield. After the reaction is complete, water is added to the reaction solution and extraction is performed using hydrocarbons, especially n-hexane, as an extraction solvent to obtain the desired dithiol di(meth)acrylate represented by the general formula (It) with high purity and high purity. It can be obtained in high yield.

[Action and effect]

According to the present invention, β-chloropropionyl chloride or β-
Esterification is carried out by reacting chloro-α-methylpropionyl chloride in a polar organic solvent in the presence of caustic soda or aqueous caustic potassium solution, and the same reaction is carried out by contacting with caustic soda, aqueous caustic potassium solution, or a tertiary amine to cause an olefination reaction. Esterification and olefination can be carried out in-system, and dithiol di(meth)acrylates represented by general formula (If) can be advantageously obtained.

β-chloropropionyl chloride or β-chloro-α-methylpropionyl chloride used in this method is an industrially easily available raw material, and the method of the present invention is economically and technically superior and has industrial significance. This is the manufacturing method. The method of the present invention can also be used as a method for producing other thiol (meth)acrylates.

(Example) Next, the present invention will be explained in detail with reference to Examples, in which all parts shown are parts by weight.

Example 1 13.5 parts (0.10 mol) of 2,2'-oxydiethane 1,000 ol was dissolved in 200 parts of acetone, and the entire amount of 39.0 parts (0.20 mol) of a 20% by weight aqueous solution of caustic soda was added while stirring. . At this time, the content liquid was cooled to maintain it at 10°C.

Next, while keeping the content at 10°C, 25.0 parts (0.20 mol) of β-chloropropionyl chloride was added dropwise over 2 hours. After 4 drops, 21 parts of triethylamine was added while keeping the content at 10°C. .6 parts (0.22 mol) was added dropwise over 2 hours.

After the reaction was completed, 500 parts of water and 250 parts of n-hexane were added while stirring. Then, the n-hexane solution layer was separated and subjected to i4 condensation. After adding 250 parts of n-hexane to the concentrated solution and dissolving it, it was washed with 300 parts of water and decolorized using 6 parts of activated carbon.The next n-hexane solution was concentrated to give a colorless syrup-like 2.2°- 21.7 parts of oxydiethanethiol diacrylate were obtained.

Analysis by liquid chromatography showed that the purity was 99%, and the yield based on 2,2'-oxydiethane 1,000 ol was 87 mol%.

Moreover, the elemental analysis values were as follows.

Elemental analysis value (χ) HS analysis value 48.60 5.91 25.84 Calculated value 48.76 6.03 26.03 Example 2 2,2′-thionoethanethiol in 120 parts of N,N-dimethylformamide Dissolve 15.4 parts (0.10 mol) of 30% caustic potassium aqueous solution 41.1 while stirring.
(0.22 mol) was added. At this time, add 2
It was cooled to maintain it at 0°C.

Next, while keeping the content at 20°C, β-chloro-α-
28.2 parts (0.20 mol) of methylpropionyl chloride was added dropwise over 2 hours. W lower ridge, content liquid at 20°
41.1 parts of a 30% by weight aqueous solution of potassium hydroxide (
0.22 mol) was added dropwise over 2 hours.

After the reaction was completed, 500 parts of water and 250 parts of n-hexane were added while stirring. Then, the n-hexane solution layer was separated and concentrated. After adding 250 parts of n-hexane to the i4 condensate again and dissolving it, it was washed with 300 parts of water and further decolorized using 6 parts of activated carbon. Next, the n-hexane solution was concentrated to obtain 24.0 parts of 2.2°-thiodiecunthiol dimethacrylate in the form of a colorless syrup.

Analysis by liquid chromatography showed that the purity was 98%, and the yield based on 2,2'-thiodiethanethiol was 81 mol%.

Moreover, the elemental analysis values were as follows.

Elemental analysis value (%) H3 analysis value 49.51 6.13 33.20 Calculated value 49.62 6.25 33.12 Example 3 1.4-butanedithiol 12.3 in 150 parts of acetone
27.5 parts (0.22 mol) of β-chloro-α-methylpropionyl chloride and 29.3 parts of 30% by weight aqueous sodium hydroxide solution while stirring and keeping the content at 15°C. (0.22 mol) were placed in separate dropping funnels and simultaneously added dropwise over 2 hours. After completing the dropwise addition, 21.6 parts (0.22 mol) of triethylamine was added to the
It dripped over time.

After the reaction was completed, 500 parts of water and 250 parts of n-hexane were added while stirring. Then, the n~hexane solution layer was separated and concentrated. After adding 250 parts of n-hexane to the concentrated solution and dissolving it, it was washed with 300 parts of water, and then 6 parts of activated carbon was added.
The n-hexane solution was then concentrated to obtain 19.5 parts of 1,4-butanedithiol diacrylate in the form of a colorless syrup.

Analysis by liquid chromatography showed that the purity was 98%, and the yield based on 1,4-butanedithiol was 85 mol%.

Moreover, the elemental analysis values were as follows.

Elemental analysis value (%) Analysis value 51.97 Calculated value 52.14 6.22 6.13 27, 69 27.84

Claims (1)

[Claims] 1) General formula (I) HS(CH_2)_mA_n(CH_2)_mSH(
I) (wherein A represents oxygen or sulfur, m is an integer of 1 or 2, and n is an integer of 0 or 1) in a polar organic solvent from -10°C to 4°C.
At a temperature of 0°C, in the presence of 1.5 to 3.0 mol of caustic soda or caustic potassium aqueous solution per 1 mol, 1.5 to 3
．． 0 moles of β-chloropropionyl chloride or β
-Chloro-α-methylpropionyl chloride, and further at a temperature of -10 to 40°C, 1.5 to 3.0 mol of caustic soda or caustic potassium aqueous solution or General formula (II) characterized by reacting a tertiary amine ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, A represents oxygen or sulfur, R represents hydrogen or a methyl group, and m is 1 or 2, n is an integer of 0 or 1.) A method for producing dithiol di(meth)acrylate represented by: