JPH0639396B2 - Method for side-chain alkylation of alkyl-substituted aromatic hydrocarbons - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an alkyl-substituted aromatic hydrocarbon (a) and an aliphatic monocarbonate in the presence of a catalyst prepared by supporting an alkali metal on a specific potassium carbonate powder. A method for producing an alkyl-substituted aromatic hydrocarbon (b) having an increased carbon number, which has a use as an intermediate in the production of medical and agricultural chemicals, monomers for resins, etc., by reacting olefin with a side chain alkylation reaction. Regarding

[Conventional technology]

As a conventional method for producing an alkyl-substituted aromatic hydrocarbon having an increased number of carbon atoms by a side chain alkylation reaction by reacting an alkyl-substituted aromatic hydrocarbon with an aliphatic monoolefin, for example, U.S. Pat. Discloses a method of using a catalyst composed of graphite and metallic sodium or metallic potassium, but there is a problem in that the catalyst easily ignites and is difficult to handle. Also, British Patent Specification No. 1269
No. 280 discloses a method of using a catalyst in which metallic sodium is supported on potassium carbonate, but the publication describes nothing about what kind of property should be used as potassium carbonate. Not actually done,
In the method specifically shown there, the conversion rate of the alkyl-substituted aromatic hydrocarbon (a) as a raw material is as low as 30 to 40%,
Therefore, there is a problem that the yield of the alkyl-substituted aromatic hydrocarbon (b) as the target product is low, that is, the activity of the catalyst is insufficient.

[Problems to be solved by the invention]

The inventors of the present invention have found that a conventional catalyst in which an alkali metal is supported on potassium carbonate, which is used as a catalyst when producing an alkyl-substituted aromatic hydrocarbon having an increased number of carbon atoms by a side chain alkylation reaction, has its activity. Admitted that it was not enough.
Therefore, in order to improve this catalyst, potassium carbonate powder having various properties was used to prepare a catalyst carrying an alkali metal on it, and the relationship between the activity of the catalyst and the preparation method was investigated. The catalyst which can produce an alkyl-substituted aromatic hydrocarbon having an increased number of carbon atoms by a chemical reaction with higher activity than before was investigated.

[Outline of Invention]

As a result, they have found that the above object can be achieved by adopting the following method, and completed the present invention. That is, according to the method of the present invention, in the side chain alkylation of an alkali-substituted aromatic hydrocarbon with an aliphatic monoolefin, the bulk density is 0.85 g / cm ³ or less, the average particle size is 100 to 800 μ, and the particle size is 100 to 800 μm. Side chain alkylation of alkyl-substituted aromatic hydrocarbons characterized by using a catalyst prepared by supporting an alkali metal on a powder of potassium carbonate whose powder weight in the range of 800μ accounts for 60% by weight or more of the total powder weight. A method is provided.

〔catalyst〕

The catalyst used in the present invention is a catalyst obtained by supporting an alkali metal on a potassium carbonate powder having the following specific properties as a carrier.

Hereinafter, the catalyst will be described in detail.

The potassium carbonate powder used in the present invention has a bulk density of usually 0.85 g / cm ³ or less, preferably 0.40 to 0.80 g / cm ^3.
Potassium carbonate powder in the range of is used. If potassium carbonate powder having a bulk density of more than 0.85 g / cm ³ is used, a highly active catalyst cannot be obtained, probably because the dispersed state of the alkali metal carried on the powder is not preferable. . In the present invention, the lower limit of the bulk density of potassium carbonate is not particularly limited, but it is preferable to use one having a bulk density of 0.4 g / cm ³ or more because it is industrially easily available.

The potassium carbonate powder used in the present invention generally has an average particle size in the range of 100 to 800 μ, and the weight of the powder in the particle size range accounts for 60% by weight or more of the total powder weight.
When the average particle size of the potassium carbonate powder is usually 100 μ or less and when the average particle size is usually 800 μ or more, the activity of the catalyst obtained by supporting an alkali metal on such potassium carbonate powder is low. It is not preferable. Further, even if the average particle diameter is usually in the range of 100 to 800 μ, if the weight of the powder in the particle diameter range is usually less than 60% of the total weight of the powder, the catalyst of the alkali metal-supported powder is It is not preferable because of low activity.

Among the potassium carbonate powders used in the present invention, among those satisfying the above-mentioned conditions, it is particularly preferable that the maximum value of the fineness distribution is in the particle size range of 100 to 800μ.

