JPH05320089A - Method for acylating aromatic compound - Google Patents

Abstract

PURPOSE:To carry out the acylation of an aromatic compound by using a recoverable Lewis acid catalyst. CONSTITUTION:The objective method for acylating an aromatic compound having at least one substitutable hydrogen in the aromatic ring is to use a rare earth-based catalyst expressed by the general formula RE(OSO2Rf)3 (RE is rare earth atom; Rf is perfluoroalkyl or perfluoroalkoxy) as a catalyst in a method for reacting the aromatic compound with an acylating agent in the presence of the catalyst and acylating the aromatic compound. Furthermore, this method for acylating the aromatic compound is to recover the rare earth- based catalyst after completing the reaction and reuse the recovered catalyst as the reactional catalyst. The catalyst which has hitherto been difficult to recover and reuse in the Friedel-Crafts reaction can be recovered and reused and this method has great industrial and practical value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for acylating aromatic compounds, wherein the compound produced by the present invention is used as a raw material for engineering plastic monomers, functional dyes, liquid crystals, pharmaceuticals, agricultural chemicals, etc. Available.

[0002]

2. Description of the Related Art As a method for acylating an aromatic compound,
The Friedel-Crafts acylation reaction in which an aromatic compound is reacted with an acylating agent is widely known (for example, H.
O. House, "Modern Synthetic Reactions" 2nd Ed. W.
A. Benjamin, California (1972) pp 734-816].
This Friedel-Crafts reaction uses a Lewis acid catalyst such as aluminum chloride as a catalyst, and the reaction mixture is usually treated with water in order to separate the product from the Lewis acid catalyst after the reaction is completed. That is, the Lewis acid catalyst is reacted with water to convert it into a water-soluble substance for separation. However, it is very difficult to regenerate the Lewis acid catalyst from this water-soluble substance, and the treatment cost is high even when it is discarded, which is a problem as a method for industrially mass-producing. ..

[0003]

The inventors of the present invention have conducted extensive studies to solve such problems, and as a result, the rare earth catalyst reacts with an aromatic compound and an acylating agent to produce an aromatic compound. It has been newly found that it can be a good catalyst for the production of group carbonyl compounds, and by using this rare earth catalyst as a reaction catalyst, it is easy to recover the catalyst after the reaction, and the recovery The present invention has been completed by finding that the catalyst thus prepared can be reused. Therefore,
An object of the present invention is to provide a method for acylating an aromatic compound by Friedel-Crafts reaction using a recoverable Lewis acid catalyst. Another object of the present invention is to provide a method for acylating an aromatic compound in which the catalyst recovered after the reaction can be easily reused.

[0004]

That is, the present invention provides a method for acylating an aromatic compound having at least one substitutable hydrogen in an aromatic ring by reacting with an acylating agent in the presence of a catalyst. , A catalyst represented by the following general formula: RE (OSO ₂ Rf) ₃ (wherein RE is a rare earth atom, and Rf represents a perfluoroalkyl group or a perfluoroalkoxy group)
Is a method for acylating an aromatic compound using a rare earth catalyst represented by: Further, the present invention is a method for acylating an aromatic compound, in which the rare earth-based catalyst used as the catalyst after the reaction is recovered, and the recovered rare earth-based catalyst is reused as the reaction catalyst.

In the present invention, examples of the aromatic compound used in the reaction include known aromatic compounds to which this type of reaction can be applied, and at least one aromatic ring constituting the aromatic compound is used. As long as it has a substitutable hydrogen, specific examples thereof include benzene, naphthalene, anthracene, naphthacene, pentacene, indene, azulene, heptalene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, triphenylene, pyrene, chrysene and perylene. Such as condensed polycyclic aromatic hydrocarbons such as, and bicyclic and phenyl aromatic ring-containing hydrocarbons such as terphenyl, and indole, isoindole, quinoline, isoquinoline, quinazoline, purine, xanthene, carbazole, acridine, phenazine, phenanthroline, etc. Condensation It can be exemplified heterocyclic aromatic compounds. Such an aromatic compound may have a substituent on its aromatic ring as long as it does not inhibit the acylation reaction.
Examples of such a substituent include a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a thio group, an amino group and an acylamino group.

As the acylating agent used in this reaction,
Usually, there can be mentioned those which can be used as an acylating agent, and specific examples include acetyl chloride, acetyl bromide, propionyl chloride, propionyl bromide, butyryl chloride, butyryl bromide, acryloyl chloride, benzoyl chloride and the like. Carboxylic acid halides, oxalic acid anhydride, acetic anhydride, propionic acid anhydride, succinic acid anhydride, acrylic acid anhydride, maleic acid anhydride, carboxylic acid anhydride represented by benzoic acid anhydride, etc. Can be mentioned.

