JP3002122B2 - Method for producing alkylene sulfide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an alkylene sulfide, and more particularly, to a method for producing an alkylene sulfide using a mercaptoalkanol. Alkylene sulfide is a useful compound that has excellent reactivity and is used in a wide range of materials, such as raw materials for manufacturing pharmaceuticals, agricultural chemicals, various industrial chemicals, and raw materials for sulfur-containing polymers.

[0002]

2. Description of the Related Art As a method for producing an alkylene sulfide, for example, US Pat. Chem. Soc. (C), P1252-125
6, (1969), mercaptoethanol is converted to a specific catalyst (NaHSO ₄ , KH
There is a method of reacting in the presence of SO ₄ ) to synthesize ethylene sulfide. In this reaction, since a large amount of a polymer is easily produced as a by-product, the above-mentioned literature describes the use of an inert gas or a hydrocarbon that vaporizes under the reaction conditions as a substance that promotes the distillation of the produced ethylene sulfide. .
However, even if such measures are taken, the suppression of by-product polymers is insufficient, the yield of ethylene sulfide is low, and it is not satisfactory as an industrial production method.

[0003] US Pat. No. 3,622,597 describes:
There is disclosed a method of synthesizing an alkylene sulfide by subjecting a mercaptoalkanol to a dehydration reaction using an acidic dehydration catalyst in a specific solvent under specific reaction conditions. This method is characterized in that alkylene sulfide generated under specific reaction conditions is promptly removed from the system in order to suppress polymerization which is a side reaction. Further, if necessary, an inert gas such as CO ₂ , N ₂ , Ar, H ₂ O, a lower alcohol, a lower alkane having 1 to 8 carbon atoms, and a volatile compound which does not react with the alkylene sulfide may be used as an accompanying gas. Are also described. However, even in the above-mentioned method, the suppression of the by-product polymer is insufficient, and the reaction activity decreases with time due to severe deterioration of the solvent, which is not satisfactory as an industrial production method.

[0004]

The problem to be solved by the present invention is to produce alkylene sulfide from mercaptoalkanol with high selectivity and high yield in a stable manner over a long period of time.

[0005]

[Means for Solving the Problems]

(1) A first method for producing an alkylene sulfide according to the present invention (hereinafter, simply referred to as a first production method) is a method for producing a mercaptoalkanol represented by the following general formula (2) in a solvent in the presence of an acidic dehydration catalyst. Including a reaction step of performing an intramolecular dehydration reaction to obtain an alkylene sulfide represented by the following general formula (1). At this time, as a solvent, a compound having an amide group substituted at the N-position with a hydrocarbon residue having 1 to 6 carbon atoms, a compound having an unsubstituted amide group, a hydrocarbon residue having 1 to 6 carbon atoms And at least one selected from a compound having a ureylene group substituted at the N-position and an unsubstituted compound having a ureylene group.

[0006]

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[0007]

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In the present specification, R ¹ , R ² , R ³ , and R ⁴ in the formulas (1) and (2) each independently represent a hydrogen atom, a carbon atom having 1 to 4 carbon atoms. Represents an alkyl group, a phenyl group, a phenyl group substituted with an alkyl group having 1 to 4 carbon atoms, or a benzyl group. Hereinafter, R ¹ , R ² , R ³ ,
It omitted a description of the R ^4. (2) In the second method for producing an alkylene sulfide according to the present invention (hereinafter, simply referred to as a second method) , the N-position is a hydrocarbon residue having 1 to 6 carbon atoms in the presence of an acidic dehydration catalyst.
Compound having a substituted amide group, unsubstituted amide group
Having a hydrocarbon residue of 1 to 6 carbon atoms at the N-position
A compound having a substituted ureylene group;
Compound having Reylene group, polyalkylene glycol
, An ether compound and an alkano having 2 to 12 carbon atoms
A step of subjecting a mercaptoalkanol represented by the following general formula (2) to intramolecular dehydration reaction in at least one solvent selected from the following to obtain an alkylene sulfide represented by the following general formula (1). Between the boiling point tb (° C.) at the reaction pressure set in the reaction step of the solvent and the reaction temperature T (° C.) set in the reaction step under a condition satisfying the relational expression represented by the following equation (A). It is characterized by reacting.

Tb−30 ≦ T ≦ tb (A)

[0010]

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[0011]

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The boiling point tb (° C.) and the reaction temperature T (° C.)
Preferably satisfies the relational expression represented by tb-15 ≦ T ≦ tb, and more preferably satisfies the relational expression represented by tb-8 ≦ T ≦ tb. When the boiling point tb (° C.) and the reaction temperature T (° C.) do not satisfy the above relational expression (A), the yield decreases due to polymerization of the product alkylene sulfide or the like, and the raw material mercapto The conversion of alkanol may be insufficient.

(3) Third method for producing alkylene sulfide according to the present invention (hereinafter, simply referred to as third production method)
Is a hydrocarbon having 1 to 6 carbon atoms in the presence of an acidic dehydration catalyst
Compound having an amide group substituted at the N-position with a residue,
Compound having a substituted amide group, hydrocarbon having 1 to 6 carbon atoms
Compound having a ureylene group substituted at the N-position with an elemental residue
Products, compounds having unsubstituted ureylene groups, polyalkyl
Len glycol, ether compound and C2-12
A specific hydrocarbon is allowed to coexist in at least one solvent selected from alkanols of the formula (I), and an alkylene represented by the following general formula (1) is obtained by intramolecular dehydration of a mercaptoalkanol represented by the following general formula (2) The present invention relates to a method for obtaining a sulfide.

[0014]

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[0015]

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According to this method, a specific hydrocarbon is intermittently or continuously coexisted in the reaction system for the purpose of suppressing the deterioration of the solvent, increasing the stability of the alkylene sulfide to be generated and efficiently collecting the same. It is characterized by making it. The hydrocarbon must have a boiling point at normal pressure of 30 ° C. or more and 180 ° C. or less, and preferably 60 ° C. or more and 170 ° C. or less. When a hydrocarbon having a boiling point lower than 30 ° C. is coexisted, the hydrocarbon is liable to vaporize, so that the loss of the hydrocarbon increases, and it may not be possible to efficiently condense or collect the hydrocarbon. When a hydrocarbon having a boiling point higher than 180 ° C. is used, the effect of coexistence with a solvent or a catalyst may be poor. Among them, those having 6 to 9 carbon atoms
The following hydrocarbons are preferably used in that they have a high coexistence effect with a solvent or a catalyst and are easily condensed or collected efficiently. Such hydrocarbons include, for example, aromatic hydrocarbons such as benzene, toluene, xylene, pseudocumene, ethylbenzene and mesitylene; halogenated aromatic hydrocarbons such as fluorobenzene and chlorobenzene; or hexane, heptane and octane. And aliphatic hydrocarbons such as cyclohexane and methylcyclohexane. Two or more of these may be used as a mixture.

In the present invention, when a hydrocarbon is allowed to coexist in the reaction solution, the concentration of the coexisting hydrocarbon in the reaction solution is maintained within a range of 0.1% by weight to 10% by weight. It is more preferable that the content is maintained at 0.5% by weight or more and 6% by weight or less. The concentration in the reaction solution is 0.1
When the amount is less than% by weight, the effect of coexistence with a solvent or a catalyst such as improvement in the yield of alkylene sulfide is small. When the concentration in the reaction solution exceeds 10% by weight, the yield of alkylene sulfide decreases. The cause of the unexpected effect when a hydrocarbon coexists in a solvent is not clear, but the coexisting hydrocarbon controls the liquid properties of the solvent during the reaction to be suitable for this reaction, and the alkylene formed It is speculated that sulfide deterioration may be suppressed.

As to the method of controlling the concentration in the reaction solution, the supply of hydrocarbons may be started at the same time as the reaction is started, and may be maintained after reaching the predetermined concentration. It may be maintained in advance.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The mercaptoalkanols usable in the present invention include 2-mercaptoethanol and 1-mercaptoethanol.
Mercapto-2-propanol, 2-mercapto-1-
Propanol, 1-mercapto-2-butanol, 3-
Mercapto-2-butanol, 2-mercapto-1-phenylethanol and the like can be mentioned.

The method for supplying the mercaptoalkanol is not particularly limited. After charging the solvent and the acidic dehydration catalyst into the reaction vessel, the mercaptoalkanol may be supplied, or after charging only the solvent, the mercaptoalkanol and the acidic dehydration catalyst may be supplied. The acidic dehydration catalyst is not particularly limited as long as it promotes the intramolecular dehydration reaction of mercaptoalkanol.
Alcohol sulfonic acid, alkyl sulfonic acid, benzene sulfonic acid, benzene sulfonic acid having a benzene ring substituted with an alkyl group, and the like. Examples of the alcohol sulfate include methyl sulfate, ethyl sulfate, butyl sulfate and dodecyl sulfate, and examples of the alkylsulfonic acid include methanesulfonic acid and dodecylsulfonic acid. Also,
Examples of the benzenesulfonic acid in which the benzene ring is substituted with an alkyl group include toluenesulfonic acid and ethylbenzenesulfonic acid. Among them, sulfuric acid and an acidic dehydration catalyst having a sulfonic acid group such as methanesulfonic acid are particularly preferable in terms of high reactivity. In addition, you may use the compound which changes into the above-mentioned acidic dehydration catalyst during a reaction as a catalyst.

