JPS5835515B2 - Production method of isocyanuric acid ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for producing incyanuric acid ester.

A method for producing incyanuric acid ester by reacting an aliphatic no-logogenated compound with an alkali cyanate in an aprotic polar solvent has been known (Japanese Patent Publication No. 1973).
-3985 publication).

In this method, as shown in the following formulas (1) and (2), isocyanate is produced as an intermediate, and then this isocyanate is trimerized (polymerized) in the same reaction system to produce incyanuric acid. It is thought to produce esters.

R1R2CHX+MeOCN−)R1R2CHNCO+
MeX(1) 3R1R2CHNCO→(R1R2CHNCO)3
(2) In the above reaction, the moisture in the reaction system is as follows (3):
This causes the side reactions shown in formulas (4) and (5), resulting in a significant decrease in the yield of incyanuric acid ester.

(In the above formula, R1, R2, Me and X will be described later.

) Also, moisture in the reaction system is reduced by the above (3), (4) and (5).
) In addition to the side reactions shown in the formula, it causes hydrolysis of the aprotic polar compound that is the solvent, which significantly hinders the production of isocyanuric acid ester.

Therefore, it is necessary to avoid the introduction of moisture into the reaction system as much as possible.

However, the aprotic polar compound used as a reaction solvent in the present invention and the alkali cyanate used as a reaction raw material are highly hygroscopic and contain a large amount of water in industrial products, making it difficult to easily remove this water. It is difficult.

The present inventor completed the present invention as a result of studies on a method for removing moisture harmful to the reaction during the production of isocyanuric acid ester.

That is, the gist of the present invention is to react an aliphatic halogenated compound and an alkali cyanate in an aprotic polar solvent to produce an incyanuric acid ester.The solvent and the alkali cyanate are charged into a reactor, and then The present invention relates to a method for producing an isocyanuric acid ester, which is characterized in that after dehydration distillation, an aliphatic halogenated compound is added and reacted.

The dehydration distillation of the present invention includes a method in which the above-mentioned solvent and alkali cyanate are charged into a reaction vessel, and then a part of the solvent is distilled under normal pressure or reduced pressure to remove water contained together with the solvent, reaction solvent, and reaction raw materials. Then, an inert organic solvent that forms an azeotrope with water, such as benzene-toluene or xylene, is added to the reaction intermediate, and water contained in the reaction solvent and alkali cyanate is removed by azeotropic distillation along with the organic solvent. Examples of methods include:

Examples of the aprotic polar solvent used in the present invention include dimethylformamide, dimethyl sulfoxide, N
- Methylacetamide, acetonitrile, tetramethylurea, etc. can be mentioned.

The aliphatic halogenated compound is generally a compound represented by the chemical formula R1R2CHX, where X represents a logen atom (chlorine, bromine or iodine), and R1 and R2 are a hydrogen atom or an aliphatic hydrocarbon group, Or it represents a partially substituted hydrocarbon group, R1, R2
may be the same or different.

Examples of aliphatic hydrocarbon groups include alkyl groups, alkenyl groups, alkynyl groups, aralkyl groups, cycloalkyl groups, and cycloalkenyl groups, and a partially substituted aliphatic hydrocarbon group refers to one hydrogen atom of the aliphatic hydrocarbon group. or two or more may be substituted with a halogen atom, a nitro group, a cyan group, a carbonyl group, or an alkoxy group, and
There is no problem even when the terminal hydrogen atoms of R1 and R2 are each substituted with a methylene group, a methine group, a phenylene group, an oxygen atom, a sulfur atom, a carbonyl group, etc., and R1 and R2 have a cyclic structure.

The alkali cyanate is generally MeOCN or Me.
In the compound represented by the chemical formula NCO, Me represents an alkali metal atom.

Typical examples are lithium cyanate, potassium cyanate,
It is a single type of cyanic acid or a mixture of two or more types.

The reaction amount ratio of aliphatic halogenated compound and alkali cyanate is 1 mole of aliphatic halogenated compound to alkali cyanate! The range of 70.8 to 5.0 moles is preferable, and as long as both have good purity, approximately equimolar amounts can be used.

However, if you want to complete the reaction quickly, it is preferable to use alkali cyanate in an amount slightly in excess of the calculated amount.
The molar ratio is not necessarily limited to the above molar ratio.

The reaction temperature is 50 to 2 when using the above-mentioned solvent.
The reaction proceeds smoothly at 50°C, generally from 70 to 150°C.

The reaction time depends on the amount and type of aliphatic halogenated compound and alkali cyanate, as well as the amount of solvent, but it is usually 1 to 20 hours.

The amount of reaction solvent used is related to the difficulty of operation and the reaction time, and the more solvent there is, the shorter the reaction time, and the less it is, the longer it will be. A range of about 1 to 10 times the weight is preferred.

The present invention is effective in the production method of producing incyanuric acid ester by the reaction of an aliphatic halogenated compound and an alkali cyanate, but a reaction accelerator such as an alkali iodide or an alkali bromide is used in the reaction system during the reaction. It's okay.

Further, a similar effect can be obtained in a method using a metal salt of Group 2 in the periodic table, such as calcium acetate or calcium benzoate, as a side reaction inhibitor.

Next, the present invention will be explained with reference to examples, but the present invention is not limited to the following examples.

Example 1 Add 10 to 9 parts of diethylformamide with a water content of 0.12%, 4.5 kg of potassium cyanate with a purity of 94% and a water content of 0.3%, and 0.3 kg of toluene to a 301 reactor, and add 110' without stirring. GK heating, toluene 0.1 by simple distillation
9 was distilled off to 5.

The residual moisture in the system was 0.02%.

Next, the temperature was raised to 120°C, and 4.32 kg of methyl iodide was added to 3
It took a long time to prepare the mixture, and the mixture was continuously stirred at 100 to 120°C for 3 hours, and then cooled.

