JP4329325B2 - Process for producing monoalkali metal salt of diallyl cyanurate - Google Patents

Description

【０００６】
本発明において、非プロトン性極性溶剤と水酸化アルカリを使用することにより、トリアリルシアヌレートからアリルアルコールが１分子のみ脱離することを見出したことで、熱安定性、高周波電気特性の優れたポリマー材料であるジアリルシアヌレートを合成することが可能になった。この一連の合成操作で生成するのは、目的物質のジアリルシアヌレート、アリルアルコール、硫酸アルカリ金属塩である。アリルアルコールはトリアリルシアヌレートの合成に再利用することが可能であり、回収した溶媒も再利用できることから、低コストの反応を実現できる。また、上記のように原料が無駄にならないことと併せて、溶媒にジメチルスルホキシド（以下ＤＭＳＯと略す）などの毒性の低い溶剤を用いることで環境負荷の少ない製造方法でもある。
【０００７】
本発明で使用する非プロトン性極性有機溶剤とは、ＤＭＳＯ、ジメチルホルムアミド（以下ＤＭＦと略す）、ジメチルアセトアミド（以下ＤＭＡＡと略す）、１−メチル−２−ピロリジノン、ジメチルイミダゾリジノン（以下ＤＭＩと略す）からなる群から選ばれた、少なくとも１種のものであり、水酸化アルカリとは、水酸化ナトリウムまたは水酸化カリウムから選ばれた、少なくとも１種のものである。
【０００８】
具体的には、ＤＭＳＯやＤＭＦなどの極性溶媒中に水酸化ナトリウムなどの水酸化アルカリを分散させ、そこへトリアリルシアヌレートを加えると、トリアリルシアヌレート分子の１つのアリルエステル部のみが加アルカリ分解され、ジアリルシアヌレートのモノアルカリ金属塩になる。この反応は、室温でも１５−１７時間でほぼ定量的に進行するが、６０℃程度の加熱を行なえば反応時間を短縮することができる。
【０００９】
この反応によって得られたジアリルシアヌレートのアルカリ金属塩の溶液から、アリルアルコールおよび溶媒を蒸留で除いた後、ジアリルシアヌレートアルカリ金属塩を水溶液とし、有機溶剤で分液操作を行なうことによって、未反応トリアリルシアヌレートやその他の微量不純物を有機層へ除くことができる。この分液操作の後、水溶液を当量の硫酸を用いて弱酸性にすることにより、晶析または有機溶剤による抽出で、フリーで純粋なジアリルシアヌレートを取り出すことが可能である。また、回収したアリルアルコールは原料であるトリアリルシアヌレートの合成原料に再利用することが可能となり、回収した溶媒も再利用することができる。
【００１０】
以下、本発明を実施例によって説明する。
【実施例１】
四つ口フラスコ（５００ｍｌ）にＤＭＳＯ１００ｍｌ、ペレット状の水酸化ナトリウム６．０ｇ（１５０ｍｍｏｌ）、トリアリルシアヌレート３７．４ｇ（１５０ｍｍｏｌ）を仕込み、室温で１７時間撹拌した。減圧蒸留によって反応溶液からアリルアルコールおよびＤＭＳＯを除き、水１００ｍｌを加え、トルエン５０ｍｌを用いた分液操作を２回行い、未反応物質やその他の不純物をトルエン層に抽出させることによって除いた。水層に酢酸エチル８００ｍｌを加え、引き続いて硫酸７．３５ｇ（７５ｍｍｏｌ）／水２０ｍｌを加えて、遊離してきたジアリルシアヌレートを分液操作にて有機層に抽出した。有機層を水１００ｍｌを用いた分液洗浄を２回行ったのち、無水硫酸ナトリウムを用いて乾燥し減圧下で濃縮すると、ジアリルシアヌレートの結晶２９．２ｇを得た（収率９３％。表１−実験番号１）。
【００１１】
【表１】

