JPH0564629B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a new method for producing isocyanurate, which includes plasticizers, agricultural chemicals, synthetic intermediates,
This invention relates to an improved method for producing isocyanurate in high yield and in large quantities, which is in high demand as a crosslinking agent, resin raw material, heat-resistant organic material, etc. By applying the present invention, it has become possible to prevent as much as possible the production of by-products associated with conventional isocyanurate production, and to perform industrial production extremely economically. [Prior Art] A method for producing isocyanurate by reacting an organic halogen compound and an alkali cyanate in a polar aprotic solvent was discovered by the present inventors.
It has been developed and technically perfected. The main points will be shown and explained in order below. , Method for producing cyanuric acid derivatives (Nittokuko, 1962)
-3985) relates to a basic method of reacting an organic halogen compound and an alkali cyanate in an organic compound containing a nitrogen atom or a sulfur atom. , Method for Producing Isocyanuric Acid Esters (Nippon Tokko, 1984-4376) relates to a basic method of trimerizing isocyanate to form isocyanurate in an organic compound having a nitrogen or sulfur atom. , Process for the Production of Isocyanuric Acid Esters (Nippon Tokko, 1972-6635) relates to a basic method of reacting cyanuric acid (or its salt) with an organic halogen compound in an organic compound containing a nitrogen or sulfur atom. It is. , Purification method of isocyanuric acid triester (Nittokuko, Akira
42-9345) is a method for extracting and removing impurities in products using glycol or glycerin. , Purification method of isocyanuric acid ester (Nittokuko, 1972-
12913) is a method of decomposing and removing impurities in products using an aqueous solution of hydrohalic acid. , Method for Producing Isocyanic Acid Derivatives (Nippon Tokko, 1976-26766) relates to an improved method in which a second metal salt is present in the reaction between an alkali cyanate and an organic halogen compound. , Method for Producing Isocyanuric Acid Triesters (Nippon Tokuko, 14395/1982) relates to a purification method in which a reaction mixture containing a crude product is heated with an alkaline aqueous solution. , a method for producing isocyanuric acid esters (Nippon Tokko, 16308/1982) is a method in which a poorly soluble transition metal compound is present in the reaction of an aliphatic halogen compound and an alkali cyanate in an acid amide to improve the yield. It is related to. , A method for removing impurities from isocyanuric acid ester (Nippon Tokuko, 1972-22588) is a method of purifying the crude product by contacting it with ammonia or amine. , A method for purifying triallyl isocyanurate (Nippon Tokko, 1972-26022) is a method for purifying a crude product by contacting it with formalin and ammonia. , a method for producing isocyanuric acid triester (Japanese Patent Publication, 1984-40633) involves the presence of sulfites and phosphites in the system in which an organic halogen compound and an alkali cyanate are reacted to prevent oxidative side reactions during the reaction. The present invention relates to a method for controlling pests and improving the yield of a target product. Although each of the above patents is representative, all related patents, including basic, improved, and refined patents, each have practical value. It is. However, it has not been achieved to completely prevent side reactions during the synthesis of isocyanurates, and even if high-quality organic halogen compounds, alkali cyanates, and solvents are used, the yield of the target product is 80 to 95%.
It has been confirmed through experiments on an experimental or industrial scale that there is a gap between the two. [Problems to be solved by the invention] The present inventors have conducted detailed research on the production method of isocyanurate, and have found that there is a delicate difference between the amount of water that promotes the reaction and the amount of water that causes side reactions. After identifying the relationship, we decided to experimentally determine the optimal amount of water required to produce isocyanurate by reacting an organic halogen compound and an alkali cyanate in a polar aprotic nitrogen-containing solvent. This was a success and led to the completion of the present invention. It was also revealed that by maintaining the technology of the present invention, it is possible to obtain isocyanurate in a much higher yield than in the past. [Means for Solving the Problem] and [Operation] The present inventors have developed a compound having at least one halogenomethyl group selected from the group consisting of alkyl halide, alkenyl halide, alkynyl halide, and aralkyl halide (hereinafter simply referred to as When reacting a halide (referred to as a halide) and an alkali cyanate in a polar aprotic nitrogen-containing solvent (hereinafter simply referred to as a solvent), the water content in the system is