The method for adding the acidic dehydration catalyst is not particularly limited, but it may be charged in the reaction vessel in advance or supplied together with the supply liquid. The optimal amount of the acidic dehydration catalyst used varies depending on conditions such as the reaction temperature and the amount of mercaptoalkanol to be supplied, but is preferably 0.1 to 50% by weight, and preferably 0.5 to 40% by weight based on the solvent. More preferably, it is% by weight. If the amount used is less than 0.1% by weight, the reaction rate will be slow and productivity will be poor. If the amount used exceeds 50% by weight, side reactions such as polymerization of the raw materials and products may occur, and the solvent may be deteriorated.

Next, the solvent will be described. In the above-mentioned first production method, the compound having an amide group substituted at the N-position with a hydrocarbon residue having 1 to 6 carbon atoms, the compound having an unsubstituted amide group, A compound having a ureylene group substituted at the N-position with a hydrogen residue and a compound having an unsubstituted ureylene group are used. In particular,
A chain amide compound such as dimethylformamide, diethylformamide, dimethylacetamide and the like; a cyclic amide compound such as N-alkylpyrrolidone such as N-methylpyrrolidone and N-ethylpyrrolidone; or tetramethylurea, 1,3-dimethyl- Urea compounds such as 2-imidazolidinone and 1,3-diethyl-2-imidazolidinone. Among them, N-alkylpyrrolidone as a cyclic compound, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone has a large difference in boiling point from the product alkylene sulfide and water, It is preferable because separation is easy, stability is high, and there is almost no deterioration. Further, N-methylpyrrolidone is particularly preferable because it has a high effect of suppressing a side reaction. You may mix and use these 2 or more types.

In the above-described second and third manufacturing methods,
As a solvent, a compound having an amide group substituted at the N-position with a hydrocarbon residue having 1 to 6 carbon atoms, a compound having an unsubstituted amide group,
It is preferable to use a compound having a substituted ureylene group and a compound having an unsubstituted ureylene group. In addition, a polyalkylene glycol or an ether compound can also be used. Among ether compounds,
Monoalkyl ethers of polyalkylene glycols and dialkyl ethers of polyalkylene glycols are more preferred as solvents with little deterioration. Examples of the polyalkylene glycol include diethylene glycol, dipropylene glycol, triethylene glycol and the like. Further, as the monoalkyl ether of polyalkylene glycol, diethylene glycol monomethyl ether,
Examples thereof include diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and triethylene glycol monomethyl ether. Examples of the dialkyl ether of polyalkylene glycol include diethylene glycol diethyl ether and triethylene glycol dimethyl ether. You may mix and use these 2 or more types.

In the second and third production methods, the solvent is not particularly limited as long as it is used for producing a mercaptoalkanol, and 2-ethylhexanol, decanol, ethylene glycol, propylene glycol and the like can be used. Alkanols having 2 to 12 carbon atoms can also be used as the solvent. The solvent is preferably one that is inert to mercaptoalkanol and the resulting alkylene sulfide.

The reaction temperature in the above reaction step is 80 ° C. to 20 ° C.
It is preferable that the temperature is set in the range of 0 ° C,
More preferably, the temperature is set in the range of 160 ° C.
When the reaction temperature is lower than 80 ° C., the reaction becomes slow,
Poor productivity. On the other hand, when the reaction temperature is higher than 200 ° C., side reactions such as polymerization of raw materials and products are caused, and the solvent is deteriorated.

As a method of controlling the reaction temperature, there is a method of monitoring the fluctuation of the reaction temperature and controlling the temperature through water or steam through a coil or a jacket attached to the reaction vessel. However, the temperature can be controlled. If it is, it is not limited to these methods. The reaction pressure in the reaction step varies depending on the reaction conditions such as the solvent used, the starting materials, and the reaction temperature.
It is preferably controlled in the range of 5 to 500 mmHg, more preferably in the range of 10 to 400 mmHg, and still more preferably in the range of 50 to 300 mmHg. When the reaction pressure is lower than the above range, expensive equipment for operating at a low pressure and expensive equipment for cooling and collecting the produced alkylene sulfide, water, and the like are required. Further, when the reaction is carried out without installing these facilities, the alkylene sulfide is scattered without being completely collected, so that not only the yield is lowered but also uneconomical. When the reaction pressure exceeds the above range, the formed alkylene sulfide is difficult to be distilled out of the reaction system, so that a side reaction is caused and the yield is reduced.