【００１２】
尚、基本的反応操作および反応スケールは上記の実施例１に従い、反応溶媒をＤＭＳＯからＤＭＦ、ＤＭＡＡ、１−メチル−２−ピロリジノン、ＤＭＩにそれぞれ置き換えて行なった実験（表１−実験番号２〜５）、水酸化アルカリとして水酸化カリウムを使用した実験（表１−実験番号６）、６０℃での加熱条件下で反応を行なった実験（表１−実験番号７）についてのジアリルシアヌレートの収率は、表１にまとめて記した。
【００１３】
【実施例２】
四つ口フラスコ（５００ｍｌ）にＤＭＳＯ１００ｍｌ、ペレット状の水酸化ナトリウム６．０ｇ（１５０ｍｍｏｌ）、トリアリルシアヌレート３７．４ｇ（１５０ｍｍｏｌ）を仕込み、室温で１７時間撹拌した。減圧蒸留によって反応溶液からアリルアルコールおよびＤＭＳＯを除き、水２００ｍｌを加え、トルエン５０ｍｌを用いた分液操作を２回行い、未反応物質やその他の不純物をトルエン層に抽出させることによって除いた。水層に硫酸７．３５ｇ（７５ｍｍｏｌ）／水１００ｍｌをゆっくり加えて遊離してきた結晶をろ過で分離し、充分に乾燥させると、ジアリルシアヌレートの結晶２９．５ｇを得た（収率９４％）。
【００１４】
【比較例】
上記の実施例１に従い、反応溶媒のみＤＭＳＯをアリルアルコールに置き換えて反応を行なったところ、ジアリルシアヌレートの結晶が１７．８ｇ（収率５７％）しか得られなかった。
【００１５】
【発明の効果】
非プロトン性極性溶剤と水酸化アルカリを使用することにより、トリアリルシアヌレートからアリルアルコールを１分子のみ脱離することを見出したことで、多用途で高機能を有するジアリルシアヌレートを高収率、低コストで合成することが可能になった。本発明に関する技術は、ジアリルシアヌレートだけにとどまらず、そこから更に高い性能を持つ新しい誘導体へと導く可能性があり、その効果は多大である。
【図面の簡単な説明】
【図１】 実施例１に示すジアリルシアヌレートの合成工程を表した図である。
【図２】 実施例２に示すジアリルシアヌレートの合成工程を表した図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a monoalkali metal salt of diallyl cyanurate which is a precursor of diallyl cyanurate useful as a raw material for plastics, a lubricant, a raw material for synthetic rubber, an electrical insulating material and the like.
[0002]
[Prior art]
Although s-triazine ring derivatives having excellent heat resistance and chemical resistance, particularly triallyl cyanurate and triallyl isocyanurate are useful as polymer raw materials, there is a problem that the resulting polymer has no flexibility at all. is there. Development of diallyl cyanurate and diallyl isocyanurate has been promoted as a technology to compensate for this. These compounds were directly synthesized by the reaction of cyanuric acid or isocyanuric acid with allyl halide in the presence of a base, but the synthesis cost was high and practical application was difficult by this method.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a versatile s-triazine ring compound having high versatility by improving the above-described difficulties associated with cyanuric acid esters. As a method for producing diallyl cyanurate, in addition to the partial allylation of cyanuric acid described above, partial hydrolysis of triallyl cyanurate can be considered, but in protic polar solvents such as water and alcohols. Partial hydrolysis of triallyl cyanurate has been difficult. Actually, as a part of studying one-pot production method of diallyl cyanurate from cyanuric chloride via triallyl cyanurate, triallyl cyanurate was hydrolyzed in allyl alcohol. It was difficult to get well. In addition, as a result of investigating the prior literature, the present invention using an aprotic polar solvent and an alkali hydroxide for the production of a monoalkali metal salt of diallyl cyanurate, which is a precursor of diallyl cyanurate, Is the method.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventors have conducted numerous experiments and intensively analyzed and studied. As a result, triallyl cyanurate is in contact with an alkali hydroxide in an aprotic polar solvent. Obtaining the knowledge that one molecule of allyl alcohol is selectively eliminated from the allyl cyanurate molecule, the present invention has been completed.
That is, the gist of the present invention lies in a method for producing a monoalkali metal salt of diallyl cyanurate, which comprises contacting an alkali hydroxide with triallyl cyanurate in an aprotic polar organic solvent.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. The following general formula (I) shows two steps according to the invention for obtaining a diallyl cyanurate monoalkali metal salt and further treating the monoalkali metal salt with an acid to obtain diallyl cyanurate. .
[Chemical 1]

