JPH0564951B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a new method for synthesizing alkenyl isocyanurate from an alkenyl halide and an alkali cyanate. , heat-resistant resin additives, agricultural chemicals, and synthetic intermediates. <Prior Art> and <Problems to be Solved by the Invention> The modern synthesis method and chemistry of isocyanuric acid esters including alkenyl isocyanurates were discovered and developed by the present inventors. For example, a method for producing cyanuric acid derivatives (Nittoku Ko, 1972-3985), a method for producing isocyanuric acid esters (Nittoku Ko, 1976-4376), a method for producing isocyanuric acid esters (Nittoku Ko, 1972) −6635),
A method for purifying isocyanuric acid triester (Nittokuko, 1972-9345), A method for purifying isocyanuric acid ester (Nittokuko, 1972-12913), A method for producing isocyanate ester (Nittokuko, 1973) −26766),
Production method of isocyanuric acid triester (Nittokuko,
1972-1439), Method for producing isocyanuric acid ester (Nittokuko, 1972-16308), Method for removing impurities from isocyanuric acid ester (Nittokuko, 1972-22588)
Basic production methods and purification methods are shown in ``Production Method of Triallyl Isocyanurate'' (Nippon Tokuko, 1972-26022). Currently, industrial production of isocyanurate is carried out using this method, but problems remain that need to be solved regarding prevention of side reactions and improvement of yield, and intensive research is continuing. . The present invention is one of the results of this research and relates to a novel technology with high industrial value. <Means for Solving the Problems> When the present inventors reacted an alkenyl halide with an alkali cyanate in an aprotic acid amide solvent, the present inventors used a catalyst having 10 to 100 ppm of water and a bridgehead structure in the reaction system. He invented a method for producing alkenyl isocyanurates characterized by the presence of Here, catalysts having a beachhead structure can be classified into the following four types. In other words, N, P, and S are placed at the bridgehead position of the alicyclic compound.
or a compound containing no active hydrogen atom that contains any of the atoms of Se, ○B alkoxyalkali compounds or aminoalka compounds having a tertiary alkyl group, ○C N- of heteroaromatic aromatic amines having an NH group. The alkali compound, any one of the catalysts ○2, ○I to ○c, is a substance that is fixed or bonded to the surface of an inorganic carrier or a polymeric carrier and is substantially insoluble in the reaction system. Of course, these can be further subdivided, but in practice they are used as catalysts in any of ○A to ○D, or in a mixed state.When used in this way, they are most effective when the water content in the reaction system is 10 ~100ppm. Typical alkenyl halide compounds are shown below in terms of chloride, but in reality either chloride or bromide is used. Namely, allyl chloride, crotyl chloride, metaallyl chloride, α-chloromethylstyrene, α-chloroethylstyrene, α
Typical examples include -chloromethylstilbene, p-vinylbenzyl chloride, α-benzyl allyl chloride, α-benzyl crotyl chloride, cinnamyl chloride, α-alkyl cinnamyl chloride, etc., and industrially important ones include allyl chloride, Crotyl chloride, metaallyl chloride, or cinnamyl chloride. Alkali cyanate refers to lithium cyanate, sodium cyanate, potassium cyanate, and cesium cyanate alone or in combination of two or more of these.The industrially important ones are sodium cyanate, potassium cyanate, or cesium cyanate. It is an inexpensive product that contains about 5 to 20% alkali carbonate as its main ingredient. Aprotic acid amide solvents include dimethylformamide, diethylformamide, formylpiperidine, formylmorpholine, dimethylacetamide,
Diethylacetamide, acetylpiperidine, acetylmorpholine, N-methylpyrrolidone, N,
N′-dimethylethyleneurea, tetramethylurea, etc. alone or in a mixture of two or more of these,