As a method of controlling the reaction pressure, there is a method of monitoring the fluctuation of the pressure in the reaction system and operating a vacuum pump through an interlocked pressure regulator to control the pressure.
The method is not limited to these methods as long as the pressure can be controlled. As a possible embodiment of the present invention, there are a semi-batch system and a continuous system. As an embodiment of the semi-batch system, for example, there is the following method. First, a solvent and a catalyst are charged into a reactor equipped with a distillation column. Next, mercaptoalkanol and hydrocarbon are supplied to the reaction vessel as a supply liquid (the mixture may be supplied, or the liquids may be supplied in separate lines).
The reaction is performed in a liquid phase while maintaining a predetermined reaction temperature and a predetermined reaction pressure. At this time, a solvent that is reduced and distilled off may be added to the feed liquid. The resulting alkylene sulfide is continuously collected from the top of the distillation column together with water and hydrocarbons.
When a side reaction occurs to produce a polymer, the polymer accumulates in the reaction vessel. Therefore, it is preferable to stop the supply of the supply liquid after a certain period of time and to collect the remaining liquid from the reaction vessel.
After the recovery, a solvent and a catalyst are newly charged and the reaction is repeated. Alternatively, the reaction can be repeated by charging a solvent, a catalyst, and a hydrocarbon into a reactor, supplying mercaptoalkanol as a supply liquid, and collecting the generated alkylene sulfide together with water. The residual liquid can be recycled after performing a polymer removal operation or the like.

As an embodiment of the continuous system, for example, there is the following method. First, a solvent and a catalyst are charged into a reactor equipped with a distillation column. Next, mercapto alkanol, a solvent, a hydrocarbon and a catalyst were supplied to the reaction vessel as a supply liquid,
The reaction is performed in a liquid phase while maintaining a predetermined reaction temperature and a predetermined reaction pressure. The resulting alkylene sulfide is continuously collected from the top of the distillation column together with water and hydrocarbons, and from the reactor,
A method of continuously or intermittently collecting a liquid corresponding to the amount increased by the supply or the reaction. The liquid recovered from the reaction vessel can be recycled after performing a polymer removal operation or the like.

Alkylene sulfide is a compound having high reactivity and easily causing polymerization. In the present invention, for the purpose of suppressing such polymerization (side reaction), a stabilizer for stabilizing the alkylene sulfide may be added. Examples of the stabilizer include divalent sulfur compounds such as hydrogen sulfide, alkyl mercaptan, alkyl sulfide, and carbon disulfide described in US Pat. No. 2,185,660, and US Pat. No. 3,557,145. Thioacetamide and the like. The stabilizer may be added to the reaction vessel in advance, or may be added together with the mercaptoalkanol.

An entrained gas may be flowed into the reaction system for the purpose of quickly removing the produced alkylene sulfide from the reaction system. However, when a non-condensable gas is entrained, collection of the alkylene sulfide may be carried out. In the process, alkylene sulfide and the like are scattered in an amount corresponding to the vapor pressure, and therefore it is preferable not to perform the process unless necessary. When using the accompanying gas, the accompanying gas used is C
Gases which are inert to the reaction of the present invention, such as O ₂ , N ₂ , Ar, He, lower alkane having 1 to 4 carbon atoms, and the like.

According to the method for producing an alkylene sulfide of the present invention, an alkylene sulfide can be produced stably over a long period of time from a mercaptoalkanol with high selectivity and high yield. Therefore, it can be said that the method of the present invention is also suitable as a method for industrially producing an alkylene sulfide from a mercaptoalkanol. In particular, in the third production method, when ethylene sulfide is produced by reacting mercaptoethanol, the effect of coexistence of a hydrocarbon with a solvent or a catalyst is remarkably high. Therefore, the process of the invention is particularly suitable for the production of ethylene sulfide.

[0032]

The present invention will be described below with reference to examples, but the present invention is not limited thereto. In addition,
The conversion of mercaptoalkanol and the yield of alkylene sulfide shall be in accordance with the following definitions, respectively. Conversion of mercaptoalkanol (%) = (moles of mercaptoalkanol consumed / moles of mercaptoalkanol supplied) × 100 Yield of alkylene sulfide (%) = (moles of alkylene sulfide generated / mercapto supplied) In this example, the reaction vessel was equipped with a magnetic reflux valve, a condenser and a distillation unit having a column and was equipped with a 500 c.
The flask from c was used. The flask is provided with a raw material supply port and a thermometer at the distillation section. A thermometer is also attached to the distillation section. The reaction temperature was controlled using an oil bath, and the reaction pressure was controlled using a constant pressure device connected to a vacuum pump. Example 1-1 150 g of 1,3-dimethyl-2-imidazolidinone as a solvent and 60 g of methanesulfonic acid as a catalyst in a reaction vessel
Was charged. Reaction temperature 100 ° C, reaction pressure 75mm
After controlling to Hg, 1-mercapto-2-
When propanol was supplied at a rate of 40 g / hr, propylene sulfide and water began to distill from the top of the reaction vessel at the start of the reaction. While confirming the temperature of each part of the reaction vessel, it was controlled by an electromagnetic reflux valve so that the distillate amount did not exceed the supply amount. The reaction was continuously performed for 20 hours, and the liquid distilled from the upper part was collected. The recovered liquid was separated into an organic phase and an aqueous phase. The liquid distilled at the 4th hour during the reaction and at the end of the reaction (20th hour) was analyzed by gas chromatography to determine the conversion of 1-mercapto-2-propanol and the yield of propylene sulfide.

