JP3537483B2 - Method for alkylating aromatic compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an alkyl-substituted aromatic compound by reacting an aromatic compound with an olefin.

[0002] Alkylation reaction between an aromatic hydrocarbon and an olefin includes AlCl ↓ 3, BF ↓ 3, FeCl ↓ 3,
It is known that the reaction proceeds in the presence of a Lewis acid catalyst such as TiCl ↓ 4 or in the presence of a protic acid such as sulfuric acid, phosphoric acid, and HF (Friedel-Crafts and Related Reason).
ction, Interscience Publishers, II, 1 (1964).). As an improved method of using aluminum chloride as a catalyst in the liquid phase and reducing the amount used, a method in which the reaction is carried out at a high temperature of 140 to 200 ° C. (JP-A-50-59332) A method of recycling and reusing the complex (JP-A-50-137933), a method of using a mixture of aluminum chloride and hydrogen chloride (German Patent No. 2141491) and the like are known. As a method for performing the reaction in the gas phase, a method using a solid phosphoric acid catalyst (German Patent No. 19)
28413, JP-A-53-108932), BF ↓ 3
A method using a supported solid catalyst (U.S. Pat. No. 4,084,289) and a method using an aluminosilicate (JP-A-51-143)
No. 625).

[0003]

In the method using a Lewis acid such as aluminum chloride, the regioselectivity of the alkylation reaction is good, but the catalytic activity is significantly impaired by the presence of water. The group compounds and olefins must be thoroughly dried before use. Further, since a part of the catalyst component is dissolved in the product layer, it is necessary to wash the product layer with water and an alkali in order to remove the catalyst component from the product layer. However, if the water used in the washing is mixed into the recovered aromatic compound, the catalyst is deactivated, so that the recovered raw material needs to be dehydrated again, which lowers the industrial value. Further, the chloride-based catalyst generates hydrogen chloride by decomposition, and corrodes the reaction device and the distillation device. Therefore, the reaction requires a corrosion-resistant device, resulting in an increase in equipment cost. The method using a protic acid catalyst such as sulfuric acid, phosphoric acid, and HF has the advantage that the catalyst component can be easily separated and recovered, but the regioselectivity of the alkylation reaction is poor, and the method of alkylating a substituted aromatic compound is poor. Is not suitable for regioselective alkylation reactions because it gives a mixture of ortho / para isomers. Furthermore, these acid catalysts are highly corrosive to the equipment,
The reaction requires a special material device. A reaction performed in a gas phase requires a high temperature of 300 ° C. or higher and a high pressure. Further, during the reaction, carbides, high-boiling substances, and the like easily adhere to the surface of the catalyst, whereby a remarkable decrease in catalytic activity is observed.

[0004]

Means for Solving the Problems The present inventors do not contain highly corrosive volatile halide, under relatively mild conditions, extensive for alkylation method does not require aromatic compound prior to drying of the raw material results of investigations, by reacting an aromatic compound and olefins, in producing the alkyl-substituted aromatic compounds, under existence of protonic acids, Sc, Y, L
a and an alkyl of an aromatic compound characterized by the presence of a trifluoromethanesulfonic acid salt of at least one element selected from the group consisting of a and a lanthanoid series (hereinafter, this may be abbreviated as a triflate compound). The present invention has been completed by finding a chemical conversion method.

According to the present invention, an alkylation reaction between an aromatic compound and an olefin can be carried out under relatively mild conditions without the necessity of drying the raw material. Also,
Since the catalyst component is stable to water, the reaction solution can be reused as a catalyst after washing the reaction solution with water and distilling off water from the aqueous phase. Unreacted raw materials can be recovered by a method such as distillation and reused without dehydration.

The aromatic compounds usable in the present invention include substituted or unsubstituted benzene, naphthalene and anthracene, which are substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, hydroxyl groups, alkoxy groups and the like. May be substituted. Specifically, hydrocarbon compounds such as benzene, toluene, ethylbenzene, cumene, t-butylbenzene, naphthalene and anthracene; hydroxyl-containing compounds such as phenol and naphthol; ether compounds such as anisole and phenetole; However, the present invention is not limited to these. In addition, these aromatic compounds can be used even if they contain 5 wt% or less of water, and may not be completely dehydrated.

[0007] As olefins which can be used in the present invention are ethylene, propylene, 1-butene, iso <br/> butene down, 1-pentene, 1-hexene, 1-octene,
Examples include, but are not limited to, olefins having a double bond at a terminal such as methylenecyclohexane, and olefins having a double bond at a non-terminal such as 2-butene, 2-pentene and cyclohexene. The amount of the olefin used is 10 moles per mole of the aromatic compound.
It can be used in the range of 0 to 1/100 mol. 1
When an olefin adduct of a molecule is obtained, it is preferable to use the olefin in an amount of 1 to 1/100 mole times the amount of the aromatic compound. The olefins may contain water within the solubility range and need not be completely dehydrated.

The triflate compound used in the present invention is
A trifluoromethanesulfonate of at least one element selected from the group consisting of Sc, Y, La, and a lanthanoid series (hereinafter, trifluoromethanesulfonate may be abbreviated as trifluorophosphate); A mixture of two or more triflate compounds may be used. Of these triflate compounds, scandium triflate is the most active and preferred. The triflate compound is easily prepared by mixing an oxide of a Group IIIA element of the periodic table with trifluoromethanesulfonic acid and then heating the mixture (Tetrahedron Letters).
tt.), 34, 3755, 1993). The amount of the triflate compound to be used is 0.1 to 1 mol of the olefins.
The range of 1 to 50 mol% is preferable, and particularly 1 to 20 mol%.
Is preferable. The amount of the triflate compound used is 0.
When the amount is less than 1 mol%, the alkylation ability is low.
If it is 0 mol% or more, the amount of the triflate compound in the reaction solution is large, so that separation and recovery become difficult.

[0009] When performing the alkylation reaction in the presence of a triflate compound coexists proton acid, Ru can increase the para selectivity in the alkylation of substituted aromatic compounds. Examples of the protonic acid used include sulfuric acid, phosphoric acid, hydrochloric acid, trifluoromethanesulfonic acid, and fluorosulfonic acid, and it is desirable to use an acid having low volatility in order to avoid corrosion of the device. The amount of the protonic acid coexisting in the reaction solution is preferably 0 to 5 mol, more preferably 0.1 to 3 mol, per 1 mol of the triflate compound. Even if the amount of the protonic acid is 5 mol times or more, there is no difference in the effect. Therefore, in order to simplify the separation step, it is preferable that the amount used is minimized.

In conducting the reaction, a solvent that does not adversely affect the reaction may be used. Solvents that can be used include hexane, cyclohexane, octane, hydrocarbon solvents such as isooctane, carbon tetrachloride, chloroform, halogenated hydrocarbon solvents inert to the reaction such as methylene chloride,
Diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, tetrahydropyran,
Examples thereof include ether solvents such as dioxane, diglyme, and triglyme, but are not limited to these solvents. Also, a mixture of these can be used as a solvent. Further, it is preferable not to mix a large amount of water and alcohols into the reaction system.

[0011] The reaction is generally carried out at a temperature in the range of 0 to 200 ° C, preferably 50 to 150 ° C.
If the temperature is 0 ° C or lower, the reaction rate is slow and a long time is required to drive the reaction. If the temperature is 200 ° C or higher, polymerization of olefins and / or polyalkylation of an aromatic compound occur, which is not preferable.

The reaction time is appropriately selected depending on the kind of the aromatic compound and the olefin as the raw materials, the amount of the triflate compound used, the reaction temperature, and the like. It is preferable to carry out the reaction under the condition that the reaction is almost completed in 1 to 10 hours.

The reaction can be carried out by any method such as a batch type or a continuous type. Further, the present invention can be carried out in a fixed bed format in which a triflate compound and a protonic acid are supported on a solid component.

[0014]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 21.6 g of anisole was placed in a magnetic stirring type autoclave.
(200 mmol), 2.24 g of isobutene (40 mm
ol), 984 mg of scandium triflate (2 mm
ol) and 196 mg (2 mmol) of sulfuric acid.
The reaction was carried out at a temperature of 1 hour. After cooling the autoclave, the reaction solution was analyzed by gas chromatography. The reaction solution contained 17.6 g of anisole, 5.66 g of p-tert-butylanisole, and 0.12 g of o-tert-butylanisole. 0.15 g of o, p-di-tert-butylanisole and a small amount of a polyalkylated product,
Although an isobutene polymer was contained, no isobutene was detected. The selectivities of the p-, o-, and o, p-substituted products based on isobutene are 86.3% and 1.
8%, and 3.4%.

Examples 2 to 9 Anisole (200 mmol) and isobutene (40
mmol), and in the same manner as in Example 1, the type of catalyst (2 mmol each) and
The reaction was carried out for one hour while changing the amounts of sulfuric acid and water used as additives and the reaction temperature. Table 1 shows the respective reaction conditions and reaction results.

Comparative Examples 1 to 3 Reactions were carried out in the same manner as in Example 1 , except that the catalyst shown in Table 1 was used instead of scandium triflate. Table 1 shows the respective reaction results obtained by the same method as in Example 1. In the example in which the aluminum chloride catalyst of Comparative Example 1 was used in the presence of a small amount of water, the progress of the reaction was extremely slow, and 70% or more of unreacted isobutene remained. Comparative Example 2
In Comparative Example 3, the ratio of the para-adduct / ortho-adduct of the alkylated product was small, and a large amount of the ortho-added product was obtained.

Example 10 18.4 g of toluene (2
00 mmol), 2.24 g (40 mmol) of isobutene
l), 984 mg of scandium triflate (2 mmo
l), 196 mg (2 mmol) of sulfuric acid, 36 mg (2
mmol) and reacted at 100 ° C. for 1 hour. The reaction results obtained in the same manner as in Example 1 are shown in Table 2.

Example 11 A reaction was carried out in the same manner as in Example 10, except that 21.6 g (200 mmol) of anisole was used instead of toluene and propylene (40 mmol) was used instead of isobutene. The reaction results obtained in the same manner as in Example 1 are shown in Table 2.

Example 12 21.6 g of anisole was placed in a magnetic stirring type autoclave.
(200 mmol), scandium triflate 984
mg (2 mmol), 196 mg (2 mmol) of sulfuric acid,
After charging 36 mg (2 mmol) of water, 10
0 kg / cm ↑ 2 until added. The autoclave was heated to 150 ° C. and reacted for 1 hour. Example 1
Table 2 shows the reaction results obtained in the same manner as in Example 1.

Example 13 To 20 g of the reaction solution obtained in Example 1, 10 g of hexane was added, and the mixture was extracted three times with 5 ml of water. Water was distilled off from the obtained aqueous phase. As a result, scandium triflate and a sulfuric acid component were removed. 0.94 g was obtained. In electromagnetically stirred autoclave,
17.3 g (160 mmol) of anisole, 1.79 g (32 mmol) of isobutene, and 0.94 g of the obtained solid component were added and reacted at 100 ° C. for 1 hour. After cooling the autoclave, the reaction mixture was analyzed by gas chromatography.
8 g, 4.54 g of p-tert-butylanisole,
0.09 g of o-tert-butylanisole, o, p
0.12 g of di-tert-butylanisole and a small amount of a polyalkylated product and an isobutene polymer were contained, but no isobutene was detected. The selectivities of the p-, o-, and o, p-substituted relative to isobutene were 86.5%, 1.8%, and 3.3%, respectively.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

According to the present invention, there has been provided a technique capable of carrying out an alkylation reaction of an aromatic compound with an olefin under relatively mild conditions without the necessity of drying the raw materials. According to the present invention, the catalyst component can be reused after washing the reaction solution with water and distilling off water from the aqueous phase. Further, unreacted raw materials can be recovered by a method such as distillation and reused without dehydration treatment.

Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI // B01J 31/02 103 B01J 31/02 103X C07B 61/00 300 C07B 61/00 300 (58) Fields investigated (Int. Cl. ⁷ , (DB name) C07C 2/66 C07C 15/02 C07C 41/30 C07C 43/205 C07B 37/02 C07B 61/00 300 B01J 31/02 103

Claims (1)

(57) [Claims] When an aromatic compound is reacted with an olefin to produce an alkyl-substituted aromatic compound,
A method for alkylating an aromatic compound, comprising conducting a reaction in the presence of a trifluoromethanesulfonic acid salt of at least one element selected from the group consisting of Sc, Y, La and a lanthanoid series and a protonic acid .