The following general formula RE (OSO ₂ Rf) ₃ used as a catalyst (wherein RE is a rare earth atom and Rf represents a perfluoroalkyl group or a perfluoroalkoxy group)
In the rare earth-based catalyst of, the rare earth atom RE is scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium,
Gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutecium and the like can be preferably used, and these REs may be only one kind or may contain two or more kinds. Further, Rf may be a perfluoroalkyl group such as a trifluoromethyl group, a pentafluoroethyl group, a nonafluorobutyl group, or a polymer having a perfluoroalkoxy group in the side chain of the polymer such as Nafion resin.

In carrying out the reaction of the present invention, the aromatic compound and the acylating agent are usually used in stoichiometric amounts, that is, equimolar amounts, but either one may be used in excess. In particular, when one of the compounds is inexpensive, for example, when the acylating agent is inexpensive such as acetic anhydride, it is preferable to use this in excess because the reaction is promoted. In the reaction of the present invention, the amount of the rare earth catalyst used is preferably 0.1 to 500 mol%, more preferably 1 to 300 mol%, based on the aromatic compound. When the amount of the rare earth-based catalyst used is less than 0.1 mol%, the reaction rate becomes slow and the reaction does not substantially proceed, but a large amount exceeding 500 mol% may be used.

The reaction of the present invention can be carried out without a solvent, but a solvent may be used. Usable solvents include dichloromethane, chloroform, dichloroethane,
Halogenated hydrocarbons represented by chlorobenzene, aliphatic or alicyclic hydrocarbons represented by hexane and cyclohexane, aromatic hydrocarbons represented by benzene, toluene, and xylene, acetonitrile, nitromethane, nitrobenzene, and nitrobenzene. Although a wide range of aprotic solvents such as carbon sulfide can be mentioned, halogenated hydrocarbons and acetonitrile, in terms of high solubility of raw materials and catalysts,
Nitromethane, carbon disulfide and the like are preferable. Moreover, it does not interfere even if these mixed solvents are used. Further, when an acylating agent such as acetic anhydride which becomes liquid at the reaction temperature is used, the acylating agent itself may be used as a solvent.

The reaction temperature will differ depending on the reaction solvent used and the amount of catalyst used, but it is usually in the range of -100 ° C to 300 ° C, preferably in the range of room temperature to 200 ° C. The reaction time also varies depending on the reaction conditions, but the reaction is usually completed in 10 minutes to 100 hours.

After completion of the reaction, the desired aromatic carbonyl compound can be recovered by various methods, but the following method is preferable because the rare earth catalyst can be easily recovered and reused. That is, the first method is a method in which the rare earth catalyst is separated from the reaction mixture as an aqueous solution, recovered, and reused. That is, after adding a solvent amount of water to the reaction mixture, any one or more of the unreacted aromatic compound, acylating agent and aromatic carbonyl compound is separated from the aqueous solution by a solvent extraction method or the like. This is a method of recovering an aqueous solution containing a rare earth catalyst and distilling water from the aqueous solution to isolate the rare earth catalyst. The second method is a method in which an unreacted aromatic compound, an acylating agent and a reaction product are separated by a distillation method to recover a rare earth catalyst as a residue. In any of these methods, the obtained reaction product is isolated and purified by a conventional method such as column chromatography, distillation and recrystallization. On the other hand, the recovered rare earth catalyst is reused as the reaction catalyst of the present invention as it is or after performing a purification operation as necessary.

[0012]

The rare earth catalyst used in the present invention is considered to function as a so-called Lewis acid catalyst, and its characteristic is that it is well soluble in water. Therefore, the product can be easily separated and the catalyst can be recovered and reused.

[0013]

The present invention will be described in more detail based on the following examples.

Example 1 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium (4.4 g), anisole (3.0 ml) and acetic anhydride (10 ml) were charged, and the mixture was reacted at 50 ° C. for 24 hours with stirring. After the reaction was completed, the obtained reaction mixture was analyzed by gas chromatography, and it was found that 15.6 mmol (yield 56.1%) of 4-methoxyacetophenone was produced.

