JP2002095971A - Friedel-Crafts catalyst and method for producing alkylated aromatic compound or benzoylated aromatic compound using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel Friedel-Crafts reaction catalyst which is easy to handle and can recover or reuse the catalyst from a reaction system, and an alkylated aromatic compound or benzoylation using the same. Provided is a novel method for producing an aromatic compound. SOLUTION: A Friedel-Crafts catalyst comprising zinc halide supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve, and an alkylated aromatic compound or benzoylation using the same. A method for producing an aromatic compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel Friedel-Crafts catalyst and a method for producing an alkylated aromatic compound or a benzoylated aromatic compound using the same.

[0002]

2. Description of the Related Art The Friedel-Crafts reaction is known as the most important reaction for introducing an alkyl group into an aromatic ring. As a catalyst, Lewis acid, particularly AlCl _3, is most widely used. However, AlCl ₃ has too strong catalytic activity and involves side reactions such as isomerization, decomposition and polymerization, and it is difficult to selectively obtain a mono-substituted product. In addition, strong hygroscopicity,
Handling and storage are troublesome. After the reaction, the catalyst is decomposed and removed with water or the like, so that it is impossible to recover and reuse the catalyst, and there is a problem that a waste liquid containing metal ions is generated.

On the other hand, ZnCl ₂ is very weak Lewis.
It is known that the acid has a very low activity as a Friedel craft catalyst.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a novel Friedel-Crafts reaction catalyst which is easy to handle and which can recover or reuse the catalyst from the reaction system, and an alkylation using the same. An object of the present invention is to provide a novel method for producing an aromatic compound or a benzoylated aromatic compound.

[0005]

SUMMARY OF THE INVENTION A first aspect of the present invention relates to a Friedel-craft catalyst comprising zinc halide supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve. .

A second aspect of the present invention relates to a Friedel-craft catalyst for an alkylation reaction, wherein a zinc halide is supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve.

A third aspect of the present invention relates to a Friedel-kraft catalyst for an acylation reaction, wherein a zinc halide is supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve.

A fourth aspect of the present invention relates to a Friedel-kraft catalyst for a benzoylation reaction, wherein a zinc halide is supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve.

A fifth aspect of the present invention is the following general formula (1):

Embedded image (Wherein, Ar ¹ is an aryl or heteroaryl group which may have a substituent.) The aromatic compound represented by the following general formulas (2) to (4)

Embedded image (Wherein, R ¹ , R ² , and R ³ are each independently an alkyl group, an alkoxy group, an alkylamino group, an optionally substituted aryl, heteroaryl, cycloalkyl group, and hydrogen. Group selected as
^At least two of ^{1 to} R ³ are an alkyl group;
r ² is an aryl or heteroaryl group which may have a substituent, and X is a halogen. ) Is reacted with an alkylating agent selected from the group represented by the following general formula (5), (6) or (7):

Embedded image (Wherein, Ar ¹ , Ar ² , R ¹ , R ² and R ³ are the same as those described above). In the method for producing an alkylated aromatic compound represented by the formula (I), alumina, silica, zeolite and molecular The present invention relates to a method for producing an alkylated aromatic compound, which comprises using a catalyst in which a zinc halide is supported on a carrier selected from the group consisting of sieves.

A sixth aspect of the present invention is the following general formula (8):

Embedded image (Wherein, Ar ¹ is an aryl or heteroaryl group which may have a substituent, and n is an integer selected from the group consisting of 1 to 3).
(4)

Embedded image (Wherein, R ¹ , R ² , and R ³ are each independently an alkyl group, an alkoxy group, an alkylamino group, an optionally substituted aryl, heteroaryl, cycloalkyl group, and hydrogen. Group selected as
^At least two of ^{1 to} R ³ are an alkyl group;
r ² is an aryl or heteroaryl group which may have a substituent, and X is a halogen. ) Is reacted with an alkylating agent selected from the group represented by the following formula (9), (10) or (11)

Embedded image (Wherein, Ar ¹ , Ar ² , R ¹ , R ² , R ³ and n are the same as those described above). In the method for producing an alkylated aromatic compound represented by the formula: And a method for producing an alkylated aromatic compound, which comprises using a catalyst in which a zinc halide is supported on a carrier selected from the group consisting of molecular sieves.

