JPH05213782A - Production of dialkyltetralin compound and its derivative - Google Patents

Abstract

PURPOSE:To obtain the subject compound useful as a raw material for polyester in high selectivity and in high yield by reacting a specific alkenylbenzene under a specific condition. CONSTITUTION:A compound of the formula [R1 is 1-4C alkyl-containing butenyl or CH2-CH2-CH2-CH=CH-R3 (R3 is 1-4C alkyl); R2 is 1-4C alkyl] is brought into contact with a silica alumina catalyst containing 0.1-50wt.% one or more metals selected from alkali metals, zinc and gallium at 200-500 deg.C substantially in the absence of hydrogen under a vapor-phase or liquid-phase condition to give the objective compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a dialkyltetralin compound using alkenylbenzenes as a raw material and a method for producing a derivative from the dialkyltetralin compound. Naphthalene dicarboxylic acid derived from dialkyl naphthalene obtained by dehydrogenating dialkyl tetralin is useful as a raw material for polyester, and particularly polyester made from 2,6-naphthalene dicarboxylic acid has excellent properties. Is well known.

Among the dialkylnaphthalenes, 1,5
-Dimethylnaphthalene and / or 1,6-dimethylnaphthalene is a compound of high industrial value that can be converted into 2,6-naphthalenedicarboxylic acid by isomerizing it into 2,6-dimethylnaphthalene and oxidizing it. The invention relates to a method for producing such useful raw materials.

[0003]

2. Description of the Related Art Conventionally, as a method for producing dimethyltetralin, it has been known to utilize an alkenylbenzene derivative as a raw material and an acid catalyst, particularly a cyclization reaction using various solid acid catalysts.

For example, in Japanese Patent Publication No. 12430/1975, o-tolyl-2-pentene is added at 100 to 350 ° C.
A method for producing 1,5-dimethyltetralin by contacting it with a solid phosphoric acid catalyst at a temperature of 1 has been proposed. In this method, tetralin selectivity is high, and although relatively stable catalytic activity can be obtained, there is a problem that an expensive material is used to prevent product contamination due to the eluted phosphoric acid component and corrosion of the device. ..

Also, USP 3,244,758, US
P3,775,496, USP3,775,497
No., USP 3,775,498, USP 3,775,
No. 500 and the like propose solid acid catalysts such as silica-alumina, silica-magnesia, silica-alumina-zirconia, and zeolite as alkenylbenzene cyclization catalysts. Especially when silica alumina or silica magnesia is used, it has been proposed to use it in a low temperature region close to room temperature in order to prevent a decrease in yield due to an undesired side reaction.

Further, in Japanese Patent Publication No. 3-500052, a temperature range of 120 ° C. to 250 ° C. and a liquid phase condition of 5-
(O-, m- or p-tolyl) -penta-1 or 2
Y-type zeolite zeolite has been proposed as a catalyst for cyclization reaction of -ene or 5-phenyl-hexa-1 or 2-ene.

On the other hand, it is already known that dehydrogenation of tetralins can lead to naphthalene derivatives. Further, it is also known that tetralin having an alkyl group on the ring can relatively easily carry out the dehydrogenation reaction although the reaction rate is slightly lowered. For example, regarding the dehydrogenation of tetralin having a methyl group at the benzyl position, there is an example of dehydrogenating in the liquid phase in the presence of a palladium-carbon catalyst. However, this method has a disadvantage that it takes a relatively long time for the dehydrogenation reaction, and since the catalyst used is fine powder, it causes some troubles in operation. Further, a decrease in catalytic activity after use is also observed, which is a problem in using as an industrial process.

There is also known a method for producing a naphthalene derivative by dehydrogenating tetralin in a gas phase using a chromia-alumina catalyst (Japanese Patent Publication No. 50-11380). However, the chromia-alumina catalyst has a drawback that a decomposition reaction mainly due to demethylation reaction easily occurs.