The reaction mixture was centrifuged, the solid was washed with diethylformamide, and the liquid f was combined and distilled under reduced pressure (67-69℃, 7℃).
15 Hg) to recover diethylformamide.

The distillation residue was poured into water, and the precipitated crystals were separated and recrystallized from methanol to obtain 1.54 ky of trimethyl incyanurate with a melting point of 176-177°C.

This is a yield of about 89% (based on methyl iodide).

Comparative Example 1 Trimethyl incyanurate was obtained in the same manner as in Example 1, except that toluene was not added to the reactor and dehydration by azeotropic distillation was not performed.

The yield is 1.13 to 9, which is about 65%.

Example 2 Into the same reactor as in Example 1, 10% dimethylacetamide with 0.1% moisture, 2.83 kg of potassium nocyanate, 94.5% purity, 62% moisture, and 0.1 m-xylene were added. 9
was added and heated to 120° C. with stirring, and 9 was distilled off to 0.07 m-xylene by simple distillation.

The residual moisture in the system was 0.03%.

Then, the temperature was raised to 130°C to give 3.7 n-propyl bromide!
g was added for 4 hours.

Thereafter, the mixture was stirred at the same temperature for 2 hours and cooled.

The reaction mixture was centrifuged, the solid matter was washed with dimethylacetamide, and the solution F was combined and distilled under reduced pressure (83-b) Tamide was recovered.

Add water and benzene to the distillation residue, extract the reaction product with benzene, distill off the benzene, and then distill under reduced pressure (116-b to produce isocyanuric acid) IJ n-propyl 2.4 kg
I got it.

This is a yield of about 94% (based on n-propyl bromide).

Comparative Example 2 Tri-n-propyl incyanurate was obtained in the same manner as in Example 2, except that xm-xylene was not added to the reactor and the dehydration operation by azeotropic distillation was not performed.

The yield is 1.71 kg, and the yield is about 67%.

Example 3 An 8 m″ reactor with a rectification column with 10 perforated plates was heated to 0.0 m of water.
6% dimethylformamide 4000kp, purity 85%
, Sodium cyanate 2000k19 with a moisture content of 0.36%
, anhydrous calcium chloride 200kg, potassium bromide 10k
g, and while stirring, the temperature was 90-95℃ and the pressure was 12℃.
Dimethylformamide 294 at 5 mvtHg, reflux 5
kg was distilled out.

The residual moisture in the system was 0.05%.

Then, the temperature was raised to 130°C, and allyl chloride (CH2
=CHCH2C1) 2050ky was added for 2.5 hours.

Thereafter, the temperature was maintained at the same temperature for 1.5 hours and cooled.

The reaction mixture was centrifuged, the solids were washed with dimethylformamide, and the lachrymal fluids were combined and distilled under reduced pressure to recover dimethylformamide.

Toluene is added to the distillation residue, and after filtration, the toluene is distilled off.
Vacuum distillation (123-b) 2104 kg of luril was obtained.

This is a yield of about 94% (based on allyl chloride).

Comparative Example 3 Triallyl isocyanurate was obtained in the same manner as in Example 3 except that dimethylamide was not distilled off.

The yield is 9 in 1455, which is about 65%.

Example 4 In 11 reactors equipped with a stirrer and a thermometer, 600 f of tetramethylurea with a water content of 0.5%, a purity of 98.5%, and a water content of 0.
2% potassium cyanate 85f? and benzene 30f?
was added and heated to 80'cK with stirring, and 152 benzene was distilled off by simple distillation.

The residual moisture in the system was 0.02%.

Next, 5ee-butyl bromide 137r was added, the temperature was raised to 130°C, and the reaction was carried out at the same temperature for 5 hours.

After cooling, the reaction mixture was filtered and washed with molecular sieves.
The solid matter was washed with tetramethylurea dehydrated using 4A, and the p liquid was combined and fractionated to obtain 72.3P of 5ee-butyl isocyanate having a boiling point of 100 to 102°C.

This is a yield of about 73% (based on 5ec-butyl bromide).

Comparative Example 4 5ec-butyl isocyanate was obtained in the same manner as in Example 4, except that benzene was not added to the reactor and the dehydration operation by azeotropic distillation was not performed.

The yield is 42.5? The yield is about 43%.

Example 5 In a reactor similar to Example 4, 100 tons of dimethyl sulfoxide 500S' with a water content of 0.2%, a purity of 94%, a water content of o, and 1% sodium cyanate were added, and the mixture was heated at 85 to 87°C under reduced pressure with stirring. Dimethyl sulfoxide 10 at 25 wHg
0Lf? was removed.

The residual moisture in the system was 0.01%.

Next, 151 g of 1-amyl bromide was added, and 700 mm
The reaction was carried out at 790° C. under reduced pressure of Hg for 20 hours.

After cooling, the reaction mixture was filtered, the solid was washed with dimethyl sulfoxide completely dehydrated using molecular sieves-4A, and the lachrymal fluid was combined and fractionated to give a boiling point of 120
72.3f of i-amyl isocyanate was obtained at ~123°C.

This is a yield of about 64% (based on 1-amyl bromide).

Comparative Example 5 1-Aluminum isocyanate was obtained in the same manner as in Example 5 except that dimethyl sulfoxide was not distilled off.

The yield is 40.7? The yield is about 36%.

Claims (1)

[Claims] 1. To produce incyanuric acid ester by reacting an aliphatic... rogogenated compound with an alkali cyanate in an aprotic polar solvent, the solvent and the alkali cyanate are charged into a reactor, and then After dehydration and distillation,
A method for producing an isocyanuric acid ester, which comprises adding and reacting an aliphatic halogenated compound.