JPH05155787A - Production of alkenylbenzene and its derivative - Google Patents

Abstract

PURPOSE:To obtain the subject compound useful as a raw material, etc., for polymers in high selectivity and yield without using a dangerous raw material by reacting an alkylbenzene with a conjugated diolefin in the presence of a catalyst prepared by carrying out mixing and dispersing treatment of metallic Na with a K alkoxide. CONSTITUTION:An alkylbenzene (e.g. toluene) is made to react with a conjugated diolefin (e.g. 1,3-butadiene) in the presence of a catalyst prepared by carrying out mixing and dispersing treatment of (A) an alkali metal (e.g. metallic sodium) with (B) a potassium alkoxide (e.g. potassium methoxide) expressed by the formula RCH2OK (R is H or 1-10C hydrocarbon) in an inert solvent such as an 8-20C paraffinic hydrocarbon having 100-230 deg.C boiling point as a catalyst in environment in the absence of oxygen and water at 140-145 deg.C to efficiently afford the objective alkenylbenzene, convertible into dialkyltetralins which are raw materials for producing naphthalenedicarboxylic acid useful as a raw material for polymers.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing alkenylbenzene efficiently and safely by reacting an alkylbenzene with a conjugated diolefin in the presence of an alkali metal. More specifically, for example, o-xylene and 1,
The alkenylbenzene, 5- (o-tolyl) -pentene, obtained by reaction with 3-butadiene, is cyclized to form dimethyltetralin, which is dehydrogenated to dimethylnaphthalene, and then oxidized to give high dimethylnaphthalene. The present invention relates to a compound having high industrial value that can be converted into naphthalenedicarboxylic acid useful as a molecular raw material, and the present invention relates to a method for producing such a useful raw material.

[0002]

2. Description of the Related Art Conventionally, a method for producing a monoalkenylbenzene by reacting alkylbenzene and 1,3-butadiene in the presence of an alkali metal is known (see US Pat. No. 3,244,758).

However, the above-mentioned method has a drawback that a large amount of expensive potassium metal must be used in order to obtain a high yield of monoalkenylbenzene. Further, in order to solve this problem, a method has been proposed in which, when 1,3-butadiene is blown into alkylbenzene to cause a reaction, metal potassium and metal sodium are used together as a catalyst so that a small amount of expensive metal potassium can be used. (Japanese Patent Publication No. 56-34570, US Pat. No. 3,766)
288, U.S. Pat. No. 3,953,535).

Further, a method has been proposed (US Pat. No. 4,990,717) in which potassium metal is supported on potassium carbonate or alumina to improve the production process in which the reaction of o-xylene and butadiene is carried out in a fixed bed.

However, since all of these methods directly use potassium metal, they are highly reactive to air, oxygen, water, etc., and ignite only by contact with these compounds, which is dangerous for fire safety. , Especially sodium-potassium (Na-K: nak) alloy is highly active against oxygen and water, ignites in contact with trace amounts of oxygen and water, and when coexisting with combustible substances (petroleum) in the vicinity, , Very dangerous.

British Patent No. 1269280 (1972)
(April 6, 2013), it is described that a diene has a reaction inhibitory action in an aromatic side chain alkylation reaction with an olefin using sodium and an anhydrous potassium compound as a catalyst.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to produce alkenylbenzene in a high yield without directly using expensive metal potassium which has a high risk of ignition. . Moreover, by reacting alkylbenzene with, for example, 1,3-butadiene in the presence of a catalyst having high activity and high selectivity for the alkenylation reaction, formation of a by-product which is difficult and complicated to separate from the target product Is intended to produce a high-purity target product, that is, alkenylbenzene, in a high yield. Further, it is an object to provide a method for producing an alkyltetralin by cyclizing the alkenylbenzene and a method for producing an alkylnaphthalene by dehydrogenating the alkyltetralin.