[0009]

When the reaction temperature is focused on in the process of cyclizing and dehydrogenating alkenylbenzene to produce dialkylnaphthalene, the cyclization reaction of alkenylbenzene is, as described above, low temperature to prevent side reaction. A reaction in the area is desirable.

On the other hand, the dehydrogenation reaction of dialkyltetralin is generally performed at a higher temperature (3
It is preferable to carry out at 100 to 500 ° C.). Therefore, when both reactions are combined, one is performed at a low temperature and the other is performed at a high temperature, which causes disadvantages such as energy loss.

Therefore, an object of the present invention is to provide a method capable of carrying out a cyclization reaction of alkenylbenzene at a relatively high temperature in a high yield.

The present invention also relates to the dialkyltetralin obtained by the above method, particularly 1,5- and / or 1,
It is an object of the present invention to provide a method for dehydrogenating 6-dimethyltetralin to obtain 1,5- and / or 1,6-dimethylnaphthalene in high yield.

[0013]

[Means for Solving the Problems]

 A. Production of Dialkyltetralin Compound The present invention provides a compound represented by the following formula [I]:

[0014]

[Chemical 2]

[In the formula, R ₁ is a butenyl group having an alkyl group having 4 or less carbon atoms, or —CH ₂ —CH ₂ —CH ₂ —
CH = CH-R ₃ (where, R ₃ represents a hydrogen atom or an alkyl group of 4 or less carbon atoms.), R ₂ represents an alkyl group having 4 or less carbon atoms. ] When producing a dialkyltetralin compound by contacting with a solid catalyst at a temperature of 200 to 500 ° C under the conditions of a gas phase or a liquid phase in the substantial absence of hydrogen, the solid catalyst is an alkali metal. A method for producing a dialkyltetralin compound, which is a silica-alumina catalyst containing 0.1 to 50% by weight of at least one metal selected from zinc, gallium and gallium.

1) Reaction Raw Material In the present invention, a substituted benzene represented by the following general formula [I] is used as a reaction raw material.

[0017]

[Chemical 3]

[In the formula, R ₁ is a butenyl group having an alkyl group having 4 or less carbon atoms, or —CH ₂ —CH ₂ —CH ₂ —
CH = CH-R ₃ (where, R ₃ represents a hydrogen atom or an alkyl group having 4 or less carbon atoms.), R ₂ represents an alkyl group having 4 or less carbon atoms. Examples of the substituted benzenes include o-tolyl-2-methylbutene-3, o-tolyl-3-methylbutene-3,
m-tolyl-2-methylbutene-3, m-tolyl-3-
Methylbutene-3, p-tolyl-2-methylbutene-
3, p-tolyl-3-methylbutene-3, o-tolylpentene-3, o-tolylpentene-4, m-tolylpentene-3, m-tolylpentene-4, p-tolylpentene-3, p-tolyl Pentene-4, o-ethylphenyl-2-methylbutene-3, o-ethylphenyl-3-methylbutene-3, m-ethylphenyl-2-methylbutene-3, p-ethylphenyl-2-methylbutene-3,
o-ethylphenylpentene-3, o-ethylphenylpentene-4, m-ethylphenylpentene-3, m-
Ethylphenylpentene-4, p-ethylphenylpentene-3, p-ethylphenylpentene-4, o-propylphenyl-2-methylbutene-3, o-propylphenyl-3-methylbutene-3, m-propylphenyl-2 -Methylbutene-3, m-propylphenyl-3-
Methylbutene-3, p-propylphenyl-2-methylbutene-3, p-propylphenyl-3-methylbutene-3, o-propylphenylpentene-3, o-propylphenylpentene-4, m-propylphenylpentene-3, m-propylphenylpentene-4, p-propylphenylpentene-3, p-propylphenylpentene-4, o-tolyl-2-ethylbutene-3, m-tolyl-ethylbutene-3, p-tolyl-2-ethylbutene- 3, o-tolyl-3-ethylbutene-3, m-tolyl-3-ethylbutene-3, p-tolyl-3-ethylbutene-3, o-tolylhexene-3, o-tolylhexene-4, m-tolylhexene -3, m-tolylhexene-4, m-tolylhexene-5, p-tolylhexene-
3, p-tolylhexene-4, p-tolylhexene-5
Etc. are used.

In the present invention, the substituted benzenes having a butenyl group react in the presence of the catalyst of the present invention, and the substituents bond with the benzene ring to form a tetralin ring.

2) Catalyst The catalyst used in the present invention contains 0.1 to 50 of at least one metal selected from alkali metals, zinc and gallium.
It is a silica-alumina catalyst containing wt%. As the catalyst, alkali metal, zinc, or gallium may be used alone,
You may use these together.

Examples of alkali metals include sodium and potassium.

The catalyst is prepared by mixing an aqueous solution of a salt such as an alkali metal, zinc or gallium with silica-alumina powder, and evaporating to dryness or dipping filtration to support these metals on silica-alumina, followed by firing to carry the metal. A silica-alumina catalyst can be obtained.

In the case of an alkali metal, it is preferable to mix an aqueous solution of sodium hydroxide or potassium hydroxide with silica-alumina powder.

Zinc and gallium can be mixed with silica-alumina powder as an aqueous solution of zinc nitrate, zinc chloride, zinc acetate, gallium nitrate, gallium chloride, gallium acetate and the like. The firing temperature is preferably in the range of 450 to 500 ° C.

Alkali metals, zinc and gallium are contained in the catalyst in an amount of 0.1 to 50% by weight. Preferably 0.5 to 20
% By weight.

As the molding method, any method can be adopted, but a molding aid can be used. That is, a molded body obtained by mixing, molding, and firing the catalyst and the molding aid can be used for the reaction. Clay as a molding aid,
Silica alumina, boehmite, alumina and the like are used, but alumina is preferred. A molding aid was added to the above catalyst in an amount of 0.
It is preferably used in a weight ratio of 5 to 1.9.

3) Reaction conditions The reaction of the substituted benzenes using the above catalyst can be carried out either in a gas phase reaction in which the raw material is brought into vapor form and brought into contact with the catalyst, or in a liquid phase reaction in which it is brought into contact with the catalyst in a liquid state. In both the gas phase reaction and the liquid phase reaction, the catalyst may be any method such as a fixed bed system, a moving bed system, a fluidized bed system and a suspension system. Furthermore, for the reaction, a system such as a continuous system or a batch system is adopted.

The reaction temperature is 200 to 500 ° C., preferably 200 to 450 ° C., and the reaction pressure is either normal pressure or increased pressure. In the case of the liquid phase reaction, the reaction may be performed under pressure so that the substituted benzenes are maintained in a liquid state.

In the reaction, the reaction raw materials can be diluted with other stable diluents. Examples of the organic diluent include benzene compounds such as benzene, toluene and xylene, and examples of the inorganic diluent include gases such as nitrogen. To be done. When the reaction raw material is diluted with a diluent, the molar ratio of diluent / reaction raw material is 0.5 to 30, preferably 1 to 15. WHSV, which is the contact time between the reaction raw material and the catalyst, is 0.1 to 20,
It is preferably 0.2 to 10.

In the present invention, if the reaction is carried out in the presence of hydrogen, the desired product cannot be obtained, and it is necessary to carry out the reaction in the substantial absence of hydrogen.

B. Production of Dialkylnaphthalene The produced dialkyltetralin can be dehydrogenated with a dehydrogenation catalyst such as platinum alumina in the presence of hydrogen at a temperature of 300 to 500 ° C. to obtain dialkylnaphthalene.

In particular, 1,5-dimethyltetralin and / or
Alternatively, in the case of reacting 1,6-dimethyltetralin in a gas phase with a platinum alumina catalyst to obtain 1,5-dimethylnaphthalene and / or 1,6-dimethylnaphthalene, (a) the catalyst calcination temperature is 300 to 400 ° C., catalyst reduction temperature 400-500 ° C., reaction temperature 350-46
Or (b) the catalyst calcination temperature is 400-500.
C, catalyst reduction temperature 300-400 C, reaction temperature 35
The temperature is preferably 0 to 460 ° C.

The 1,5-dimethyltetralin and / or 1,6-dimethyltetralin used in such a method are as follows:
It is preferable that the concentration of each of 1,5, 1,6 or a mixture thereof is 90 mol% or more. That is, dimethyltetralin containing 10 mol% or more of isomers 1,7-dimethyltetralin, 1,3-dimethyltetralin and the like gives a product separated from the main purpose,
Not very good.

In such a method, 5-o-tolylpentene (2) and / or 5-m-tolylpentene (2) (hereinafter simply referred to as pentenes) is treated with an acidic catalyst such as solid phosphoric acid,
It is particularly preferable to apply it to the dehydrogenation reaction of dimethyltetralins obtained by the intramolecular cyclization reaction using HF, BF ₃ , H ₂ SO ₄ , H ₃ PO ₄ , silica alumina, silica magnesia and the like.

In such a method, the platinum-alumina used as a dehydrogenation catalyst can be easily obtained by, for example, absorbing an aqueous chloroplatinic acid solution in alumina, followed by drying, followed by firing and reduction. The platinum content in the platinum alumina is preferably in the range of 0.05 to 3.0% by weight, particularly preferably 0.1 to 0.5% by weight. If necessary, a small amount of a metal such as K, Na, Ca or Zn can be supported as a co-catalyst. In that case, the supporting method may be such that the metal nitrate is absorbed, dried, then calcined and reduced.

In order to obtain a high yield in the reaction in such a method, it is necessary to activate the catalyst by calcining and reducing it before the reaction. This temperature is (a) a catalyst calcination temperature of 300 to 400 ° C. and a catalyst reduction temperature of 400.
˜500 ° C. or (b) catalyst calcination temperature of 400˜
The temperature is set to 500 ° C and the catalyst reduction temperature is set to 300 to 400 ° C. At temperatures outside the range of these conditions, the conversion rate is low from the initial stage of the reaction, or the conversion rate is high in the early stage of the reaction, but the conversion rate decreases rapidly.

If catalyst calcination and catalyst reduction are carried out within the range of these conditions, the reaction can be carried out at a high conversion rate.
A more preferable temperature range is a catalyst calcination temperature of 320 to
390 ° C., catalyst reduction temperature 400 to 470 ° C. or catalyst calcination temperature 400 to 470 ° C., catalyst reduction temperature 3
It is to be 20 to 390 ° C.

The catalyst calcination time is preferably 1 to 20 hours, and more preferably 3 to 10 hours, depending on the catalyst calcination temperature. The catalyst reduction temperature is preferably 2 minutes to 6 hours, and more preferably 15 minutes to 3 hours, although it depends on the catalyst reduction temperature.

The reaction temperature in this method is 350 ° C. or higher and 460 ° C. or lower. At a temperature lower than 350 ° C., the selectivity of the reaction is high, but the conversion rate decreases rapidly. 460
If the temperature is higher than ° C, the proportion of the demethylation reaction increases, which is not preferable. The reaction can be carried out with a high selectivity within the above range, but a more preferable reaction temperature range is 350 to 430 ° C.

In carrying out this method, benzene,
The use of toluene, hydrocarbons such as n-hexane, etc., nitrogen gas, etc. as diluents gives good results since the reaction can often be controlled under favorable conditions.

The 1,5-dimethylnaphthalene and / or 1,6-dimethylnaphthalene obtained by this method can be obtained by a method known per se, that is, silica-alumina, ZS.
Solid acid catalyst such as M-5, Y type zeolite and 200-45
By contacting at a temperature of 0 ° C. for 5 seconds to 10 hours,
It can be isomerized to 2,6-dimethylnaphthalene.

Further, by oxidizing the 2,6-dimethylnaphthalene, 2,6 which is useful as a raw material for a polymer is obtained.
-It is possible to produce naphthalenedicarboxylic acid.

[0043]

INDUSTRIAL APPLICABILITY According to the present invention, the cyclization reaction of alkenylbenzene which has been conventionally carried out at a relatively low temperature to prevent a side reaction can be carried out at a relatively high temperature with a high selectivity and a high yield. Became. According to the present invention, it is possible to carry out the cyclization reaction of alkenylbenzene in the same temperature range as the dehydrogenation reaction of dialkyltetralin, and it is possible to perform the cyclization reaction and the dehydrogenation reaction with high energy efficiency without changing the reaction temperature. It became possible to do in. Since the series of reactions of cyclization and dehydrogenation proceed in almost the same temperature region, they can be carried out continuously, sequentially or by a combination thereof.

Further, according to the method of the present invention, dialkyltetralin, particularly 1,5-dimethyltetralin and / or 1,6-dimethyltetralin is used in the vapor phase with a platinum alumina catalyst, and (a) the catalyst calcination temperature is 300-400
℃, catalyst reduction temperature 400 ~ 500 ℃, reaction temperature 35
0 to 460 ° C. or (b) the catalyst calcination temperature is 400
˜500 ° C., catalyst reduction temperature 300˜400 ° C., reaction temperature 350˜460 ° C. and 1,5-dimethylnaphthalene and / or 1,6-dimethylnaphthalene in higher yield than existing methods. , It became possible to obtain with high selectivity.

[0045]

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

[0046]

Example 1 (1) Preparation of catalyst Silica-alumina catalyst (N631HN manufactured by JGC, alumina 2
10 g of powder (containing 8% by weight) was added to 100 ml of an aqueous solution containing 70 mmol of NaOH, and the mixture was stirred at room temperature for 4 hours. Then, the powder was filtered off, thoroughly washed with 500 ml of pure water, and then dried overnight in an electric dryer at 120 ° C. in an air atmosphere. Then, in a 500 ° C muffle furnace, in an air atmosphere, 8
Burned for hours. As a result of analysis of this product, Na was contained in an amount of 1.91% by weight based on silica alumina. This Na-containing silica-alumina powder was well mixed with an equal weight of γ-alumina (300 mesh for Wako chromatography), pelletized, and the particle size was adjusted to 10-20 mesh to obtain catalyst B.

The content of NaOH is 22 mmole and 14
When an aqueous solution of 0 mmole was used, the same procedure as above yielded sodium alumina catalysts containing sodium of 0.63% by weight and 3.81% by weight, respectively. Using this,
Catalyst A and catalyst C were obtained in the same manner as above. Similarly K
A catalyst D containing 3.23% by weight of potassium was prepared using a ₂ CO ₃ aqueous solution.

The same silica-alumina powder 1 used above
50 ml of an aqueous solution containing 6.8 g of zinc nitrate hexahydrate
In addition, the mixture was stirred at 50 ° C. for 4 hours. Then, the mixture was dried by a rotary evaporator, dried in an electric dryer in an air atmosphere at 120 ° C. overnight, and then fired in a 500 ° C. muffle furnace in an air atmosphere for 8 hours to prepare a 15 wt% zinc-supported silica-alumina powder. .. Using this, molding was carried out in the same manner as above to obtain catalyst F.

Catalyst E was prepared by changing the amount of zinc nitrate used.
Catalyst G using silica alumina powder containing 0.63% Na
Further, gallium chloride was used in place of zinc nitrate to obtain catalysts H and I. The catalysts A to I prepared above are summarized in Table 1. In the table,% represents% by weight.

[0050]

[Table 1]

(2) Reaction 5 g of the catalyst obtained above was preliminarily charged in an electric muffle furnace at 450 ° C.
After pre-calcining for 4 hours in an air atmosphere, after filling the reaction tube made of glass, the catalyst layer was set to the reaction temperature, and 1 of a mixture of o-tolylpentene-3 and o-tolylpentene-4 was prepared.
A 0% toluene solution was fed with WHSV1. Samples collected 12 hours after the start of oil passage and analyzed by gas chromatography are summarized in Table 2 below.

The terms in the table have the following definitions. This definition is based on o-tolylpentene-3 and -4 as a raw material, and it goes without saying that when other raw materials are used, the product or the like is appropriately changed and calculated.

[0053]

[Equation 1]

[0054]

[Table 2]

[0055]

Example 2 In a glass reaction tube having a tube diameter of 20 mm and a tube length of 600 mm, 3 parts of platinum-alumina catalyst (platinum content: 0.3% by weight) calcined at 350 ° C. for 4 hours was put, and hydrogen gas was added at 60 ml /
The catalyst was reduced for 2 hours at 450 ° C. with a flow rate of minutes. Then, while flowing hydrogen gas at a rate of 130 ml / min, a toluene solution of 1,5-dimethyltetralin (1,
(Ratio of 5-dimethylnaphthalene: 10% by weight) was dropped from the upper part of the reaction tube at a rate of 3 parts per hour, the reaction was carried out at 400 ° C., and the dehydrogenated product was cooled and collected in the lower part of the reaction tube. When the reaction product after 18 hours was analyzed by gas chromatography, the conversion was 99.3% and the selectivity was 91.5.
%, And the yield was 90.9%.

In Example 2 (the same applies to the following Examples and Comparative Examples), the reaction products were analyzed by gas chromatography, and the conversion, selectivity, and
The yield was calculated (needless to say, when other starting materials are used, the products, etc. are replaced by the corresponding ones). The term "parts" simply means parts by weight.

[0057]

[Equation 2]

[0058]

Examples 3 to 7 As Examples 3 to 7, the catalyst calcination temperature,
The reaction was carried out under the same conditions as in Example 2 except that the catalyst calcination time, catalyst reduction temperature, catalyst reduction time, and reaction temperature were variously changed. The results are shown in Table 3.

[0059]

[Table 3]

[0060]

Comparative Examples 1 to 4 In order to compare with the above Examples 2 to 7,
A part or all of the catalyst calcination temperature, the catalyst reduction temperature and the reaction temperature were out of the range of the conditions of the present invention, and the other conditions were the same as in Example 1 above. The results are shown in Table 4.

[0061]

[Table 4]

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C07C 5/367 15/24 8619-4H // C07B 61/00 300

Claims (4)

[Claims] 1. A compound represented by the following formula [I]: [Wherein R ₁ is a butenyl group having an alkyl group having 4 or less carbon atoms or —CH ₂ —CH ₂ —CH ₂ —CH═CH—
R ₃ (wherein R ₃ represents a hydrogen atom or an alkyl group having 4 or less carbon atoms) and R ₂ represents an alkyl group having 4 or less carbon atoms. ] When producing a dialkyltetralin compound by contacting with a solid catalyst at a temperature of 200 to 500 ° C under the conditions of a gas phase or a liquid phase in the substantial absence of hydrogen, the solid catalyst is an alkali metal. A method for producing a dialkyltetralin compound, which is a silica-alumina catalyst containing 0.1 to 50% by weight of at least one metal selected from zinc, gallium and gallium. 2. A process according to claim 1, wherein a shaped catalyst is used with a shaping aid. 3. A method for producing a dialkylnaphthalene, which comprises dehydrogenating the dialkyltetralin compound obtained by the method according to claim 1. 4. A product obtained by the method according to claim 1,
5- and / or 1,6-dimethyltetralin in a gas phase using a platinum alumina catalyst, and (a) a catalyst calcination temperature of 300 to 400 ° C and a catalyst reduction temperature of 400 to 500 ° C.
The reaction temperature is 350 to 460 ° C., or (b) the catalyst calcination temperature is 400 to 500 ° C., and the catalyst reduction temperature is 300 to 4
A method for producing 1,5-dimethylnaphthalene and / or 1,6-dimethylnaphthalene, which comprises reacting at 00 ° C and a reaction temperature of 350 to 460 ° C.