A seventh aspect of the present invention is the following general formula (12):

Embedded image (In the formula, Ar ¹ is an aryl or heteroaryl group which may have a substituent, and m is 0 or 1.) An aromatic compound represented by the following general formula (2)
(4)

Embedded image (Wherein, R ¹ , R ² , and R ³ are each independently an alkyl group, an alkoxy group, an alkylamino group, an optionally substituted aryl, heteroaryl, cycloalkyl group, and hydrogen. Group selected as
^At least two of ^{1 to} R ³ are an alkyl group;
r ² is an aryl or heteroaryl group which may have a substituent, and X is a halogen. ) Is reacted with an acylating agent selected from the group represented by the following general formula (13), (14) or (15)

Embedded image (Wherein, Ar ¹ , Ar ² , R ¹ , R ² , R ³ and m are the same as those described above). In the method for producing an alkylated aromatic compound represented by the formula: And a method for producing an alkylated aromatic compound, which comprises using a catalyst in which a zinc halide is supported on a carrier selected from the group consisting of molecular sieves.

An eighth aspect of the present invention is the following general formula (16):

Embedded image (In the formula, Ar ¹ is an aryl or heteroaryl group which may have a substituent, and R ⁴ is an alkyl group.) An oxyalkylated aromatic compound represented by the following general formula (17)

Embedded image (Wherein, Z is a group selected from the group consisting of an alkyl group and an aryl or heteroaryl group which may have a substituent, and X is a halogen). And the following general formula (18)

Embedded image (In the formula, Ar ¹ , Z and R ⁴ are the same as described above.)
In the method for producing a benzoylated aromatic compound represented by the above, characterized in that as a catalyst, a carrier obtained by supporting a zinc halide on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve The present invention relates to a method for producing a benzoylated aromatic compound.

The aryl group in the present invention is a monocyclic or polycyclic aromatic group such as phenyl, naphthyl, and anthranyl, and the heteroaryl group is N, S,
Examples thereof include a monocyclic or polycyclic 3- to 8-membered ring containing a hetero atom such as O, a condensed ring with an aryl ring, and the like. Note that examples of the substituent in the optionally substituted aryl or heteroaryl include an alkyl group, halogen, and NO ₂ .

The zinc halide is ZnC
l ₂ , ZnBr ₂ , ZnF ₂ , and ZnI _2.
Cl ₂ or ZnBr ₂ is preferred.

As a carrier for supporting zinc halide,
Alumina, silica, zeolites and molecular sieves are used, with silica being most preferred. As alumina, acidic alumina is most preferable, and then neutral alumina is preferable. The silica is preferably used in the form of silica gel. As the molecular sieve, molecular sieve 5A and the like can be mentioned.

The catalyst of the present invention may be prepared by dissolving zinc halide in water, adding a carrier to the solution, leaving it for a predetermined time (preferably under stirring), and then drying.

Preferred examples of the reaction using the catalyst of the present invention are shown below. (1) Alkylation of aromatic hydrocarbon

Embedded image (Wherein, R ⁵ represents an alkyl group, an alkoxy group, an alkylamino group, a halogen, a nitro group, a cyano group, a carboxyl group, a carboxylate group, an optionally substituted aryl, heteroaryl, cycloalkyl It may be a group or a group which forms a condensed ring together with the six-membered ring in the formula, and these substituents may be plural instead of one, and Q ¹ is C (R ¹ R ² R ³ ) — or Ar ² CH
_2- , R ^{1 to} R ³ and Ar ² are the same as described above, and X is halogen. )

Embedded image (In the formula, R ⁵ , Ar ² , and X are the same as described above.)

(2) Aralkylation of phenols

Embedded image (In the formula, Q ¹ , R ⁵ , Ar ² , and X are the same as described above.)

(3) Aralkylation of aromatic hydrocarbon with alcohol

Embedded image (In the formula, R ⁵ and Ar ² are the same as described above.)

