JP2002302460A - Process for producing exo-tetrahydrodicyclopentadiene and catalyst for isomerization reaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for isomerizing endo-tetrahydrodicyclopentadiene to produce a corresponding exo-form, which simplifies operations such as catalyst measurement and charging and suppresses the generation of by-products. In addition, the present invention provides a method for industrially advantageously producing exo-THDC by significantly reducing the reaction time. SOLUTION: Endo-tetrahydrodicyclopentadiene is isomerized using an oily catalyst obtained by reacting anhydrous aluminum halide and hydrogen halide in the presence of a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing exo-tetrahydrodicyclopentadiene and a catalyst for an isomerization reaction. More particularly, the present invention relates to a method for isomerizing endo-tetrahydrodicyclopentadiene to produce a corresponding exo form, and a catalyst for an isomerization reaction.

[0002]

2. Description of the Related Art Exo-tetrahydrodicyclopentadiene (hereinafter also referred to as exo-THDC) has a boiling point of 1%.
It is a known substance with a colorless faint smell at 87 ° C (under normal pressure) and a melting point of -79 ° C. Conventionally, endo-tetrahydrodicyclopentadiene (hereinafter also referred to as endo-THDC) isomerized in the presence of anhydrous aluminum chloride to give exo-THD.
Methods for producing C are known.

For example, Japanese Patent Application Laid-Open No. 50-13370 discloses that a Friedel-Craft type catalyst such as anhydrous aluminum chloride or anhydrous aluminum bromide and an aromatic solvent are used.
A method for isomerizing endo-THDC to produce exo-THDC has been described. Further, it has been proposed to increase the catalytic activity by using tertiary butyl chloride, isopropyl bromide or the like as a co-catalyst in this method. However, when the amount of the catalyst used is a raw material (End-TH
It is not an industrially advantageous production method because it is 20% by weight or more with respect to DC) and the by-product (decalin) reaches as much as 4%.

[0004] US Patent No. 4,086,284 discloses a method for synthesizing exo-THDC from endo-THDC in the presence of an anhydrous aluminum chloride catalyst in order to suppress the formation of by-products (decalin, adamantane, etc.) An inert solvent is used as the reaction solvent, and the reaction temperature is 9
It has been proposed to control the temperature to 0 ° C. or lower, preferably to about 70 ° C. However, this method uses an end-THD
The conversion of C is low, and is not sufficiently satisfactory.

[0005] Improvements in the isomerization reaction using anhydrous aluminum chloride as a catalyst as described above have also been reported. For example, Japanese Patent Application Laid-Open No. 57-32232 discloses a method in which the reaction temperature is increased to 100 to 150 ° C., and endo-THDC is brought into direct contact with sludge containing aluminum chloride to increase the conversion of endo-THDC. Have been. However, such relatively high temperatures (100
When the reaction is carried out at a temperature of about 150 ° C., by-products such as trans-decalin (boiling point at normal pressure; 185 ° C.) and adamantane generally tend to be easily produced. Since the boiling point of by-produced trans-decalin is very close to that of exo-THDC (normal pressure boiling point: 187 ° C.), it is difficult to separate it by ordinary simple distillation.

As described above, in the conventional method for producing exo-THDC using an anhydrous aluminum chloride catalyst,
(1) When the reaction temperature is 100 ° C. or lower, the reaction time becomes longer because the initial reaction activity of the catalyst is low, and the production efficiency of the target product is low. (2) When the reaction temperature is 100 ° C. or higher, There was a problem that a by-product was easily formed.

The anhydrous aluminum chloride used in the conventional method for producing exo-THDC is a granular or powdery substance having a high hygroscopic property. The operation such as charging into the container was extremely complicated. Furthermore, since the reaction system becomes non-uniform, the reaction speed is generally slow, and it has been necessary to rotate the stirrer vigorously to prevent the catalyst from settling.

Japanese Patent Publication No. 45-7307 discloses a homogeneous medium in the presence of a liquid three-way catalyst comprising almost equivalent amounts of aluminum halide, hydrogen halide and aromatic hydrocarbon or a mixture thereof. A method for producing a petroleum resin characterized by polymerizing light steam cracking naphtha is described therein, but the use of such a liquid catalyst in an isomerization reaction is not known at all.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for isomerizing endo-THDC to produce exo-THDC, which simplifies operations such as catalyst measurement and charging and reduces the generation of by-products. It is an object of the present invention to provide a method for producing exo-THDC which is industrially advantageous while suppressing the reaction time and greatly reducing the reaction time. Another object of the present invention is to provide a catalyst for an isomerization reaction which is excellent in handleability and has high activity.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an endo-tetrahydrodicyclopentadioxide using a catalyst obtained by reacting anhydrous aluminum halide and hydrogen halide in the presence of a solvent. Disclosed is a method for producing exo-tetrahydrodicyclopentadiene, which isomerizes pentadiene. The present invention also provides an isomerization reaction catalyst obtained by reacting anhydrous aluminum halide and hydrogen halide in the presence of a solvent.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the exo-THDC of the present invention will be described.
The production method and the catalyst for the isomerization reaction will be described in detail by dividing into the items of the raw material, the catalyst, the isomerization reaction, and the target product.

Raw Material: Endo-THDC The raw material Endo-THDC of the present invention is a known substance having a boiling point of 193 ° C. (under normal pressure) and a melting point of 77 ° C. and having a colorless slight odor. The target exo-THDC described below has a stereoisomeric relationship.

The method for producing the raw material endo-THDC is not particularly limited, and any one obtained by a conventionally known method may be used. Dicyclopentadiene having a purity of 93% by weight or more (hereinafter, also referred to as DCP) is used. It is preferable to use those obtained by hydrogenation.

[0014] Such DCP, for example, DCP obtained by the process and the remaining C ₅ fraction obtained by extracting isoprene from C ₅ fraction by-produced during pyrolysis of naphtha treating dimerization
A fraction having a relatively high content can be obtained by removing unreacted substances and by-products using a rectification apparatus generally used in industry and increasing the DCP content. Such high purity D
The impurities contained in the CP in trace amounts are, for example, vinyl norbornene, isopropenyl norbornene, propenyl norbornene, tricyclopentadiene and the like.

The method of hydrogenating the above-mentioned DCP to convert it into endo-THDC, which is a raw material of the present invention, is not particularly limited, and it may be hydrogenated according to a conventional method using a known hydrogenation catalyst such as a palladium catalyst. Since DCP usually exists as a heat energy stable end body, THDC obtained by hydrogenation has an end structure. In this hydrogenation step, endo-THDC is not isomerized to exo-THDC. The purity of such endo-THDC is usually at least 90% by weight, preferably at least 92% by weight,
It is more preferably at least 94% by weight.

Catalyst The catalyst used in the production method of the present invention and the catalyst for the isomerization reaction of the present invention are oily catalysts obtained by reacting anhydrous aluminum halide and hydrogen halide in the presence of a solvent. Here, the “catalyst for the isomerization reaction” refers to a catalyst that converts one of the structural isomers or stereoisomers represented by the same molecular formula into the corresponding other isomer, but is preferably a stereoisomer. It is a catalyst that causes an isomerization reaction between isomers. As a specific example, End-THD
And isomerization of C to exo-THDC.

It is essential that the catalyst is prepared in the presence of a solvent. The solvent is not particularly limited,
Aromatic hydrocarbons or mixtures of aromatic hydrocarbons are preferably used. As the aromatic hydrocarbon, for example, benzene, toluene, ortho-xylene, meta-xylene,
Examples include para-xylene, ethylbenzene, n-propylbenzene, isopropylbenzene, mesitylene, chlorobenzene, dichlorobenzene, and nitrobenzene. Preferably, toluene, xylene, mesitylene and the like are used. A commercially available solvent may be used as it is, but it is preferable to use a solvent that has been brought into contact with a dehydrating agent (drying agent) such as molecular sieves in advance and dehydrated. The amount (weight ratio) of the solvent used is usually 1 to 50 times, preferably 2 to 4 times, that of the anhydrous aluminum halide described below.
It is 0 times.

Although the anhydrous aluminum halide is not particularly limited, anhydrous aluminum chloride, anhydrous aluminum bromide and the like are preferable, and anhydrous aluminum chloride is more preferable. As the anhydrous aluminum halide, a commercially available product may be obtained and used. For example, generally available industrial anhydrous aluminum chloride (powder) or the like may be used as it is or may be further pulverized if necessary. be able to.
Although the hydrogen halide is not particularly limited, hydrogen chloride, hydrogen bromide and the like are preferable, and hydrogen chloride is more preferable. The gaseous hydrogen halide is usually used.

As a method for preparing the catalyst, for example, an anhydrous aluminum halide is suspended in a solvent such as toluene or xylene, and a reaction is performed by blowing a hydrogen halide gas such as hydrogen chloride into the suspension. This reaction is preferably performed with stirring. The reaction temperature is usually -20 to 80
° C, preferably -10 to 50 ° C, more preferably 0 to 3 ° C.
0 ° C. Usually, an excess amount of hydrogen halide gas is introduced until the anhydrous aluminum halide is dissolved (oiled) in the solvent. Preferably, 2 to 15 times the molar amount of hydrogen halide is used relative to anhydrous aluminum halide.

The amount of the oily isomerization catalyst prepared in this manner is not particularly limited, but is converted into the amount of anhydrous aluminum halide contained in the solution.
C, usually 0.1 to 20% by weight, preferably 0.1 to 20% by weight.
It is 2 to 15% by weight, more preferably 0.5 to 10% by weight. The oily catalyst is usually separated into two layers from the solvent used in the preparation of the catalyst. However, only the catalyst layer (lower layer) may be used for the isomerization reaction, or it may be used together with the solvent layer (upper layer). Good. After preparing the oily catalyst, another inert solvent may be added to the oily catalyst to be subjected to the isomerization reaction.

The isomerization reaction of the present invention is characterized in that endo-THDC is isomerized to exo-THDC in the presence of the oily anhydrous aluminum halide catalyst described above. This isomerization reaction can be carried out either in the presence or absence of a reaction solvent. When a reaction solvent is not used, it is necessary to heat the raw material of the end-THDC to a temperature higher than the melting point and react it in a liquid state. When using a reaction solvent,
It is preferable to use an inert solvent that does not affect the catalytic activity. Such inert solvents include, for example, aromatic hydrocarbons, linear (linear or branched) or cyclic aliphatic hydrocarbons, and the like.

Examples of the aromatic hydrocarbon include benzene, toluene, ethylbenzene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene and the like. Examples of the linear aliphatic hydrocarbon include, for example, n-pentane, n-hexane, n-heptane, isohexane, isoheptane, n-octane, isooctane, n-decane, isodecane, n-undecane,
n-dodecane, n-tridecane and the like. As the cyclic aliphatic hydrocarbon, for example, cyclopentane,
Methylcyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, decalin, paramenthane, bicyclohexyl and the like can be mentioned.

In general, the use of an inert solvent having a boiling point close to that of the target exo-THDC causes a problem that the purification of the target is complicated. There is no problem doing
It is preferably used in the present method.

The amount of the inert solvent to be used is not particularly limited, but is usually 2 to the raw material of end-THDC.
-100% by weight, preferably 4-80% by weight. Excessive use is not economical. If the amount is excessively reduced, the effect of using the inert solvent becomes poor.

The reaction temperature is not particularly limited, but is usually 40
To 150 ° C, preferably 50 to 130 ° C, more preferably 60 to 100 ° C. When the above reaction solvent is not used, it is necessary to adopt a reaction temperature higher than the melting point of exo-THDC. Although the reaction time is not particularly limited, it is generally 10 minutes to 20 hours, preferably 20 minutes to 10 hours, more preferably 30 minutes to 5 hours.

The post-treatment method of the isomerization reaction is not particularly limited, and a method generally used in industry may be applied. For example, a method of adding an alkaline water to a reaction solution and mixing well, and then separating an organic layer and an aqueous layer can be used. Purification of the target substance may be performed according to a conventional method.

Object: exo-THDC The exo-THDC obtained by the method of the present invention is a solvent having no unsaturated bond in the molecule and having little irritating property to human skin and mucous membrane. It is preferably applied to technical applications. Its uses include, for example, paint solvents, diluents, surfactant diluents, waxes, cleaners, polish diluents, detergents, mold release agents, semiconductor detergents, blanket detergents, metalworking detergents, Solvents for agricultural chemicals, auxiliary solvents for pressure sensitive paper, cleaning solvents, aluminum rolling oil, ink solvents, resin dispersants, lubricating oils, punching oils, cutting oils and the like.

[0028]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples below, but the present invention is not limited to these examples. Parts and% in Examples and Comparative Examples are by weight unless otherwise specified. In addition, the analysis of the purity and the yield of the raw material and the reaction product was performed based on gas chromatography (GC) analysis. The analysis conditions are shown below.

GC equipment: GC-14A manufactured by Shimadzu Corporation Column: HP5 (30 m capillary column, inner diameter 0.3
2 mm), Injection temperature: 200 ° C, Column heating condition: Hold at 50 ° C for 12 minutes, and 280 ° C at 10 ° C / 1 minute
And maintained at 280 ° C for 5 minutes, developing gas: helium, internal standard material: normal decane

Production Example 1 Production of End-THDC In an autoclave equipped with a stirrer, 314 parts by weight of dicyclopentadiene of 94% by weight and 5% by weight of Nippon Zeon Co., Ltd.
Three parts of palladium carbon were charged. The inside of the autoclave was replaced with nitrogen gas several times. After the inside of the autoclave was replaced with hydrogen gas several times, hydrogen gas of 0.6 MPa (gauge pressure) was pressurized. 2 at 100 ° C with stirring
The reaction was hydrogenated for hours. After the completion of the reaction, hydrogen gas was released, and the content was filtered while hot (about 80 ° C.) to remove the catalyst.
The obtained filtrate (300 parts) immediately solidified in the filter receiver. A small amount of this solid is collected, dissolved in toluene and
As a result of C analysis, no peak of dicyclopentadiene as a raw material was observed. The retention time of the main component is End-T
It was completely identical to the HDC sample, and its purity was 94.5%. Impurities are components whose GC retention time is shorter than End-THDC (low boiling components in Tables 1 to 6): 4.1%, components whose GC retention time is longer than End-THDC (high boiling components in Tables 1 to 6): It was 1.4%.

EXAMPLE 1 Oily anhydrous aluminum chloride
Preparation of Medium Two parts of anhydrous aluminum chloride (Kanto Denka Kogyo Co., Ltd., 16 mesh) and 70 parts of toluene were charged into a glass reaction vessel equipped with a stirrer, a gas inlet tube, a reflux condenser, and a thermometer. Under cooling to 5 ° C., hydrogen chloride gas was introduced while stirring the suspension. After 5 minutes, the temperature of the reaction solution was raised to 25 ° C.
, And stirring was further continued for 10 minutes. The anhydrous aluminum chloride thus charged became oily, and no solid substance was observed. The amount of hydrogen chloride gas introduced during this period was equivalent to about 10 times the molar amount of anhydrous aluminum chloride. The oily catalyst and toluene were separated into two layers. A dry nitrogen gas was flowed into the system to remove the remaining hydrogen chloride gas.

Example 2 Preparation of exo-THDC Oily anhydrous aluminum chloride 2 prepared in Example 1 above
Parts (1% based on endo-THDC) and toluene 70
A homogeneous solution obtained by mixing 200 parts of the endo-THDC obtained in Production Example 1 and 70 parts of toluene was added to the catalyst solution composed of 1 part. The contents were heated to 80 ° C. and the isomerization reaction was carried out for 4 hours while stirring well. A small amount of the reaction solution was sampled every hour during the reaction, and the progress of the reaction was investigated by GC analysis. After completion of the reaction, 50 parts of a 25% aqueous sodium hydroxide solution was added, and the mixture was stirred at 50 ° C. for 30 minutes, and then cooled to room temperature. The aqueous layer separated into two layers was removed to obtain 332 parts of an oil layer. Table 1 shows the results of the analysis of the reaction progress by GC analysis.
Shown in However, in Table 1, toluene was excluded.

[0033]

[Table 1]

Example 3 Production of exo-THDC The isomerization reaction and post-treatment were carried out in the same manner as in Example 2 except that the temperature of the isomerization reaction was set to 100 ° C., to obtain 331 parts of an oil layer. The results of GC analysis of the course of the reaction in the same manner as in Example 2 are shown in Table 2. However, in Table 2, toluene was excluded.

[0035]

[Table 2]

As can be seen from Tables 1 and 2, even at a relatively low reaction temperature of 80 to 100 ° C., most of the raw material endo-THDC is exo-THD, which is the target product, 1 to 2 hours after the start of the reaction.
It can be seen that it was converted to C. In addition, it can be seen that the generation of by-products (tetralin, adamantane) is suppressed.

Example 4 Preparation of exo-THDC In a catalyst solution comprising 2 parts of oily anhydrous aluminum chloride (1% based on endo-THDC) and 70 parts of toluene prepared in the same manner as in Example 1 above, A homogeneous solution obtained by mixing 200 parts of endo-THDC produced in the same manner as in Example 1 and 135 parts of exo-THDC prepared separately was added. The isomerization reaction and post-treatment were carried out in the same manner as in Example 2 above.
396 parts of an oil layer were obtained. Table 3 shows the results of GC analysis of the course of the reaction. However, Table 3 excludes toluene and exo-THDC used as an isomerization reaction solvent.

[0038]

[Table 3]

From Table 3, it can be seen that two hours after the start of the reaction, most of the raw material endo-THDC was converted to the desired exo-THDC. In addition, it can be seen that the generation of by-products (tetralin, adamantane) is suppressed.

Example 5 Production of exo-THDC Endo-THD produced in the same manner as in Example 1 above was placed in a glass reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer.
Add 300 parts of C and end-T at oil bath temperature of 85 ° C
HDC was dissolved. 4.5 parts of oily anhydrous aluminum chloride taken out from the catalyst solution prepared in the same manner as in Example 1 and separated into two layers (1.5 parts with respect to End-THDC)
%) Was added. Internal temperature 80 ° C with good stirring
The isomerization reaction was performed for a time. After completion of the reaction, post-treatment was carried out in the same manner as in Example 2 to obtain 288 parts of an oil layer (organic layer).
Table 4 shows the results of GC analysis of the course of the reaction.

[0041]

[Table 4]

From Table 4, it can be seen that one hour after the start of the reaction, most of the starting endo-THDC was converted to the desired exo-THDC. In addition, it can be seen that the generation of by-products (tetralin, adamantane) is suppressed.

Comparative Example 1 End-T obtained in the same manner as in Production Example 1 was placed in a glass reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer.
200 parts of HDC, 70 parts of toluene and 2 parts of powdery anhydrous aluminum chloride (1% based on endo-THDC) were charged. The contents were heated to 80 ° C. and the isomerization reaction was carried out for 4 hours while stirring well. A small amount of the reaction solution was collected every hour during the reaction, and the progress of the reaction was examined by GC analysis. After completion of the reaction, 50 parts of a 25% aqueous sodium hydroxide solution was added, and the mixture was stirred at 50 ° C. for 30 minutes, and then cooled to room temperature. The aqueous layer separated into two layers was removed to obtain 256 parts of an oil layer.
Table 5 shows the results of examining the course of the reaction by GC analysis. However, in Table 5, toluene as a reaction solvent was excluded.

[0044]

[Table 5]

Comparative Example 2 GC analysis of the isomerization reaction and the progress of the reaction was carried out in the same manner as in Example 5 except that the oily catalyst used in Example 5 was replaced with 4.5 parts of anhydrous aluminum chloride powder. Was. After the reaction,
50 parts of a 25% aqueous sodium hydroxide solution was added, and the mixture was stirred at 50 ° C. for 30 minutes, and then cooled to room temperature. The aqueous layer separated into two layers was removed to obtain 285 parts of an oil layer (organic layer). Table 6 shows the results of examining the course of the reaction by GC analysis.

[0046]

[Table 6]

From Tables 5 and 6, it can be seen that when powdered anhydrous aluminum chloride is used, the catalytic activity is reduced and the reaction rate is significantly reduced. In addition, it can be seen that although the conversion of endo-THDC is low as compared with Tables 1 to 4, the generation of by-products tends to increase.

[0048]

The catalyst for the isomerization reaction of the present invention is an oily anhydrous aluminum halide catalyst, which can be compared with the conventional method when applied to a method for isomerizing endo-THDC to produce exo-THDC. As a result, the production of by-products can be suppressed, and the reaction time can be significantly reduced, which is an industrially extremely advantageous effect.

Claims (2)

[Claims] An exo-tetrahydrodicyclopentadiene characterized in that endo-tetrahydrodicyclopentadiene is isomerized using a catalyst obtained by reacting anhydrous aluminum halide and hydrogen halide in the presence of a solvent. Manufacturing method. 2. A catalyst for an isomerization reaction obtained by reacting anhydrous aluminum halide and hydrogen halide in the presence of a solvent.