JPS60158163A - Preparation of polythioaikylene dimercaptan - Google Patents

Abstract

PURPOSE:To obtain the titled compound in high yield and purity, by reacting a specific sulfur-containing compound with thiourea and a mineral acid in the presence of a thiuronium salt, and decomposing the reaction product with an alkaline compound. CONSTITUTION:A sulfur-containing compound of formula I (R is 2-3C alkylene; n is a natural number 1-4) and/or formula II (m is a natural number 1-4) is reacted with thiourea and a mineral acid to form a thiuronium salt, which is then decomposed with an alkaline compound to afford the aimed polythioalkylene dimercaptan of formula III and/or formula IV. In the process, the reaction is carried out in the presence of a thiuronium salt the same or different from the thiuronium salt prepared in the production process of the above-mentioned thiuronium salt.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improved method for producing polythioalkylene dimercaptans, and more particularly to mono- or dihydroxy poly(
This invention relates to a method for thiolating mono)thioalkylenes.

PRIOR ART A thiuronium salt as shown below is formed by reacting nanomata it dihydrotetraxypoly(mono)thioalkylenes (hereinafter abbreviated as H8A) with thiourea and hydrogen chloride, and then converting the thiuronium salt with an alkaline substance. The method of decomposing polythioalkylene dimercaptans (hereinafter referred to as SADMs) is well known.

However, this method has traditionally had unavoidable drawbacks such as low yield and low purity of SADMs.

Problems to be Solved by the Invention The present inventors have arrived at the present invention as a result of various studies aimed at solving the above problems and obtaining high-yield, high-purity SADMs.

Means for Solving the Problems The present invention aims to coexist the same or different types of thiuronium salts produced in the thiuronium salt production step of the above-mentioned manufacturing process and/or in the alkali decomposition step of the thiuronium salt. SADMs of the same type or different from SADMs
This is an improved method for producing SADMs characterized by the coexistence of metal salts of the following types.

In carrying out the method of the present invention, H8As used as starting materials are represented by the following general formulas 〇〇 and/or 0.

HO(R8) nl-1・・・・・・・・・・・・・・・
・・・・・・ α〕HO(R8)mROH・・・・・・
(2) Specific examples of these H8As include 2-mercaptoethanol (HOCH
, CH, SH), 1-hydroxy-5-mercapto-3
-thiopentane (HOC for Cl-1!SCH,Cl-1,SH), 1-hydroxy-8-mercapto-3,6-cythiooctane (
-11-mercapto-3,6,9-trithioundecane (HO(CHICH戈5)4H), thiodiglycol (
1.11
- Dihydro-tetraxy3.6.9-trithio-undecane (1-10 (CI-1, CH, 8), CH, CH, OH
), 1,14-dihydroxy-3,6,9,12-tetrathio-tetradecane (HO(CpengC)1.8), CH
, CH, OH), etc., as well as 2-methyl-2-mercaptoethanol, thiodipyrene glycol, and similar compounds in which part or all of the ethylene group of the above compound group has been replaced with a tetrapyrene group. I can give an example.

In the production of thiuronium salts as described above, generally H8
Group A and thiourea are reacted in the presence of a mineral acid. It is usually preferable to use thiourea and mineral acid in an amount equal to or more than 1 mole or equivalent to the hydroxyl group of H8A, but if more than 2 times the mole or 2 times the equivalent is used, post-reaction treatment should be taken into consideration. It is not desirable. Mineral acids include hydrochloric acid,
Sulfuric acid is preferred. Since this thiuronium salt production reaction is accompanied by heat generation, H8As or thiourea is usually added continuously or intermittently in small amounts, and the reaction temperature is generally set at 50°C or higher, and the concentration of all reaction raw materials in the aqueous solution is 10 to 50% by weight is preferred.

On the other hand, according to the method of the present invention, it is preferable that the raw thiuronium salt and the same type of thiuronium salt or a different type of thiuronium salt coexist.

(If they are not allowed to coexist, the coexistence of SADM metal salts becomes essential in the decomposition stage of the thiuronium salt, as will be described later.

).

