JPH0761982B2 - Method for producing cinnamic acid esters - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing cinnamic acid esters which are important as raw materials for perfumes, agricultural chemicals, photosensitive resins and the like.

More specifically, the present invention relates to a method for producing cinnamic acid esters by the catalytic reaction of styrenes, carbon monoxide, alcohols and oxygen.

[Conventional technology]

Conventionally, cinnamic acid has been produced on a small scale by a reaction using a derivative of benzaldehyde and acetic acid as a main raw material. However, this method is not industrially satisfactory because it uses relatively expensive raw materials. Therefore, as a method of using a cheaper raw material, a method of reacting styrenes, carbon monoxide, alcohol and oxygen in the presence of a catalyst to produce cinnamic acid esters has been attempted. −15
242, JP-A-57-70836, JP-A-60-94940, JP-A-60-1
26245 etc. have been proposed. In these methods, a compound of palladium metal or its compound and copper is essential as a catalyst component, and various compounds are added as catalyst components in order to further improve the reaction results. However, these methods have not yet been sufficiently industrially satisfied with the reaction results and the activity of the catalyst.

As a more effective proposal, JP-A-60-92242 discloses a method of using palladium metal or a compound thereof, a salt of copper or iron and a compound of a rare earth element as a catalyst component. However, the catalyst activity is not sufficient even by the method of this publication, and the yield and selectivity are still unsatisfactory.

[Problems to be solved by the invention]

An object of the present invention is to provide a more advantageous industrial production method of cinnamic acid esters using styrenes, carbon monoxide, alcohol and oxygen as raw materials, and more specifically, a catalyst activity of extremely expensive palladium. To provide a method for producing cinnamic acid esters by further improving the reaction performance.

[Means for solving problems]

The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and in a method for catalytically producing cinnamic acid esters from styrenes, carbon monoxide, alcohols and oxygen, palladium metal is used as a catalyst portion. Or, knowing that the compound, the compound of copper and the compound of the rare earth element, and the compound of halogen play an important role,
Further, when the copper atom donor compound and the halogen atom donor compound are different from each other, or at least part of them are different compounds, the copper atom donor compound and the halogen atom donor compound are It has been found that the catalytic activity and reaction performance are superior to the case of using the same compound. In addition, it is surprising that the reaction is carried out by adding a specific concentration of carbon dioxide using such a catalyst system. The inventors have found that the activity of the catalyst is higher than that in the case where carbon dioxide is not used, and that cinnamate esters can be obtained with high reaction results, and thus reached the present invention.

That is, the present invention relates to a method for producing a corresponding cinnamic acid ester by catalytically reacting styrenes, carbon monoxide, alcohol and oxygen, wherein (1) palladium metal or its compound and (2) copper are used as catalysts. The compound of (3) rare earth element and the compound of (4) halogen are used, and the reaction is carried out by adding carbon dioxide so that the concentration of carbon dioxide in the reaction mixture gas is 15% by volume to 95% by volume. And a method for producing cinnamic acid esters.

It should be noted that no example has been found in which the reaction was carried out by adding a specific concentration of carbon dioxide to the reaction system as in the method of the present invention. Although there is an example suggesting carbon dioxide merely as an example of an inert gas for diluting oxygen (for example, Japanese Patent Application Laid-Open No. 56-22749), no examples are described, and a report demonstrating the effect thereof is provided. Has not been done yet.

Therefore, the method of the present invention in which carbon dioxide is used not as a simple oxygen diluent but by using carbon dioxide exerts a special effect on the activity of the catalyst and the reaction results is completely unpredictable from the conventional known methods. That's the method.

The styrenes used in the method of the present invention include:
Specifically, styrene, α-methylstyrene, β-methylstyrene, α-ethylstyrene, β-ethylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, m-ethylstyrene, p-ethyl. Styrene, p-tert-butylstyrene, p-isopropyl-β-methylstyrene and other styrene alkyl derivatives, or p-chlorostyrene, p-methoxystyrene, 3,4-dimethoxystyrene and other substituents that do not interfere with the reaction Examples thereof include styrene derivatives having an aromatic ring.

Examples of alcohols include alcohols such as methanol, ethanol, propanol, butanol, pentanol, octanol, cyclopentanol, cyclohexanol, phenol, benzyl alcohol, ethylene glycol, polyethylene glycol and propylene glycol, which are halogen or alkoxy groups. It may have a substituent which does not inhibit the reaction such as. The amount of these alcohols used is 0.5 to 1 with respect to 1 mol of styrenes.
The amount is 00 parts by mole, and may be used not only as a reaction raw material but also as a solvent.

Further, the method of the present invention may be carried out in a solvent that does not inhibit the reaction. Examples of such a solvent include n-hexane and n-hexane.
Aliphatic or alicyclic hydrocarbons such as pentane and cyclohexane, aromatic hydrocarbons such as benzene, toluene, p-xylene, ethylbenzene, chlorobenzene and dichlorobenzene or substituted compounds thereof, diethyl ether, dipropyl ether, ethyl Ethers such as methyl ether, ethyl phenyl ether, diphenyl ether, tetrahydrofuran, dioxane, ethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, ketones such as acetone, ethyl methyl ketone, acetophenone, methyl acetate, ethyl acetate, methyl propionate, etc. Esters, propylene carbonate, carbonates such as dimethyl carbonate, amide compounds such as dimethylformamide, acetonitrile, benzonitrite Nitriles etc., aromatic nitro compounds such as nitrobenzene, and the like sulfone compounds such as sulfolane.

Examples of the palladium metal or its compound which is the first component of the catalyst of the present invention include palladium metal on activated carbon,
Silica gel, alumina, silica alumina, diatomaceous earth,
Supported on a carrier such as magnesia, pumice, molecular sieves, palladium metal such as palladium black, dibenzylideneacetone complex of palladium or zero-valent palladium complex such as tetrakis (triphenylphosphine) palladium, palladium chloride, etc. Palladium halides, palladium inorganic salts such as palladium sulfate, palladium phosphate, palladium nitrate, organic acid salts such as palladium acetate, palladium propionate or palladium benzoate, bis (acetylacetonato) palladium, cycloocta A divalent palladium compound such as a palladium complex such as diene chloropalladium, a palladium chloride benzonitrile complex or a palladium chloride ammine complex may be used.

The amount of these palladium metals or their compounds used is
The amount of palladium metal atom is 0.1 gram atom or less, preferably 5 × 10 ⁻⁶ to 1 mol of styrene as a raw material.
It is in the range of 1 × 10 ^-2 gram atom.

Examples of the copper compound which is the second component of the catalyst of the present invention include copper halides such as copper chloride and copper bromide, copper carbonate such as copper carbonate and copper nitrate, copper acetate, copper propionate and copper stearate. , Copper cinnamate, copper benzoate and other organic acid salts of copper, or copper acetylacetonate, copper benzoylacetonate and other complex compounds of copper, and the valence of copper in these compounds is monovalent. Or may be bivalent.

These copper compounds can be used alone or in admixture of two or more, and in particular, when copper halide is used as a mixture of two or more with other copper compounds, excellent reaction results can be obtained. can get.

These compounds are preferably dissolved in the reaction mixture, but it does not matter if some of them remain insoluble.
The amount of these copper compounds used is the reaction liquid 1 as copper atoms.
It is in the range of 0.004 to 0.4 gram atom per
The range is from 0.008 to 0.3 gram atom.

As the compound of the rare earth element which is the third component of the catalyst of the present invention, compounds of lanthanoid element such as scandium, yttrium and lanthanum, cerium, neodymium, europium and dysprosium are used. For example, cesium oxide, yttrium oxide, lanthanum oxide, Examples include oxides of samarium oxide, hexapraseodymium oxide 11 and the like, mixtures of oxides of several rare earth elements, or complex oxides.Also, neodymium chloride, samarium oxide, halides such as cerium bromide, yttrium nitrate, and nitric acid. Examples thereof include inorganic acid salts such as cesium, cesium sulfate, and neodymium sulfate, and organic acid salts such as cesium acetate, lanthanum acetate, and cerium benzoate, and various compounds depending on the valence of the rare earth element.

The amount of these rare earth element compounds used is such that the ratio of rare earth atoms to copper atoms present in the reaction mixture is 0.01 to
It is 50, preferably 0.05 to 10.

Examples of the halogen compound as the fourth component of the catalyst of the present invention include halogen molecules such as chlorine, bromine or iodine and solutions thereof, hydrogen halides such as hydrogen chloride, hydrogen bromide and hydrogen iodide and solutions thereof, and Phosphorus halides such as phosphorus chloride, phosphorus pentachloride, phosphorus tribromide, phosphorus pentabromide, phosphorus oxyhalides such as phosphoryl chloride and phosphoryl bromide, sulfur oxyhalides such as thionyl chloride and thionyl bromide, Tellurium halides such as tellurium chloride and tellurium tetrabromide, sodium chloride, potassium bromide, calcium chloride, titanium chloride, zirconium bromide,
Metal halide or oxyhalogen such as vanadium trichloride, molybdenum chloride, manganese chloride, iron chloride, iron iodide, platinum chloride, copper chloride, copper bromide, zinc chloride, tin chloride, antimony chloride according to the valence of the metal In addition, phosgene, carbonic acid derivatives containing halogen such as methyl chloroformate, tertiary alkyl halides such as tert-butyl chloride and tert-butyl bromide, or halogen such as acid halides such as acetyl chloride and benzoyl bromide. Examples thereof include organic halides that easily generate ions.