Here, the particle size distribution refers to a so-called frequency and particle size, which is represented by the number or weight of particles belonging to a particle size range of a certain size, for a sample of potassium carbonate powder composed of various particle sizes. It is a conventionally known graph obtained by examining the relationship and plotting the particle diameter on the horizontal axis and the frequency on the vertical axis. As a method of obtaining the graph,
For example, the sample is divided into particle groups of a size corresponding to the opening of the sieve by the sieving method defined in JIS standard, the weight of each particle group is measured, and this is passed and the remaining sieve opening is analyzed. A known method of knowing the size and compiling the results in a column diagram (histogram) can be shown, and the particle size distribution obtained by the method is used in the present invention. Further, in the present invention, the maximum value of the particle size distribution refers to the most frequent part in the particle size distribution represented by the above histogram, and in the present invention, it is the most in the particle size distribution chart among the potassium carbonate powders. It is preferable to use a potassium carbonate powder in which all the particle sizes in the range corresponding to the section (class) to which the column of the high frequency part belongs belong to the above-mentioned particle size range of 100 to 800 μm.

In the present invention, when the average particle size of the potassium carbonate powder is in the range of less than 100μ, in other words, the particle size of the particles that make up the major part of the powder is usually less than 100μ. When a potassium carbonate powder mainly composed of particles having a small particle size is used, the fluidity of the potassium carbonate powder is reduced when the catalyst is prepared by supporting the alkaline metal on this powder as a carrier. In addition to being a hindrance to the preparation of the catalyst because it is bad, since the affinity of the molten alkali metal with the powder is poor, the dispersibility of the alkali metal on the support decreases, and in extreme cases, alkali A catalyst having a high activity cannot be obtained because the metal is supported on only a part of the carrier and the alkali metal is separated into spherical spheres. On the other hand, the average particle size of potassium carbonate powder is 8
In the range greater than 00μ, in other words,
Most of the major particles composing the powder are in the large area of 800 μm or more, and when potassium carbonate powder mainly composed of large particles is used, this powder is used as a carrier. Even if the catalyst is prepared by supporting alkali metal on the above, the outer surface of the potassium carbonate particles becomes smaller than that of the powder having a small particle size, so that the compatibility of the potassium carbonate powder and the alkali metal is not sufficient, so that the supported state is It is not preferable because it tends to be non-uniform, which makes it difficult to prepare a highly active catalyst.

In the potassium carbonate powder used in the present invention, the weight of the powder having a particle size distribution in the range of 100 to 800μ is usually 60% by weight or more, preferably 80% by weight of the total powder weight.
It is necessary to be above. When the weight of the powder in the particle size range is small, usually less than 60% of the total powder weight, and the ratio of the fine powder having a small particle size and / or the powder having a large particle size is large, As for the powder portion containing small particles, the dispersion state of the alkali metal is likely to be non-uniform because of poor affinity with the alkali metal as described above. Similarly, since the outer surface of the particles becomes small, the state of carrying alkaline metal is poor and the particles tend to become non-uniform, and as a result, the catalyst obtained by using such powder is low in activity as a whole, which is not preferable.

As long as the potassium carbonate powder used in the present invention satisfies all of the above powder characteristics, various conventionally known production methods, for example, a method of passing CO ₂ under pressure to a potassium hydroxide solution or potassium chloride as a raw material. It is possible to use the potassium carbonate powder produced by various methods such as the above-mentioned Leblanc soda method. As is well known, even if the powder characteristics are the same in the manufacturing method, it depends on how the manufacturing conditions are set, for example, the conditions of various factors such as temperature, concentration, pH and aging time. Although a potassium carbonate powder having different powder characteristics can be obtained, in the method of the present invention, when the powder satisfies all the conditions of the powder characteristics of the present invention described above, it is used as it is as it is. Needless to say, it can be used as a carrier for the catalyst of the present invention, but in the method of the present invention, other than this, a potassium carbonate powder that does not satisfy some of the conditions of the powder characteristics of the present invention described above can be used. Also, for example, even if the potassium carbonate powder obtained by the above-mentioned production method does not satisfy the conditions of the particle size distribution of the present invention in its particle size distribution as it is, each of the different particle size ranges by the sieving method. Sieve for section (each grade) By removing the powders belonging to each section or adjusting the ratio of the amounts appropriately, the powders satisfying the condition of the particle size distribution of the present invention can be obtained. If the powder obtained as described above satisfies the above-mentioned condition regarding the bulk density which is another condition for the powder characteristics of the present invention, the potassium carbonate powder obtained by this method is also the catalyst of the present invention. Can be used as a carrier.