Example 2 Tris (trifluoromethanesulfonic acid) was placed in a reaction vessel.
Ytterbium (2.53 g), anisole (1.06 ml) and acetic anhydride (10 ml) were charged, and the mixture was reacted under stirring at 50 ° C. for 96 hours. As a result of analyzing the obtained reaction mixture by gas chromatography, it was found that 4-methoxyacetophenone was produced in 7.0 mmol (yield 70.0%).

Example 3 Tris (trifluoromethanesulfonic acid) was placed in a reaction vessel.
Ytterbium 0.127g, Anisole 1.06ml
And 10 ml of acetic anhydride were charged, and the mixture was stirred at 50 ° C. for 96 hours.
Reacted for hours. As a result of analyzing the obtained reaction mixture by gas chromatography, it was found that 3.23 mmol (yield 32.2%) of 4-methoxyacetophenone was produced.

Example 4 Tris (trifluoromethanesulfonic acid) was placed in a reaction vessel.
Ytterbium (2.53 g), anisole (1.06 ml) and acetic anhydride (10 ml) were charged, and the mixture was reacted under stirring at room temperature for 96 hours. As a result of analyzing the obtained reaction mixture by gas chromatography, it was found that 2.23 mmol (yield 22.3%) of 4-methoxyacetophenone was produced.

Example 5 Tris (trifluoromethanesulfonic acid) was placed in a reaction vessel.
Ytterbium (2.53 g), anisole (1.06 ml) and acetic anhydride (10 ml) were charged, and the mixture was reacted at 50 ° C. for 3 hours with stirring. As a result of analyzing the obtained reaction mixture by gas chromatography, it was found that 5.32 mmol (yield 53.2%) of 4-methoxyacetophenone was produced.

Example 6 Unreacted acetic anhydride and anisole were distilled off under reduced pressure from the reaction mixture obtained in the reaction of Example 1, 200 ml of water was added to this residue, and the product was extracted with ethyl acetate ( 200 ml × 5 times). The aqueous layer was concentrated under reduced pressure, and the residue was dried under reduced pressure at 190 ° C. for 14 hours to recover 1.76 g of tris (trifluoromethanesulfonic acid) ytterbium. This recovered tris (trifluoromethanesulfonic acid) ytterbium 1.26
g, 0.53 ml of anisole and 5 ml of acetic anhydride were charged into a reaction vessel and reacted at 50 ° C. for 8 hours with stirring. As a result of analyzing the obtained reaction mixture by gas chromatography, 4-methoxyacetophenone was 3.74 mmol.
(Yield 74.8%) It was found to be produced.

Example 7 Tris (trifluoromethanesulfonic acid) was placed in a reaction vessel.
Ytterbium 1.26 g, anisole 0.53 ml,
0.47 ml of acetic anhydride and 5.0 ml of acetonitrile were charged, and the mixture was reacted at 50 ° C. for 90 hours with stirring. As a result of analyzing the obtained reaction mixture by gas chromatography, 4-methoxyacetophenone was 3.25 mmol.
(Yield 65.0%) It was revealed that it was produced.

Example 8 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 1.26 g, anisole 0.53 ml,
Acetyl chloride (0.08 ml) and acetonitrile (5.0 ml) were charged, and the mixture was reacted under stirring at 50 ° C. for 90 hours. The obtained reaction mixture was analyzed by gas chromatography to find that 4-methoxyacetophenone was 1.54.
It was found that mmol (yield 30.8%) was produced.

Example 9 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 1.26 g, anisole 0.53 ml,
0.47 ml of acetic anhydride and 5.0 ml of acetonitrile were charged, and the mixture was reacted at 50 ° C. for 8 hours with stirring. As a result of analyzing the obtained reaction mixture by gas chromatography,
2.0 mmol of 4-methoxyacetophenone (yield 4
0.0%) was generated.

Example 10 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 1.26 g, anisole 0.53 ml,
Acetyl chloride (0.08 ml) and acetonitrile (5.0 ml) were charged, and the mixture was reacted at 50 ° C. for 8 hours with stirring. The obtained reaction mixture was analyzed by gas chromatography to find that 4-methoxyacetophenone was 1.02 m.
It was found that mol (yield 20.4%) was produced.

Example 11 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 1.26 g, anisole 0.53 ml,
Acetyl chloride (0.08 ml) and 1,2-dichloroethane (10.0 ml) were charged, and the mixture was reacted at 50 ° C. for 8 hours with stirring. As a result of analyzing the obtained reaction mixture by gas chromatography, it was found that 0.55 mmol (yield 11.0%) of 4-methoxyacetophenone was produced.