They found that when the water content was maintained at 200 ppm, the yield of the target product was much better than when the reaction was carried out at other water contents. Silica gel, alkali silicate, zeolite, dehydrated clay mineral, zirconium silicate phosphate, and silicate ester are used to maintain the water content in the reaction system, that is, the amount of water eluted into the reaction solution, at 10 to 200 ppm. At least one silicon compound selected from the group consisting of They recognized that it is also effective to allow them to coexist and react. The halide referred to in the present invention is generally a primary halide represented by the following chemical formula. RCH ₂ There is no problem. Moreover, or iodide, and prefixes such as normal, cyclo, iso, secondary, ortho, meta, para, etc. are omitted). Namely, methyl chloride, ethyl chloride, propyl chloride, butyl chloride, amyl chloride, hexyl chloride, heptyl chloride,
Octyl chloride, nonyl chloride, decyl chloride, undecyl chloride, lauryl chloride, cetyl chloride, stearyl chloride, allyl chloride, methalyl chloride, crotyl chloride, isopropenyl chloride, butenyl chloride, pentenyl chloride, oleyl chloride, propargyl chloride,
Benzyl chloride, phenylethyl chloride, methylbenzyl chloride, xylyl chloride, and the like are general-purpose compounds having a monohalogenomethyl group. The halides containing some substituents mentioned above include 1,2-
dichloroethane, 1,3-dichloropropane,
1,4-dichlorobutane, 1,5-dichloropentane, 1,6-dichlorohexane, neopentyl chloride, chlorbenzyl chloride, methoxybenzyl chloride, butyl hydroxybenzyl chloride, dibutyl hydroxybenzyl chloride, xylylene dichloride, Phenoxybenzyl chloride is a typical example. Alkali cyanate refers to lithium cyanate, sodium cyanate, potassium cyanate, cesium cyanate, etc. alone or as a mixture.Industrially, sodium cyanate, potassium cyanate, or 5 to 20% by weight of these as main components are used. % of alkali carbonate is available. Solvents referred to in the present invention include dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, acetonitrile, propionitrile, adiponitrile, benzonitrile, nitromethane, nitroethane, nitrobenzene, N-formylpiperidine, N-acetylpiperidine, N-formylmorpholine, N-acetylmorpholine, N, ^N1 -diformylpiperazine,
N,N ¹ -Diacetylpiperazine, N,N-dimethylbenzamide, N,N-dimethylbenzenesulfamide, tetramethylurea, dimethylaminocyanide, dimethylaniline, etc., which have highly polar and easily dissociated active hydrogen atoms. A nitrogen-containing solvent alone or a mixture of two or more thereof, or a mixture with an anhydrous organic solvent containing no active hydrogen and containing 70% by weight or more of these nitrogen-containing solvents. Now, whether or not the water content in the system, that is, the amount of water eluted into the solution, is maintained at 10 to 200 ppm can be determined by quantifying the supernatant liquid or distillate of the reaction mixture using Karl-Fitschier analysis. You can know. The most important issue regarding water is the purification of the solvent used in the reaction.
Commercially available solvents used in the present invention are generally 500 ppm (0.05%), unless they are of particularly poor quality.
Contains about 1000ppm (0.1%) of water. This level of moisture is sufficient for normal use as a solvent, and if dehydration is particularly required, a desiccant is added and then purified by distillation. The following table shows the results of measuring the type of desiccant and drying limit of dimethylformamide (DMR), a typical solvent, and examining the degree of decomposition of the solvent. The table below shows 1000ml of DMF with a moisture content of 700ppm and a desiccant agent.
100g was added and left to stand for 3 days, then carefully distilled and analyzed.

