JP2510089B2 - Method for producing mercapto ether compound - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improved method for producing a mercapto ether compound, and more specifically, to a mercapto conversion of a halogenated ether compound with thiourea And a method for producing a mercapto ether compound with regeneration of thiourea.

"Prior Art" A halogenated ether compound is reacted with thiourea to form a thiuronium salt shown below, Then, the thiuronium salt is treated with an alkaline compound,
For example, a method of producing a mercapto-ether compound by decomposing a compound such as sodium hydroxide as a decomposing agent is well known. However, this method has a drawback in that the thiourea used becomes a mixture of various by-products, and this by-product becomes a large amount of waste.

Therefore, if by-products such as those produced by the reaction with the decomposition of the thiuronium salt in the decomposition step can be returned to thiourea at the same time, the decomposition of the above-mentioned decomposition can be performed by adding a halogenated ether compound to the reaction system again. The reaction can be repeated.

As a result of diligent studies by the present inventors in consideration of the above points, if ammonium hydrogen sulfide is used as the above decomposing agent or a mixture of the above components by reaction is used, thiourea can be repeatedly used and is produced. The inventors have found that the quality of the mercapto-ether compound does not deteriorate, and arrived at the present invention.

"Means for Solving the Problem" That is, in the present invention, a halogenated ether compound represented by the following general formulas [I] and / or [II] and thiourea are mixed with X (RO) mH ... [I] X (RO) nRX ... [II] (wherein R is an alkylene group having 2 or 3 carbon atoms, X is a chlorine atom or a bromine atom, and m and n are natural numbers of 1 to 4) To produce a mercaptan by decomposing the thiuronium salt and then producing a mercaptan, in the decomposing step, at least one decomposing agent selected from the group consisting of ammonium hydrogen sulfide, an ammonium salt and an alkali hydrogen sulfide, or hydrogen sulfide and ammonia is used. The following general formula [II] characterized by being accompanied by regeneration of thiourea by using
[I] or [IV] is a method for producing a mercapto ether compound.

HS (RO) mH ...... [III] HS (RO) nRSH ...... [IV] (wherein R, m and n are the same groups as described above) The above-mentioned general formula [I] used in the present invention or Examples of the halogenated ether compound represented by [II] include ethylene chlorohydrin, ethylene bromohydrin, 2-
Chloroethoxyethanol, 2-bromoethoxyethanol, 1-chloro-8-hydroxy-3.6-dioxaoctane, 1-bromo-11-hydroxy-3,6,9-trioxaundecane, 1,5-dichloro-3- Oxapentane, 1,5-dibromo-3-oxapentane, 1,8-dichloro-3,6-dioxaoctane, 1,11-dibromo-3,6,9-
Trioxaundecane, 1,14-dichloro-3,6,9,12-tetraoxatetradecane or 1,2- of these compounds
Examples thereof include compounds of the same kind in which a part or all of the ethylene group is substituted with a 1,2-propylene group.

In the method of the present invention, first, a thiuronium salt is produced. The method for producing this salt is not particularly limited, and any known method may be used. Generally, a halogenated ether compound and thiourea are used as the halogen atom of the ether.
Using 1 mol or more and 2 mol or less per mol, 50 to 150 ° C,
The reaction is preferably carried out in a solvent such as water at a temperature of 80 to 110 ° C. Examples of the solvent also include lower alcohols such as methanol, ethanol, propanol and ethylene glycol, and ethers such as ethylene glycol monomethyl ether, dioxane and tetrahydrofuran. The amount of these solvents used is preferably 1/5 to 5 times the weight of the halogenated ether compound.

Next, in decomposing the produced thiuronium salt,
In the method of the present invention, as described above, at least one decomposing agent selected from the group consisting of ammonium hydrogen sulfide, ammonium salts and alkali hydrogen sulfide, or hydrogen sulfide and ammonia is used. The ammonia component of the agent is involved, and hydrogen sulfide has an effect of returning the by-product derived from thiourea to thiourea again. That is, although various decomposing agents have been proposed, they all bring about the same effect when added to the decomposition reaction of the thiuronium salt.

When ammonium hydrogen sulfide is used for decomposing the thiuronium salt, the amount used may be 1 mol or more and 2 mol or less with respect to 1 mol of the terminal end of the thiuronium salt. It is easily obtained by dissolving.