(4) Acylation of alkoxy-substituted aromatic hydrocarbon

Embedded image (Wherein, R ⁵ and X are the same as described above, R ⁶ is an alkyl group or an aryl which may have a substituent, a heteroaryl group, R ⁷ is an aryl which may have a substituent,
It is a group independently selected from the group consisting of heteroaryl and cycloaryl groups. )

(5) Acylation of alkoxy-substituted aromatic hydrocarbon with acetic anhydride

Embedded image (In the formula, R ⁵ and R ⁶ are the same as described above.) The number of carbon atoms in the alkyl group, alkoxy group, and alkylamino group is not particularly limited, but is usually 1 to 20, preferably 1 to 6. is there. The aryl may be monocyclic or polycyclic, and may include a benzene ring, a naphthalene ring, an anthracene ring, and the like. The heteroaryl may be any of a heteroaryl monocyclic ring, a condensed ring of a heteroaryl monocyclic ring and a carbon ring, and a heteroaryl polycyclic ring.

[0022]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited thereby.

Example 1 (1) Silica gel-supported zinc chloride (ZnCl ₂ / Si)
Preparation of O ₂ ) 10 g of zinc chloride was dissolved in 100 ml of water to prepare an aqueous zinc chloride solution, and this was added to Wakogel C-20.
Add 0 (silica gel) 40 g and stir for 30 minutes. After distilling off water with a rotary evaporator, the mixture is dried under reduced pressure (150 ° C./14 mmHg) for 10 hours.

(2) Silica gel-supported zinc bromide (ZnBr)
₂ / SiO ₂ ) The procedure was the same as in (1) above, except that zinc bromide was used instead of zinc chloride.

Examples 2 to 4

Embedded image Using the silica gel-supported zinc chloride catalyst prepared in (1) of Example 1, 5 ml of benzene and AX in Table 1 below were used.
And at 30 ° C. for the reaction time shown in Table 1,
0.136 g of the desired product was obtained. The yield is as shown in Table 1. After the reaction, the catalyst was easily separated by filtration.

[0026]

[Table 1]

Example 5 After completion of the reaction of Example 4, the catalyst was recovered by filtration, and the reaction of Example 4 was repeated using the catalyst. As shown in the table, even after repeated use six times, the conversion and the yield hardly changed, and the ninth use showed a slight tendency to decrease.

[0028]

[Table 2]

Embodiment 6

Embedded image The above reaction components were reacted in the proportions shown in the following table. R ⁵ is 1-
In any case of methyl, 1,4-dimethyl and 1,3,5-trimethyl, the desired product was obtained quantitatively.

[0030]

[Table 3]

In the case of toluene, the ratio of the o-position / p-position of the product is 42/58, and the reactivity of polymethylbenzene increases as the number of CH ₃ groups increases. The relative rates of conversion were benzene (1) <toluene (7.3) <p-xylene (15.5) <mesitylene (98).

Examples 7 to 9

Embedded image The indication of R ^{8 in} the formula is shown in Table 4.

[0033]

[Table 4]

When the substituent at the para position (R ⁸ ) is a CH ₃ group, the reactivity increases as compared with the case where there is no substituent. However,
The yield of the monobenzylated compound was slightly reduced due to the by-product of the polybenzylated compound. When R ⁸ is a CH ₃ group, if AlCl ₃ is used as a catalyst, various side reactions such as isomerization and decomposition occur, and it is difficult to selectively obtain the target compound. However, the ZnCl ₂ / SiO of the present invention is difficult to obtain. _{In the case of 2} , the target compound could be selectively obtained with very few side reactions.

Embodiment 10

Embedded image The yield of (a) is 88%, and there is almost no product of (b). On the other hand, when only AlCl ₃ is used,
A large amount of the compound (b) is generated, and the yield of the compound (a) is extremely low.

Embodiment 11

Embedded image Ar ³ used was as shown in the following table.

[0037]

[Table 5]

Embodiment 12

Embedded image

[0039]

[Table 6] Even when AlCl ₃ —CH ₃ NO ₂ is used as the catalyst, the above (e) is not obtained at all, a small amount of a polymer is formed, and most of the product is unreacted. The reaction proceeds, and the desired product (e) is obtained in the yield shown in the table.