[0008]

According to the present invention, when an alkenylbenzene is produced by reacting an alkylbenzene with a conjugated diolefin such as 1,3-butadiene in the presence of a catalyst, (a) an alkali is used as a catalyst. Using a catalyst obtained by mixing and dispersing a metal with a (b) potassium alkoxide represented by the following formula (I), and in an environment where oxygen and water are substantially absent, alkylbenzene and a conjugated diolefin (for example, 1, A method for producing alkenylbenzene and its derivatives, which comprises reacting with 3-butadiene).

[0009]

Embedded image RCH ₂ OK (I) (R represents a hydrogen atom or a C _{1 to} C ₁₀ hydrocarbon group.) That is, when alkenylbenzene is produced by reacting alkylbenzene with a conjugated diolefin. An alkylbenzene in the presence of a catalyst in which (a) an alkali metal and (b) a potassium alkoxide represented by the formula (I) are mixed and dispersed without causing oxygen and water to substantially exist. An alkenyl which is characterized in that it is difficult to separate it from a target substance by reacting it with 1,3-butadiene, and the production of complicated by-products is suppressed to produce a high-purity alkenylbenzene in a high yield. A method for producing benzene and its derivatives. The present invention will be described in detail below.

The raw material alkylbenzene used in the method of the present invention is an alkylbenzene having 1 to 2 methyl groups or ethyl groups in the benzene nucleus, and specific compounds include toluene, ethylbenzene, o-xylene, m-xylene and p. -Xylene is given. It is preferable to use each of these alkylbenzenes individually, and if a mixture is used, it becomes difficult to separate the target product from the alkenylbenzenes, which are reaction products, in high purity.

For example, in the reaction of o-xylene and 1,3-butadiene, if alkylbenzene such as toluene, p-xylene, m-xylene or ethylbenzene is mixed as an impurity, the purity of the target product is remarkably lowered. Therefore, the purity of o-xylene is preferably 95% or more, more preferably 98% or more. However, a trace amount of hydrocarbons having no alkyl group such as benzene and cyclohexane may be mixed.

Similarly, when toluene, ethylbenzene, m-xylene, or p-xylene is used, the purity of each individual product is preferably 95% or more, preferably 98% or more, and an alkyl group such as benzene or cyclohexane is preferably used. It does not matter that a small amount of hydrocarbons that do not have is mixed.

It is preferable that the starting material, alkylbenzene, is dehydrated and used in the reaction. As a dehydration method,
For example, adsorption separation by a suitable desiccant (for example, activated alumina, silica gel, molecular sieves, activated carbon, etc.), cryogenic separation, or a method of dehydrating by contacting with metallic sodium or metallic potassium in advance. The lower the water content in the raw material, the more preferable it is, and it is particularly preferable that the water content is not more than the measurement sensitivity of the Karl Fischer method, which is a usual water content measuring method, for example, several ppm or less.

Examples of the conjugated diolefin used in the present invention include 1,3-butadiene and isoprene. The 1,3-butadiene may be produced by any method, and the purity of the 1,3-butadiene may be any. For example, crude butadiene obtained by dehydrogenating butane or butene may be used as it is, or 1,3-butadiene obtained by purifying the crude butadiene by a method such as extraction may be used. Further, 1,3-butadiene is preferably dehydrated and used in the reaction. Examples of the dehydration method include adsorption separation using a suitable desiccant such as activated alumina, silica gel, molecular sieves, activated carbon, etc. or cryogenic separation. The lower the water content in 1,3-butadiene, the more preferable it is,
pm or less is particularly preferable.

The catalyst used in the reaction of the alkylbenzene and the conjugated diolefin in the present invention is a catalyst obtained by mixing and dispersing (a) an alkali metal and (b) a potassium alkoxide represented by the following formula (1).

[0016]

Embedded image RCH ₂ OK (I) (R is a hydrogen atom or a C _{1 to} C ₁₀ hydrocarbon group.) (A) The alkali metal is preferably sodium, and the higher the purity, the better. It does not matter even if it contains a small amount of a metal such as potassium, calcium, magnesium or aluminum. The purity is preferably 90% or more, and more preferably 99% or more.