When an ammonium salt and an alkali hydrogen sulfide are used as the decomposer, ammonium sulfate and ammonium chloride are preferably used as the salt. Further, sodium hydrogen sulfide and potassium hydrogen sulfide are preferably used as the alkali hydrogen sulfide. The amount of the ammonium salt used is preferably 0.05 mol to 1.5 mol per mol of the thiuronium terminal, and the amount of less than 0.05 mol is not preferable because the decomposition of the thiuronium salt is incomplete, and the amount exceeding 1.5 mol is not preferable. meaningless. The amount of alkali hydrogen sulfide used with respect to 1 mol of the end of the thiuronium salt is preferably 1 mol or more and 2 mol or less.

Further, when hydrogen sulfide and ammonia are used as the decomposing agent, it is preferable to first add ammonia to the reaction system to decompose the thiuronium salt and then add hydrogen sulfide. This ammonia can be added to the reaction system in the form of an aqueous solution or a gas, and the amount used is the same as in the case of using the ammonium salt. Further, it is easy to add hydrogen sulfide in a gaseous state, and the amount of hydrogen sulfide added is the same as in the case of the above-mentioned alkali hydrogen sulfide.

In carrying out the above-mentioned thiuronium salt decomposition, that is, the mercaptan formation reaction, the reaction temperature and the temperature at the time of adding the decomposition agent are preferably in the range of 20 to 80 ° C. If the temperature is lower than 20 ° C, the long-term reaction cannot be avoided in the decomposition of the thiuronium salt,
Further, at a temperature above 80 ° C., a phenomenon occurs in which ammo and hydrogen sulfide remarkably vaporize without reaction, both of which are not preferable.

After the decomposition of the thiuronium salt, that is, the mercaptan formation reaction, a solvent such as toluene was added in order to completely separate the aqueous layer and the organic layer, the formed mercaptan was extracted, and the amount of ammonium hydrogen sulfide used was excessive, which remained. If necessary, decompose with mineral acid, etc., and then if necessary, known method,
For example, a high-purity mercapto-ether compound can be obtained by purifying by washing or distillation. It is also possible to add the above-mentioned solvent even at the start of the decomposition reaction of the thiuronium salt.

In particular, when the amount of ammonium salt used is less than 1 mol per 1 mol of the end of the thiuronium salt, the addition of a solvent at the start of the decomposition reaction of the thiuronium salt makes it possible to improve the quality such as reduction of by-product disulfide.

On the other hand, a large amount of thiourea is regenerated and present in the water layer, but at the same time, a by-product inorganic salt is also present. If this inorganic salt is separated from the aqueous layer by utilizing the difference in solubility with thiourea, the above aqueous solution is used as it is in the next reaction.
Further, this aqueous layer is cooled to crystallize thiourea, which is recovered by filtration and used again in the thiuronium chlorination reaction, whereby the mercapto ether can be efficiently produced. I can.

As described above, when the method of the present invention is used, it is possible not only to reduce the amount of expensive thiourea used in producing a mercapto-ether compound, but also to reduce the amount of by-products to be discarded.

"Example" Hereinafter, the method of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the invention is not limited thereto.
In the following description, "part" means "part by weight".

Example 1 215 parts of thiourea and 235 of water in a glass reaction vessel of 1000 parts by volume.
Parts were put, and the mixture was stirred and heated. When the temperature reaches 70 ℃
The addition of 220 parts of 1,8-dichloro-3,6-dioxaoctane was started and added at 90 ° C or lower over 1 hour. Then, the temperature was raised to 100 ° C. and the aging reaction was continued for 3 hours. After the reaction was completed, a colorless transparent liquid was present in the container.

After cooling this liquid, a 50% aqueous solution of hydrogen sulfide ammonia 290
Parts in a nitrogen atmosphere at 30 ° C for 30 minutes, and then
The temperature was raised to 50 ° C., and the mixture was stirred and reacted for 2 hours. Next, 55 parts of concentrated hydrochloric acid was added to this liquid, and the mixture was treated at 60 ° C. for 30 minutes to decompose excess ammonium hydrogen sulfide.

The solution was separated at 60 ° C., and the obtained organic layer was washed with 50 parts of water and subjected to simple distillation to obtain 202 parts of a colorless transparent liquid. When this product was analyzed by gas chromatography, the purity was 99.4.
% 1,8-dimercapto-3,6-dioxaoctane.