Example 1-2 The procedure of Example 1-1 was repeated except that 150 g of N-methylpyrrolidone was used as a solvent, 2 g of sulfuric acid was used as a catalyst, and 2-mercapto-2-propanol was supplied at a rate of 35 g / hr as a feed solution. The same reaction and analysis were performed. Table 1 shows the experimental conditions and experimental results of Examples 1-1 and 1-2.

[0034]

[Table 1]

Example 2-1 A reaction vessel was charged with 150 g of 1,3-dimethyl-2-imidazolidinone as a solvent and 20 g of sulfuric acid as a catalyst. After controlling the reaction temperature to 150 ° C. and the reaction pressure to 300 mmHg, a toluene solution prepared so as to have a 33% by weight composition of 2-mercaptoethanol as a feed solution was added in 6 parts.
When supplied at a rate of 0 g / hr, ethylene sulfide, water and toluene began to distill from the top of the reaction vessel at the start of the reaction. While checking the temperature of each part of the reaction vessel,
The distillate amount was controlled by an electromagnetic reflux valve so as not to exceed the supply amount. The reaction was continuously performed for 30 hours, and the liquid distilled from the upper part was collected. The recovered liquid was separated into an organic phase and an aqueous phase. A part of the liquid distilled at the 4th hour during the reaction and at the end of the reaction (30th hour) and a part of the bottom liquid at that time were extracted and analyzed by gas chromatography, and the conversion of 2-mercaptoethanol and the recovery of ethylene sulfide were analyzed. The rate was determined.

Table 2 shows the experimental conditions and experimental results of Example 2-1.

[0037]

[Table 2]

Comparative Example 1 Example 1-2 was repeated except that 150 g of triethylene glycol monobutyl ether, which was a monoalkyl ether of a polyalkylene oxide used in the examples of US Pat. No. 3,622,597, was used as a solvent. (The boiling point of the solvent under the reaction pressure at this time was 204 ° C.)

Comparative Example 2 An experiment was conducted without using a solvent. In a reaction vessel, 150 g of 1-mercapto-2-propanol as raw materials and 2 g of sulfuric acid
And was charged. Reaction temperature 140 ° C, reaction pressure 300
mmHg, and 1-mercapto-
When 2-propanol is supplied at a rate of 35 g / hr,
With the start of the reaction, propylene sulfide and water began to distill from the upper part of the reaction vessel. Three hours after the start of the reaction, the viscosity of the bottom liquid in the flask became high and the reaction was stopped. The distillate was analyzed by gas chromatography to determine the conversion of 1-mercapto-2-propanol and the yield of propylene sulfide.

Comparative Example 3 The reaction was carried out without coexisting hydrocarbons in the reaction solution. As a solvent, triethylene glycol dimethyl ether 15
0 g, sulfuric acid 7 g as a catalyst, and 2-mercaptoethanol 10 g / hr as a supply liquid. The boiling point of the solvent under the reaction pressure at this time was 151 ° C.

When the reaction was carried out without the coexistence of hydrocarbons, it was confirmed that a white solid adhered to the distillation column attached to the upper part of the reaction vessel. For this reason, problems such as clogging occur, and it is difficult to industrially produce ethylene sulfide. Table 3 shows the experimental conditions and experimental results of Comparative Examples 1 to 3.

[0042]

[Table 3]

Example 3-1 A reaction vessel was charged with 150 g of N-methylpyrrolidone as a solvent and 2 g of sulfuric acid as a catalyst. At this time, when N-methylpyrrolidone and sulfuric acid were mixed, considerable heat generation was confirmed. Reaction temperature 140 ° C, reaction pressure 150mmHg
Then, when 1-mercapto-2-propanol was supplied as a supply liquid at a rate of 35 g / hr, propylene sulfide and water began to distill from the upper part of the reaction vessel at the same time as the reaction was started. While confirming the temperature of each part of the reaction vessel, it was controlled by an electromagnetic reflux valve so that the distillate amount did not exceed the supply amount. The reaction was continuously performed for 20 hours, and the liquid distilled from the upper part was collected. The recovered liquid was separated into an organic phase and an aqueous phase. The liquid distilled at the 4th hour during the reaction and at the end of the reaction (20th hour) was analyzed by gas chromatography,
The conversion of 1-mercapto-2-propanol and the yield of propylene sulfide were determined.