In R of the above formula, the C ₁ -C ₁₀ hydrocarbon group is a carbon group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group and the like. Examples thereof include alkyl groups having 1 to 10 carbon atoms, cyclopentyl groups, cycloalkyl groups having 3 to 10 carbon atoms such as cyclohexyl groups, and phenyl groups.

Specific examples of the compound of formula (I) include potassium methoxide (potassium methylate), potassium ethoxide (potassium ethylate), potassium propoxide (potassium propylate), potassium butoxide (potassium butyrate). , Potassium amyloxide (potassium amylate), potassium hexyl alkoxide (potassium hexylate), potassium heptyl alkoxide (potassium heptylate), potassium octyl alkoxide (potassium octylate), potassium nonyl alkoxide (potassium nonylate), potassium cyclohexyl Examples thereof include potassium alkoxide compounds such as methoxide (potassium cyclohexyl methylate) and potassium benzyl oxide (potassium benzylate).

(Preparation of catalyst) The ratio of (a) metallic sodium and (b) the potassium alkoxide of the formula (I) used as a catalyst in the present invention may be any ratio, but (a) metallic sodium The final ratio is (a) metallic sodium / (b) the molar ratio of the potassium alkoxide of the formula (I) is from 1: 0.5 to 1:20. The amount of sodium metal used as a catalyst for alkylbenzene is 0.01: 100 to a weight ratio with respect to alkylbenzene.
It is used in a range of 1:10, preferably 0.05: 100 to 5: 100.

The catalyst used in the process of the present invention is prepared by subjecting (a) metallic sodium to (b) a mixed dispersion activation treatment with a potassium alkoxide of the formula (I). Mixed dispersion treatment is nitrogen, helium, argon,
It is carried out in an inert gas such as hydrogen, and is adopted in a so-called wet dispersion method of dispersing with an inert solvent and a dry dispersion treatment method without using a solvent, but in the present invention, the former wet dispersion activation treatment is used. Is preferably performed from various viewpoints.

The dispersion treatment method is carried out in an inert solvent by rapidly stirring (a) metallic sodium with (b) the potassium alkoxide of the formula (I) in an inert solvent. For example, when (a) 3 wt% of metal sodium is dispersed, (a) 97 parts of potassium alkoxide of the formula (I) is used as a dispersion activation treatment agent in 3 parts of metal sodium and (b) 100 parts of solvent o-xylene. Put at the same time 130-160 ℃
It is carried out by high-speed stirring in a closed manner with a dispersion liquid prepared in advance at an appropriate dispersion mixing ratio, and then a solvent is further added to the dispersion liquid, or the formula (b) is a potassium alkoxide of the formula (I). It can also be carried out by a method of charging and dispersing.

Examples of the inert solvent include n-octane, n-nonane, decane, undecane, dodecane and the like having 8 to 8 carbon atoms.
The boiling point of 20 is 100 to 230 ° C., preferably 13
Examples thereof include paraffin at 0 to 200 ° C., and among them, it is industrially most preferable to use alkylbenzene used as a reaction raw material. The catalyst thus uniformly dispersed is pretreated with a mixture of alkylbenzene and the catalyst at 100 to 200 ° C. for 1 to 5 hours before reacting by introducing a conjugated diolefin such as 1,3-butadiene. The reaction can improve the selectivity and the activity.

The catalyst obtained by mixing and dispersing the alkali metal (a) used in the present invention with the potassium alkoxide of the formula (I) (b) can further use a carbonate such as potassium carbonate or sodium carbonate. That is, (a)
A carbonate may be present during the mixing treatment of the alkali metal and the potassium alkoxide of the formula (I). Examples of the carbonate include sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate and the like.

According to the method of the present invention, alkylbenzene and 1,3
-The reaction with butadiene is carried out in an environment in which water and oxygen are not substantially present. Therefore, it is desirable that the raw materials introduced into the reaction system from outside the system, that is, the alkylbenzene and the conjugated diophine, are dehydrated as described above. Further, since the space of the reaction system is substantially free of oxygen and moisture, it is filled with a dry inert gas such as dry nitrogen or dry argon, or the space is filled with alkylbenzene under a reaction condition of the boiling point of alkylbenzene or higher. It is desirable to fill with steam such as.