On the other hand, the weight of the remaining aqueous layer was 796 parts, and when the thiourea contained in this was analyzed by the method shown in JIS-K8635, it was found that 98.1% was regenerated with respect to the thiourea used. found.

Example 2 The aqueous layer after the reaction shown in Example 1 was used as it is,
Example 1 except that a 1500 volume part glass reactor was used.
The method described was followed. However, after decomposing excess ammonium hydrogen sulfide, it was heated to 80 ° C. and then the by-product inorganic salts were filtered and separated.

The obtained organic layer was subjected to simple distillation to obtain 207 parts of a colorless and transparent distillate. As a result of analysis by gas chromatography, it was 1,8-dimercapto-3,6-dioxaoctane having a purity of 98.8%. The yield was 95.4%.

The total weight of the aqueous layer was 892 parts, and when thiourea was analyzed, 96.4% was regenerated.

Comparative Example 1 215 parts of thiourea and 235 water in a glass reaction vessel of 1000 parts by volume.
Parts were put, and the mixture was stirred and heated. When the temperature reaches 70 ℃
The addition of 220 parts of 1,8-dichloro-3,6-dioxaoctane was started and added at 90 ° C or lower over 1 hour. Then, the temperature was raised to 100 ° C. and the aging reaction was continued for 3 hours. After the reaction was completed, a colorless transparent liquid was present in the container.

After cooling the reaction system, 260 parts of 40% sodium hydroxide was added at 50 ° C.
Was added for 30 minutes, and the reaction was aged for 30 minutes at the same temperature. To this, 55 parts of concentrated sulfuric acid was added and treated at 60 ° C. for 30 minutes to neutralize excess sodium hydroxide.

This solution was separated at 60 ° C., the organic layer was washed with 50 parts of water, and then 186 parts of a colorless transparent liquid was obtained by simple distillation. When this liquid was analyzed by gas chromatography, the purity was 98.5.
% 1,8-dimercapto-3,6-dioxaoctane. The yield of this product was 85.5%.

On the other hand, the total weight of the remaining aqueous layer was 798 parts, and thiourea was not contained in this.

However, the COD of this aqueous layer diluted with 10 times the weight of water was 31,000 ppm.

Example 3 230 parts of thiourea and 230 parts of water in a glass reaction vessel of 1000 parts by volume
Parts were put, and the mixture was stirred and heated. When the temperature reaches 80 ℃
The addition of 180 parts of 1,5-dichloro-3-oxapentane was started and added at 90 ° C or lower for 1 hour. Then 95
The temperature was raised to ° C and the aging reaction was continued for 4 hours. After the reaction was completed, a colorless transparent liquid was present in the container.

After cooling this reaction liquid, 160 parts of ammonium sulfate was added thereto, 390 parts of a 40% sodium hydrogen sulfide aqueous solution was added at 50 ° C. in a nitrogen atmosphere for 30 minutes, and further an aging reaction was carried out at 55 ° C. for 30 minutes.

When treated according to the method described in Example 1, the purity is 99.5%.
161 parts of 1,5-dimercapto-3-oxapentane was obtained. The yield was 92.1%.

The total weight of the aqueous layer is 1047 parts, of which thiourea is
It was played 97.9%.

Example 4 15 parts of ammonium chloride and 180 parts of toluene were added to the thiuronium chlorination reaction solution obtained according to Example 3, and the mixture was added at 40 ° C. to 40%.
% Sodium hydrogen sulfide aqueous solution 390 parts under nitrogen atmosphere 1
It was added over time and aged at 55 ° C. for 30 minutes.

Then, this reaction solution was treated according to the method described in Example 1 to obtain 165 parts of 1,5-dimercapto-3-oxapentane having a purity of 99.2%. The yield was 94.1%.

The remaining aqueous layer was cooled with ice water to precipitate crystals, which were filtered to obtain 203 parts of white crystals. When analyzed, it was a thiourea mixture with a content rate of 91.2% and a recovery rate of 80.5.
% And water content was 7.5%.

The filtrate was 693 parts, and the COD of an aqueous solution obtained by diluting this with 10 times by weight of water was 5400 ppm.