There are no particular restrictions on the coexisting thiuronium salt, but SADM
Taking into consideration the separation and purification after the production of the USA species, it is preferable that the thiuronium salt is derived from the USA species, in other words, it is the same as the thiuronium salt that is originally produced. There is no specific KIS1% method for adding thiourea to the reaction system for coexistence, but examples include adding thiourea to a mixture of H8As, mineral acids, and thiuronium salts to coexist as described above, and adding thiourea to a mixture of H8As and mineral acids to coexist. Salt mixture K H
Examples include a method in which 8A class and a mineral acid are preferably added separately. This amount of coexistence is 10 to 50 with respect to the starting H8As.
If the weight% is less than the lower limit, the coexistence effect is not significant,
If the amount used exceeds the upper limit, the efficiency of the production and reaction of cough thiuronium salt will drop significantly, which is not preferable.

If the reaction is carried out under the above reaction conditions, the desired thiuronium salt will be produced in a high yield in an aqueous solution as described above in 5 to 10 hours. This aqueous solution can be referred to as the formation reaction of SMjlv@.
Used for alkaline decomposition reaction of thiuronium salt.

This alkaline decomposition reaction is an exothermic reaction, and it is generally preferable to add the alkaline compound to the reaction system continuously or intermittently, and it is preferable to maintain the reaction temperature between 30 and 80°C. As the alkaline compound used in this alkaline decomposition reaction, an alkali metal hydroxide is generally preferred and the same holds true when carrying out the method of the present invention. Sodium hydroxide and potassium hydroxide are preferable as the alkaline compound, and the amount used is preferably at least the equivalent mole and at most 2 times the mole based on all the thiuronium groups present in the system after the thiuronium salt is formed, and the above-mentioned Needless to say, if mineral acids remain, an additional alkaline compound is required to neutralize them.

On the other hand, when a thiuronium salt is subjected to alkaline decomposition according to the method of the present invention, it is preferable to coexist a metal salt of the same or different type of SADM to be produced in the reaction system.

(However, if this SADM metal salt is not allowed to coexist, the coexistence of a thiuronium salt as described above is essential.) There is no particular limitation on this coexisting SADM metal salt, but the desired S
Considering the separation and purification after the production of ADMs, it is preferable to use the same kind of SADMs for the purpose of production.
Moreover, as the salt, an alkali metal salt is preferable. The amount of this coexisting SADM metal salt is preferably 10 to 50% by weight based on the thiuronium salt to be subjected to alkaline decomposition, and the effect will not be noticeable if the amount used is less than the lower limit, so it is necessary to use more than 50% by weight. Not.

As mentioned above, if the method of the present invention is carried out, the metal salts of the coexisting SADMs will remain in the reaction system, and in order to recover them, K can be recovered by neutralizing the coexisting salts with the mineral acid described above. good. In addition, even in the original alkaline decomposition, even if an alkaline compound is used in an amount greater than that required for decomposing the thiuronium salt, some of the H8DMs intended to be produced also exist as metal salts. Salts should also be neutralized using mineral acids and recovered as H8DMs.

Thus, if the method of the present invention is carried out, H8DMs can be obtained in higher yields than in the general method described above.
I) Since the M group is separated from the aqueous solution as mentioned above, it is necessary to separate it and wash it with water or other solvent, or use the known M11! Highly pure H8DMs can be easily obtained by purification using a method such as Kurobe.

EXAMPLES The method of the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Note that the parts described below indicate parts by weight.

Example 1 (Thiuronium chloride reaction) 98 parts of 31.5% hydrochloric acid and 194 parts of thiourea were charged into a 4-volume flask equipped with a stirrer, a thermometer, an Allene condenser, and a dropping device.
bis(2-hydroxyethyl) sulfide 14 in a solution of
5 parts were gradually added dropwise, and after the addition was completed, stirring was continued at 100° C. for 4 hours. Thereafter, it was cooled and the reaction solution was divided into approximately three equal parts. This will be referred to as the reaction solution--Kin (Ugo) and (Q).

The above reaction solution (6) was returned to the reactor and the above thiuronium salt reaction was repeated in the presence of the thiuronium salt. After cooling, the reaction solution was divided into two equal parts and these were equalized at 11°.

(Mercaptization reaction) Reaction liquid 0 was placed in the same reactor as above, and 413 parts of 50% sodium hydroxide aqueous solution was gradually added dropwise at 60°C for 30 minutes.
The reaction was performed below. After cooling and neutralizing with an aqueous hydrochloric acid solution, 84 parts of xylene was added and the organic layer was separated. This organic layer was separated, and the black part of the xylene was removed under reduced pressure to obtain 116 parts of the desired dimercapto diethyl sulfide. Raw material screw (
The yield based on 2-hydroxyethyl) sulfide is 85
%, and the purity was 90%.

Example 2 The above reaction solution (c) was put into a similar reactor, and 64 parts of sodium salt of dimercapto diethyl sulfide was added and completely dissolved, followed by 413 parts of a 50% aqueous sodium hydroxide solution.
was slowly added dropwise, and the mixture was allowed to react at 60°C for 30 minutes. After cooling, the excess alkali is neutralized with hydrochloric acid, and the
The organic layer was separated. This organic layer was separated and xylene was removed from the black part under reduced pressure, yielding 154 parts of the desired dimercapto diethyl sulfide. The yield of newly produced dimercapto diethyl sulfide after subtracting the initially added amount was 82% and the purity was 85% based on the raw material bis(2-hydroxyethyl) sulfide.

Example 3゜'The reaction solution described in Example 1 (the odor was introduced into a similar reactor,
Furthermore, the sodium salt of dimercapto diethyl sulfide 6
After adding and dissolving 4 parts, 413 parts of a 50% aqueous sodium hydroxide solution was slowly added dropwise, and the mixture was reacted for 30 minutes while maintaining the temperature at 60° C. or lower.

After that, the method described in Example 1 (mercaptation reaction) K was repeated, and a new raw material bis(2-
The yield based on hydroxyethyl) sulfide was 92% and the purity was 95%.

Comparative Example 1 The reaction solution (Q) described in Example 1 was placed in a similar reactor, and the reaction described in Example 2 was repeated without adding the sodium salt of dimercapto diethyl sulfide. Yield was 69%.
, the purity was 71%.

Example 4 Brown A 31.5% hydrochloric acid aqueous solution 7 was added to the same reactor as in Example 1.
4 parts and 49 parts of thiourea were added to prepare a homogeneous solution. This solution K was charged with 118 parts of 1-human tetraxy-8-mercapto-3,6-cythiooctane, and a thiuronium salt reaction was carried out under the same conditions as in Example 1.

After cooling, the reaction solution was divided into two equal parts and these were designated as reaction solution (F)0.

This reaction solution (F) was placed in a similar reactor, and the raw materials were charged under the same conditions as described above to carry out the thiuronium chloride reaction again. Next, 34 parts of potassium salt of 1,8-dimercapto-3,6-sithiooctane was added to this reaction solution to form a homogeneous solution, and then 217 parts of a 30% potassium hydroxide aqueous solution was slowly added dropwise, and the mixture was heated at a temperature of 60°C or lower for 1 hour. Made it react. 1 after this
．． When treated in the same manner as described in Example 1, 224 parts of 1,8-dimercapto-3,6-cythiooctane were obtained. The yield after subtracting the added amount is 95%, and the purity is 9.
It was 2%.

Comparative Example 2 0 prepared in Example 4 was placed in a similar reactor and 1.8-
The mercapto-forming reaction and post-reaction treatment described in Example 4 were repeated using 72 parts of a 30-potassium hydroxide aqueous solution without adding the dimercapto-3,6-sithiooctane metal solution. The obtained 1,8-dimercapto-
3,6-cythiooctane was 124 parts. Yield is 7
0%, and the purity was 68%.

Example 5 and Comparative Example 3 31.5% hydrochloric acid 1 was added to the same reactor as used in Example 1.
49 parts of thiourea and 97 parts of thiourea were added to prepare a homogeneous solution. Kl and 11-dihydroxy-3,6,9-trithioundecane were added to carry out the thiuronium salt reaction described in Example 1. Divide this reaction solution into two equal parts and divide them into reaction solution 011.
, (J).