Example 12 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 1.26 g, anisole 0.53 ml,
Acetic anhydride 0.47 ml and 1,2-dichloroethane 1
0.0ml was charged, and the mixture was reacted at 50 ° C for 8 hours with stirring. The obtained reaction mixture was analyzed by gas chromatography to find that 4-methoxyacetophenone was 0.41 m.
It was found that mol (yield 8.2%) was produced.

Example 13 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Samarium 47.8 mg, 1,2-dimethoxybenzene 55.2 mg, n-caproyl chloride 59.2 mg
And 3.0 ml of dichloromethane were charged, and the mixture was reacted for 60 hours at room temperature with stirring. Then, 10 ml of water was added and the mixture was extracted with dichloromethane. The obtained extract is washed with water (10
(ml × 3 times), dried (Na ₂ SO ₄ ) and concentrated under reduced pressure, the residue was purified by column chromatography, and the reaction product 1- (3,4) was obtained as a clear oily substance.
-Dimethoxyphenyl) -hex-1-one 9.8 mg
(Yield 12.0%) was obtained. IR and NMR of the obtained reaction product were measured. The results are shown below.

[0027] ^{IR (neat): 1672cm -1 1} H-NMR (CDCl 3) σ: 0.83 (t, 3H,
J = 6.9 Hz), 1.23 to 1.34 (m, 4H),
1.53-1.71 (m, 2H), 2.84 (t, 2)
H, J = 7.4), 3.86 (S, 3H), 3.87.
(S, 3H), 6.79 to 6.82 (m, 1H), 7,
45-7.53 (m, 2H) ¹³ C-NMR (CDCl ₃ ) σ: 13.89, 22.4
6, 24.39, 31.5, 38.03, 55.87,
55.96, 109.87, 110.08, 122.5
9, 130.28, 148.93, 153.01, 19
9.19

Example 14 Tris (trifluoromethanesulfonic acid) was placed in a reaction vessel.
Ytterbium 1.26g, 4-methoxybiphenyl 9
Charge 20 mg and acetic anhydride 5.0 ml, and stir 5
The reaction was carried out at 0 ° C for 96 hours. As a result of analyzing the obtained reaction mixture by gas chromatography, 4-methoxy-4
-Acetylbiphenyl 0.45 mmol (yield 8.9
%) Was found to have been generated.

Example 15 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 1.26 g, 2-methoxynaphthalene 7
Charge 10 mg and 5.0 ml of acetic anhydride and stir 5
The reaction was carried out at 0 ° C for 96 hours. The obtained reaction mixture was analyzed by gas chromatography to find that it was 2-methoxy-6.
-Acetylnaphthalene 0.95 mmol (yield 19
%) Was found to have been generated.

Example 16 Tris (trifluoromethanesulfonic acid) in a reaction vessel
3.10 g of ytterbium, 0.54 ml of anisole,
0.47 ml of acetic anhydride and 5 ml of acetonitrile were charged, and the mixture was reacted at 50 ° C. for 24 hours with stirring. The obtained reaction mixture was analyzed by gas chromatography, and as a result, 4
2.6 mmol of -methoxyacetophenone (yield 5
2.0%). The results are shown in Table 1.

Examples 17 to 20 The same reaction as in Example 16 was repeated except that n-butyronitrile, nitromethane, nitrobenzene or dichloroethane was used instead of acetonitrile used as the reaction solvent, and 4-methoxy was used as the reaction product. I got acetophenone. The yield of the obtained reaction product is shown in Table 1.
Shown in.

[0032]

[Table 1]

Examples 21 to 23 In Example 16, in place of 3.1 g of tris (trifluoromethanesulfonic acid) ytterbium used as the rare earth catalyst, 2.93 g of tris (trifluoromethanesulfonic acid) lanthanum and tris (trifluoromethane) were used, respectively. Sulfonic acid) europium 2.99 g or tris (trifluoromethanesulfonic acid) erbium 3.0
The same reaction was performed except that 7 g was used to obtain 4-methoxyacetophenone as a reaction product. The yield of the obtained reaction product is shown in Table 2.

[0034]

[Table 2]

Examples 24 to 32 In place of 0.54 ml of anisole used as an aromatic compound in Example 16, as shown in Table 3, 0.64 ml of N, N-dimethylaniline and 0.62 ml of thioanisole, respectively. 0.60 ml of o-xylene, 0.60 ml of m-xylene, 0.60 ml of p-xylene, 0.69 ml of mesitylene, 920 m of 4-methoxybiphenyl
g, 2-methoxynaphthalene 910 mg or dibenzofuran 840 mg was used in the same reaction, and it was confirmed by gas chromatography that the reaction products shown in Table 3 were obtained in the yields shown in Table 3. The results are shown in Table 3.

