JPH11322672A - Diacyloxylation of side chain of aromatic compound substituted by alkyl group and catalyst therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for diacyloxylating the side chain of an alkyl group- substituted aromatic compound by reacting the alkyl group-substituted aromatic compound with a carboxylic acid anhydride and an oxygen-containing gas in the presence of a specific catalyst in a liquid phase, capable of obtaining the diacyloxy compound useful as a perfume, etc., in high productivity, capable of inhibiting the decomposition of the carboxylic acid anhydride, and capable of being industrially applied. SOLUTION: This method for diacyloxylating the side chain of an alkyl group- substituted aromatic compound comprises reacting the alkyl group-substituted aromatic compound (preferably a methyl group-substituted aromatic compound such as m- chlorotoluene) with a carboxylic acid anhydride (preferably an aliphatic carboxylic acid anhydride such as acetic anhydride) in the presence of a heavy metal compound having an oxidation catalyst ability [for example, cerous (III) acetate monohydrate] and a halogen compound not containing crystal water and ammonium ion (preferably a bromine compound such as magnesium di bromide) in an oxygen-containing gas preferably in the coexistence of a zinc compound in a liquid phase preferably at 60-350 deg.C. Thus, the objective compound (for example, m-chlorobenzylidene diacetate) is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a side chain disiloxy compound of an alkyl-substituted aromatic compound by reacting an alkyl-substituted aromatic compound with a carboxylic anhydride in the presence of an oxygen-containing gas, and a catalyst thereof. About. The side-chain disiloxy compound of an alkyl group-substituted aromatic compound is itself useful as a fragrance, and benzaldehydes obtained by hydrolyzing the disiloxy compound are useful as intermediates for pesticides, medicines, fragrances and as resin additives. .

[0002]

2. Description of the Related Art A method for producing a side-chain disiloxy compound from an alkyl-substituted aromatic compound is described in (A)
No. 45572 discloses a method of using a cobalt compound as a catalyst in a liquid phase in the presence of acetic anhydride,
(B) In JP-A-56-10486, a bromine compound is added as a cocatalyst to a cobalt compound and / or a manganese compound catalyst in the liquid phase in the presence of acetic anhydride to improve the catalytic activity, and to improve the side chain disiloxy compound. Methods are disclosed that also enhance selectivity.

[0003]

However, in order to carry out the reaction industrially, in the above-mentioned method (A), the selectivity of the side-chain disiloxy compound is extremely low, and the industrially substituted alkyl group cannot be substituted. It is not preferable as a method for producing a side chain disiloxy compound of an aromatic compound. In the above method (B), ammonium bromide is used as a co-catalyst. However, ammonium ions are oxidized during the reaction to generate 2 moles of water from 1 mole of ammonium ions. As a result, the carboxylic anhydride present in the reaction system quickly reacts with the produced water to form carboxylic acid. That is, when ammonium ions were present in the reaction system, the carboxylic acid anhydride as an acetoxylating agent was largely decomposed. Also, when water of crystallization was contained, the carboxylic acid anhydride was frequently decomposed for the same reason. Therefore, this method is not preferable as an industrial method for producing a side chain disiloxy compound of an alkyl group-substituted aromatic compound.

An object of the present invention is to provide a method for producing a side chain disiloxy compound of an alkyl-substituted aromatic compound which is industrially applicable and has high productivity and a catalyst therefor.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that when a heavy metal compound having an oxidation catalytic activity and a halogen compound are used as a catalyst, water of crystallization and ammonium By using a halogen compound containing no ion, it has been found that an alkyl group-substituted aromatic compound and a carboxylic anhydride can be efficiently reacted in the presence of an oxygen-containing gas, and that the decomposition of the carboxylic anhydride can be suppressed. The present invention has been reached.