In the method of the present invention, a catalyst is obtained by using potassium carbonate powder satisfying all the above-mentioned conditions of powder characteristics and carrying an alkali metal on it. The amount of alkaline metal supported in this case is usually 0.3 to 10% by weight, preferably 1 to 7% by weight, based on the carrier. If the supported amount of alkali metal is usually less than 0.3%, the activity of the obtained catalyst is low, which is not preferable.
If it exceeds 10%, not only the activity of the obtained catalyst is low, but also it is easy to ignite, which is dangerous. Specific examples of the alkali metal used in the present invention include lithium, sodium, potassium, rubidium and cesium, of which sodium is preferably used. As a method of supporting alkaline metal, a generally known method such as a vapor deposition supporting method and a melt supporting method can be adopted. Separately from this, a method newly developed by the present inventors, that is, a liquid inert to alkali metals such as benzene, toluene, xylene, n-hexane, isohexane, n-octane, isooctane, and n-decane. It is possible to use a method of supporting by mixing an alkali metal and potassium carbonate powder at a temperature equal to or higher than the melting point of alkaline metal in a dispersion medium composed of the above hydrocarbon.

The catalyst prepared by carrying the alkali metal by the above method, when the vapor deposition carrying method or the melt carrying method is adopted, is followed by carrying the alkali metal and then dehydrating it with an inert gas atmosphere containing no moisture such as dry nitrogen. It is stored until reaction in an inert hydrocarbon solvent. When the method of supporting an alkali metal in an inert dispersion medium as described above is adopted, the dispersion medium may be removed after loading and stored in an inert gas atmosphere, or as it is. It may be stored in a dispersion medium. In this case, when the alkyl-substituted aromatic hydrocarbon (a) used as a raw material for the side chain alkylation reaction of the present invention described below is used as the above-mentioned inert hydrocarbon solvent or dispersion medium, the prepared catalyst is It is preferable because it can be directly used in the next reaction. Therefore, as the method of supporting the alkali metal, the method of melting and supporting in the above-mentioned inert dispersion medium is preferable, and in this case, the alkali metal is more uniformly dispersed and supported by the potassium carbonate powder of the carrier. Therefore, the activity of the catalyst for the reaction of the present invention described later is also high, which is preferable.

Referring to the structure of the catalyst of the present invention, when, for example, sodium is used as the alkali metal supported on potassium carbonate, sodium partially exchanges with potassium of potassium carbonate to cause a reaction to form metal potassium and sodium carbonate. For example, K ₂ CO ₃ / Na ₂ CO ₃ / (K) (Na) C
It is considered that a mixture such as O ₃ is formed and metal sodium and metal potassium are supported on the mixture. Among the catalysts obtained by the method of the present invention, it is preferable to use a catalyst in which an alkali metal is extremely uniformly dispersed in a carrier without forming a glaster because the activity of the reaction described later is high.

The potassium carbonate powder used in the present invention is a porous particle in which the bulk density is small as described above, and accordingly the pore structure is three-dimensionally developed. In the present invention, among them, the alkali metal is uniformly dispersed. It is very convenient to support the catalyst by using a potassium carbonate powder composed of a group of particles with a specially developed pore structure having a so-called "sponge-like" structure. It is particularly preferable because it has high activity.

In the present invention, in the presence of the catalyst obtained by the above method,
The alkyl-substituted aromatic hydrocarbon (a) is reacted with an aliphatic monoolefin to produce a side-chain alkylation reaction to produce an alkyl-substituted aromatic hydrocarbon (b) having an increased number of carbon atoms.

Specific examples of the alkyl-substituted aromatic hydrocarbon (a) used in the present invention include toluene, ethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, sec-butylbenzene, isobutylbenzene, n-decylbenzene, Examples include xylene, mesitylene, tetramethylbenzene, methylnaphthalene, ethylnaphthalene, and the like, and alkyl-substituted benzene and alkyl-substituted naphthalene having at least one alkyl group having a hydrogen atom bonded to the α-position carbon in the side chain alkyl group. . Of these, alkyl-substituted benzene is preferable in the present invention, and toluene, ethylbenzene, and xylene are particularly preferable.