Embodiment 13

Embedded image

[0041]

[Table 7] Even if the above reaction is carried out using AlCl ₃ as a catalyst, A is converted into -AlCl ₂ instead of H in the phenol OH group.
Although the reaction does not proceed due to the reaction of lCl ₃ ,
When the catalyst of the present invention is used, the reaction proceeds smoothly with the above yield.

Embodiment 14

Embedded image Even if the above reaction is carried out using AlCl ₃ as a catalyst, A
Although 1Cl ₃ reacted with the alcohol and the reaction did not proceed, when the catalyst of the present invention was used, the reaction was carried out as shown in the above formula, and the desired product was obtained in high yield (79%).

Examples 15 to 17

Embedded image In the formula, R ⁹ and X are shown in Table 8.

[0044]

[Table 8]

As shown in Table 8, the acylation reaction of an active aromatic compound such as anisole proceeds easily. In particular, the reaction with acetyl bromide proceeded sufficiently even at 30 ° C.

Embodiment 18

Embedded image 3 mmol of methylanisole and 9 mmol of benzoyl bromide are dissolved in 10 ml of benzene, and 80 ° C. using a silica gel catalyst supporting 1.8 mmol of zinc bromide.
For 1 hour, the target product was obtained in a yield of 74%. On the other hand, when the reaction was carried out only with 0.27 g of zinc bromide without being supported on silica gel, the yield of the target product was only 15%.

Examples 19 to 20

Embedded image In the formula, R ¹⁰ is shown in Table 9 below. Methoxy naphthalene 1
Mmol and 3 mmol of R ¹⁰ COBr were dissolved in 10 ml of benzene, 0.3 mmol of zinc bromide supported on silica gel was added, and the mixture was reacted under stirring under the conditions shown in the table. As a result, the desired product was selectively produced. .

[0048]

[Table 9]

Embodiment 21

Embedded image

Embodiment 22

Embedded image

Embodiment 23

Embedded image 3 mmol of methylmethoxybenzene and benzoyl bromide 9
The mmol was dissolved in benzene (10 ml), and silica gel-supported zinc bromide (0.1 equivalent) prepared according to Example 1 was added thereto, followed by stirring reaction for 1 hour. As a result, benzoylmethylmethoxybenzene was obtained in high yield.

[0052]

EFFECT OF THE INVENTION (1) Halides such as AlCl ₃ and ZnCl ₂ have high hygroscopicity and are difficult to store and handle. However, the catalyst of the present invention has a sufficiently long-term activity when stored at a desiccator level. Because it is kept, it is excellent in storage and handling. (2) The use of a halogenated solvent is indispensable in using a conventional Friedel-Crafts catalyst, but the present invention does not require the use of a halogenated solvent. Therefore,
There is no need for environmental problems after the use of the halogenated solvent and the associated costs. (3) Since zinc halide is insoluble in a relatively small polar organic solvent such as benzene, it does not elute from the support surface into the reaction solution. Therefore, the catalyst can be easily separated and recovered by filtration or the like after the reaction. (4) The recovered catalyst can be regenerated by washing with an aromatic hydrocarbon such as benzene or toluene and drying, and the catalyst activity is hardly reduced. (5) The catalyst of the present invention can be used for alkylation of phenols, and the corresponding alkyl phenol can be obtained in good yield. On the other hand, AlCl ₃ , which is the most common Friedel craft catalyst, cannot be used because AlCl ₃ is strongly coordinated to the hydroxyl group of phenol and deactivated. If the hydroxyl group is protected with an appropriate protecting group, it may be usable, but the number of steps of adding a protecting group to the hydroxyl group and removing the protecting group from the hydroxyl group increases.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C07C 15/16 C07C 15/16 17/266 17/266 25/18 25/18 37/18 37/18 39 / 12 39/12 45/46 45/46 49/84 49/84 F 201/12 201/12 205/06 205/06 // C07B 61/00 300 C07B 61/00 300 (72) Inventor Takashi Takeda Hyogo 1-3-3, Higashikawasaki-cho, Chuo-ku, Kobe-shi BA64 FC52 FE13 FG29 4H039 CA19 CA41 CA62 CD20 CL25