That is, when an alkyl-substituted aromatic compound is reacted with a carboxylic anhydride in the presence of an oxygen-containing gas to produce a side-chain disiloxy compound of the alkyl-substituted aromatic compound, the compound has an oxidation catalytic activity as a catalyst. A method for producing a side-chain disiloxy compound of an alkyl-substituted aromatic compound, characterized in that the halogen compound does not contain water of crystallization and ammonium ion in a method using a heavy metal compound and a halogen compound, and a catalyst thereof.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the heavy metal compound having an oxidation catalytic activity in the present invention, specifically, vanadium, chromium, manganese, iron, cobalt, nickel, copper, niobium, molybdenum, ruthenium, rhodium, palladium, tungsten, Compounds such as rhenium, osmium, iridium, platinum and cerium are exemplified. Preferably, they are cobalt, manganese, and cerium. The forms of these heavy metal compounds include organic salts such as citrate, acetate, propionate, butyrate, valerate, caproate, and naphthenate, and chlorides, bromides, iodides, oxides, hydroxides. , Carbonate,
Inorganic salts such as sulfates, nitrates and perchlorates are exemplified. Further, these heavy metal compounds may be immobilized on a carrier. The carrier is not particularly limited, but an inorganic compound is preferably used in terms of heat stability and solvent resistance.
For example, zeolite, alumina, silica alumina, silica, titania, activated clay, activated carbon and the like,
Particularly, zeolite, alumina, silica alumina and activated carbon are preferred.

The amount of the heavy metal compound to be used is 0.0001 to 0.5 mol times, preferably 0.001 to 0.1 mol times, relative to the starting alkyl-substituted aromatic compound.

The halogen compound used in the present invention does not contain water of crystallization and ammonium ion, and is preferably at least one selected from chlorine compounds and bromine compounds. More preferably, it is a bromine compound. It should be noted that a halogen compound containing water of crystallization has a similar effect that may be used after dehydration treatment.

Examples of the chlorine compound include organic chlorine compounds such as alkyl chlorides and organic acid chlorides, alkaline earth metals, and transition metal chlorides. Concretely, chlorine, magnesium chloride, calcium chloride, strontium chloride, barium chloride, manganese chloride, cobalt chloride, zinc chloride, aluminum chloride, hydrogen chloride, benzyl chloride, benzal chloride, benzoyl chloride, dichloroethane, tetrachloroethane, acetyl chloride, etc. Is exemplified.

Examples of the bromine compound include organic bromine compounds such as alkyl bromide and organic acid bromide, and bromides of alkaline earth metals and transition metals. Specifically, bromine, magnesium bromide, calcium bromide, strontium bromide, barium bromide, manganese bromide, cobalt bromide, zinc bromide, aluminum bromide, hydrogen bromide, ammonium bromide, benzyl bromide, Examples include benzal bromide, benzoyl bromide, dibromoethane, tetrabromoethane, acetyl bromide and the like. It is preferably at least one selected from zinc bromide, magnesium bromide and bromine.

The amount of the halogen compound to be used is 0.0001 to 0.5 times, preferably 0.001 to 0.1 times the mole of the alkyl-substituted aromatic compound as the raw material.

The zinc compound used in the present invention is not particularly limited. For example, sulfate, nitrate, formate, acetate, propionate, phosphate, oxalate, carbonate,
Hydroxide, oxide, bromide, chloride, naphthenate, benzoate, stearate, acetylacetonate and the like.

The amount of the zinc compound to be used is 0.0001 to 0.5 mol times, preferably 0.001 to 0.1 mol times, relative to the starting alkyl-substituted aromatic compound.

The alkyl group-substituted aromatic compound used in the present invention includes an aromatic compound substituted with one alkyl group, or an aromatic ring substituted with an alkyl group, an allyl group, an aryl group, a halogen group, a nitro group, Examples thereof include an aromatic compound in which at least one substituent selected from a cyano group, an amino group, an amide group, an alkoxyl group, an acyl group, a carboxyl group, a formyl group, an acyloxy group, a hydroxyl group, and a hydroxymethyl group is directly bonded. .

A specific example is as follows. toluene,
Ethylbenzene, o-xylene, m-xylene, p-xylene, methyltoluene, diethylbenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, dichlorotoluene, o-nitrotoluene, m-nitrotoluene,
p-nitrotoluene, o-methoxytoluene, m-methoxytoluene, p-methoxytoluene, o-phenoxytoluene, m-phenoxytoluene, p-phenoxytoluene,
o-cyanotoluene, m-cyanotoluene, p-cyanotoluene o-toluic acid, m-toluic acid, p-toluic acid,
o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, o-cresol, m-cresol, p-cresol,
o-methylbenzyl alcohol, m-methylbenzyl alcohol, p-methylbenzyl alcohol and the like.

The carboxylic acid anhydride used in the present invention may be either an aromatic carboxylic acid anhydride or an aliphatic carboxylic acid anhydride, but is preferably an aliphatic carboxylic acid anhydride.

Specifically, acetic anhydride, chloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, propionic anhydride, n-butyric anhydride, iso-butyric anhydride, valeric anhydride, Examples thereof include maleic anhydride, succinic anhydride, phthalic anhydride, and benzoic anhydride.