Example 5 Using 201 parts of the recovered thiourea mixture obtained in Example 4 and 47 parts of thiourea freshly, Example 4 was repeated, and 99.5% pure 1,5-dimercapto-3-oxapentane 167 was obtained.
Parts were obtained. The yield was 95.0%.

In the aqueous layer, 97.1% of thiourea was regenerated, and when this was separated and crystallized, 209 parts of white crystals were obtained. As a result of analysis, it was a mixture containing 90.8% of thiourea. . The recovery rate was 82.5%.

Example 6 The thiuronium salt solution obtained by the method described in Example 1 was cooled, 160 parts of 28% aqueous ammonia was added thereto, and the mixture was treated at 50 ° C. for 1 hour. After separation, 88 parts of hydrogen sulfide gas is added to the water layer at 50 ° C.
It took 1 hour to install.

The organic layer was washed with water and then subjected to simple distillation to obtain 204 parts of 1,8-dimercapto-3,6-dioxaoctane having a purity of 99.5%. The yield is
It was 94.7%.

 On the other hand, 90.7% of thiourea was regenerated in the water layer.

Example 7 126 parts of thiourea and 325 of water in a glass reaction vessel of 1000 parts by volume.
Parts were put, and the mixture was stirred and heated. When the temperature reaches 80 ℃
The addition of 130 parts of 1,8-dichloro-3,6-dioxaoctane was started and added at 90 ° C or lower over 1 hour. Then, the temperature was raised to 100 ° C. and the aging reaction was continued for 5 hours.

Ammonia chloride was added to the obtained thiuronium chlorination reaction liquid.
And 130 parts of toluene are added, and flakes at 70% at 50 ° C.
116 parts of sodium hydrogen sulfide was added in a nitrogen atmosphere for 1 hour, and the mixture was aged at 55 ° C. for 30 minutes. Next, 35 parts of concentrated hydrochloric acid was added to this solution and treated at 60 ° C. for 30 minutes to decompose excess ammonium hydrogen sulfide.

The organic layer was treated according to Example 1 to give 1,8 of 99.3% purity.
118 parts of dimercapto-3,6-dioxaoctane were obtained.
The yield was 92.5%.

On the other hand, the weight of the remaining aqueous layer was 569 parts, in which thiourea was regenerated by 97.9%.

Then, using this aqueous layer as it was, the thiuronium chlorination reaction and the subsequent steps were repeated according to the above method. However, in the thiuronium conversion reaction, 3 parts of thiourea was newly added, but water was not added. Also, 1 part of ammonium chloride was added during the thiolation reaction. After decomposing excess ammonium hydrogen sulfide, the mixture was heated to 80 ° C., then the by-produced inorganic salts were separated by filtration and separated.

The same procedure was repeated twice with the thiourea thus recovered. However, a shortage of thiourea was newly replenished as compared with the first method. The results are shown in Table 1.

Examples 8 to 13 Using the halogenated ethers and decomposing agents shown in Table 2,
The method described in Example 1 and Example 6 was repeated, and the results are shown in Table 2.

"Effects of the Invention" When a mercapto ether compound is produced from a halogenated ether compound by using the method of the present invention, thiourea can be regenerated and used, and waste can be significantly reduced, but the obtained mercapto ether can be obtained. The purity and yield of the compound is also improved.

Claims (2)

(57) [Claims] 1. A halogenated ether compound represented by the following general formula [I] and / or [II] and thiourea: X (RO) mH ...... [I] X (RO) nRX ...... [II] (Here, R is an alkylene group having 2 or 3 carbon atoms, X is a chlorine atom or a bromine atom, and m and n are natural numbers of 1 to 4.) The reaction is performed to form a thiuronium salt, and then the thiuronium salt. In the production of mercaptan by decomposing thiourea by using at least one decomposing agent selected from the group consisting of ammonium hydrogen sulfide, ammonium salt and alkali hydrogen sulfide, or hydrogen sulfide and ammonia in the decomposition step. The following general formula [III] characterized by
Alternatively, a method for producing the mercapto-ether compound represented by [IV]. HS (RO) mH ...... [III] HS (RO) nRSH …… [IV] (wherein R, m and n represent the same groups as described above). 2. The method according to claim 1, wherein the amount of the ammonium salt used in the decomposing agent is 0.05 mol to 1.5 mol per 1 mol of the thiuronium terminal.