Example 3-2 20 g of sulfuric acid as a catalyst and 1-mercapto-
The same reaction and analysis as in Example 3-1 were performed, except that 2-propanol was supplied at a rate of 30 g / hr. Example 3-3 1,3-Dimethyl-2-imidazolidinone 1 as a solvent
The same reaction as in Example 3-1, except that 50 g, sulfuric acid 2.5 g as a catalyst, and 2-mercapto-1-phenylethanol as a supply liquid were supplied at a rate of 20 g / hr,
Analysis was carried out.

Example 3-4 The same reaction and analysis as in Example 3-1 were carried out except that the reaction temperature was higher than the boiling point of the solvent at the reaction pressure. Table 4 shows the experimental conditions and experimental results of Examples 3-1 to 3-4.

[0046]

[Table 4]

Example 4-1 A reaction vessel was charged with 150 g of N-methylpyrrolidone as a solvent and 0.3 g of sulfuric acid as a catalyst. Reaction temperature 150
C. and a reaction pressure of 300 mmHg. Then, when a xylene solution prepared so as to have a 33% by weight composition of 2-mercaptoethanol was supplied at a rate of 90 g / hr as a supply liquid, ethylene sulfide, water and xylene were supplied at the start of the reaction. Began to distill from the top of the reaction vessel. While confirming the temperature of each part of the reaction vessel, it was controlled by an electromagnetic reflux valve so that the distillate amount did not exceed the supply amount. The reaction was continuously performed for 20 hours, and the liquid distilled from the upper part was collected. The recovered liquid was separated into an organic phase and an aqueous phase. The liquid distilled at the 4th hour during the reaction and at the end of the reaction (20th hour) and a part of the bottom liquid at that time were withdrawn and analyzed by gas chromatography to determine the conversion of 2-mercaptoethanol and the yield of ethylene sulfide. I asked.

Example 4-2 Example 4 was repeated except that 7.5 g of sulfuric acid was used as a catalyst.
The same reaction and analysis as in -1 were performed. Example 4-3 12 g of sulfuric acid as a catalyst and 1-mercapto as a feed solution
The same reaction and analysis as in Example 4-1 were performed, except that a xylene solution prepared so that 2-propanol had a composition of 50% by weight was supplied at a rate of 80 g / hr.

Example 4-4 60 g of P-toluenesulfonic acid as a catalyst and a mesitylene solution prepared so as to have a 50% by weight composition of 1-mercapto-2-propanol as a supply liquid were supplied at a rate of 80 g / hr. Except for the above, the same reaction and analysis as in Example 4-1 were performed.

Example 4-5 1,3-Dimethyl-2-imidazolidinone 1 as a solvent
Example 4 was repeated except that 50 g, sulfuric acid 0.9 g as a catalyst, and a hexane solution prepared to have a 33% by weight composition of 2-mercapto-1-phenylethanol as a supply liquid were supplied at a rate of 80 g / hr. The same reaction and analysis as in Example 1 were performed.

EXAMPLE 4-6 150 g of N, N-dimethylacetamide as a solvent, 30 g of sulfuric acid as a catalyst, and a cyclohexane solution prepared so as to have a composition of 40% by weight of 2-mercaptoethanol as a feed solution at a rate of 80 g / hr. Except for the supply, the same reaction and analysis as in Example 4-1 were performed.

Example 4-7 The reaction was carried out at a reaction temperature lower than the boiling point of the solvent at the reaction pressure by 30 ° C. or more. 150 g of 1,3-dimethyl-2-imidazolidinone as a solvent, sulfuric acid 1 as a catalyst
Example 4 was repeated except that 2 g of a toluene solution prepared such that 1-mercapto-2-propanol had a composition of 50% by weight was supplied at a rate of 80 g / hr.
The same reaction and analysis as in Example 1 were performed.

Example 4-8 150 g of N, N-dimethylformamide as a solvent, 25 g of sulfuric acid as a catalyst, and a toluene solution prepared so as to have a 50% by weight composition of 2-mercaptoethanol as a feed solution at a rate of 20 g / hr. Except for the supply, the same reaction and analysis as in Example 4-1 were performed.