[0006]
In the present invention, it was found that by using an aprotic polar solvent and an alkali hydroxide, only one molecule of allyl alcohol is desorbed from triallyl cyanurate, which is excellent in thermal stability and high-frequency electrical characteristics. It has become possible to synthesize diallyl cyanurate, a polymer material. This series of synthesis operations produces the target substances diallyl cyanurate, allyl alcohol, and alkali metal sulfate. Allyl alcohol can be reused in the synthesis of triallyl cyanurate, and the recovered solvent can be reused, so that a low-cost reaction can be realized. In addition to the fact that the raw materials are not wasted as described above, it is also a production method with less environmental impact by using a low-toxic solvent such as dimethyl sulfoxide (hereinafter abbreviated as DMSO) as the solvent.
[0007]
The aprotic polar organic solvent used in the present invention is DMSO, dimethylformamide (hereinafter abbreviated as DMF), dimethylacetamide (hereinafter abbreviated as DMAA), 1-methyl-2-pyrrolidinone, dimethylimidazolidinone (hereinafter referred to as DMI). At least one member selected from the group consisting of (abbreviated), and the alkali hydroxide is at least one member selected from sodium hydroxide or potassium hydroxide.
[0008]
Specifically, when an alkali hydroxide such as sodium hydroxide is dispersed in a polar solvent such as DMSO or DMF and triallyl cyanurate is added thereto, only one allyl ester portion of the triallyl cyanurate molecule is added. Alkaline decomposition results in dialkyl cyanurate monoalkali metal salt. This reaction proceeds almost quantitatively at room temperature in 15-17 hours, but the reaction time can be shortened by heating at about 60 ° C.
[0009]
After removing allyl alcohol and the solvent by distillation from the diallyl cyanurate alkali metal salt solution obtained by this reaction, the diallyl cyanurate alkali metal salt is made into an aqueous solution and subjected to a liquid separation operation with an organic solvent. Reaction triallyl cyanurate and other trace impurities can be removed to the organic layer. After this liquid separation operation, the aqueous solution is made weakly acidic with an equivalent amount of sulfuric acid, whereby free and pure diallyl cyanurate can be taken out by crystallization or extraction with an organic solvent. Further, the recovered allyl alcohol can be reused as a raw material for synthesizing triallyl cyanurate, and the recovered solvent can also be reused.
[0010]
Hereinafter, the present invention will be described by way of examples.
[Example 1]
A four-necked flask (500 ml) was charged with 100 ml of DMSO, 6.0 g (150 mmol) of pelleted sodium hydroxide and 37.4 g (150 mmol) of triallyl cyanurate, and stirred at room temperature for 17 hours. Allyl alcohol and DMSO were removed from the reaction solution by distillation under reduced pressure, 100 ml of water was added, and a liquid separation operation using 50 ml of toluene was performed twice to remove unreacted substances and other impurities into the toluene layer. 800 ml of ethyl acetate was added to the aqueous layer, then 7.35 g (75 mmol) of sulfuric acid / 20 ml of water were added, and the released diallyl cyanurate was extracted into the organic layer by a liquid separation operation. The organic layer was separated and washed twice with 100 ml of water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 29.2 g of diallyl cyanurate crystals (yield 93%, table). 1—Experiment number 1).
[0011]
[Table 1]

[0012]
The basic reaction operation and reaction scale were the same as in Example 1 described above, except that the reaction solvent was changed from DMSO to DMF, DMAA, 1-methyl-2-pyrrolidinone, and DMI, respectively (Table 1-Experiment No. 2 5) Experiments using potassium hydroxide as the alkali hydroxide (Table 1-Experiment No. 6), diallyl cyanurate for experiments (Table 1-Experiment No. 7) in which the reaction was conducted under heating conditions at 60 ° C Yields are summarized in Table 1.
[0013]
[Example 2]
A four-necked flask (500 ml) was charged with 100 ml of DMSO, 6.0 g (150 mmol) of pelleted sodium hydroxide and 37.4 g (150 mmol) of triallyl cyanurate, and stirred at room temperature for 17 hours. Allyl alcohol and DMSO were removed from the reaction solution by distillation under reduced pressure, 200 ml of water was added, a liquid separation operation using 50 ml of toluene was performed twice, and unreacted substances and other impurities were extracted into the toluene layer. 7.35 g (75 mmol) of sulfuric acid / 100 ml of water was slowly added to the aqueous layer, and the released crystals were separated by filtration and sufficiently dried to obtain 29.5 g of diallyl cyanurate crystals (yield 94%). .
[0014]
[Comparative example]
According to Example 1 described above, DMSO was replaced with allyl alcohol in the reaction solvent alone, and only 17.8 g (yield 57%) of diallyl cyanurate crystals were obtained.
[0015]
【The invention's effect】
By finding that only one molecule of allyl alcohol is eliminated from triallyl cyanurate by using an aprotic polar solvent and alkali hydroxide, high yield of versatile and highly functional diallyl cyanurate is obtained. It became possible to synthesize at low cost. The technology related to the present invention is not limited to diallyl cyanurate, but may lead to a new derivative having higher performance therefrom, and its effect is great.
[Brief description of the drawings]
1 is a diagram showing a synthesis process of diallyl cyanurate shown in Example 1. FIG.
2 is a diagram showing a synthesis process of diallyl cyanurate shown in Example 2. FIG.

Claims (3)

  A method for producing a monoalkali metal salt of diallyl cyanurate, comprising contacting an alkali hydroxide and triallyl cyanurate in an aprotic polar organic solvent.   The diallyl according to claim 1, wherein the aprotic polar organic solvent is at least one selected from the group consisting of dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1-methyl-2-pyrrolidinone and dimethylimidazolidinone. A process for producing a monoalkali metal salt of cyanurate.   The method for producing a monoalkali metal salt of diallyl cyanurate according to claim 1, wherein the alkali hydroxide is at least one selected from sodium hydroxide and potassium hydroxide.

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