JPH05112477A - Production of alkenylbenzene and its derivative - Google Patents

Abstract

PURPOSE:To obtain the title compound in high efficiency by reaction of an alkylbenzene with a butadiene. CONSTITUTION:The objective compound can be obtained by reaction of an alkylbenzene with 1,3-butadiene under such a condition as to be virtually free from both oxygen and water in the presence of a catalyst prepared by dispersion treatment of (A) metallic sodium with (B) an inorganic composition containing potassium carbonate dehydrated under roasting.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing alkenylbenzene safely and efficiently by reacting alkylbenzene and butadiene in the presence of sodium metal. More specifically, for example, 5- (o-tolyl) -pentene, which is an alkenylbenzene obtained by the reaction of o-xylene and 1,3-butadiene, is cyclized to form dimethyltetralin, which is dehydrogenated. The present invention relates to a compound having a high industrial value, which can be converted into naphthalenedicarboxylic acid useful as a polymer raw material by converting it to dimethylnaphthalene and then oxidizing it. 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 metal potassium must be used in order to obtain a monoalkenylbenzene in a high yield. 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 in which metal potassium is supported on potassium carbonate or alumina and the production process is improved by carrying out the reaction of o-xylene and butadiene in a fixed bed (US Pat. No. 4,990, 717).

However, since all of these methods directly use potassium metal, they are highly reactive to air, oxygen, water, etc., and ignite only when they come into contact with these compounds to burn combustible substances (petroleum) in the vicinity. It is extremely dangerous in the coexistence with

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 1,3-butadiene in the presence of a catalyst having a high activity and a high selectivity for the alkenylation reaction, it is possible to produce a by-product that is difficult and complicated to separate from the target product. The object is to suppress the production of 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 alkylbenzene and 1,3-butadiene are reacted in the presence of a catalyst to produce alkenylbenzene, sodium carbonate as a catalyst is calcined and dehydrated. Using an inorganic composition containing potassium and a dispersion-treated catalyst,
In addition, the method for producing alkenylbenzene is characterized in that alkylbenzene and 1,3-butadiene are reacted in an environment where oxygen and water do not substantially exist.

That is, in the production of alkenylbenzene by reacting alkylbenzene and 1,3-butadiene, oxygen and water are not substantially present, and sodium carbonate is calcined and dehydrated as a catalyst. In the presence of an inorganic composition containing potassium and a dispersion-treated supported catalyst, alkenylbenzene and 1,3-
An alkenylbenzene characterized by producing a high-purity alkenylbenzene in a high yield, which is difficult to separate from a target substance by reacting with butadiene, and suppresses the generation of complicated by-products. It is a method for producing the derivative.

The present invention will be described in detail below. Alkylbenzene as a raw material used in the method of the present invention has 1 to 1 in the benzene nucleus.
It is an alkylbenzene having two methyl groups or ethyl groups, and specific compounds include toluene, ethylbenzene, o-xylene, m-xylene and p-xylene. Each of these alkylbenzenes is preferably used alone, and when a mixture is used, it becomes difficult to separate the desired product from the alkenylbenzenes, which are the 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.

In the present invention, 1,3-butadiene is
It may be manufactured by any method, 1,3-
The purity of 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 of 1,3-butadiene, the more preferable it is a few ppm or less.

In the present invention, alkylbenzene and 1,
The catalyst used for the reaction with 3-butadiene is a catalyst obtained by subjecting sodium metal to a dispersion treatment with an inorganic composition containing potassium carbonate subjected to calcination and dehydration treatment.

The higher the purity of metallic sodium, the better, but it does not matter if it contains a small amount of potassium, calcium or magnesium. The purity is preferably 90% or higher, and preferably 99.0% or higher.

The potassium carbonate used for the calcination and dehydration treatment preferably has a purity of 95% or more. In order to effectively exhibit the activity as a catalyst, high temperature, preferably 20
It is necessary to dehydrate at 0 ° C or higher, more preferably 250 to 500 ° C. In order to exhibit high performance with a small amount of potassium carbonate, it is mixed with an inorganic oxide such as alumina or calcium silicate and subjected to a calcination and dehydration treatment to obtain an excellent calcination and dehydration inorganic composition containing potassium carbonate. Further, this potassium carbonate may contain a carbonate such as sodium carbonate, calcium carbonate, magnesium carbonate, barium carbonate,
In some cases, high performance may be obtained by mixing these carbonates in an appropriate ratio.

(Preparation of Carrier) In the method of the present invention, the carrier of sodium metal (dispersion treating agent) is a mixture of potassium carbonate and an inorganic oxide such as alumina, calcium silicate, magnesium silicate, zeolite or silica-alumina, and the mixture is calcined and dehydrated. Prepared by processing. Calcination dehydration treatment is over 200 ℃,
It is preferably carried out at a temperature of 250 to 500 ° C. The weight ratio of potassium carbonate to the above-mentioned inorganic oxide such as alumina may be in the range of 0.1: 99.9 to 50:50, and the ratio is preferably from the viewpoint of reactivity of alkenylation and preparation of the carrier. Potassium: solid oxide = 0.5 to 30: 99.5 to 70
The range of (weight ratio) is preferable.

As a method for preparing this carrier, there are typically two methods. That is, a dry method and a wet method. In the dry method, powder of potassium carbonate and the solid oxide such as alumina are well mixed and pulverized, heated to 130 to 150 ° C., stirred and dispersed and mixed at this temperature, and then 250 to 5
A method of baking and drying at 00 ° C is adopted. This method is often used when the amount of potassium carbonate exceeds 10% with respect to the total weight of the carrier, but when the amount of potassium carbonate is 10% or less, it is not preferable from the viewpoint of uniform dispersion. Therefore, when the mixing weight ratio of potassium carbonate is small, the wet method is adopted. That is, an appropriate amount of potassium carbonate corresponding to 0.1 to 10% is dissolved in water, and the above solid oxide such as alumina is added to this aqueous solution, and after immersion and impregnation, 100 to 150 ° C.
And dried at 250 to 500 ° C. for 2 to 10 hours to prepare a carrier.

(Preparation of catalyst) The proportion of metallic sodium and the inorganic oxide carrier carrying potassium carbonate may be any proportion, but the final proportion of metallic sodium is 0.1 to 30 relative to the total weight of the catalyst. % By weight, preferably 1.0-2
It is 0% by weight. As a method of preparing the catalyst used in the method of the present invention, a method of dispersing metallic sodium on the fine particles of the inorganic oxide carrier supporting potassium carbonate is used. The dispersion treatment is preferably performed in an inert gas such as nitrogen, helium, argon or hydrogen.

As the dispersion treatment, an inert solvent dispersion supporting method, that is, a method of carrying a dispersion by using an inert solvent, and a so-called dry dispersion supporting method which does not use a solvent are adopted. In this method, the catalyst prepared by any method can be used. The temperature at which the carrier is dispersed and supported is 100.
To 250 ° C, preferably 110 to 200 ° C. For example, in an inert solvent dispersion supporting method, when 3% by weight of metallic sodium is dispersed and supported, 97 parts of potassium carbonate-supported alumina serving as a carrier is added to 3 parts of metallic sodium as a solvent o.
-Put in 1000 parts of xylene simultaneously and pressurize 110-1
A method of high-speed stirring at 60 ° C. is adopted, but it is also possible to prepare a dispersion liquid having an appropriate dispersion ratio in advance and further add an alumina carrier in a solvent to disperse the dispersion liquid.

Examples of the inert solvent include m-octane and n-octane.
Nonane, decane, undecane, todecane, etc. have 8 carbon atoms
To 20 and having a boiling point of 100 to 250 ° C., preferably 1
Examples thereof include paraffins at 50 to 200 ° C., and among them, it is industrially preferable to use alkylbenzene used as a reaction raw material.

The carrier catalyst thus uniformly dispersed and supported is
The activity can be improved by reacting the mixture of alkylbenzene and the catalyst with pretreatment at 100 to 200 ° C. for 1 to 5 hours before introducing and reacting with 1,3-butadiene.

In the method of the present invention, alkylbenzene and 1,3
-The reaction with butadiene is carried out in the substantial absence of water and oxygen. Therefore, it is desirable that the raw materials introduced into the reaction system from outside the system, that is, alkylbenzene and 1,3-butadiene, are dehydrated as described above. Furthermore, since the space of the reaction system does not allow oxygen and water to substantially exist,
For example, it is desirable to fill with a dry inert gas such as dry nitrogen or dry argon, or to fill the space with a vapor such as alkylbenzene under a pressurized reaction condition that is higher than the boiling point of alkylbenzene.

In the present invention, the reaction is 100 ° C 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-metal sodium / g-potassium carbonate), reaction temperature (° C) and the ratio of alkylbenzene to 1,3-butadiene (g-alkylbenzene / g-1,3-butadiene), respectively. Therefore, an appropriate time is adopted depending on the purity of the target product and the usage pattern of the catalyst, for example, the presence or absence of recycling. Generally, the reaction time becomes longer as the numerical value of the above factors decreases, but the preferable reaction time is 0.2 to 8 hours, particularly preferably 0.3 to
4 hours.

The reaction is a batch reaction in which the raw material alkylbenzene, 1,3-butadiene and a catalyst are simultaneously charged from the beginning, and the reaction is carried out first. First, alkylbenzene and the catalyst are charged, and then 1,3-butadiene is quantitatively determined with the lapse of reaction time. Either a semi-batch reaction for introducing or a continuous reaction for continuously introducing alkylbenzene, 1,3-butadiene and a catalyst into the reactor may be adopted, or an appropriate combination thereof may be used. Alternatively, a continuous reaction is preferable.

Two formats are employed for the continuous reaction. That is, in the method of the present invention, the catalyst is a solid fine powder catalyst in which metallic sodium, an inorganic composition containing potassium carbonate and a dispersion treatment are dispersed. Therefore, alkylbenzene is continuously flowed through a fixed bed of the catalyst to obtain 1,3 in the alkylbenzene. There are a method of carrying out a continuous reaction while introducing butadiene, and a method of carrying out the reaction while dispersing and stirring the catalyst in the reaction system.

The continuous reaction system may be a tubular reactor, a column reactor or 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 inlet of 1,3-butadiene to cause a clogging phenomenon. Therefore, 1,3-
Mixed phase of butadiene and alkylbenzene, such as liquid phase mixture of liquid butadiene and alkylbenzene, gaseous 1,3-butadiene and gaseous alkylbenzene-
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 space of the reaction zone and causing the absorption reaction on the surface of the reaction liquid containing the catalyst. It is also possible to increase the stirring effect at the same time when the butadiene is introduced together with the carrier gas. As the carrier gas, an inert gas from which oxygen and water have been removed, such as nitrogen, argon or hydrogen is 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 have 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, the used catalyst can be separated from the reaction product system by a known means such as centrifugal sedimentation or gravity sedimentation, or liquid-solid phase at a lower temperature. Any known means such as separation of solid phase from, for example, filtration, centrifugation and the like 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 sodium is deactivated in the phase of the carrier carrying potassium carbonate. Therefore, it can be reused by being oxidized and baked as it is with the organic substance attached, treated with metallic sodium, 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, and in the reaction of o-xylene with 1,3-butadiene, 5- (o-tolyl) -pentene is reacted with p-xylene and 1,3-butadiene. In the reaction of 5- (p-tolyl) -pentene, 5- (m-tolyl) pentene in the reaction of m-xylene with 1,3-butadiene, and 5- (phenyl) -hexene in the reaction of ethylbenzene and butadiene. Are respectively 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 drugs 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 main objects phenyl-pentene, phenyl-hexene,
The so-called arylalkene olefinic double bond of tolyl-pentenes has a position of 1 or 2, but in the conventionally known method, isomers having different olefinic double bond positions, for example, o-xylene and butadiene. The reaction of 5- (o-tolyl) -pentene- (1), 5- (o
-Tolyl) -Pentene- (2), 5- (o-Tolyl)-
Penten- (3), 5- (o-tolyl) -pentene-
(4) etc. are produced as a by-product in a considerable amount and are 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, and the desired alkyl It reacts with tetralin to form a high boiling point product, which lowers the yield of the desired product. Moreover, it is extremely difficult to remove the isomer having the olefinic double bond at the 4,5-position from the alkenylbenzene, which is the target product of the method of the present invention. For example, o-xylene and 1,3-butadiene can be removed. Reaction mixture (the desired product is 5
The crude rectification of (o-tolyl) -pentene- (2) and 5- (o-tolyl) -pentene- (1) was carried out at a reflux ratio of 20 using a rectification column with 50 theoretical plates. The isomers can hardly be separated even by rectification. In contrast,
The reaction product obtained by the method of the present invention is characterized in that such side products which are difficult to separate are extremely small, and therefore the yield of the cyclization reaction product is also 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 minute.

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, dimethylnaphthalene, which is a compound useful as a raw material for polymer materials, can be produced from alkylbenzene as follows.

That is, for example, o-xylene and 1,3-
By reacting butadiene with metallic sodium on a solid oxide support carrying potassium carbonate, a catalyst obtained by dispersion treatment is used to produce 5- (o-tolyl-pentene, and then the 5- (o-tolyl) -pentene is prepared by Cyclization by a method known per se to produce 1,5-dimethyltetralin,
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.

[0041]

INDUSTRIAL APPLICABILITY Among the reaction products obtained by the method of the present invention, the side products which are difficult to separate are extremely small, and therefore the yield of the cyclization reaction product is extremely high.

According to the method of the present invention, metal oxide as a catalyst is allowed to exist in a substantially non-existent state, and metallic sodium is used as a catalyst, and fine powder of a solid oxide carrier carrying potassium hydroxide dehydrated by high temperature calcination and a specific ratio. By reacting alkylbenzene with 1,3-butadiene in the presence of a catalyst treated by dispersion, the metal sodium-potassium (Na-K: Nak) alloy, which is expensive and has a high risk of ignition, is not used directly. In addition, 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, suppressing the production of by-products, and producing a high-purity target substance in a high yield. 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.

[0043]

EXAMPLES 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 entire reaction mixture at room temperature, about 500 g of the reaction mixture was passed through a Widmer rectification column to obtain 22 mmHg (ab
It was distilled under reduced pressure of s) and separated into a fraction having a rectification column top temperature of 75 ° C or lower, a fraction having a temperature 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.

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

Similarly, for the reaction product of toluene and butadiene, the contents of 5-phenylpentene (1) and 5-phenyl-pentene (2) were 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.

[0048]

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

[0049]

[Equation 2]

[0050]

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 dehydrated with a molecular sieve to contain substantially no water. Dry high purity nitrogen (oxygen content of 1 ppm or less, moisture content of 0.1 ppm or less) was blown into 500 parts of o-xylene to expel and remove dissolved oxygen, and then 3.0 parts of metallic sodium (purity 99.9%). And was emulsified and dispersed at 110 to 120 ° C. for 30 minutes in the above nitrogen atmosphere using an emulsification disperser to prepare an emulsified dispersion of metallic sodium.

(B) Preparation of Potassium Carbonate-Supported Alumina Carrier and Dispersion Liquid 21 parts of potassium carbonate having a reagent grade purity of 89.5% was dissolved in 80 parts of water and calcined at 450 ° C. for 3 hours to obtain 8 alumina powders.
1 part was added, impregnated, dipped, water was evaporated to dryness at 100 ° C. to 150 ° C., and then baked and dried at 400 to 450 ° C. for 5 hours to obtain 100 parts of an alumina carrier. Average particle size 100
The particles are micronized to μm, further dried in a flask at 200 ° C. in a nitrogen atmosphere, 1000 parts of the above dehydrated o-xylene is added, and the mixture is dispersed for 30 minutes using an emulsification disperser to support potassium carbonate. The dispersion was an alumina carrier.

(C) Preparation of mixed dispersion of metallic sodium-potassium carbonate-supported alumina The fine dispersion of metallic sodium was added to the above alumina carrier dispersion under high speed stirring and heated to 160 ° C. under pressure to 160 ° C. And heat-treated for 1 hour to obtain a predetermined catalyst dispersion.

(D) Synthesis Reaction of 5- (o-Tolyl) Pentene The catalyst dispersion prepared in (C) above was charged with o-xylene dehydrated and purified as described above under a nitrogen atmosphere with stirring.
The catalyst shown in Table 1 was o-xylene. Then 140-1
After stirring at 45 ° C. for 1 hour, 1,3-butadiene was introduced at a ratio of 0.1 mol to 1 mol of o-xylene and reacted.

