JP5209201B2 - Method for producing high-purity organic acid chloride having an unsaturated group in the molecule - Google Patents

Description

  The present invention relates to a method for producing a high-purity organic acid chloride having an unsaturated group in the molecule, which is important as a raw material for producing many chemical products, pharmaceuticals, agricultural chemicals and electronic materials.

  Organic acid chlorides, represented by alkyl, allyl, aralkyl, alkenoyl, and alkynyl-chloride, are one of the important raw materials essential for the production of chemical materials, pharmaceuticals, agricultural chemicals, and electronic materials. Among them, organic acid chloride having an unsaturated group in the molecule is particularly in demand.

  A typical methacrylic acid chloride as an organic acid chloride having an unsaturated group in the molecule can be produced by a reaction between methacrylic acid and phosphorus trichloride (Patent Document 1). Acrylic acid chloride or methacrylic acid chloride can be produced by reacting acrylic acid or methacrylic acid with phosgene using dimethylformamide as a catalyst in the presence of a polymerization inhibitor (Patent Document 2). Furthermore, an unsaturated carboxylic acid halide can be produced by reacting an unsaturated carboxylate with a halogenating agent (Patent Document 3).

JP 60-243041 A JP 2003-277319 A JP 2005-343793 A

  In recent years, the demand for organic acid chlorides having an unsaturated bond in the molecule has increased, but those that have been produced industrially are not stable in quality and have low purity. Typical impurities contained in commercially available products are organic halides, polymers, or free HCl, but S and P compounds are also included depending on the production method.

When a conventional commercial product of an organic acid chloride having an unsaturated bond in the molecule is used as it is or after simple distillation, the following reaction is carried out, often causing a side reaction such as elimination to produce a by-product. Accompanied by. By-products not only reduce the reaction rate, but also impair the purity of the resulting product, and the purification requires a lot of time and money. Especially in electronic materials that require high accuracy, purity is related to product performance, and impurities such as S and P cause problems by inducing corrosion.
Against this background, we intensively studied to increase the purity of organic acid chloride and established a new purification method.

ここに、n=0-10であり、R₁, R₂, R₃はすべて水素原子であるか、又は、R₁、R₂、R₃のいずれかがメチル基であり他は水素原子である。 The organic acid chloride having an unsaturated group in the molecule represented by Formula 1 can be made highly pure by adding a tertiary amine and distilling it.

Here, n = 0-10, and R ₁ , R ₂ , R ₃ are all hydrogen atoms, or any of R ₁ , R ₂ , R ₃ is a methyl group and the other is a hydrogen atom. is there.

Examples of the tertiary amine include triethylamine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] octane, N, N-dimethylaminopyridine, hexamethylenetetramine and N , it can be suitably used either or a combination of N- tetramethyl-1,2-ethylenediamine. Among these, hexamethylenetetramine, which is a cyclic tertiary amine, can be particularly preferably used. The molecular structure of hexamethylenetetramine is shown in Formula 2.

  This method can be particularly preferably used when the organic acid chloride is acrylic acid chloride or methacrylic acid chloride.

The organic acid chloride and a tertiary amine having an unsaturated group in the molecule from by mixing ten minutes, atmospheric pressure or at a temperature near the boiling point of the organic acid chloride by distillation under reduced pressure, to obtain a particularly favorable results Can do.

  By this method, the purity of the organic acid chloride having an unsaturated group in the molecule can be remarkably improved. The purity of methacrylic acid chloride with a purity of 95% became 99% or more by this method. Acrylic acid chloride with a purity of 94% was also more than 99% pure by this method.

  When the organic acid chloride having an unsaturated group in the high-purity molecule according to the present invention is used as a raw material for producing another compound, as shown in the examples, a higher-purity product than a commercial product is used. The yield can be obtained.

これら不純物を除くには、塩基性物質と選択的に反応させ、反応物を分離することが有効と考えられる。我々は種々の塩基性物質を検討した結果、第3級アミン、特にヘキサメチレンテトラミンが有効であることを見出した。 Organic acid chloride reagents and industrial products having unsaturated groups in the molecule contain many impurities. What impurities are mixed and how much depends on the manufacturing method, but the common ones are organic halogen compounds, free acids, free hydrochloric acids, polymers, P or S compounds as shown in Formula 3. is there.

In order to remove these impurities, it is considered effective to selectively react with a basic substance to separate the reactants. As a result of examining various basic substances, we have found that tertiary amines, particularly hexamethylenetetramine, are effective.

The organic acid and free HCl contained in the organic acid chloride are heated and distilled with a tertiary amine salt to become an amine salt as shown in Formula 4 and remain as a kettle residue.

この効果を得るには、分子内に不飽和基を有する有機酸クロライドと有機アミンを混合して後、まず両者を十分に反応させる必要がある。用いる有機酸クロライドと有機アミンの組み合わせによっては、混合しただけで直ちに反応が進行する場合もあるが、室温でしばらく放置するか、あるいは80℃以下の温度に加温して反応させる必要がある場合もある。反応が十分進行した後、常圧又は減圧下で有機酸クロライドの沸点付近の温度で蒸溜することにより、高純度品が得られる。 The HCl adduct of organic acid chloride desorbs in the system and returns to the target product as shown in Formula 5. Therefore, free HCl and an adduct of HCl are not contained in the distillate.

In order to obtain this effect, after mixing an organic acid chloride having an unsaturated group in the molecule and an organic amine, it is necessary to first sufficiently react them. Depending on the combination of organic acid chloride and organic amine used, the reaction may proceed immediately after mixing, but it may be necessary to leave at room temperature for a while or to warm to 80 ° C or lower for the reaction. There is also. After the reaction has sufficiently proceeded, a high-purity product is obtained by distillation at a temperature near the boiling point of the organic acid chloride under normal pressure or reduced pressure.

When hexamethylenetetramine is used as an organic amine, the following characteristics occur.
(1) Since it has four base ends in the molecule, it strongly captures one of impurities, HCl and free organic acid.
(2) An organic acid chloride having an unsaturated group is easily polymerized, but hexamethylenetetramine does not accelerate the polymerization.
(3) Some synthetic methods contain P and S compounds. Capture this thing strongly.
(4) The residue after distillation is liquid and can be easily taken out from the still.
(5) After taking out the residue after distillation, it can be charged immediately.
(6) The price is low.

  When hexamethylenetetramine is used, formaldehyde is produced at 1% or less, but this does not affect the next reaction. By-products containing oligomers and polymers have a large boiling point difference from organic acid chlorides, and can be easily separated and removed by distillation.

  Specific embodiments of the present invention are described below as examples. However, the present invention is not limited to the embodiments shown in the examples.

An example of producing high-purity methacrylic acid chloride from industrial methacrylic acid chloride using hexamethylenetetramine is shown below.
Add 100ppm MEHQ (hydroquinone monomethyl ether) and hexamethylenetetramine to 2.5kg in industrial methacrylic acid chloride (Gas chromatograph (GC) analysis purity 95%) at 70-75 ℃ (bath temperature). The mixture was stirred overnight under heating. Subsequently, it was distilled at about 65 ° C./200 mmHg. The yield was 0.9 kg (recovery rate 90%), and the GC analysis purity was 99% or more.
The kettle residue was liquid and could be easily removed. After removing the kettle residue, the purification process was resumed. Even if the purification process is repeated 10 times, the yield is 80-90%, which is the same as the first. According to the results of GC analysis, 100% with the FID detector (flame ionization detector) and TCD detector ( The thermal conductivity detector (active to halogen) had a purity of 99% or more.

An example of producing high purity methacrylic acid chloride from methacrylic acid chloride for reagents using hexamethylenetetramine is shown below.
100 ppm of MEHQ and hexamethylenetetramine were added to 500 g of commercially available reagent methacrylic acid chloride (GC analysis purity 98%) to a concentration of 2.5%, and the mixture was stirred at 70-75 ° C. (bath temperature) for 1 hour. Subsequently, it was distilled at 75 ° C. (bath temperature) / 200 mmHg. The yield was 470 g (recovery rate 94%), and the GC analysis purity was 99% or more.
The kettle residue was liquid and could be easily removed. In the same manner as in Example 1, after removing the kettle residue and repeating the acid chloride purification step several tens of times in the same manner, a high-purity product was obtained in the same manner.

An example of producing high-purity acrylic acid chloride from industrial acrylic acid chloride using hexamethylenetetramine is shown below.
100 ppm of MEHQ and hexamethylenetetramine were added to 1 kg of industrial product acrylic acid chloride (GC analysis purity 94%) to a concentration of 2.5%, and the mixture was stirred at 45-50 ° C. (bath temperature) for 1 hour. Subsequently, it was distilled at 48 to 55 ° C. (bath temperature) / 200 mmHg. The yield was 0.87 kg (recovery rate 87%), and the GC analysis purity was 99% or more.
The kettle residue was liquid and could be easily removed. After removing the kettle residue, acid chloride was newly added and the purification process was repeated 10 times. The yield was 80-95%. As a result of GC analysis, the purity was 100% with an FID detector and 99% or more with a TCD detector (active to halogen).

An example of producing high-purity acrylic acid chloride from reagent-use acrylic acid chloride using hexamethylenetetramine is shown below.
100 ppm of MEHQ and hexamethylenetetramine were added to 500 g of reagent acrylic acid chloride (GC analysis purity 98%) to a concentration of 2.5%, and the mixture was stirred overnight at 45-50 ° C. (bath temperature). Subsequently, it was distilled at 48 to 55 ° C. (bath temperature) / 200 mmHg. The yield was 480 g (recovery 96%), and the GC analysis purity was 99% or more.
The kettle residue was liquid and could be easily removed. Similarly to Example 3, even when the kettle residue was removed and the same purification process was repeated several tens of times, a high-purity product could be obtained similarly.

An example of producing high-purity methacrylic acid chloride from industrial methacrylic acid chloride using 4-dimethylaminopyridine is shown below.
While adding 100ppm MEHQ and 4-N, N'dimethylaminopyridine to 2.5kg in 1kg of industrial product methacrylic acid chloride (GC analysis purity 95%), keep it at 70-75 ℃ (bath temperature) , Stirred overnight. Subsequently, it was distilled at 75 ° C. (bath temperature) / 200 mmHg. The yield was 0.8 kg (80% recovery rate), and the GC analysis purity was 99% or more.
The kettle residue was a solid. For the removal, IPA (isopropyl alcohol) was first added to wash the kettle. Subsequently, methanol was gradually added while suppressing heat generation, and the acid chloride was completely neutralized with a 10% NaOH solution of IPA / water (1: 1). The IPA solution was removed, washed with water, and washed with THF (tetrahydrofuran) and methanol. Further, in order to wash the distillation tower, first, atmospheric distillation was carried out with THF and then with methanol, and after washing, it was dried under vacuum.

  As shown in this example, when an organic amine other than hexamethylenetetramine is used, the original purpose of obtaining a high-purity product can be achieved, but the solid residue remains in the kettle, so that the removal becomes complicated. . Industrially, it is important to use the kettle easily and repeatedly, so it is desirable to use hexamethylenetetramine.

The activities of the high-purity methacrylic acid chloride obtained in Example 1 and the methacrylic acid chloride for commercial reagents were compared by the esterification method shown in Formula 6.

180 mL of THF was added to 20 g of 2-adamantanone, and 10.1 g of methyl chloride was bubbled under cooling at around -20 ° C. Subsequently, Li was added and completely dissolved to obtain a Li form (formula 6, compound 1) with a yield of approximately 99%.
1.2 equivalents of methacrylic acid chloride of various purity was dropped into the Li body, and the product (formula 6, compound 3) was analyzed by GC (gas chromatography) method. Taking the amount used as 1, the conversion of the target product (formula 6, compound 3) was determined.

  The result of the esterification reaction is shown in FIG. In FIG. 1, the horizontal axis represents the reaction time, and the vertical axis represents the esterification rate. Reaction time 0 was set immediately after completion of the dropping. Since the reaction is fast, it is quite advanced at this point. The symbol ♦ indicates the case where the high purity methacrylic acid chloride obtained in Example 1 is used (Lot101). (1) shows the case where a commercially available reagent for methacrylic acid chloride is simply distilled under reduced pressure (Lot102). A triangle indicates a case where a commercially available methacrylic acid chloride reagent is used as it is (Lot103).

  When 16.5 g of high-purity methacrylic acid chloride obtained by the method of Example 1 was reacted dropwise at about −20 ° C. to the above Li-form (formula 6, compound 1), the reaction was carried out after about 30 minutes. Upon completion, the conversion was 99.45% (GC). After completion of the reaction, washing and concentration yielded 32.1 g (crude yield: 103%) of 2-methyl-2-adamantyl methacrylate (formula 6, compound 3). The GC purity at that time is 99.4%, and the target product can be obtained almost quantitatively (FIG. 1, Lot 101). The crude product thus obtained was purified to obtain a high-purity product with an actual yield of about 90%.

16.5 g of methacrylic acid chloride obtained by simple distillation of a commercially available reagent product was dropped into a Li form (formula 6, compound 1) and reacted as described above. After completion of the reaction, washing and concentration yielded 31.2 g (yield: 100%) of crude 2-methyl-2-adamantyl methacrylate (FIG. 1, Lot 102). The GC purity at that time was about 87%. The crude product was purified to obtain the target product with an actual yield of about 59%.
A similar reaction was attempted using the commercial reagent as it was without distillation. As a result, 29 g (average yield: 93%) of crude 2-methyl-2-adamantyl methacrylate (formula 6, compound 3) was obtained. The GC purity at that time was 73% (FIG. 1, Lot103). The crude product was purified to obtain the target product with an actual yield of about 45%. As the above results show, when the acid chloride obtained by the method of the present invention is used, the target product can be obtained in high yield.

  According to FIG. 1, when using the methacrylic acid chloride purified by the method of the present invention, a conversion of 99.45% (GC) was obtained and the esterification was almost complete. On the other hand, when an impure acid chloride was used, the yield was greatly reduced. If the organic acid chloride purified by the method of the present invention is used, the reactivity is high and the reaction is completed within about 30 minutes.

  When the methacrylic acid chloride for reagent is used as it is or simply distilled and used for the esterification reaction, the reaction does not proceed completely and the yield is low. This result predicts the presence of impurities that cannot be analyzed by GC. In particular, when used as it is, the decrease in the conversion rate after 120 minutes seems to be due to the progress of side reactions due to impurities.

2-Adamantanone 20gからLi体をほぼ99%のGC転化率で得た（式７、化合物１）。いろいろな純度のアクリル酸クロライドをLi体（式７、化合物１）の1.2当量滴下し、生成物をGC法により分析した。使用したLi体の量を1として、目的物（式７、化合物３）の転化率を求めた。 Acrylic acid chlorides were also compared by the same method as shown in Formula 7.

Li-form was obtained from 20 g of 2-Adamantanone with a GC conversion of approximately 99% (Formula 7, Compound 1). 1.2 equivalents of Li-form (formula 7, compound 1) were added dropwise with acrylic acid chloride of various purity, and the product was analyzed by GC method. The conversion rate of the target product (formula 7, compound 3) was determined with the amount of Li-form used being 1.

14.5 g of acrylic acid chloride distilled by the method of Example 3 was dropped and reacted with the obtained Li form (formula 7, compound 1). After completion of the reaction, washing and concentration yielded 32.1 g (yield: 110%) of crude 2-methyl-2-adamantyl acrylate. The GC purity at that time was 98%, and the conversion rate showed that the target product was obtained almost quantitatively. The resulting crude product was purified to obtain the target product with an actual yield of about 85%.
The esterification reaction was similarly carried out using acrylic acid chloride obtained by simple distillation of the reagent. Similarly, 14.5 g of simple distilled acrylic acid chloride was added dropwise to the Li body (formula 7) obtained and reacted. After completion of the reaction, washing and concentration yielded 27.8 g (yield: 95%) of crude 2-methyl-2-adamantyl acrylate. The GC purity at that time was about 75%.

The results are shown in FIG. Since the reaction time 0 is immediately after completion of the dropping, the reaction is almost complete at this point. The symbol ♦ indicates the case where high-purity acrylic acid chloride purified by the method of Example 3 is used (Lot105). (2) shows the case where the reagent acrylic acid chloride is simply distilled under reduced pressure (Lot106).
According to this figure, when the organic acid chloride purified by the method of the present invention was used, a high conversion rate exceeding 98% (GC) was obtained, and the esterification was almost complete. In contrast, the use of impure acid chloride significantly reduced the yield. Moreover, if the organic acid chloride refine | purified by the method of this invention is used, reaction will be complete | finished very rapidly.

In addition, it is good to increase / decrease the density | concentration of the organic amine added when distilling an organic acid chloride suitably according to the purity of the organic acid chloride before distillation. Considering the purity of the commercially available organic acid chloride, generally, a high-purity organic acid chloride can be produced by adding an organic amine to a concentration of 1 to 20%.
If the reagent is used as it is or simply distilled and used in the esterification reaction, the reaction does not proceed completely and the yield is low. This is due to the coexistence of impurities that cannot be analyzed by GC.

The comparison figure of reaction conversion rate when using three types of methacrylic acid chlorides. The comparison figure of the reaction conversion rate when using two types of acrylic acid chlorides.

Claims (5)

A method for producing a high-purity organic acid chloride having an unsaturated group in a molecule, wherein a tertiary amine is added to the organic acid chloride having an unsaturated group in the molecule represented by Formula 1 and distilled.

Here, n = 0-10, and R ₁ , R ₂ , R ₃ are all hydrogen atoms, or any of R ₁ , R ₂ , R ₃ is a methyl group and the other is a hydrogen atom. is there. Examples of the tertiary amine include triethylamine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] octane, N, N-dimethylaminopyridine, hexamethylenetetramine and N, characterized by using one or a combination of N- tetramethyl-1,2-ethylenediamine, process for producing a high purity organic acid chloride having unsaturated groups in the molecule of claim 1 . The method for producing a high-purity organic acid chloride having an unsaturated group in the molecule according to claim 1, wherein hexamethylenetetramine is used as the tertiary amine.   The method for producing a high-purity organic acid chloride having an unsaturated group in the molecule according to any one of claims 1 to 3, wherein the organic acid chloride is acrylic acid chloride or methacrylic acid chloride. The organic acid chloride and a tertiary amine having an unsaturated group in the molecule were allowed to mix sufficiently, atmospheric or characterized by distillation under reduced pressure, a temperature around the boiling point of the organic acid chloride, according to claim 1 The manufacturing method of the high purity organic acid chloride which has an unsaturated group in the molecule | numerator in any one of Claim 1-4.

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