Specific examples of the aliphatic monoolefin used in the present invention include ethylene, propylene, 1-butene, 2-butene,
Isobutylene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, 3-hexene, 1-heptene, 2
-Heptene, 2-octene, 2-decene, 3-methyl-
1-butene, 2-methyl-2-butene, 4-methyl-1
Examples thereof include pentene, and among them, ethylene, propylene, 1-butene, 2-butene, isobutene, 1-
The use of pentene, 2-methyl-1-butene 3-methyl-1-butene is preferred.

In the method of the present invention, as a condition for reacting the above-mentioned alkyl-substituted aromatic hydrocarbon (a) with an aliphatic monoolefin, the charging ratio of these raw materials is 100 mol of the alkyl-substituted aromatic hydrocarbon (a). The amount of the aliphatic monoolefin is usually 0.2 to 20 parts by mol, preferably 0.5 to 10 parts by mol based on parts. Regarding the amount of the catalyst used, the above-mentioned catalyst is of the alkyl-substituted aromatic hydrocarbon (a).
It is usually used in an amount of 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight, per 100 parts by weight.

In the present invention, if necessary, a saturated aliphatic hydrocarbon such as n-hexane, n-octane, and n-decane, an aromatic hydrocarbon such as benzene, triethylamine, cyclohexylamine, aniline, etc. Aliphatic amines such as toluidine, alicyclic amines and aromatic amines may be used in appropriate amounts as reaction solvents.

Specific examples of the alkyl-substituted aromatic hydrocarbon (b) having an increased number of carbons, which is the target product produced by the method of the present invention, include n-propylbenzene, n-propyltoluene, and n-propyltoluene.
-Propylxylene, sec-butylbenzene, sec-butyltoluene, tert-amylbenzene, isobutylbenzene, isobutyltoluene, 2-methylbutylbenzene,
2-methylbutyltoluene, n-propylnaphthalene,
Isobutylnaphthalene and the like can be exemplified, among which n
-Propylbenzene, isobutylbenzene, sec-butylbenzene, n-propylnaphthalene, etc. are produced well.

In the method of the present invention, the reaction can be carried out, for example, by the following method. A method is shown in which a reactor such as an autoclave is charged with an alkyl-substituted aromatic hydrocarbon (a), a catalyst and a predetermined amount of the above solvent as required, and the temperature is raised to a predetermined temperature, and then a predetermined amount of aliphatic monoolefin is injected. However, the present invention is not necessarily limited to this method. The reaction is carried out with stirring, and the reaction temperature is usually 130 to 220 ° C, preferably 140 to 180 ° C.
And the reaction pressure is usually in the range of 5 to 50 atm.
The reaction time is usually 1 to 10 hours.

After the reaction yield, the reaction mixture was filtered to remove the catalyst, distilled,
The alkyl-substituted aromatic hydrocarbon (b) having an increased number of carbon atoms can be separated by a side chain alkylation reaction, which is an object of the present invention, by an ordinary separation means such as crystallization.

〔The invention's effect〕

When the method of the present invention is adopted, the alkyl-substituted aromatic hydrocarbon (b) having an increased number of carbon atoms can be obtained by a side chain alkylation reaction in a higher yield than in the conventional method.

〔Example〕

Next, the method of the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Incidentally, the particle size distribution of the carrier shown in the examples, the average particle size,
And the bulk density was measured as follows.

(1) Measurement of particle size distribution of potassium carbonate powder A combination of JIS standard sieves from 16 mesh to 200 mesh is combined, and about 150 g of anhydrous Karimu powder powder sample is put on top of it, and the whole is made of polyethylene bag. Put it in and seal it. This sieve was set on a loader type vibrating sieve shaker (Kurihara Seisakusho 19-45), and the shaking number 290
Sieving was carried out for 10 minutes with a hammer speed of 156 times / minute. The weight of the anhydrous potassium compound on each sieve after sieving was measured, the weight percentage was calculated, and the average particle diameter (median diameter Dmed) was measured from the RRS diagram.