The amount of the carboxylic acid anhydride to be used is 0.1 to 50 times, preferably 1 to 10 times the mole of the alkyl-substituted aromatic compound as a raw material. If the amount is too small, the effect of the present invention is reduced. If the amount is too large, the cost for recovering the unreacted carboxylic anhydride increases, which is industrially disadvantageous.

The oxygen-containing gas used in the present invention does not need to be pure oxygen, but oxygen diluted with an inert gas or the like.
For example, air may be used. The theoretical amount of oxygen required is 0.5 mole per mole of the alkyl-substituted aromatic compound to be reacted. A stoichiometric amount of oxygen may be present to increase the reaction rate, or pressurization may be performed to increase the solubility of oxygen in the reaction solution.

The present invention is carried out in a liquid phase reaction. The reaction temperature is usually 20-500 ° C, preferably 60-350 ° C.

The reaction pressure is not particularly limited, but must be set so as to keep the reaction system in a liquid phase. It goes without saying that the above reaction conditions are appropriately selected depending on the combination of the alkyl-substituted aromatic compound and the carboxylic anhydride to be reacted.

Although the present invention is generally practiced with only the reactants,
Of course, it is also possible to use a solvent. The solvent is not particularly limited, but it is necessary that the solvent be stable and inert to the reactants under the reaction conditions, for example, acetic acid, ethyl acetate, dimethyl sulfoxide, chloroethane, dichloroethane, hexane, cyclohexane, petroleum ether , Diethyl ether, tetrahydrofuran, benzene, chlorobenzene, nitrobenzene, carbon disulfide and the like. It is preferable that the amount of the solvent used is usually 1 to 10 times the total amount of the organic reactants to be reacted.

After completion of the reaction, the side-chain disiloxy compound of the alkyl-substituted aromatic compound formed from the reaction solution can be separated and purified by a usual distillation method, crystallization method, chromatography method or the like.

Alternatively, the side-chain disiloxy compound may be hydrolyzed before separation and purification, and may be taken out as an aromatic aldehyde. When the unreacted raw material is recovered, it can be used again for the disiloxylation reaction.

As described above, according to the present invention, the side chain of the alkyl-substituted aromatic compound can be diasiloxylated with high yield, which is extremely advantageous as an industrial process for producing the side-chain disiloxy compound of the alkyl-substituted aromatic compound. is there.

[0027]

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

Nacalai Tesque's special grade cerous (III) acetate monohydrate and Katayama Chemical's manganese (II) acetate tetrahydrate as heavy metal compounds, magnesium bromide (MgBr2) from ALDRICH as halides, Wako Pure Chemical Industries, Ltd. Zinc bromide (Z
nBr2) and bromine, ammonium bromide and magnesium bromide hexahydrate (MgBr2.6H2O) manufactured by Katayama Chemical, and primary zinc acetate (II) dihydrate manufactured by Katayama Chemical were used as zinc compounds.

The alkyl group-substituted aromatic compounds used in the examples were special grade m-chlorotoluene and m-chlorotoluene manufactured by Tokyo Chemical Industry.
A primary acetic anhydride manufactured by Kanto Chemical Co., Ltd. was used as a disiloxylating agent in cyanotoluene.

Example 1 In a glass three-necked flask, 53.65 g of acetic anhydride, 0.67 g of cerous (III) acetate monohydrate as a catalyst, and zinc acetate (I
I) 0.88 g of dihydrate and 0.73 g of magnesium (II) bromide were added, and air was blown at 150 ml / min under normal pressure while stirring at a speed of 500 rpm using a stirring blade. Subsequently, the flask was heated in an oil bath and kept at 90 ° C., and 16.08 g of m-chlorotoluene was added at once from the dropping funnel to start the reaction.
After the reaction for a predetermined time, analysis was performed by high performance liquid chromatography. The conversion of m-chlorotoluene, selectivity of m-chlorobenzyl acetate, and selectivity of m-chlorobenzylidene diacetate were calculated by the following formulas. The decomposition of acetic anhydride was represented by the number of moles of acetic anhydride (acetic anhydride decomposition rate) decomposed into acetic acid when 1 mol of m-chlorobenzylidene diacetate was formed.

[0031]

(Equation 1) Table 1 shows the reaction results.

Example 2 The procedure of Example 1 was repeated, except that 0.73 g of magnesium bromide was replaced by 0.90 g of zinc bromide.

Example 3 The procedure was as in Example 1, except that 0.73 g of magnesium bromide was replaced by 3.10 g of bromine.