Example 4-9 1,3-Dimethyl-2-imidazolidinone 1 as a solvent
Example 4 was repeated except that 50 g of a toluene solution prepared such that 1-mercapto-2-propanol had a composition of 60% by weight was supplied at a rate of 50 g / hr.
The same reaction and analysis as in -1 were performed.

Example 4-10 150 g of N-ethylpyrrolidone as a solvent, 30 g of P-toluenesulfonic acid as a catalyst, and 40 g / hr of a xylene solution prepared so as to have a 50% by weight composition of 2-mercaptoethanol as a feed solution. The same reaction and analysis as in Example 4-1 were performed, except that the solution was supplied at a constant rate.

Tables 5 and 6 show the experimental conditions and results of Examples 4-1 to 4-10.

[0057]

[Table 5]

[0058]

[Table 6]

Example 5-1 A reaction vessel was charged with 150 g of diethylene glycol monobutyl ether as a solvent and 20 g of sulfuric acid as a catalyst.
At this time, diethylene glycol monobutyl ether and sulfuric acid were mixed. The reaction temperature was 110 ° C and the reaction pressure was 30.
After controlling the pressure to mmHg, an octane solution prepared so as to have a 25% by weight composition of 2-mercaptoethanol was supplied at a rate of 40 g / hr as a supply liquid. At the start of the reaction, ethylene sulfide, water and octane were added to the upper part of the reaction vessel. Began to distill from. While confirming the temperature of each part of the reaction vessel, it was controlled by an electromagnetic reflux valve so that the distillate amount did not exceed the supply amount. The reaction was continuously performed for 20 hours, and the liquid distilled from the upper part was collected. The recovered liquid was separated into an organic phase and an aqueous phase. The fourth hour during the reaction and at the end of the reaction (20
A part of the liquid distilled at the time point) and the bottom liquid at that time were extracted and analyzed by gas chromatography to determine the conversion of 2-mercaptoethanol and the yield of ethylene sulfide.

Example 5-2 Triethylene glycol dimethyl ether 1 as a solvent
Same as Example 5-1 except that 50 g, 15 g of sulfuric acid as a catalyst, and a toluene solution prepared so that 1-mercapto-2-propanol had a 33% by weight composition as a supply liquid at a rate of 30 g / hr. Was analyzed and analyzed.

Example 5-3 The reaction was carried out at a reaction temperature lower than the boiling point of the solvent at the reaction pressure by 30 ° C. or more. 150 g of diethylene glycol monobutyl ether as a solvent and sulfuric acid 4 as a catalyst
g, except that a mesitylene solution prepared so that 1-mercapto-2-propanol had a composition of 50% by weight was supplied at a rate of 30 g / hr.
The same reaction and analysis as in Example 1 were performed.

Table 7 shows the experimental conditions and experimental results of Examples 5-1 to 5-3.

[0063]

[Table 7]

As is evident from these results, according to the method of the present invention, alkylene sulfide can be obtained with high activity and with high yield in a stable manner over time.

[0065]

According to the process for producing an alkylene sulfide of the present invention, an alkylene sulfide can be produced stably over a long period of time from a mercaptoalkanol with high selectivity and high yield. In addition, the following (1)-
By appropriately combining the three features of the present invention (3), alkylene sulfide can be stably produced over a long period of time with higher selectivity and higher yield.

(1) As a solvent, a compound having an amide group substituted at the N-position with a hydrocarbon residue having 1 to 6 carbon atoms,
At least one compound selected from a compound having an unsubstituted amide group, a compound having a ureylene group substituted at the N-position with a hydrocarbon residue having 1 to 6 carbon atoms, and a compound having an unsubstituted ureylene group Use (2) In the reaction step according to the present invention, 1 to 6 carbon atoms
Having an amide group substituted at the N-position with a hydrocarbon residue
Compound, compound having an unsubstituted amide group, having 1 to 6 carbon atoms
Has a ureylene group substituted at the N-position with two hydrocarbon residues
, A compound having an unsubstituted ureylene group,
Lialkylene glycol, ether compound and carbon number
At least one selected from 2 to 12 alkanols
Using a kind of solvent, the solvent is represented by the following formula (A) between the boiling point tb (° C.) at the reaction pressure set in the reaction step of the solvent and the reaction temperature T (° C.) set in the reaction step. Satisfy the relational expression.