After completion of the reaction, the mixture was immediately cooled 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.
The desired product 5- (o-tolyl) pentene was distilled under a reduced pressure of 22 mmHg abs. To determine the yield and purity of 5- (p-tolyl) pentene. The results are shown in Table 1.

[0055]

[Table 1]

[0056]

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.

[0057]

[Table 2]

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

[0059]

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 preparation and reaction of the catalyst 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, 5- (p-
It can be seen that trilyl) pentene is obtained.

[0061]

[Table 3]

[0062]

Example 14 (A) Preparation of catalyst In this example, a catalyst prepared by melting metallic sodium and carrying it dispersedly on alumina supporting 30% by weight of potassium carbonate was used. That is, an alumina carrier prepared by calcining alumina carrying 30% by weight of potassium carbonate at 450 ° C. for 5 hours was made into fine particles having an average particle size of 100 μm or less, further dried at 200 ° C. in a nitrogen atmosphere, and then cooled 190.
Add 6 parts of metallic sodium to 6 parts of carrier, and add 6 parts at 150 ° C.
After a high speed dispersion treatment for 0 minutes, the mixture was cooled to 130 ° C., 1000 parts of dehydrated ethylbenzene was added, and the mixture was treated at 135 ° C. for 60 minutes to prepare a catalyst.

(B) Synthesis reaction of 5- (phenyl) -hexene 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%.

[0064]

Example 15 The reaction between toluene and 1,3-butadiene was carried out at a reaction temperature of 105 to 115 ° C. using a metal sodium-potassium carbonate-supported alumina dispersion treatment catalyst prepared under the same conditions as in the operation method of Example 14. went. As a result 85%
5-Phenyl-pentene having a purity of 98.5% was obtained in a yield.

[0065]

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-
1,5-Dimethylnaphthalene was obtained with a conversion of dimethyltetralin of 99% and a selectivity of 1,5-dimethylnaphthalene of 97%.

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

As a result of carrying out an isomerization reaction under 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.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication C07C 5/31 9280-4H 5/367 9280-4H 13/48 8619-4H 15/24 8619-4H // C07B 61/00 300

Claims (12)

[Claims] 1. An inorganic composition containing sodium carbonate as a catalyst, which is obtained by reacting alkylbenzene with 1,3-butadiene in the presence of a catalyst to produce alkenylbenzene, and which contains potassium carbonate after calcined and dehydrated. A method for producing alkenylbenzene, which comprises reacting an alkylbenzene with 1,3-butadiene in an environment in which oxygen and water are substantially absent, using a dispersion-treated catalyst. 2. The method according to claim 1, wherein the alkylbenzene is any one of toluene, ethylbenzene, o-xylene, m-xylene and p-xylene. 3. The method according to claim 1, wherein the inorganic composition is obtained by calcining and dehydrating potassium carbonate in the presence of at least one selected from alumina, magnesium silicate, calcium silicate, zeolite and silica-alumina. 4. The method according to claim 1, wherein a carbonate is additionally used in the baking dehydration treatment. 5. The method according to claim 1, wherein the baking dehydration treatment is performed at 200 ° C. or higher. 6. The method according to claim 1, wherein the dispersion treatment is carried out in an inert gas. 7. The inert gas is nitrogen, helium, argon,
The method according to claim 6, which is at least one selected from hydrogen. 8. The method according to claim 1, wherein the dispersion treatment is performed at 100 to 250 ° C. 9. The method according to claim 1, wherein the dispersion treatment is carried out by an inert solvent dispersion supporting method. 10. An inert solvent having an alkylbenzene and / or a carbon number of 8 to 20 and a boiling point of 100 to 250.
Process according to claim 9, using paraffins at ℃, preferably 150-200 ℃. 11. A method for producing alkyltetralin, which comprises cyclizing the alkenylbenzene obtained by the method according to claim 1. 12. A method for producing alkylnaphthalene, which comprises dehydrogenating the alkyltetralin obtained by the method according to claim 11.