In the present invention, the reaction is 100 to 200 ° C.
It is preferable to carry out at a temperature in the range. Reaction temperature is 100
When the temperature is lower than 0 ° C, the reaction time becomes long, and when the temperature exceeds 200 ° C, side reaction products increase, which is not preferable. The preferred reaction temperature is 110 to 180 ° C. The reaction molar ratio of 1,3-butadiene to alkylbenzene can be appropriately selected under ordinary conditions. For example, alkylbenzene: 1,3-butadiene = 1: 0.001-0.5, preferably 1:
0.01-0.3, particularly preferably 1: 0.05-0.
It can be carried out in a range of 2.

A reaction time of 0.05 to 10 hours is adopted. The reaction time depends on the amount of catalyst (g-catalyst / g
-Alkylbenzene), catalyst composition (g- (a) metallic sodium / (b) potassium alkoxide of the formula (I), reaction temperature (° C) and ratio of alkylbenzene to 1,3-butadiene (g-alkylbenzene / g-1, 3-butadiene), and an appropriate time is adopted depending on the purity of the target product and the mode of use of the catalyst, for example, the presence or absence of circulation, etc. Generally, the reaction time becomes longer as the values of the above factors decrease. However, the preferable reaction time is 0.2 to 10 hours, particularly preferably 0.3 to 5 hours.

The reaction is a batch reaction in which the starting materials alkylbenzene, 1,3-butadiene and a catalyst are simultaneously charged and reacted, first alkylbenzene and the catalyst are charged, and then 1,3-butadiene is quantitatively determined as the reaction time elapses. Any reaction method of a semi-batch reaction for introducing and a continuous reaction for continuously introducing alkylbenzene, 1,3-butadiene and a catalyst into the reactor may be adopted, and an appropriate combination thereof may be used. Reaction or continuous reaction is preferable.

Two formats are employed for the continuous reaction. That is, a method of carrying out the reaction while continuously supplying a predetermined amount of alkylbenzene and 1,3-butadiene in a reaction system while dispersing and stirring the catalyst in the reaction system, and a method of dispersing the metal sodium and potassium alkoxide catalyst in a solid such as alumina. There is a method in which alkylbenzene is continuously flowed through a fixed bed of a catalyst supported on fine powder, and continuous reaction is carried out while introducing 1,3-butadiene into the alkylbenzene.

The continuous reaction system may be any of a tubular reactor, a column reactor and a tank reactor. A preferred method for continuous reaction is to provide a plurality of reaction zones,
This is a so-called cross-flow type continuous system in which 1,3-butadiene is quantitatively introduced into each reaction zone.

The reaction procedure is not particularly limited as long as the alkylbenzene and 1,3-butadiene can be sufficiently mixed in the catalyst in the presence of a catalyst.
In the introduction method of introducing 3-butadiene, a resinous or gum-like substance which is presumed to be a heavy product of 1,3-butadiene tends to adhere to the vicinity of the 1,3-butadiene inlet to cause a clogging phenomenon. Therefore, a mixed phase of 1,3-butadiene and an alkylbenzene, for example, a liquid phase mixture of liquid butadiene and an alkylbenzene, a gas phase of 1,3-butadiene and a liquid alkylbenzene is added to a reaction system in the presence of a catalyst.
A method of introducing 1,3-butadiene and alkylbenzene in the form of a liquid mixture is preferable.

Alternatively, the clogging phenomenon can be prevented by supplying 1,3-butadiene to the reaction zone space and causing the absorption reaction on the surface of the reaction solution in which the catalyst is present. It is also possible to increase the stirring effect at the same time when the butadiene is introduced together with the carrier gas. As a carrier gas, oxygen, an inert gas from which water has been removed,
For example, nitrogen, argon and hydrogen are suitable.

Further, the reaction can be preferably carried out by providing appropriate agitation, but it is also possible to introduce 1,3-butadiene in the gas phase into the reaction system and to provide an agitation effect with the gas. It is desirable that the stirring is of a strength necessary for uniformly dispersing the catalyst in the reaction system and further for uniformly mixing the reaction raw material and the reaction product.