[0036]

[Table 3]

Example 33 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 0.62g, Anisole 0.54ml,
0.47 ml of acetic anhydride and 5 ml of nitromethane were charged, and the mixture was reacted at 50 ° C. for 48 hours with stirring. The obtained reaction mixture was analyzed by gas chromatography, and as a result, 4
-Methoxyacetophenone 3.01 mmol (yield 6
0.2%). The results are shown in Table 4.

Examples 34-40 In Example 33, the amount of tris (trifluoromethanesulfonic acid) ytterbium used, the amount of acetic anhydride used,
The same reaction was performed except that the reaction temperature and the reaction time were changed as shown in Table 4, and the obtained reaction mixture was analyzed by gas chromatography to confirm that 4-methoxyacetophenone was produced. Table 4 shows the reaction conditions and results.
Shown in.

[0039]

[Table 4]

Example 41 Unreacted acetic anhydride and anisole were distilled off from the reaction mixture obtained in the reaction of Example 36 under reduced pressure, 50 ml of water was added to the obtained residue, and the product was extracted with chloroform. Was extracted (100 ml × 5 times). The remaining aqueous layer was concentrated under reduced pressure, and the obtained residue was dried under reduced pressure at 190 ° C. for 14 hours to recover 0.60 g of tris (trifluoromethanesulfonic acid) ytterbium. The collected tris (trifluoromethanesulfonic acid) ytterbium (0.60 g), anisole (0.53 ml) and acetic anhydride (10 ml) were placed in a reaction vessel and reacted at 50 ° C. for 18 hours with stirring. As a result of analyzing the obtained reaction mixture by gas chromatography, 4-methoxyacetophenone was found to be 4.
It was found that 64 mmol (yield 92.8%) was produced.

Example 42 Tris (trifluoromethanesulfonic acid) in a reaction vessel
Ytterbium 0.62g, Anisole 0.54ml,
Acetic anhydride 0.94 ml and nitromethane 5 ml were charged, and the mixture was reacted at 50 ° C. for 1 hour while stirring. As a result of analyzing the obtained reaction mixture by gas chromatography, 4-
2.48 mmol of methoxyacetophenone (yield 4
9.6%) was produced.

Example 43 8.54 g of scandium oxide was added to 50 ml of water and stirred. 50 g of trifluoromethanesulfonic acid was slowly added dropwise to this solution. After dripping, while heating under reflux, further 3
The reaction was allowed to stir for hours. Unreacted scandium oxide is filtered off from this reaction mixture. The obtained filtrate was concentrated under reduced pressure and then dried under reduced pressure at 190 ° C. for 48 hours to give scans (trifluoro (methanesulfonic acid)) scandium 52.
2 g was obtained as white crystals. 0.49 g of scandium tris (trifluoromethanesulfonate) obtained by the above preparation method, 0.54 ml of anisole, acetic anhydride
94 ml and nitromethane 5 ml were added sequentially, and 1 at 50 ℃
The reaction was carried out under stirring for 8 hours. The reaction mixture was analyzed by gas chromatography. As a result, it was found that 4.98 mmol (yield 99.5%) of 4-methoxyacetophenone was produced. The results are shown in Table 5.

Examples 44 to 55 The same reaction as in Example 43 was carried out except that a predetermined amount of various trifluoromethanesulfonic acid rare earth metal salts were used instead of 0.49 g of scandium tris (trifluoromethanesulfonic acid) scandium. 4-Methoxyacetophenone was obtained as a reaction product. The results are shown in Table 5.

[0044]

[Table 5]

Examples 56 to 57 In the same manner as in Example 43 except that the reaction time was set to 2 hours and 4 hours, the same reaction was carried out to obtain 4-methoxyacetophenone as a reaction product. The results are 89.4% when the reaction time is 2 hours, and 93.4% when the reaction time is 4 hours.
It was 0%.

Example 58 Tris (trifluoromethanesulfonic acid) ytterbium (0.62 g), 2-methoxynaphthalene (790 mg), acetic anhydride (0.94 ml) and nitromethane (5 ml) were sequentially added,
The reaction was carried out at 50 ° C. for 18 hours with stirring. The reaction mixture was analyzed by gas chromatography. As a result, 1-
Acetyl-2-methoxynaphthalene 67.4%, 2-
It was found that acetyl-6-methoxynaphthalene was produced in a yield of 8.8%. The results are shown in Table 6.