The industrially important ones are dimethylformamide, diethylformamide, dimethylacetamide, N-
These include methylpyrrolidone and tetramethylurea. The presence of 10 to 100 ppm of water in the reaction system has the following meaning. That is, when an alkenyl halide and an alkali cyanate are reacted in an aprotic acid amide solvent, alkenyl isocyanate is first produced, which is then trimerized to form alkenyl isocyanurate, but when the water content in the reaction system is 10 ppm The inventors' research has confirmed that below, the production of alkenyl isocyanate due to the substitution reaction is inhibited and the reaction becomes extremely slow, whereas at 10 ppm or more the reaction is carried out smoothly. However, when the water content in the reaction system exceeds 100 ppm, the alkenyl isocyanate that has been produced will react with water to form dialkenyl urea, and the dialkenyl urea thus produced will act cooperatively with the water in the reaction system. The present inventors have discovered that the cyclization and trimerization of alkenyl isocyanate is inhibited, resulting in a significant decrease in the production yield of alkenyl isocyanurate. The water present in the reaction system can be determined by collecting the reaction mixture and using the Karl Fischer analysis of the supernatant or liquid. According to detailed experiments conducted by the present inventors, the reaction conditions for producing alkenyl isocyanurate from alkenyl halide in the best yield are such that the water content in the reaction system is 10 to 10%.
It has been confirmed that the water content is 100 ppm, preferably 20 to 80 ppm, and that this level of moisture is within a specific range that only has the effect of promoting the reaction and does not have the effect of consuming isocyanate. It was. Therefore, as long as the conditions of the present invention are complied with, the yield of the target alkenyl isocyanurate is high regardless of the structure described above.
It gives satisfactory results of 90-100%, especially 93-100% in many cases. Now, in order to limit the moisture content in the reaction system to 10 to 100 ppm, it is necessary to pay sufficient attention to the selection and purification of the reaction raw materials, and to ensure that the reaction equipment is completely moisture-proof. When using a raw material that inadvertently produces water as a by-product in the reaction system (for example, sodium cyanate containing sodium carbonate), this water can be selectively adsorbed or selectively reacted with this water. It is necessary to coexist a third substance in the reaction mixture to forcibly remove water and fix it outside the reaction system. This means that water is fixed as a solid that does not participate in the reaction so that it does not substantially affect the reaction system, and of course does not necessarily mean that it is removed from the reaction mixture. By fixing water suitable for these purposes, the water in the reaction system can be reduced to 10 to 10% by equilibrium.
Materials that maintain the concentration at 100 ppm include dehydrating solid acids with active surfaces such as silica gel, zeolite, zirconium silicate, and zirconium phosphosilicate. It is possible to achieve the purpose of Furthermore, the present inventors have developed a catalytic substance that accelerates the desired reaction while maintaining the above reaction conditions, and the use of this catalyst can lower the reaction temperature and save reaction time. This made it clear that That is, the catalyst having a beachhead structure as used in the present invention is generally a compound represented by the following chemical formula. ○B A beachhead compound that does not contain an active hydrogen atom and contains any of N, P, S, or Se atoms at the beachhead position of an alicyclic compound.

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[Formula] The above are typical basic substances, and compounds containing inert substituents can also be used as catalysts. ○B A beachhead compound that is an alkoxyalkali compound or an aminoalkali compound (R represents an alkyl group) having a tertiary alkyl group. tert−C ₄ H ₉ ONa, tert−C ₄ H ₉ OK, tert−C ₄ H ₉
OCS, tert−C ₄ H ₉ NRNa, tert−C ₄ H ₉ NRK,

【formula】

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[Formula] ○C Beachhead compound that is an N-alkali compound of a heteroaromatic amine having an NH group

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The above are typical basic substances, and compounds containing inert substituents can also be used as catalysts. ○D Substances in which any of the catalysts listed in ○A to ○C are fixed or bonded to the surface of an inorganic carrier or polymeric carrier and are substantially insoluble in the reaction system. Substances in which the compound is adsorbed on the surface of carbon, silica, alumina, zeolite, etc.; Substances in which the compound is bonded as a substituent to the main chain or side chain of a polymer; sodium salt or potassium phthalocyanine modified into a polymer type. salts, amines having a beachhead structure processed into cation exchange resins, or all-cyclic sulfonium salts or all-cyclic selenonium salts. The present inventors have developed a new production method for synthesizing alkenyl isocyanurate under special conditions using the above-mentioned catalyst, and in order to further explain the technical content in detail, representative experimental examples have been extracted and described below. This will be shown as an example. <Example> Examples 1 to 7 Alkenyl halides shown in Table 1 (1 mol, water
30-50 ppm), 91% sodium cyanate (1.5 mol, moisture 70-80 ppm, sodium carbonate 8.9%), 350 ml dimethylformamide (dried with barium oxide, rectified and stored on a molecular sieve. A mixture of catalysts whose water content was adjusted to 60 to 80 ppm (use the supernatant liquid as is) was stirred well and reacted under the reaction conditions shown in Table 1, and then the reaction mixture was cooled on ice and filtered. The inorganic salts were removed, the liquid was concentrated under reduced pressure at 50 mmHg to recover most of the dimethylformamide, the remainder was poured into water, ether extraction was performed, and the extract was dehydrated with anhydrous potassium carbonate. The residue or the product was separated by recrystallization. The relationship between the yield of alkenyl isocyanurate produced here and the reaction conditions is shown in Table 1 below.

[Table] Examples 8 to 12 Alkenyl halides shown in Table 2 (1 mol, water
30-40ppm), 99% potassium cyanate (1.2 mol,
water 80-100ppm), dimethylacetamide 300ml
(3.23 mol, moisture 60-70 ppm) and the catalyst were reacted under the conditions shown in Table 2. The reaction mixture was cooled with ice, the precipitated inorganic salts were filtered off, and the liquid was concentrated using a rotary evaporator. 50 ml of methanol was added to the residue, poured into cold water, and extracted with ether. The ether layer was dried over anhydrous sodium sulfate and distilled, and the residue after distilling off the ether was fractionally distilled to obtain isocyanurate. However, if the residue solidified, it was recrystallized from isopropanol to obtain the desired product. (Example 10). The relationship between the yield of the alkenyl isocyanurate produced and the reaction conditions is shown in the following table.

[Table] Examples 13 to 17 Alkenyl halide shown in Table 3 (1.0 mol, moisture 50 ppm), 98% sodium cyanate (0.6 mol,
water 40ppm), 98% potassium cyanate (0.6 mol,
water 30ppm), aprotic acid amide dissolved (water
After reacting 350 ml of 70 ppm) and the catalyst at 140°C for 1 hour, the same procedures as in Examples 1 to 7 were performed to determine the yield of alkenyl isocyanurate. The results are shown in Table 3.

[Table] Comparative Examples 1 to 6 When the reactions of Examples 13 to 15 were carried out without using a catalyst, the results of Comparative Examples 1 to 3 in Table 4 were obtained. Comparative Example 4~
6 results were obtained. However, when dioxane was used as a solvent, the reaction was carried out under pressure.

[Table] <Effects of the Invention> The present invention improves the conventional method for producing alkenyl isocyanurate and makes it possible to improve its yield. That is, the present invention enables the reaction between an alkenyl halide and an alkali cyanate in an aprotic acid amide solvent to be carried out by keeping the water content in the reaction system within a predetermined range and using a predetermined catalyst as a catalyst. The process was successfully carried out efficiently, and combined with the high usefulness of the target, it is expected to have industrial applicability.

Claims (1)

[Claims] 1. When reacting an alkenyl halide and an alkali cyanate in an aprotic acid amide solvent,
1. A method for producing alkenyl isocyanurate, which comprises allowing 10 to 100 ppm of water and a catalyst having a bridgehead structure to be present in the reaction system. 2 A catalyst having a beachhead structure contains any one of N, P, S or Se atoms at the beachhead position of an alicyclic compound, a compound containing no active hydrogen atom, an alkoxyalkali compound having a tertiary alkyl group, or Amino alkali compounds and NH
2. The method for producing alkenyl isocyanurate according to claim 1, wherein the alkenyl isocyanurate is at least one substance selected from the group consisting of N-alkali compounds of heteroaromatic amines having groups. 3. The alkenyl according to claim 1 or 2, wherein the catalyst having a beachhead structure is fixed or bonded to the surface of an inorganic carrier or a polymeric carrier and is substantially insoluble in the reaction system. Production method of isocyanurate.