When the reaction is carried out in a liquid phase dispersion reaction system, after the reaction,
For separating the used catalyst from the reaction product system, known means such as centrifugal sedimentation and gravity sedimentation, or separation of solid phase from liquid-solid phase at lower temperature, such as filtration, centrifugation, etc. The known means may be used. The separated catalyst can be recycled and reused in the reaction system.

When the catalyst is deactivated and the catalytic function is lost, metallic potassium is deactivated in the potassium alkoxide phase. Therefore, it can be reused by being oxidized and calcined with the organic substance attached, regenerated and reused.

According to the method of the present invention, toluene and 1,3-
In the reaction of butadiene, 5-phenyl-pentene is synthesized, in the reaction of o-xylene and 1,3-butadiene, 5- (o-tolyl) -pentene is produced, and in the reaction of p-xylene and 1,3-butadiene, Is 5- (p-tolyl) -pentene, 5- (m-tolyl) pentene is used in the reaction of m-xylene and 1,3-butadiene, and 5- (phenyl) -hexene is used in the reaction of ethylbenzene and butadiene. Each is synthesized.

As described above, the alkenylbenzene which is the target product of the present invention is subjected to a cyclization reaction and then dehydrogenation to give a compound useful as a raw material for pharmaceuticals and polymer materials, that is, monoalkylnaphthalene and dialkylnaphthalene. Can be

In this case, the purity of pentene or hexene when cyclizing phenyl-pentene, phenyl-hexene or tolyl-pentene becomes a problem.

That is, the so-called arylalkene olefinic double bond of the main objects phenyl-pentene, phenyl-hexene and tolyl-pentene has a position of 1 or 2, but in the conventionally known method, olefin is used. In the reaction of butadiene with different positions of the sex double bond, for example, 5- (o-tolyl) -pentene- (1), 5- (o-tolyl) -pentene-
(2), 5- (o-tolyl) -pentene- (3), 5-
A considerable amount of (o-tolyl) -pentene- (4) etc. is by-produced and mixed. In other phenylpentene, phenylhexene, and tolylpentene synthesized by the reaction of toluene, ethylbenzene, p-xylene, m-xylene and butadiene, isomers having different olefinic double bond positions are by-produced and mixed.

Among these isomers, those having an olefinic double bond at the 1 or 2 position can be cyclized and converted into alkyltetralin, but other isomers cannot be converted into alkyltetralin, It reacts with the product alkyltetralin to form a high-boiling product, which reduces the yield of the desired product.

In addition, the olefinic double bond is changed to 3,4,5 from the alkenylbenzene which is the target product of the method of the present invention.
It is extremely difficult to remove the isomer at the position of, for example, a reaction mixture of o-xylene and 1,3-butadiene (the desired product is 5- (o-tolyl) -pentene-
The crude rectification of (2) and 5- (o-tolyl) -pentene- (1)) is carried out at a reflux ratio of 20 using rectification with 50 theoretical plates, The bodies are almost inseparable. On the other hand, in the reaction product obtained by the method of the present invention, the number of such side reactions that are difficult to separate is extremely small,
Therefore, the yield of the cyclization reaction product is extremely high.

The alkenylbenzene is cyclized into an alkyltetralin by a method known per se, that is, by contacting with an acid catalyst such as sulfuric acid, solid phosphoric acid or silica-alumina at a temperature of 100 to 250 ° C. for 10 seconds to 10 hours. You can

Alkyl tetralins are prepared in a manner known per se, ie, alumina-chromia, Pt / Al ₂ O ₃
5 seconds to 10 at a temperature of 350 to 450 ° C. with a dehydrogenation catalyst such as
The alkylnaphthalene can be dehydrogenated by contacting for a time.

Alkylnaphthalene is prepared by a method known per se, that is, a solid acid catalyst such as silica-alumina, ZSM-5, Y-type zeolite, H-type mordinite and 200
The isomerization can be carried out by catalyzing at a temperature of ~ 450 ° C for 5 seconds to 10 hours. For example, 1,5-dimethylnaphthalene can be changed to 2,6-dimethylnaphthalene.

According to the present invention, it is possible to produce dimethylnaphthalene, which is a compound useful as a raw material for polymer materials, from alkylbenzene as follows.

That is, for example, o-xylene and 1,3-
Butadiene is reacted with a catalyst obtained by dispersing sodium metal with potassium alkoxide to produce 5- (o-tolyl) pentene, and then the 5- (o-tolyl) pentene is cyclized by a method known per se. 1
5-dimethyltetralin is produced and then the 1,5-
Dimethylnaphthalene can be isomerized to produce 2,6-dimethylnaphthalene.

By further oxidizing the 2,6-dimethylnaphthalene, naphthalene-2,6-dicarboxylic acid can be produced.

[0047]

INDUSTRIAL APPLICABILITY The reaction product obtained by the method of the present invention contains very few by-products which are difficult to separate.
The yield of cyclization reaction product is also very high.

According to the method of the present invention, (a) metallic sodium is mixed and dispersed with the potassium alkoxide of the formula (I) at a specific ratio as a catalyst without causing oxygen and water to substantially exist. By reacting alkylbenzene with 1,3-butadiene in the presence of a catalyst, without directly using a metal sodium-potassium (Na—K: nuck) alloy, which has a high risk of expensive ignition,
Moreover, it is highly active in the alkenylation reaction and has high selectivity, so that it is difficult and complicated to separate it from the target substance, and it is possible to suppress the production of by-products and to produce a high-purity target substance in a high yield. It became possible. The catalyst used in the method of the present invention has the advantage that it can be easily separated without the need for separation such as nuck when preparing a catalyst, and the cost is low.

[0049]

The present invention will be described in detail below with reference to examples.

Needless to say, the present invention is not limited to this embodiment. In the following Examples and Comparative Examples, the yield and purity of the target product are as defined below. In addition, “part” simply means “part by weight”.

(Yield and Purity) After filtering the whole reaction mixture at room temperature, about 500 g of the reaction mixture was placed in a Widmer rectification column at 22 mmHg (abs).
) Was distilled under reduced pressure to separate a fraction having a rectification column top temperature of 75 ° C. or lower, a fraction of 75 to 170 ° C., and a residue. Then, a fraction at 75 to 175 ° C. was collected as an alkenyl compound obtained by alkenylating xylene with 1,3-butadiene. The yield of alkenyl compound in the total reaction mixture was calculated from the ratio of this alkenyl compound fraction in the sample.

The fraction of the alkenyl compound is analyzed by gas chromatography to determine the content (wt%) of 5- (tolyl) -pentene (2) and 5- (tolyl) pentene (1). The yield of the product was calculated. The unreacted xylene was contained in the alkenyl compound fraction in an amount of 0.1% by weight or less.

Similarly for the reaction product of toluene and butadiene, 5-phenylpentene (1) and 5-phenyl-
The content of the penten (2) was determined and the yield of the desired product was calculated.

The yield when xylenes and ethylbenzene were used as the alkylbenzene was calculated by the following formula.

[0055]

[Equation 1] The reaction product of toluene and butadiene was calculated by the following formula.

[0056]

[Equation 2]

[0057]

Example 1 (A) Preparation of Fine Particle Dispersion Liquid of Metallic Sodium It was heated under reflux in the presence of metallic sodium in advance, distilled, and then dehydrated with a molecular sieve to contain substantially no water. Into 500 parts of o-xylene, dry high-purity nitrogen (oxygen content of 1 ppm or less, water content of 0.1 ppm or less) was blown, dissolved oxygen was expelled and removed, and then metallic sodium (purity 99.9%) was added. 110-under nitrogen atmosphere
Emulsify and disperse for 30 minutes at 120 ° C using an emulsifying disperser,
An emulsified dispersion of metallic sodium was prepared.

(B) Preparation of Metal Sodium / Potassium Alkoxide Dispersion Catalyst A predetermined amount of potassium alkoxide was added to the emulsified dispersion liquid of metal sodium prepared as described above, and the mixture was stirred under high speed.
A metal sodium / potassium alkoxide dispersion catalyst was prepared by stirring and heating dispersion treatment at 0 to 144 ° C. for 1 hour.

(C) Synthesis Reaction of 5- (o-Tolyl) Pentene The catalyst dispersion prepared in (B) above was charged with o-xylene dehydrated and purified as described above in a nitrogen atmosphere with stirring.
The composition as described in 1. was stirred at 140 to 145 ° C. for 1 hour, and 1,3-butadiene was introduced at a ratio of 0.1 mol with respect to 1 mol of o-xylene and reacted.

After completion of the reaction, immediately cool to 100 ° C.,
While maintaining the temperature at 100 ° C., stirring was stopped and the mixture was allowed to stand for 30 minutes to separate the reaction product mixture into a catalyst and a target liquid phase. 22-mmHg o of target 5- (o-tolyl) pentene
Table 1 shows the results of the yield and purity of 5- (o-tolyl) pentene obtained by distillation under reduced pressure.

[0061]

[Table 1]

[0062]

Examples 2 to 8 and Comparative Examples 1 to 7 Further, as Examples 2 to 8 and Comparative Examples 1 to 7, under the same conditions as in Example 1 except that the catalyst composition, amount, reaction temperature and reaction time were variously changed. The results obtained by carrying out the reaction are shown in Tables 1 and 2.

[0063]

[Table 2] As can be seen from Tables 1 and 2, according to the method of the present invention, high-purity 5- (o-tolyl) pentene can be obtained in high yield.

[0064]

Examples 9 to 13 and Comparative Examples 8 to 9 In Example 1, p-xylene was used instead of o-xylene, and 1,3
-Alkenylation reaction with butadiene was performed.

The catalyst preparation and reaction were carried out under the same conditions and operating methods as in Example 1. The results are shown in Table 3.

As can be seen from Table 3, according to the method of the present invention, high-purity 5- (p-tolyl) pentene can be obtained in high yield.

[0067]

[Table 3]

[0068]

Example 14 (A) Preparation of catalyst In this example, a method of melting and dispersing metallic sodium was performed. That is, 6 parts metallic sodium and 450 ° C
64 parts of sodium carbonate baked and dehydrated for 5 hours at 150 ° C
After high-speed dispersion treatment for 60 minutes, cool to 120 ° C, add 1000 parts of dehydrated ethylbenzene, and add 30 parts of potassium-t-butoxide to the dispersion liquid dispersed under high-speed stirring, and treat at 130 ° C for 60 minutes. To prepare a catalyst.

(B) 5- (Phenyl) -hexene synthesis reaction To the catalyst prepared in (A) above, 2000 parts of ethylbenzene dehydrated and purified as in Example 1 was added, and the temperature was adjusted to 135 to 140 ° C.
Then, 150 parts of 1,3-butadiene was introduced for 1.5 hours to cause a reaction. After completion of the reaction, immediately cool to 80 ° C., stop stirring while maintaining the temperature, and let stand for 30 minutes.
The reaction product liquid was separated into a catalyst and a target liquid phase. The desired product, 5-phenyl-hexene, was distilled under a reduced pressure condition of 25 mmHg abs. The yield and purity were determined. As a result, the purity was 98.5.
%, And the yield was 88.7%.

[0070]

Example 15 Using a metal sodium-potassium-t-butoxide dispersion-treated catalyst prepared under the same conditions as in Example 14, the reaction of toluene with 1,3-butadiene at a reaction temperature of 105 to 115 ° C. I went.

As a result, 5 with a yield of 85% and a purity of 99.2% was obtained.
-Phenyl-pentene was obtained.

[0072]

Example 16 This example is an example of synthesizing 2,6-dimethylnaphthalene by cyclization reaction, dehydrogenation reaction and isomerization reaction of 5- (o-tolyl) -pentene.

(A) Synthesis of 1,5-dimethyltetralin by cyclization reaction of 5- (o-tolyl) -pentene 5- (o-tolyl) -pentene having a purity of 99.0% obtained in Example 1 The cyclization reaction was carried out using a 10% toluene solution of. Using solid phosphoric acid as a catalyst, the reaction temperature is 15
As a result of carrying out in a nitrogen atmosphere at 0 to 200 ° C., the conversion rate of the raw material was 100%, and the production selectivity of 1,5-dimethyltetralin which was a cyclization product was 95% or more.

(B) Synthesis of 1,5-dimethylnaphthalene by dehydrogenation reaction of 1,5-dimethyltetralin Dehydration using a 10% toluene solution of 1,5-dimethyltetralin obtained by the method of (A) above. An elementary reaction was performed.
As a result of dehydrogenation at 400 ° C. in a hydrogen atmosphere using a 0.3% Pt / Al ₂ O ₃ catalyst as a dehydrogenation catalyst, 1,5-
When the conversion of dimethyltetralin was 100%, the selectivity of 1,5-dimethylnaphthalene was 97%, and 1,5-dimethylnaphthalene was obtained.

(C) Synthesis of 2,6-dimethylnaphthalene by isomerizing 1,5-dimethylnaphthalene 1,5-dimethylnaphthalene obtained by dehydrogenation by the method (B) above is isomerized to give 2,5-dimethylnaphthalene. An experiment was conducted to synthesize 6-dimethylnaphthalene.

Results of carrying out isomerization reaction in a nitrogen atmosphere in the presence of an alumina dispersed catalyst containing 30% of H-type mordenite at a temperature of 350 to 400 ° C. using a 10% toluene solution of 1,5-dimethylnaphthalene. , 1,5-dimethylnaphthalene 10%, 2,6-dimethylnaphthalene 43
%, 1,6-dimethylnaphthalene 44%, and another naphthalene compound 3%. When this was crystallized and separated, 50% of 98% pure 2,6-dimethylnaphthalene was recovered.

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Claims (12)

[Claims] 1. When (a) an alkali metal is used as a catalyst when an alkenylbenzene is produced by reacting an alkylbenzene with a conjugated diolefin in the presence of a catalyst,
(B) A potassium alkoxide represented by the following formula (I): RCH ₂ OK (I) (R represents a hydrogen atom or a C _{1 to} C ₁₀ hydrocarbon group) and mixed and dispersed. A method for producing alkenylbenzene and a derivative thereof, which comprises reacting an alkylbenzene with a conjugated diolefin in an environment where a catalyst is used and oxygen and water are substantially absent. 2. The method according to claim 1, wherein the alkylbenzene is any one selected from toluene, ethylbenzene, o-xylene, p-xylene and m-xylene. 3. The production method according to claim 1, wherein the conjugated diolefin is 1,3-butadiene or isoprene. 4. The method according to claim 1, wherein the alkali metal (a) is sodium. 5. The process according to claim 1, wherein the potassium alkoxide of formula (I) is at least one selected from the group consisting of potassium methoxide, potassium ethoxide, potassium propoxide, potassium butoxide, potassium amyloxide. Method. 6. The production method according to claim 1, wherein the mixing and dispersing treatment is performed in an inert solvent. 7. An inert solvent as alkylbenzene,
The production method according to claim 6, wherein a paraffinic hydrocarbon having a carbon number of 8 to 20 and a boiling point of 100 to 230 ° C, preferably 120 to 200 ° C is used. 8. The manufacturing method according to claim 1, wherein the mixing and dispersing treatment is performed in an inert gas atmosphere. 9. The method according to claim 8, wherein at least one selected from nitrogen, helium, argon and hydrogen is used as the inert gas. 10. The production method according to claim 1, wherein a catalyst prepared by coexisting a carbonate is used in the mixing and dispersing treatment. 11. A method for producing an alkyltetralin, which comprises cyclizing the alkenylbenzene obtained by the method according to claim 1. 12. A method for producing an alkylnaphthalene, which comprises dehydrogenating alkyltetralin obtained by the method according to claim 11.