Examples 59 to 66 In Examples 58, various perfluoroalkylsulfonic acid rare earth metal salts were used in place of 0.62 g of tris (trifluoromethanesulfonic acid) ytterbium, and the reaction time was changed. Was similarly reacted to obtain 1-acetyl-2-methoxynaphthalene and 2-acetyl-6-methoxynaphthalene as reaction products. The results are shown in Table 6.

[0048]

[Table 6]

Example 67 Tris (nonafluorobutanesulfonic acid) ytterbium 1.07 g, anisole 0.54 ml, acetic anhydride 0.
94 ml and nitromethane 5 ml were added sequentially, and 1 at 50 ℃
The reaction was allowed to stir for hours. The reaction mixture was analyzed by gas chromatography. As a result, it was found that 4-methoxyacetophenone was produced at a yield of 76.7%.

Example 68 Tris (trifluoromethanesulfonic acid) ytterbium (1.24 g), anisole (1.08 ml), acetyl chloride (1.43 ml) and nitromethane (10 ml) were sequentially added, and the mixture was reacted at 50 ° C. for 1 hour with stirring. The reaction mixture was analyzed by gas chromatography. As a result, 4
It was found that -methoxyacetophenone was produced in a yield of 42.0%.

Examples 69 to 72 Tris (trifluoromethanesulfonic acid) ytterbium 0.62 g, anisole 0.54 ml, acetic anhydride 0.
94 ml and nitromethane 5 ml were sequentially added, and the mixture was reacted at 50 ° C. for a predetermined time with stirring. The reaction mixture was analyzed by gas chromatography. As a result, it was found that 4-methoxyacetophenone was produced. Result is,
In the case of 1 hour reaction, 2 hour reaction, 4 hour reaction and 6 hour reaction, 45.8%, 55.6% and 65.1 respectively.
% And 87.1%.

Example 73 Scandium tris (trifluoromethanesulfonate) 0.49 g, anisole 0.54 ml, benzoyl chloride 1.16 ml, and nitromethane 5 ml were sequentially added to give 5
The mixture was reacted at 0 ° C. for 18 hours with stirring. The reaction mixture was analyzed by gas chromatography. As a result, it was found that 4-methoxybenzophenone was produced in a yield of 79.3%.

Examples 74 to 76 In Example 73, 1.16 ml of benzoyl chloride
Was replaced by 1.89 ml of benzoic anhydride, and the reaction time was changed to 1 hour, 4 hours, and 18 hours, and the same reaction was performed. These reaction mixtures were analyzed by gas chromatography. The results were 1 hour reaction, 4 hour reaction and 18 hours.
In case of time reaction, 50.1% and 64.3% respectively
And 90.1%.

Examples 77-78 In Example 73, tris (trifluoromethanesulfonic acid) ytterbium 0.62 was used in place of tris (trifluoromethanesulfonic acid) scandium 0.49 g.
g, benzoyl chloride 1.16 ml was replaced with benzoic anhydride 1.89 ml, the reaction time was 6 hours and 18
The reaction was performed in the same manner except that the time was set. These reaction mixtures were analyzed by gas chromatography. The results show that for the 6-hour reaction and the 18-hour reaction, respectively, they were 18.9 sequentially.
% And 31.5%.

[0055]

INDUSTRIAL APPLICABILITY According to the present invention, it becomes possible to recover and reuse the Lewis acid catalyst, which has been difficult in the prior art, in the Friedel-Crafts acylation reaction. This is of great industrial and practical value.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Mitamura 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa, Nippon Steel Corporation Advanced Technology Research Institute (72) Inventor Atsushi Kawada 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Address, Nippon Steel Corporation Advanced Technology Research Center

Claims (2)

[Claims] 1. A method of acylating an aromatic compound having at least one substitutable hydrogen in an aromatic ring by reacting with an acylating agent in the presence of a catalyst, wherein a catalyst represented by the following general formula RE (OSO ₂ Rf) ₃ (wherein RE is a rare earth atom, and Rf represents a perfluoroalkyl group or a perfluoroalkoxy group)
A method for acylating an aromatic compound, which comprises using a rare earth catalyst represented by: 2. The method for acylating an aromatic compound according to claim 1, wherein the rare earth-based catalyst used as a catalyst is recovered after the completion of the reaction, and the recovered rare earth-based catalyst is reused as a reaction catalyst.