Tb−30 ≦ T ≦ tb (A) (3) The N-position is substituted by a hydrocarbon residue having 1 to 6 carbon atoms.
Having an amide group, having an unsubstituted amide group
Compound, wherein the N-position is substituted with a hydrocarbon residue having 1 to 6 carbon atoms
Having a substituted ureylene group, unsubstituted ureylene
Compound having a group, polyalkylene glycol, ether
Compounds and alkanols having 2 to 12 carbon atoms
A specific hydrocarbon coexists in at least one selected solvent. The boiling point of the hydrocarbon at normal pressure is 30 ° C. or higher and 1
When the temperature is 80 ° C. or lower, the above effect is further improved. When the carbon number of the hydrocarbon is 6 or more and 9 or less, the above effect is further improved.

When the concentration of the hydrocarbon in the reaction solution is maintained in the range of 0.1% by weight or more and 10% by weight or less,
The above effect is further improved.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ishikawa ▼ Ryu ▲ ichi Nippon Shokubai Co., Ltd. 5-8 Nishiburi-cho, Suita-shi, Osaka (56) References JP-A-5-339257 (JP, A) JP-B-45-6011 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C07D 331/02

Claims (7)

(57) [Claims] 1. A compound having an amide group substituted at the N-position with a hydrocarbon residue having 1 to 6 carbon atoms, a compound having an unsubstituted amide group, and a compound having 1 to 6 carbon atoms in the presence of an acidic dehydration catalyst. The compound represented by the following general formula (2) in at least one solvent selected from a compound having a ureylene group substituted at the N-position with N hydrocarbon groups and a compound having an unsubstituted ureylene group. A method for producing an alkylene sulfide, comprising a reaction step of subjecting a mercapto alkanol to an intramolecular dehydration reaction to obtain an alkylene sulfide represented by the following general formula (1). Embedded image Embedded image (Wherein R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a phenyl substituted with an alkyl group having 1 to 4 carbon atoms. Group or a benzyl group.) 2. A method for producing an alkylene sulfide represented by the following general formula (1), comprising: a hydrocarbon residue having 1 to 6 carbon atoms in the presence of an acidic dehydration catalyst.
In the compound having an A bromide group N-position is substituted, the unsubstituted
Compound having an amide group, hydrocarbon residue having 1 to 6 carbon atoms
Having a ureylene group substituted at the N-position with a group,
Compounds having substituted ureylene groups, polyalkylenes
Recall, ether compound and C 2 -C 12 alcohol
A reaction step of subjecting a mercaptoalkanol represented by the following general formula (2) to an intramolecular dehydration reaction in at least one solvent selected from canols , wherein the boiling point of the solvent at a reaction pressure set in the reaction step tb (° C.) and the reaction temperature T set in the above reaction step
(C) under a condition satisfying a relational expression represented by the following formula (A): A method for producing an alkylene sulfide. tb-30 ≦ T ≦ tb (A) Embedded image (Wherein, R ¹ , R ² , R ³ , and R ⁴ are each independently substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, and an alkyl group having 1 to 4 carbon atoms. Represents a phenyl group or a benzyl group.) 3. A process for producing an alkylene sulfide represented by the following general formula (1), comprising a hydrocarbon residue having 1 to 6 carbon atoms in the presence of an acidic dehydration catalyst.
A compound having an amide group substituted at the N-position with
Compound having an amide group, hydrocarbon residue having 1 to 6 carbon atoms
Having a ureylene group substituted at the N-position with a group,
Compounds having substituted ureylene groups, polyalkylenes
Recall, ether compound and C 2 -C 12 alcohol
A hydrocarbon having a boiling point of 30 ° C. or more and 180 ° C. or less at normal pressure coexists in at least one kind of solvent selected from canols to convert a mercaptoalkanol represented by the following general formula (2) into an intramolecular dehydration reaction. A process for producing an alkylene sulfide comprising a reaction step of Embedded image Embedded image (Wherein, R ¹ , R ² , R ³ , and R ⁴ are each independently substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, and an alkyl group having 1 to 4 carbon atoms. Represents a phenyl group or a benzyl group.) 4. The method according to claim 3, wherein the hydrocarbon has 6 to 9 carbon atoms. 5. The method for producing an alkylene sulfide according to claim 3, wherein in the reaction step, the concentration of the hydrocarbon in the reaction solution is in the range of 0.1% by weight to 10% by weight. 6. The acidic dehydration catalyst is a compound selected from sulfuric acid, phosphoric acid, alkyl sulfate having 1 to 20 carbon atoms, alkyl sulfonic acid, benzene sulfonic acid, and alkyl group-substituted benzene sulfonic acid. Item 6. The method for producing an alkylene sulfide according to any one of Items 1 to 5 . 7. The reaction step, wherein the reaction temperature is 80 ° C. to 20 ° C.
It is controlled within the range of 0 ° C. and the reaction pressure is 5 to 500 mmHg
The method for producing an alkylene sulfide according to any one of claims 1 to 6 , which is a step controlled in the range of: