JP2921543B2 - Purification method of monoalkenylbenzenes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an aromatic hydrocarbon compound in which one or more hydrogen atoms are bonded to the α-position of a side chain by using a conjugated diene having 4 or 5 carbon atoms. The present invention relates to a method for producing monoalkenylbenzenes by alkenylation with a metal catalyst and then purifying the monoalkenylbenzenes from a reaction product solution. Monoalkenylbenzenes are useful as intermediate raw materials for various organic compounds such as high molecular monomers and pharmaceuticals. For example, 5- (O-tolyl)-produced from O-xylene and 1,3-butadiene After ring closure, 2-pentene can be converted to industrially useful 2,6-naphthalenedicarboxylic acid by dehydrogenation, isomerization and oxidation.

[0002]

2. Description of the Related Art Catalysts for producing monoalkenylbenzenes by alkenylating the side chains of aromatic hydrocarbon compounds with conjugated dienes having 4 or 5 carbon atoms include alkali metals such as sodium, potassium and the like. A method using an alloy of, a carrier obtained by calcining a mixture of a basic potassium compound and alumina, under an inert gas, a method using a mixture obtained by heat treatment by adding sodium metal,
There is known a method of using a metal sodium or metal potassium supported on an alkali metal oxide or an alkaline earth metal oxide. When monoalkenylbenzenes are separated and recovered from a reaction product solution obtained using an alkali metal such as sodium or potassium and an alloy thereof among these catalysts, after the reaction is completed, the product solution is cooled and allowed to stand. When the method is used to separate the catalyst and the liquid phase containing the target substance by decantation or filtration and then separate and recover the monoalkenylbenzenes by distillation, alteration of the monoalkenylbenzenes occurs, resulting in high recovery and high purity. It is known that monoalkenyl benzene cannot be obtained.

Therefore, various processing methods have been proposed to solve such a problem. JP-A-51-4127
Has proposed that the total concentration of the alkali metal and the organic alkali metal compound in the hydrocarbon used as the distillation material be in the range of 0.09 to 15 milligram atoms of the alkali metal component per 1 kg of the hydrocarbon phase. However, this method does not mean that all of the alkali metal catalyst components have been removed, but that some of them are mixed into the liquid phase as soluble alkyl or alkenyl complexes. When this product liquid is introduced into the distillation column as it is, monoalkenylbenzenes further react with unreacted alkylbenzenes and monoalkenylbenzenes themselves in the presence of an active catalyst to produce high molecular weight by-products, A reverse reaction returns to the starting material alkylbenzenes, or the transfer of a double bond produces an isomer other than the desired monoalkenylbenzene.

[0004] Decreasing the total concentration of the alkali metal and the organic alkali metal compound only reduces the degree thereof, and it is impossible to prevent the deterioration at all. In addition, when the distillation column is operated for a long period of time, a small amount of alkali metal and organic alkali metal compounds are concentrated in the distillation column, so that high-purity monoalkenylbenzenes cannot be obtained at the end, and the recovery rate is low. Will also decrease. Modification of monoalkenyl benzene can be suppressed to some extent by lowering the distillation temperature, but for this purpose it is necessary to carry out distillation under reduced pressure, and to avoid any alteration of monoalkenyl benzene. Requires a high vacuum and is not an industrial economic process.

Japanese Patent Application Laid-Open No. 49-70929 discloses a method in which a catalyst is separated and removed from a reaction product and then treated with carbon dioxide for distillation, or a reaction product is treated with carbon dioxide and then the catalyst is separated and removed for distillation. Has been proposed. In this method, the alkali metal and the organic alkali metal compound are completely deactivated by the carbon dioxide treatment, and the deterioration of the monoalkenyl benzene can be prevented in the distillation, but the generated alkali carbonate such as alkali carbonate and alkali carboxylate can be prevented. Is soluble in the organic solvent and introduced into the distillation column. And when unreacted aromatic hydrocarbons are distilled off in the distillation,
The alkali salt having a solubility or higher precipitates as a solid and accumulates inside the distillation column. For this reason, the gas-liquid contact in the distillation column is reduced and the distillation efficiency is not only lowered, but finally the distillation column is closed and the distillation operation cannot be performed. That is, unless the alkali metal component is completely removed, the distillation column is operated stably, and it becomes impossible to obtain high-purity monoalkenylbenzenes.

Japanese Patent Publication No. 57-26489 proposes a method in which alkenylbenzene is brought into contact with water, the water is adjusted to pH 6 or less, and the alkali metal catalyst is made water-soluble, followed by separation. However, in this method, when the reaction product liquid is brought into contact with water, there is a risk of ignition in addition to the generation of a large amount of reaction heat. Although the reaction can be controlled to some extent by the amount of water or reaction solution to be brought into contact, when the reaction is carried out on an industrial scale, a long processing time is required and the equipment becomes large, which is not practical. Also, US
In P3,244,758, an undesired side reaction during distillation is prevented by adding isopropanol in advance before distillation to inactivate alkali metals and alkali metal compounds contained in the product solution. . In this method, a large amount of reaction heat and danger of ignition caused by contact with water can be avoided, but the deactivated alkali metal catalyst is introduced into the distillation column as an alkali metal alcoholate soluble in an organic solvent. This is not preferable because of the following problems.

On the other hand, it has been found that a catalyst having an alkali metal supported on a carrier other than the alkali metal or alloy is effective for the alkenylation reaction. Among the various supported alkali metal catalysts, it has been found that the catalyst prepared by the following treatment exhibits extremely high activity in the alkenylation reaction and has extremely low ignitability. That is, a carrier obtained by calcining a mixture of a hydroxide of potassium and alumina hydrate, a carrier obtained by calcining a mixture of a basic potassium compound and alumina, and an alkaline earth metal oxide containing a potassium compound. Product carrier, a zirconium oxide carrier containing a potassium compound, and an alkali metal-supported catalyst obtained by heat-treating these carriers under addition of metallic sodium under an inert gas, has a very high activity in the alkenylation reaction. Is shown. At present, no treatment method has been proposed yet when using such an alkali metal-based supported catalyst.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have prepared a reaction product obtained using an alkali metal-based catalyst,
After the mixture was allowed to stand and separated by filtration into a catalyst and a liquid phase containing the target substance, a purification method was used in which monoalkenylbenzenes were separated and recovered by distillation. Monoalkenylbenzenes could not be obtained with high purity and high recovery. In addition, accumulation of insoluble compounds occurs in the distillation column,
Eventually, the distillation operation could not be performed due to the blockage of the distillation column. That is, the reaction product liquid was allowed to stand, and separation of the catalyst and the liquid phase containing the target substance was attempted by filtration. However, filtration alone could not completely remove the fine particle catalyst, and also a part of the alkali metal. Is mixed into the liquid phase as a soluble alkyl or alkenyl complex. When this product liquid is introduced into the distillation column as it is, monoalkenylbenzenes further react with unreacted alkylbenzenes and monoalkenylbenzenes themselves in the presence of an active catalyst to produce high molecular weight by-products, A reverse reaction returns to the starting material alkylbenzenes, or the transfer of a double bond produces an isomer other than the desired monoalkenylbenzene. Therefore, high-purity monoalkenylbenzenes cannot be obtained, and the recovery rate also decreases.

The alteration of the monoalkenyl benzene can be suppressed to some extent by lowering the distillation temperature. However, for this purpose, it is necessary to carry out the distillation under reduced pressure, and the alteration of the monoalkenyl benzene does not occur at all. Requires a high vacuum and requires industrial equipment,
Operational costs are high and impractical. A part of the alkali metal is also introduced into the distillation column as an alkali salt soluble in an organic solvent, and when unreacted aromatic hydrocarbons are distilled off in the distillation, the alkali salt having a solubility or higher is precipitated as a solid and distilled off. It accumulates inside. Therefore, not only the gas-liquid contact in the distillation column is reduced and the distillation efficiency is reduced, but also the distillation column is finally clogged and the distillation operation cannot be performed. That is, this problem cannot be avoided only by the distillation operating conditions. In view of the above, an object of the present invention is to use a conjugated diene having 4 or 5 carbon atoms for the side chain of an aromatic hydrocarbon compound having one or more hydrogen atoms bonded to the α-position of the side chain. In the production of monoalkenylbenzenes by alkenylation with an alkali metal-based supported catalyst, a method for separating and recovering monoalkenylbenzenes from the reaction product solution with high purity and high recovery rate is to be developed.

[0010]

Means for Solving the Problems The present inventors have alkenylated an aromatic hydrocarbon compound at the α-position with a supported alkali metal catalyst using a conjugated diene having 4 or 5 carbon atoms to convert monoalkenylbenzenes. As a result of intensive studies on the method of producing and separating and recovering monoalkenylbenzenes from the reaction product solution , the reaction product solution was mixed with air, oxygen and water vapor.
Gas, carbon dioxide, mixed gas of carbon dioxide and oxygen, dioxide
Alkali metal system by contact with mixed gas of carbon and steam
In addition to deactivating the supported catalyst, the reaction product was filtered to remove
The inventors have found that monoalkenylbenzenes can be purified with high purity and high recovery by separating and recovering monoalkenylbenzenes by distillation after removing the supported alkali metal catalyst, and have completed the present invention. That is, the present invention
Aromatic hydrocarbons having one or more hydrogen atoms bonded to the α-position of
Use a conjugated diene having 4 or 5 carbon atoms for the side chain of the hydrogen compound
Alkenylation with an alkali metal supported catalyst
When producing alkenyl benzenes, the reaction product
Between the solution and (1) oxygen or a mixture of oxygen and an inert gas
Contact, (2) steam, or a mixture of steam and an inert gas
(3) carbon dioxide, or carbon dioxide and acid
Alkali by contact with elemental and / or water vapor mixed gas
Deactivation of metal-supported catalyst and reaction product liquid of 5 microns or less
Remove the alkali metal supported catalyst using the filter below
After that, monoalkenylbenzenes are separated by distillation.
Monoalkenylbenzenes characterized by separation and recovery
Is a purification method . In the present invention, the reaction product liquid
Before separation and recovery of monoalkenylbenzenes by distillation,
Deactivation operation of the supported catalyst of the alkali metal and the flow of
A filtration operation using a filter is performed.
The order of over-operation is not limited. And the air is (1) with oxygen
Corresponds to a mixture of inert gases .

Hereinafter, the present invention will be described in detail. As the aromatic hydrocarbon compound having one or more hydrogen atoms bonded to the α-position of the side chain used in the present invention, the following compounds are used. Monocyclic aromatic hydrocarbons include monoalkylbenzenes such as toluene, ethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, sec-butylbenzene, isobutylbenzene, o-, m- and p-xylene, o-, dialkylbenzenes such as m- and p-ethyltoluene, o-, m- and p-diethylbenzene, trialkylbenzenes such as mesitylene and pseudocumene, 1,2,3,5-tetramethylbenzene, 1,2,4,5 Polyalkylbenzenes such as tetramethylbenzene, pentamethylbenzene, and hexamethylbenzene are used, and polycyclic aromatic hydrocarbons include 1- and 2-methylnaphthalene, dimethylnaphthalenes, tetrahydronaphthalene,
Indane or the like is used. Carbon number 4 as one raw material
Alternatively, 1,3-butadiene, 1,3-pentadiene, and isoprene are used as the conjugated dienes.

The alkali metal supported catalyst used in the present invention includes a carrier obtained by calcining a mixture of potassium hydroxide and alumina hydrate at 350 ° C. to 700 ° C., a basic potassium compound, 35 mixed with alumina
A carrier obtained by calcining at 0 ° C. to 700 ° C., an alkaline earth metal oxide carrier containing a potassium compound, a zirconium oxide carrier containing a potassium compound, and
There is a mixture obtained by heat-treating these carriers at 100 ° C. to 300 ° C. under an inert gas and adding metal sodium. In using these catalysts for the reaction, various reaction systems are adopted, but generally, a method of making aromatic hydrocarbons, which is one of the raw materials, excessively present relative to conjugated dienes is monoalkylbenzene. Selectivity to the class can be improved. For this purpose, a method of continuously supplying conjugated dienes to the reaction system by a semi-batch method is preferable. When the reaction is continuously performed by a complete mixing method or a fixed bed flow method, the reactor is divided into multiple stages, and the concentration of conjugated dienes in the reactor is reduced by supplying conjugated dienes to each stage. It is preferable to employ a reaction method capable of achieving a high selectivity because a high selectivity can be obtained.

The reaction temperature in the method of the present invention is 100 to 2
It is in the range of 00 ° C. If it is lower than this, the reaction occurs, but a sufficient reaction rate cannot be obtained, and the selectivity tends to decrease. If the temperature is higher than this, by-products such as tar are increased, which is not preferable. In the present invention, the reaction is carried out under the condition that the starting aromatic hydrocarbon and the product are in a substantially liquid state. The reaction pressure is not particularly limited as long as the raw material aromatic hydrocarbon and the product are substantially present as a liquid, and is not particularly limited.
Atmospheric pressure, preferably in the range of 0.1 to 2 atm. In the process of the present invention, the ratio of the conjugated diene having 4 or 5 carbon atoms, which is one of the raw materials, to the aromatic hydrocarbon raw material is generally in the range of 0.01 to 1, preferably 0.03 to 0.5 in molar ratio. It is. When the amount of diene is larger than this, the generated monoalkenylbenzene further reacts with the diene to increase the production of a compound in which two or more molecules of diene are added to one molecule of aromatic hydrocarbon, and polymerization of the diene is likely to occur. It is not preferable because the rate decreases. The amount of the catalyst used in the method of the present invention is at least 0.01% by weight, preferably at least 0.05%, based on the amount of the starting aromatic hydrocarbon. The method of the present invention employs a reaction system such as a batch system, a semi-batch system, and a completely mixed circulation system. Is adopted. In the case of the fixed bed circulation system, usually, the LSV of the aromatic hydrocarbon is 0.1 to 10 h ^-1 .

When the reaction is carried out by suspending the catalyst, the reaction solution is usually allowed to stand after the reaction, and most of the catalyst is first settled.
Next, the product liquid is withdrawn from the reaction tank. At this time, as one method, first, a large amount of the alkali metal supported catalyst is removed by filtration using a filter of 5 μm or less. When a coarser filter is used, a part of the particulate catalyst is contained in the recovered product liquid,
Unfavorable to cause a deterioration of the alkenyl benzene. Even when the alkali metal-based catalyst is removed by filtration using a filter of 5 μm or less, a part of the alkali metal is mixed into the liquid phase as a soluble alkyl or alkenyl complex or alkali salt. When this product liquid is introduced into the distillation column as it is, the active soluble catalyst causes the alteration of monoalkenylbenzene. Although the amount of the soluble catalyst is not large, the quality of the monoalkenylbenzene increases to a considerable extent when it is concentrated in the distillation column retentate and operated for a long period of time. Therefore, the active soluble catalyst needs to be deactivated before the product liquid is introduced into the distillation column. The other is to first deactivate the alkali metal catalyst component from the product solution containing the particulate insoluble alkali metal supported catalyst and a soluble alkyl or alkenyl complex or alkali salt, and then use a 5 μm or smaller filter to filter the alkali metal. This is a method of removing the metal-supported catalyst by filtration. Although any of the above methods can be used, when the first method is used, the active alkali metal-based catalyst collected on the filter causes the alteration of monoalkenylbenzene on the filter to cause high molecular weight monoalkenylbenzene. Of polymer and may cause clogging of the filter. Therefore, the latter method is more preferably used. A part of the carrier of the alkali metal supported catalyst is contained in the product liquid in the form of fine particles, and the entire amount cannot be removed only by sedimentation. Therefore, the operation of removing the solid by the filter must be performed.

To deactivate the catalyst, a gas such as air, oxygen, water vapor, carbon dioxide, a mixed gas of carbon dioxide and oxygen, or a mixed gas of carbon dioxide and water vapor is brought into contact with a product liquid.
A method of converting an active alkali metal-based supported catalyst into an alkali oxide, an alkali hydroxide, or an alkali carbonate is employed. When using air, oxygen, and steam, potassium, sodium, or alloys of them may cause a large amount of reaction heat or fire when deactivated, so use inert gas such as nitrogen, helium, or argon in a timely manner. Although it is necessary to dilute with a gas, it is not always necessary to dilute with an inert gas when using an alkali metal supported catalyst. This is considered to be due to the reactivity of the alkali metal on the carrier, and the handling can be advantageously performed. Although the deactivation reaction can be controlled by the gas introduction rate, a larger introduction rate can be selected as compared with the case where potassium, sodium, or an alloy thereof is used as a catalyst.

The contact time is not particularly limited, and may be a time sufficient to deactivate the active alkali metal supported catalyst. The contact temperature can be selected from a wide range of room temperature to the boiling point of the starting aromatic hydrocarbon, but room temperature is sufficient. As a contact system, a reaction system such as a batch system, a semi-batch system, a complete mixing and distribution system, and the like are employed. However, any system can be used as long as gas-liquid contact is sufficient. If air, oxygen, water vapor, carbon dioxide, a mixed gas of carbon dioxide and oxygen, a gas such as a mixed gas of carbon dioxide and water vapor and contact the product liquid,
If the alkali metal-based catalyst cannot be completely removed by deactivating the active alkali-metal-supported catalyst and removing the alkali metal-based catalyst using a filter, water, an acid aqueous solution, alcohol, etc. Alternatively, a method of deactivating and removing the alkali metal-based catalyst using a solid such as a liquid, a solid acid, a carbon material, and a cationic ion exchange resin may be used in combination.

[0017]

As described above, in the case where alkenylbenzene is separated and recovered by distillation from the alkenylbenzene-producing liquid in which the alkali metal-based supported catalyst has been deactivated and / or removed, alteration occurs even by atmospheric distillation. In addition, high purity alkenylbenzene can be obtained at a high recovery rate, and the distillation column can be operated stably, and its industrial significance is extremely large.

[0018]

The method of the present invention will be described in detail below with reference to examples and comparative examples. Note that the present invention is not limited to the scope of the following embodiments. The Al ₂ O ₃ powder (Mizusawa Industrial Chemicals Ltd. DN-1A) 5.8 kg was added to an aqueous solution containing Example 1 KOH 2.09kg, was mixed and stirred for 1 hour at room temperature. After drying overnight at 115 ° C., it was further fired at 500 ° C. in air. 500 g of this mixed and baked product
Was stirred at 150 ° C. under a nitrogen atmosphere, and after adding 60 g of metallic Na, the mixture was stirred for 30 minutes. 100 kg of O-xylene dehydrated using a molecular sieve was added to the catalyst powder thus obtained in a nitrogen stream and heated to 140 ° C. 1,3-butadiene while stirring under normal pressure
0 kg was introduced in 1 hour to cause a reaction. After the reaction, stirring was stopped, the mixture was allowed to stand, the temperature was lowered, and the product liquid was extracted. A part of this product liquid was taken and analyzed by gas chromatography. The results are shown in Table 1. 5- (O based on 1,3-butadiene
-Tolyl) -2-pentene selectivity was 83.0%. After bubbling air through the reaction product solution to completely deactivate the alkali metal supported catalyst, the product solution was passed through a stainless sintered metal filter having a pore diameter of 1 micron to an ortho-xylene recovery tower at 10 kg / hr. Introduced at speed. Table 2 shows the composition and weight of the top liquid and the bottom liquid when the orthoxylene recovery tower was operated at a normal temperature and a kettle temperature of 230 ° C. 5- in the bottom product of the target product
No alteration of (O-tolyl) -2-pentene was observed. Next, the 5- (O-tolyl) -2-pentene purification tower was operated at normal pressure and a kettle temperature of 250 ° C.
(O-tolyl) -2-pentene was recovered. Purity 9
It was 9.8% and the recovery was 98.5%.

Example 2 The same procedure as in Example 1 was carried out except that the deactivation of the alkali metal-supported catalyst was carried out with steam diluted with nitrogen. 5- (O
-Tolyl) -2-pentene purity was 99.7% and recovery was 98.4%. Example 3 Example 3 was carried out in the same manner as in Example 1 except that the deactivation of the alkali metal-based supported catalyst was performed using a mixed gas of carbon dioxide and air. 5-
The (O-tolyl) -2-pentene purity was 99.6% and the recovery was 98.3%. Example 4 Example 4 was carried out in the same manner as in Example 1 except that the deactivation of the alkali metal-based supported catalyst was performed using a mixed gas of carbon dioxide and water vapor.
5- (O-tolyl) -2-pentene purity is 99.5
%, And the recovery was 98.5%.

Example 5 CaO 5 was added to an aqueous solution containing 2.09 kg of KOH.
Add 8kg, stir and mix at room temperature for 1 hour,
And dried overnight, followed by the same procedure as in Example 1 except that a carrier calcined in air at 500 ° C. was used. 5- (O-
The purity of (tolyl) -2-pentene was 99.5%, and the recovery was 98.3%. Example 6 ZrO _{2 in} an aqueous solution containing 2.09 kg of KOH.
Add 8 kg, stir at room temperature for 1 hour, mix,
And dried overnight, followed by the same procedure as in Example 1 except that a carrier calcined in air at 500 ° C. was used. 5- (O-
The purity of (tolyl) -2-pentene was 99.8% and the recovery was 98.1%.

Comparative Example 1 In Example 1, the product solution after the alkenylation reaction was allowed to stand, and the temperature was lowered. This product liquid was directly introduced into the ortho-xylene recovery tower at a rate of 10 kg / hr without passing through a filter. Table 2 shows the composition and weight of the top liquid and the outlet liquid when the orthoxylene recovery tower was operated at a normal temperature and a kettle temperature of 230 ° C. 5- (O-tolyl) -2-pentene in the bottom product of the desired product was altered,
High-boiling components further reacted with (O-tolyl) -2-pentene and ortho-xylene, increase of ortho-xylene by reverse reaction of alkenylation reaction, transfer of double bond of 5- (O-tolyl) -2-pentene Formation of the isomers 5- (O-tolyl) -3-pentene and 5- (O-tolyl) -4-pentene was observed.

Comparative Example 2 In Example 1, the product liquid after the alkenylation reaction was allowed to stand and cooled, and then the reaction product liquid was extracted through a stainless sintered metal filter having a pore diameter of 1 micron. This product liquid is used as it is without deactivating the alkali metal catalyst component.
It was introduced at a rate of 10 kg / hr into an orthoxylene recovery tower operated under a reduced pressure of 0 mmHg and a kettle temperature of 120 ° C. Table 2 shows the composition and weight of the top liquid and the bottom liquid one day after the operation of the ortho-xylene recovery tower. 5- (O
-Tolyl) -2-pentene had reduced variable mass but failed to control by-products. Comparative Example 3 Table 2 shows the composition and weight of the top liquid and the bottom liquid after operating the orthoxylene recovery tower for 5 days in Comparative Example 2. The variable mass of 5- (O-tolyl) -2-pentene increased. Concentration of the alkali metal catalyst occurs in the distillation column,
Under the operating conditions of the distillation column alone, the variable mass of 5- (O-tolyl) -2-pentene was reduced and purification could not be performed at a high recovery rate. Comparative Example 4 In Comparative Example 2, the orthoxylene recovery tower was further operated for 10 days. However, solids precipitated near the distillation column feed stage, and the supply of the product liquid became difficult, and the operation was stopped.

[0023]

[Table 1] Ortho-xylene 81.87 wt% OTP-2 16.10 wt% OTP-3 0.003 wt% OTP-4 0.016 wt% C20H 0.071 wt% Other high-boiling by-products 2.03 wt% ────────────────────────── OTP-2 5- (O-tolyl) -2-pentene; OTP-3; 5- (O-tolyl) -3-pentene. OTP-4; 5- (O-tolyl) -4-pentene. C20H; a compound having a molecular weight of 266 formed by reacting 5- (O-tolyl) -2-pentene with orthoxylene.

[0024]

[Table 2] Example 1 Comparative Example 1 Comparative Example 2 Comparison Example 3 塔 overhead liquid weight kg / hr 8.19 28 8.21 8.31 Composition wt% ortho-xylene 99.99 99.99 99.99 99.99 OTP-2 0.001 0.001 0.001 0.001 ───────────────────────── Discharge from kettle Weight kg / hr 1.81 1.72 1.79 1.69 Composition wt% ortho-xylene 0 0.001 0.001 0.001 0.001 OTP-2 88.36 71.46 85.43 60.45 OTP-3 0.015 0.71 0.14 0.83 TP-4 0.088 4.73 0.95 6.28 C20H 0.39 2.67 0.53 4.06 Other high-boiling by-products 11.15 20.42 12.95 28.38 ─────────────────────────────── OTP-2; 5- (O-tolyl) -2-pentene. OTP-3; 5- (O-tolyl) -3-pentene. OTP-4; 5- (O-tolyl) -4-pentene. C20H; a compound having a molecular weight of 266 formed by reacting 5- (O-tolyl) -2-pentene with orthoxylene.

Continuation of front page (56) References JP-A-51-26823 (JP, A) JP-A-49-70929 (JP, A) JP-A-5-97722 (JP, A) JP-A-5-140005 (JP, A) JP-A-5-112478 (JP, A) Japanese Patent Publication No. 50-17973 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 15/44 B01J 23/04 C07C 2/72

Claims (5)

(57) [Claims] An aromatic hydrocarbon compound having at least one hydrogen atom bonded to the α-position of the side chain is alkenyl-substituted with an alkali metal supported catalyst using a conjugated diene having 4 or 5 carbon atoms. (1) Oxygen or oxygen and inert gas from the reaction product liquid when producing monoalkenyl benzenes
(2) water vapor or water vapor
Contact with a mixture of active gases, or (3) carbon dioxide,
Or in contact with a mixture of carbon dioxide and oxygen and / or water vapor
Deactivation and Reaction Formation of Alkali Metal Supported Catalyst by Contact
Alkali metal using a filter of 5 micron or less
A method for purifying monoalkenylbenzenes , comprising removing the supported catalyst , and separating and recovering the monoalkenylbenzenes by distillation. 2. To a compound obtained by calcining a mixture of potassium hydroxide and alumina hydrate at 350 ° C. to 700 ° C., add sodium metal under an inert gas to obtain a compound.
The method according to claim 1, wherein the mixture obtained by heat treatment at 0 ° C to 300 ° C is used as an alkali metal-based supported catalyst. 3. A compound obtained by calcining a mixture of a basic potassium compound and alumina at 350 ° C. to 700 ° C., and adding sodium metal under an inert gas at 100 ° C. to 300 ° C. The method according to claim 1, wherein the mixture obtained by the heat treatment is used as an alkali metal supported catalyst. 4. The process according to claim 1, wherein a mixture obtained by heat-treating an alkaline earth metal oxide containing a potassium compound and metal sodium under an inert gas is used as an alkali metal-based catalyst. 5. A mixture obtained by heat-treating a zirconium oxide containing a potassium compound and metallic sodium under an inert gas is used as an alkali metal-based supported catalyst.
The described method.