JPH107626A - Method for ring alkylation of N-alkyl aromatic amine - Google Patents

Abstract

(57) [Object] To improve para-selectivity in ring alkylation of an aromatic amine. A ring alkylation can be performed with high paraselectivity by reacting an N-alkyl aromatic amine having an alkyl group added to an N atom in the presence of zeolite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for ring-alkylating an N-alkyl aromatic amine. More specifically, the present invention relates to a method of reacting an N-alkyl aromatic amine with an olefin and / or an alcohol in the presence of a zeolite to carry out a highly para-selective ring alkylation.

[0002]

2. Description of the Related Art A method for alkylating an aromatic compound by reacting it with an olefin and an alcohol is widely known. The reaction is performed in the presence of a homogeneous or heterogeneous catalyst. Ring-alkylated aromatic amines have wide applications as raw materials for dyes and agricultural chemicals. A conventional method for producing a ring-alkylated aromatic amine is shown below.

[0003] West German Patent 1,051,271 discloses the ring alkylation of anilines with olefins in the presence of kaolin or aluminum and aluminum alloys. The predominantly ring alkylated product at the ortho position.

[0004] US Pat. Nos. 3,649,932 and 3,923,892 disclose the reaction of an aromatic aniline with an olefin in the presence of an aluminum anilide containing a Friedel-Crafts catalyst as a cocatalyst to form a ring-alkylated aromatic. Disclosed are methods for preparing aromatic anilines. Examples of the reaction product in this case include 2-ethylaniline in which the ortho position is alkylated.

[0005] US Patent No. 3,275,690, JP-A-56-110652 and West German Patent No. 10
No. 51271 discloses various methods for preparing an alkylated aromatic amine by reacting an aromatic amine with an olefin in combination with a Friedel Crafts catalyst in the presence of a Friedel Crafts catalyst and in the presence of aluminum halide. It has been disclosed. In this case, 2-cyclohexylaniline in which the ortho position is alkylated is mentioned.

[0006] EP 336134 discloses a method for alkylating aniline with isobutylene in the presence of a silica-alumina catalyst. In this case, the main product was 2-tert-butylaniline, which was alkylated at the ortho position.

[0007] European Patent Nos. 286029, 240018, 222681, and US Pat. No. 5,026,912 disclose a method of alkylating aniline with an olefin in the presence of a crystalline aluminosilicate. I have. In this case, the ortho-alkylated product was the main product.

Japanese Patent Application Laid-Open No. 4-69366 discloses a method for alkylating aniline with propanol in the presence of crystalline aluminosilicate. In this method, 4-isopropylaniline having an alkylated para position is the main product, but its selectivity is about 77%, which is not a satisfactory level.

[0009]

When an aromatic amine is alkylated, the ortho-orientation is strong, so that the ortho-position of the aromatic ring is easily alkylated by a conventionally known method, and the alkylation to the para-position is difficult. Sex was not satisfactory. Therefore, a method of performing ring alkylation with high para-selectivity has been strongly desired.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on a method of paraselectively ring-alkylating an aromatic amine, and as a result, have found that an N-alkylaromatic compound in which an alkyl group is added to the N atom of an aromatic amine. Group amines as olefins and / or
Alternatively, the present inventors have found that when alkylation is carried out by reacting with an alcohol, it is possible to carry out para-selective ring alkylation by reacting in the presence of zeolite, and arrived at the present invention.

That is, the present invention provides a method for alkylating an N-alkyl aromatic amine by reacting the same with an olefin and / or an alcohol in the presence of a catalyst containing a zeolite. The present invention relates to a method for ring alkylation of an aromatic amine.
Hereinafter, the method of the present invention will be described.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The zeolite used in the present invention is not particularly limited, and various zeolites such as natural products and synthetic products can be used. Examples include faujasite, beta, mordenite, pentasil, offretite, chabazite, clinoptilolite, heurandite, ferrierite, and the like. Preferably, pentasil, mordenite, beta,
Faujasite is used. When these zeolites are first prepared, the cations in the zeolite are usually alkali metals. In carrying out the present invention, the alkali metal cation may be left as it is, but the cation is ion-exchanged with a rare earth metal such as lanthanum and cerium, a transition metal such as nickel, chromium and copper, an alkaline earth metal, and a proton. May be.

When the above zeolite is used in the method of the present invention, it can be used in the form of a powder or a molded product. In the case of forming a molded body, the molding method is not particularly limited, and for example, a rolling method, an extrusion method, a compression method, and the like are used. At the time of molding, if necessary, a binder such as alumina sol or clay can be added. Further, at the time of molding, it is also possible to add and knead the compound containing the metal cation. This zeolite molded body is usually 300 to 700 ° C.
Activated by calcining to form a catalyst. The method of the present invention is a method in which an alkyl group is bonded to the N atom of an aromatic amine so that paraalkylation is more likely to occur structurally and more effectively.

The alkyl group bonded to the N atom of the N-alkyl aromatic amine used in the method of the present invention is an alkyl group having 1 to 7 carbon atoms, that is, a methyl group, an ethyl group,
n-propyl group, isopropyl group, n-butyl group, isobutyl group, tertiary butyl group, cyclohexyl group,
It is preferably a benzyl group or the like. In the case of a methyl group, an ethyl group, or the like, those in the form of N-dialkyl can be used. An alkyl group having 8 or more carbon atoms is not preferable because it becomes difficult to enter the zeolite pores and to achieve high selectivity. After para-selective alkylation of the N-alkyl aromatic amine, a para-selectively alkylated aromatic amine may be obtained by optionally dealkylating the alkyl group bonded to the nitrogen atom. it can. In this case, the alkyl group preferably has 3 or more carbon atoms.

The alkylating agent used in the process of the present invention can be an olefin or an alcohol or a mixture thereof. For example, olefins can include aliphatic acyclic or cyclic olefins such as ethylene, propylene, butene, isobutene, isoamylene, cyclohexene, 1-methylcyclohexene, and halogenated derivatives thereof. Examples of the alcohol include aliphatic alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol and tertiary butanol. 1-7 carbon atoms
If it is larger than this, it is difficult to enter the zeolite pores, and it is difficult to achieve high selectivity.

In the ring alkylation of an N-alkyl aromatic amine, the molar ratio of the alkylating agent to the aromatic amine affects the selectivity of the reaction. The molar ratio of the aromatic amine to the alkylating agent is usually in the range of 0.1 to 10,
Preferably it is in the range of 0.5 to 5. Increasing the proportion of the alkylating agent increases the conversion of the aromatic amine, but increases the proportion of by-products such as polyalkylated products. Conversely, when the proportion of the alkylating agent is small, the conversion of the aromatic amine is low, which is economically undesirable.

The reaction temperature is usually from 200 to 400 ° C., preferably from 230 to 370 ° C. Reaction temperature 2
If the temperature is lower than 00 ° C., a large amount of N, N-dialkylated products are produced, and if it is higher than 400 ° C., a metaalkylated product is produced by isomerization, which is not preferable.

The reaction pressure is not particularly limited, but is preferably set so that the reaction system maintains a liquid phase.

The weight hourly space velocity (WHSV), which is the feed rate of the raw material per catalyst weight, is usually 0.01 to 10 hr ^-1.
And preferably 0.1 to 5 hr ^-1 . WHSV
If the ratio is high, the selectivity is improved, but the conversion is low and the amount of recycle increases, which is economically undesirable. Conversely, WHS
If V is low, the conversion is high, but the selectivity is low, which is not preferable.

The type of reaction is not particularly limited, but it is preferable to use a fixed-bed flow system because it is expected to improve the production efficiency by recycling unreacted substances, suppress the accumulation of high-boiling substances, and prolong the life of the catalyst.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[0022]

【Example】

(Zeolite synthesis) Zeolite 1 In a beaker, 591 g of ion-exchanged water and sodium hydroxide 1 were added.
9.3 g was added and stirred well. Subsequently, sodium aluminate (Sumitomo Chemical; Al ₂ O ₃ = 18.5%, NaO
After adding 16.8 g of H = 26.1% and H ₂ O = 55.4%), 21.5 g of tartaric acid (Katayama Chemical) was added and stirred well. Finally, hydrated silica powder (Nihon Silica Kogyo; S
(iO ₂ = 93.3%, H ₂ O = 6.7%) 112 g was added. This slurry was placed in a 1000 cc stainless steel autoclave and stirred at 160 ° C. under sufficient stirring.
The reaction was performed for 2 hours. Then, after cooling, the content was taken out, filtered, washed with water, and dried at 120 ° C. overnight to obtain a pentasil-type zeolite. Analysis showed that SiO ₂
/ Al ₂ O ₃ (molar ratio) = 35.

Zeolite 2 In a beaker, 302 g of ion-exchanged water and sodium hydroxide 1
4.8 g was added and stirred well. Subsequently, sodium aluminate (Sumitomo Chemical; Al ₂ O ₃ = 18.5%, NaO
H = 26.1%, after the addition of _{H 2 O = 55.4%) 21.9g} , was stirred well put tartaric acid (Katayama Chemical) 14.9 g. Finally, hydrated silica powder (Nihon Silica Kogyo; S
(iO ₂ = 93.3%, H ₂ O = 6.7%) 71.6 g were added. This slurry was placed in a 500 cc stainless steel autoclave and stirred at 160 ° C. under sufficient stirring.
The reaction was performed for 2 hours. Then, after cooling, the content was taken out, filtered, washed with water, and dried at 120 ° C. overnight to obtain a mordenite zeolite. As a result of the analysis, SiO
₂ / Al ₂ O ₃ (molar ratio) = 20.

A zeolite 3 beaker was charged with 254 g of ion-exchanged water, and 96.2 g of a 20 wt% aqueous solution of tetraethylammonium hydroxide (Sanyo Kasei) and sodium aluminate (Sumitomo Chemical Co .; A)
l ₂ O ₃ = 18.5%, NaOH = 26.1%, H ₂ O
= 55.4%) was dissolved. This aqueous solution was mixed with hydrated silica powder (Nihon Silica Kogyo; SiO ₂ = 93.3).
%, H ₂ O = 6.7%) and stirred to prepare a mixture slurry. This slurry is filled with 500
cc in a stainless steel autoclave and reacted at 160 ° C. for 11 days under sufficient stirring. After cooling, the contents were taken out, filtered, washed with water, and then cooled to 120 ° C.
And dried overnight to obtain beta zeolite. As a result of the analysis, SiO ₂ / Al ₂ O ₃ (molar ratio) was 25.

(Preparation of Catalyst) Catalyst 1 To 100 parts by weight of zeolite 1, 55 parts by weight of alumina sol (Nissan Chemical No. 200; Al ₂ O ₃ = 10 wt%) and 18.6 parts by weight of barium acetate (Katayama Chemical) are added and molded. After drying at 120 ° C. overnight, baking was performed at 570 ° C. for 2 hours.
This zeolite molded body was treated at 85 ° C. for 4 hours using a 16.7 wt% ammonium chloride aqueous solution. The ammonium ion-exchanged zeolite was washed with water five times at 85 ° C. for 30 minutes. After draining, the mixture was dried at 120 ° C. overnight, and then calcined at 550 ° C. for 1 hour to prepare a pentasil-type zeolite catalyst.

Catalyst 2 Y-type zeolite (Tosoh: SiO ₂ / Al ₂ O ₃ = 5.
5) 100 parts by weight of alumina sol (Nissan Chemical No. 200;
(Al ₂ O ₃ = 10 wt%), 150 parts by weight were added, molded, dried at 120 ° C. overnight, and calcined at 500 ° C. for 2 hours to prepare a Y-type zeolite catalyst.

Catalyst 3 150 parts by weight of alumina sol (Nissan Chemical No. 200; Al ₂ O ₃ = 10 wt%) was added to 100 parts by weight of zeolite 2, molded, dried overnight at 120 ° C., and calcined at 500 ° C. for 2 hours. did. This zeolite molded body was treated with a 16.7 wt% ammonium chloride aqueous solution at 85 ° C. for 4 hours, and then washed with water five times at 85 ° C. for 30 minutes. After draining, the mixture was dried at 120 ° C. overnight, and then calcined at 550 ° C. for 1 hour to prepare a mordenite zeolite catalyst.

Catalyst 4 A beta zeolite catalyst was prepared in the same manner as in catalyst 3, except that zeolite 3 was used. (Alkylation reaction of N-isopropylaniline) Example 1 An alkylation reaction of N-isopropylaniline with propylene was performed using a fixed bed flow reactor. 20 g of the catalyst 1 was charged into a stainless steel (SUS316) reaction tube, the reaction temperature was 300 ° C., the reaction pressure was 8 MPa, N-isopropylaniline / propylene = 1/1 (molar ratio), N-
The alkylation reaction was performed under the condition of WHSV = 0.5 hr ^{-1 based on} isopropylaniline. Table 1 shows the results of the reaction 15 hours after the start of the reaction.

Examples 2 to 4 The reaction was carried out in the same manner as in Example 1 except that catalysts 2 to 4 were used. Table 1 shows the reaction results.

Comparative Example 1 An alkylation reaction of aniline with propylene was performed using a fixed bed flow reactor. 20 g of the catalyst 1 was filled in a stainless steel (SUS316) reaction tube, and the reaction temperature was set to 300.
° C, reaction pressure 8MPa, aniline / propylene = 1/1
The alkylation reaction was carried out under the conditions (molar ratio) and WHSV = 0.5 hr ^{-1 based on} aniline. Table 1 shows the results of the reaction 15 hours after the start of the reaction.

Comparative Example 2 A reaction was carried out in the same manner as in Comparative Example 1 except that the catalyst 2 was used. Table 1 shows the reaction results.

[0032]

[Table 1] As is evident from Table 1, it was found that the alkylation can be performed with high para-selectivity by bringing the N-alkylaromatic amine in which an alkyl group is added to the N atom of the aromatic amine into contact with zeolite and performing the alkylation.

[0033]

According to the present invention, there is provided a method for alkylating N-alkyl aromatic amine with high para-selectivity by reacting N-alkyl aromatic amine with olefin and / or alcohol in the presence of zeolite. can do.

Claims (7)

[Claims] 1. A method for ring-alkylating an N-alkyl aromatic amine, comprising reacting the N-alkyl aromatic amine with an olefin and / or an alcohol in the presence of a catalyst containing a zeolite. 2. The N-alkyl aromatic amine of claim 1, wherein the para-position of the N-alkyl aromatic amine is cyclically alkylated.
A method for ring alkylation of an alkyl aromatic amine. 3. The method according to claim 1, wherein the alkyl group of the N-alkyl aromatic amine has 1 to 7 carbon atoms. 4. The method according to claim 1, wherein the olefin and / or alcohol has 1 to 7 carbon atoms. 5. The zeolite according to claim 1, wherein the zeolite is a zeolite selected from pentasil, mordenite, beta and faujasite.
9. A method for ring-alkylating an N-alkyl aromatic amine according to the above item. 6. The method according to claim 1, wherein the reaction temperature is 200 to 400 ° C. 7. The process according to claim 1, wherein the reaction is carried out in a liquid phase.