【table】

[Table] Although the above table uses DMF as an example, it has been revealed through numerous studies by the present inventors that the drying limit and degree of decomposition of polar aprotic solvents by desiccant tend to be roughly the same. Ta. A model experiment was conducted for the following reaction using the dehydrated solvent as described above. 3C ₆ H ₅ CH ₂ Cl + 3KNCO → (C ₆ H ₅ CH ₂ NCO) The C ₆ H ₅ CH ₂ Cl used for ₃ is dehydrated and distilled using anhydrous potassium carbonate, and then distilled using a molecular sieve. Use dry material with a moisture content of 150 ppm.
Potassium cyanate is a self-synthesized KNCO with a purity of 99.8% (K ₂ CO ₃ 0.2% or less, moisture 50 ppm,
100 mesh powder) was used. Using 30 moles of solvents with different drying limits, 3 moles of benzine chloride and 4 moles of potassium cyanate were prepared in 120
Tribenzylisocyanurate was synthesized by reacting at ~150°C for 3 to 4 hours, and the results are as follows.

【table】

〔Example〕

Examples 1 to 10 Halides shown in the following table (1 mol, moisture 20~
30ppm), silicon compounds (the amount added is shown in the table below)
99.5% potassium cyanate powder (2 mol, water
40 ppm) and 250 ml of dimethylformamide (the amount of water in the supernatant of the reaction mixture is shown in the table below) were placed in a magnetic stirring autoclave and reacted at 150°C for 3 hours, then cooled and the reaction mixture was poured into ice water. After extraction with ether and drying the extract over anhydrous sodium sulfate, the yield of isocyanurate obtained by distillation was determined. The results are shown in the table below.

[Table] Examples 11 to 20 Halides shown in the following table (0.5 mol, moisture 20 to
30ppm), silicon compounds (the amount added is shown in the table below),
98.2% sodium cyanate powder (0.70 mol, but containing about 0.9% _Na2CO3 ) and the solvent shown in the following table (5 _mol , moisture 50-75 ppm) were placed in a closed glass reaction vessel and heated at 150-160℃. The reaction mixture was immersed in an oil bath and stirred for 4 hours, then cooled. The reaction mixture was poured into water and extracted with ether. The extract was dried over anhydrous sodium sulfate and distilled to determine the yield of isocyanurate. I asked for it. The results are shown in the table below. The amount of water dissolved in the system is shown in the solvent section.

【table】

[Table] Examples 21 to 28 A flask equipped with a dropping funnel, a backflow condenser, a stirrer, and a thermometer was equipped with the solvent shown in the following table (10 mol, the amount of water in the supernatant liquid of the reaction mixture is shown in the table below), industrial Sodium cyanate powder (100g, however, Na ₂
Add CO ₃ (approximately 9% content, moisture 200 ppm) and the silicon compounds shown in the following table (the amounts added are shown in the next table).
The halides shown in the following table (1 mol, moisture 20-30 ppm) were added dropwise from the dropping funnel at 150 to 160°C with stirring over a period of 1 hour, and the reaction was continued for 2 hours and cooled. After separating the inorganic salts from the reaction mixture, the liquid was distilled to determine the yield of isocyanurate, as shown in the following table.

〔Effect of the invention〕

The present invention is useful for improving the yield in the conventional production of isocyanurate, that is, isocyanuric acid triester.
The key point is that the highest yield can be achieved when the amount of water in the reaction system, that is, the amount of water in the solution involved in the reaction, is between 10 and 200 ppm, and one method to ensure this condition is achieved. This indicates that a silicon compound coexists in the reaction system, and in the presence of this compound, the presence of alkali or alkaline earth metal carbonate or oxide as an impurity in the alkali cyanate also occurs in the reaction system. The point is that it has become possible to maintain the moisture content at 10 to 200 ppm and obtain various industrially useful isocyanurates in good yields. The present invention is an important invention in the chemical industry, and the isocyanurate synthesized by this method is used industrially as a plasticizer, agricultural chemical, synthetic intermediate, crosslinking agent, resin raw material, heat-resistant organic material, etc. Contains many things.

Claims (1)

[Claims] 1. A compound having at least one halogenomethyl group selected from the group consisting of alkyl halides, alkenyl halides, alkynyl halides and aralkyl halides is reacted with an alkali cyanate in a polar aprotic nitrogen-containing solvent. A method for producing isocyanurate, which is characterized in that the water content in the system is maintained at 10 to 200 ppm. 2 Silica gel, alkali silicate, zeolite,
The method for producing isocyanurate according to claim 1, characterized in that at least one silicon compound selected from the group consisting of dehydrated clay minerals, zirconium phosphate silicates, and silicate esters is present. 3. In order to maintain the water content in the system between 10 and 200 ppm, from the group consisting of alkali or alkaline earth metal carbonate, silica gel, alkali silicate, zeolite, dehydrated clay mineral, zirconium phosphate silicate, and silicate ester. The method for producing isocyanurate according to claim 1, characterized in that at least one selected silicon compound is present. 4. From the group consisting of alkali or alkaline earth metal oxides, silica gel, alkali silicates, zeolites, dehydrated clay minerals, zirconium phosphate silicate, and silicate esters to maintain the water content in the system between 10 and 200 ppm. The method for producing isocyanurate according to claim 1, characterized in that at least one selected silicon compound is present.