44 parts of sodium salt of 1,11-dimercapto-3,6,9-trithioundecane was added to reaction solution 0; Example 5) Not added to reaction solution (J) (comparative example 3) 50%;
Example 1 (
Mercaptization reaction) The results obtained by repeating the method described above are shown in Table 1.

Table 1 Yield for unused 1,11-dihydroxy-3,6,9-trithioundecane Example 6 and Comparative Example 4 A 31.5% aqueous hydrochloric acid solution was added to the same reactor as used in Example 1. 149 parts and 97 parts of thiourea were added to form a homogeneous solution. Then this solution K 110 parts of 2-mercapto-
Example 1 by slowly dropping 1-methylethyl alcohol
The method described for the thiuronium chloride reaction was repeated.

After cooling, this reaction solution was divided into two equal parts, and these were used as reaction solutions.

The reaction solution (2) was returned to the above-mentioned reactor, and the above-mentioned thiuronium chlorination reaction was repeated. To this reaction solution K, 39 parts of the sodium salt of 1.2-dimercapto-1-methylethane was added, and the mercaptation reaction described in Example 1 was repeated using 186 parts of a 50% aqueous sodium hydroxide solution. (Example 6) On the other hand, the mercaptation reaction described in Example 1 was repeated using only 62 parts of the reaction solution and 50% aqueous sodium hydroxide solution. (Comparative Example 4) These results are shown in Table 2. -Second Table 11.2-Dimercapto 1-methylethane 22-
Yield for mercapto-1-methylethyl alcohol The method of the present invention improves both the purity and yield of the target compound.To clarify this, all the results of Examples and Comparative Examples are shown. are shown in Table 3.

Effect of the invention In the method of the present invention, mono- or dihydroxy poly(7))
Polythioalkylene dimercaptans can be produced from thioalkylenes in high yield and with high purity.

Claims (1)

[Claims] 1. HO represented by the following general formula ω and/or (2)
(R8)nH・・・・・・・・・・・・・・・・・・
・・・・・・ ■HO(R8)nROH・・・・・・・・・
・・・・・・・・・・・・・・・ (2) Reacting a sulfur-containing compound with thiourea and a mineral acid to form a thiuronium salt,
Next, the thiuronium salt is decomposed using an alkaline compound to complete the reaction, and the following general method is characterized in that a thiuronium salt similar to or different from the thiuronium salt produced in step f of producing the thiuronium salt is allowed to coexist. A method for producing polythioalkylene dimercaptans represented by formula (3) and/or (4) K. H8(R8)nH・・−・−・−・−・・・・・・・・
...... (3) H8 (R8) mR8H...
・・・・・・・・・・・・・・・ 02, HO(R8)nH... shown in the following general formula 〇] and/or (2)...
・Four...songs/songs (1) HO (R8) mROH...
・・・・・・・・・・・・・・・ (2) React a sulfur-containing compound with thiourea and a mineral acid to form a thiuronium salt, then decompose the thiuronium salt using an alkaline compound to carry out the reaction. In completing the process, the following general formulas (3) and it or (4)K are characterized in that in the decomposition step of the thiuronium salt, a metal salt of the same or different type of polythioalkylene dimercaptan is allowed to coexist with the decomposition product. A method for producing polythioalkylene dimercaptans shown in H8(R8)nH・・・・・・・・・・・・・・・
・Song... nH8 (R8) mR8H...
・・・・・・・・・・・・ [R3, general formula α below]
and/or HO(R8)nH... shown in (2)
・・・・・・・・・・・・・・・ α〕HO(R
8) mROH・・・・・・・・・・・・・・・・・・
... (2) When reacting the sulfur-containing compound with thiourea and mineral acid, the cough thiuronium salt and the same or different types of thiuronium salts are made to coexist in the production stage of the thiuronium salt, and in the decomposition stage of the thiuronium salt. A method for producing polythioalkylene dimercaptans represented by the following general formulas (1) and/or (a), characterized in that a metal salt of the same or different type of polythioalkylene dimercaptans is allowed to coexist with the decomposition product. H8(R8)nH・・・・・・・・・・・・・・・
... (3) H8 (R8) mR8H ...
・・・・・・・・・・・・ (4)