Example 4 0.67 g of cerous (III) acetate monohydrate was added to manganese acetate
(II) Instead of 0.49 g of tetrahydrate, 107.3 g of 53.65 g of acetic anhydride
The procedure was performed in the same manner as in Example 1 except for the above.

Comparative Example 1 The procedure of Example 1 was repeated, except that 0.78 g of ammonium bromide was used instead of 0.73 g of magnesium bromide. Table 2 shows the reaction results.

Comparative Example 2 Magnesium bromide 0.73 g was replaced with magnesium bromide hexahydrate 1.1
The procedure was performed in the same manner as in Example 1 except that the amount was changed to 6 g.

Comparative Example 3 The procedure of Example 4 was repeated except that 0.73 g of magnesium bromide was replaced by 0.78 g of ammonium bromide.

Example 5 In a glass three-necked flask, 106.3 g of acetic anhydride, 0.67 g of cerous (III) acetate monohydrate as a catalyst, and zinc acetate (I
I) 0.88 g of dihydrate and 0.73 g of magnesium (II) bromide were added, and air was blown at 150 ml / min under normal pressure while stirring at a speed of 500 rpm using a stirring blade. Subsequently, the flask was heated in an oil bath to maintain the temperature at 90 ° C., and 14.9 g of m-cyanotoluene was added at once from the dropping funnel to start the reaction. After the reaction for a predetermined time, analysis was performed by high performance liquid chromatography. The conversion of m-cyanotoluene, the selectivity of m-cyanobenzyl acetate, and the selectivity of m-cyanobenzylidene diacetate were calculated by the following equations.

[0039]

(Equation 2) Table 1 shows the reaction results.

Comparative Example 4 Magnesium bromide 0.73 g was replaced with magnesium bromide hexahydrate 1.1
The procedure was performed in the same manner as in Example 4 except that the amount was changed to 6 g.

[0041]

[Table 1]

[0042]

[Table 2]

From the above results, in the method of using a heavy metal compound having an oxidation catalytic activity and a halogen compound as a catalyst in producing a side chain disiloxy compound of an alkyl group-substituted aromatic compound, the halogen compound is composed of water of crystallization and ammonium. It was found that when an ion-free material was used, the disiloxylation reaction could proceed efficiently and the decomposition of the carboxylic anhydride could be suppressed.

[0044]

According to the present invention, there is provided a method for using a heavy metal compound having an oxidation catalytic activity and a halogen compound as a catalyst, wherein the halogen compound does not contain water of crystallization and ammonium ion, and the alkyl group-substituted aromatic compound is used. By reacting an aromatic compound with a carboxylic anhydride in the presence of an oxygen-containing gas, a side-chain disiloxy compound can be produced in a high yield, and the decomposition of the carboxylic anhydride can be suppressed.

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Claims (9)

[Claims] 1. A method for producing a side-chain disiloxy compound of an alkyl-substituted aromatic compound by reacting an alkyl-substituted aromatic compound with a carboxylic anhydride in a liquid phase in the presence of an oxygen-containing gas. A method for using a heavy metal compound having a catalytic activity and a halogen compound, wherein the halogen compound does not contain water of crystallization and ammonium ion, and the side chain diacylation of an alkyl group-substituted aromatic compound. 2. The method for side-chain disiloxylation of an alkyl-substituted aromatic compound according to claim 1, wherein the alkyl-substituted aromatic compound is a methyl-substituted aromatic compound. 3. The method according to claim 2, wherein the methyl-substituted aromatic compound is m-phenoxytoluene, m-chlorotoluene or m-cyanotoluene. . 4. The method according to claim 1, wherein the carboxylic acid anhydride is an aliphatic carboxylic acid anhydride. 5. The alkyl-substituted aromatic compound according to claim 1, wherein the heavy metal compound is at least one compound selected from the group consisting of cobalt, manganese and cerium. Chain disiloxylation method. 6. The method according to claim 1, wherein the halogen compound is a bromine compound. 7. The method according to claim 6, wherein the bromine compound is at least one selected from zinc bromide, magnesium bromide and bromine. . 8. The method according to any one of claims 1 to 7, wherein the reaction is carried out in the presence of a zinc compound. 9. A side chain disiloxylation of an alkyl-substituted aromatic compound according to any one of claims 1 to 8, comprising a catalyst of a heavy metal compound having an oxidation catalytic activity and a halogen compound containing no water of crystallization and ammonium ions. Catalyst used in the method.