(2) Measurement of bulk density of potassium carbonate powder A sample outlet is provided at the lower end, and the inner diameter is 26.5 mm, the inner diameter at the upper end is 94 mm, and the height is 100 mm.
A 50 ml wet funnel was fixed vertically so that the height from the lower end of the wet funnel to the sample drop opening was 100 mm. Immediately below the sample dropping port of this wet funnel, the inner diameter is 39 mm, the height is 81 mm, and the inner volume is 9 mm.
An 8.0 ml cylindrical receiver was placed. Powder of the anhydrous potassium compound sample was put in the wet funnel, the sample drop opening at the lower end was opened, and the powder of the sample was dropped into the receiver. The raised sample on top of the receiver was horizontally scraped. The weight of the sample in the receiver was measured to determine the bulk density.

Example 1 A slurry of potassium carbonate 1.5 hydrate was atomized and dried at 150 ° C. to obtain a granular powder, which was calcined at 400 ° C. for 2 hours, and then,
The bulk density and particle size distribution were measured under a dry nitrogen atmosphere.
The bulk density of this potassium carbonate is 0.67 g / ml, the average particle diameter (Dmed) is 420 μ, and the particle size distribution has its maximum value at 350 to 590 μ, and particles of 100 to 800 μ account for 92% of the whole. It was

A catalyst was prepared by placing 57 g of this potassium carbonate powder and 3 g of sodium metal together with 200 ml of toluene in an autoclave (1) and stirring at 190 ° C. for 2 hours at 600 rpm. After the temperature was lowered to 160 ° C., 400 ml of toluene was further added, propylene was injected under pressure, and the initial reaction pressure was set to 60 kg / cm ² . At the same time as the introduction of propylene, the reaction started and the pressure dropped. The pressure in the container is 30 kg
When the pressure reaches / cm ² , propylene is pressed in again and 50 kg
The pressure was returned to / cm ² and the reaction was continued. After repeating this operation three times, the reaction was terminated, and the contents were analyzed by gas chromatography (column PEG 6000, 4 m). The results are shown in Table 1.

Example 2 An aqueous potassium carbonate solution was concentrated using an evaporator,
The obtained crystals were dehydrated with a centrifuge and then calcined at 400 ° C. for 2 hours to obtain potassium carbonate powder. When the bulk density and the particle size distribution were measured according to Example 1, the bulk density was 0.78 g / ml, and the average particle size (Dmed) was 3
At 20μ, the particle size distribution has a maximum value between 250 and 350μ, 100
Particles with a particle size of ˜800 μ accounted for 85% of the total.

Put 70 g of this potassium carbonate in a 500 ml separable flask, raise the temperature to 300 ° C. with flowing dry nitrogen, and add 4 g of metallic sodium little by little with good stirring, and then continue stirring for 2 hours. Then, the alkali metal was supported on potassium carbonate.

Using 50 g of the catalyst thus obtained, toluene was reacted with 1-butene. Reaction temperature 160 ℃, initial pressure 60kg, 7
The reaction results after the lapse of time are shown in Table 2.

Comparative Example 1 Potassium carbonate STD grade manufactured by Nippon Soda Co., Ltd. obtained by dehydrating an aqueous solution of potassium carbonate 1.5 hydrate with a steam / tube dryer has a bulk density of 1.05 g / ml and an average particle diameter (Dmed) of
At 270μ, the particle size distribution had a maximum value in the range of 350-590μ, and the proportion of particles of 100-800μ was 97% of the whole.

Using 57 g of potassium carbonate thus obtained and 3 g of metallic sodium, a catalyst was prepared according to the method of Example 1, and then a reaction between toluene and propylene was carried out.

Comparative Example 2 Potassium Carbonate Powder Grade manufactured by Futsuka USA Inc.
After firing at ℃, the bulk density and particle size distribution were measured according to Example 1 to find that the bulk density was 0.54 and the average particle size (Dmed)
Is 65μ, and its particle size distribution has its maximum value at 63-74μ, and particles of 100μ or less account for 87% of the total 100-800μ
The particles were only 13%. Using this potassium carbonate powder, the catalyst was prepared and the reaction of toluene and propylene was carried out according to the method of Example 1.

Claims (1)

[Claims] 1. When alkylating an alkyl-substituted aromatic hydrocarbon by side chain alkylation with an aliphatic monoolefin, the bulk density is
Alkali metal is supported on a potassium carbonate powder carrier which has a powder weight of 0.85 g / cm ³ or less, an average particle size of 100 to 800μ and a particle size of 100 to 800μ, which accounts for 60% by weight or more of the total powder weight. A method for side-chain alkylation of an alkyl-substituted aromatic hydrocarbon, characterized by using the above catalyst.