Claims (8)

[Claims] 1. A Friedel-craft catalyst comprising a zinc halide supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve. 2. A Friedel-kraft catalyst for an alkylation reaction, wherein a zinc halide is supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve. 3. A Friedel-kraft catalyst for acylation reaction, wherein a zinc halide is supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve. 4. A Friedel-kraft catalyst for a benzoylation reaction, wherein a zinc halide is supported on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve. 5. The following general formula (1): (Wherein, Ar ¹ is an aryl or heteroaryl group which may have a substituent.) An aromatic compound represented by the following general formulas (2) to (4): (Wherein, R ¹ , R ² , and R ³ are each independently an alkyl group, an alkoxy group, an alkylamino group, an optionally substituted aryl, heteroaryl, cycloalkyl group, and hydrogen. Group selected as
^At least two of ^{1 to} R ³ are an alkyl group;
r ² is an aryl or heteroaryl group which may have a substituent, and X is a halogen. ) Is reacted with an alkylating agent selected from the group represented by the following formula (5), (6) or (7): (Wherein, Ar ¹ , Ar ² , R ¹ , R ² and R ³ are the same as those described above). In the method for producing an alkylated aromatic compound represented by the formula ( ¹ ), alumina, silica, zeolite and molecular A method for producing an alkylated aromatic compound, comprising using a catalyst in which a zinc halide is supported on a carrier selected from the group consisting of sieves. 6. The following general formula (8): (Wherein, Ar ¹ is an aryl or heteroaryl group which may have a substituent, and n is an integer selected from the group consisting of 1 to 3).
(4) (Wherein, R ¹ , R ² , and R ³ are each independently an alkyl group, an alkoxy group, an alkylamino group, an optionally substituted aryl, heteroaryl, cycloalkyl group, and hydrogen. Group selected as
^At least two of ^{1 to} R ³ are an alkyl group;
r ² is an aryl or heteroaryl group which may have a substituent, and X is a halogen. ) Is reacted with an alkylating agent selected from the group represented by the following formula (9), (10) or (11): (Wherein, Ar ¹ , Ar ² , R ¹ , R ² , R ³ and n are the same as those described above). In the method for producing an alkylated aromatic compound represented by the formula: alumina, silica, zeolite And a catalyst comprising zinc halide supported on a support selected from the group consisting of molecular sieves and a molecular sieve. 7. The following general formula (12) (In the formula, Ar ¹ is an aryl or heteroaryl group which may have a substituent, and m is 0 or 1.) An aromatic compound represented by the following general formula (2)
(4) (Wherein, R ¹ , R ² , and R ³ are each independently an alkyl group, an alkoxy group, an alkylamino group, an optionally substituted aryl, heteroaryl, cycloalkyl group, and hydrogen. Group selected as
^At least two of ^{1 to} R ³ are an alkyl group;
r ² is an aryl or heteroaryl group which may have a substituent, and X is a halogen. ) Is reacted with an acylating agent selected from the group represented by the following formula (13), (14) or (15): (Wherein, Ar ¹ , Ar ² , R ¹ , R ² , R ³ and m are the same as those described above). In the method for producing an alkylated aromatic compound represented by the formula: And a catalyst comprising zinc halide supported on a carrier selected from the group consisting of molecular sieves and an alkylated aromatic compound. 8. The following general formula (16): (In the formula, Ar ¹ is an aryl or heteroaryl group which may have a substituent, and R ⁴ is an alkyl group.) An oxyalkylated aromatic compound represented by the following general formula (17) Embedded image (Wherein, Z is a group selected from the group consisting of an alkyl group and an aryl or heteroaryl group which may have a substituent, and X is a halogen). The following general formula (18) (In the formula, Ar ¹ , Z and R ⁴ are the same as described above.)
In the method for producing a benzoylated aromatic compound represented by the above, characterized in that as a catalyst, a carrier obtained by supporting a zinc halide on a carrier selected from the group consisting of alumina, silica, zeolite and molecular sieve A method for producing a benzoylated aromatic compound.