Of these, chlorine, hydrogen chloride, hydrogen bromide, phosphorus pentachloride,
Phosphoryl chloride, vanadium trichloride oxide, chromium trichloride, manganese chloride, iron chloride, iron bromide, copper chloride, copper bromide,
Zinc chloride, tin chloride, bismuth chloride and the like are preferable.

These halogen compounds may be used alone or in combination of two or more. When using a palladium halide as the first component of the catalyst and / or a rare earth element halide as the third component, these may also serve as all or part of the halogen compound of the fourth component of the catalyst. When part of the copper halide is used as the second component of the catalyst, it may also serve as all or part of the halogen compound of the fourth component of the catalyst.

The amount of the halogen compound used is 0.004 to 0.8 gram atom, and preferably 0.008 to 0.6 gram atom, as the halogen atom per reaction mixture solution.

In the method of the present invention, the gas components are carbon monoxide, oxygen and carbon dioxide, but these gases are nitrogen,
It may be diluted with an inert gas such as argon.

The partial pressure of carbon monoxide is 50 atm (absolute pressure, the same applies below) or less, and preferably 0.005 to 40 atm. The partial pressure of oxygen is 50 atm or less, preferably 0.002 to 30 atm. Air can also be used as the oxygen source. The partial pressure of carbon dioxide is 500 atm or less, preferably 0.1 to
It is 300 atm. The preferred partial pressure of carbon dioxide with respect to the total pressure of the reaction is 15% (pressure ratio) to 95%, that is, the concentration of carbon dioxide in the reaction mixture gas is 15% to 95% by volume.
Is the range. At 15% by volume, the effect of carbon dioxide ceases to appear, and when it exceeds 95% by volume, carbon monoxide and oxygen are diluted and the reaction becomes slow.

Carbon monoxide, oxygen, and carbon dioxide, and an inert gas when further used may be charged in a required amount in a batch in a reactor, or a method of continuously or intermittently adding a required gas, or those Alternatively, the mixed gas may be continuously or intermittently circulated. Among these, the method of adding and the method of distributing are more preferable methods.

The mixed gas to be subjected to the reaction may be one newly adjusted each time, but it may be used repeatedly after adjusting the concentration of each component gas as needed for the residual gas once used in the reaction or the exhaust gas in the method of flowing. it can.

In the method of the present invention, the reaction system may be either a batch system or a continuous flow system.

The total pressure of the reaction in the method of the present invention depends on the carbon monoxide used, oxygen and carbon dioxide, or the partial pressure of the inert gas, but is usually 500 atm or less, preferably 1 to 300.
Atmospheric pressure. The reaction temperature is room temperature to 200 ° C, preferably 40 to 1
60 ° C. The reaction time varies depending on the reaction conditions, but is usually 0.01
~ 24 hours, preferably 0.05-10 hours.

After the completion of the reaction, the cinnamic acid ester can be separated from the reaction product solution by a conventional separation method such as distillation or extraction.

Example 1 11.23 mg (0.050 mmol) of palladium (II) acetate and copper (II) acetate monohydrate 1.8 in a cylindrical glass container.
7 g (9.37 mmol), cerium (III) acetate monohydrate 5.23 g (15.6 mmol), copper (II) chloride 0.42 g (3.12 mmol), and styrene 26.04 g (25
0.0 mmol), and add methanol to bring the total volume to 125 ml.
And The glass container was placed in a 500 ml autoclave in which the stirring blade was made of glass and the temperature measuring tube was also protected by glass. The autoclave has a partial pressure ratio of 8.1: 5.3: 8.
A mixture gas of carbon monoxide, oxygen, and carbon dioxide of 6.6 is stirred at 100 ° C while being stirred while passing a reaction pressure of 10 atm and an outlet gas amount of 1.0 liter / min (standard state).
And reacted for 3 hours. During this time, the outlet gas was discharged through a water-cooled reflux condenser. After completion of the reaction, the reaction liquid cooled and taken out was analyzed by high performance liquid chromatography to find that styrene was 16.8 mmol and methyl cinnamate was 215.0.
It was contained in millimoles. The conversion rate of styrene is 93.3%, and the selectivity of methyl cinnamate (yield based on styrene consumption) is
The yield of 92.2% and methyl cinnamate (the yield based on the charged styrene) was 86.0%. The number of moles of cinnamic acid esters formed per gram atom of palladium (hereinafter referred to as Pd turnover rate), which is a value indicating the catalytic activity of palladium, is 43.
It was 00.

Comparative Example-1 All of Example-1 except that the mixed gas in Example-1 was changed to a mixed gas in which the partial pressure ratio of carbon monoxide: oxygen: nitrogen was 8.2: 5.3: 86.5 and did not contain carbon dioxide. The same reaction was performed.

Styrene conversion 80.3%, methyl cinnamate selectivity and yield 88.6% and 71.1%, respectively, Pd turnover 3560
The results were inferior to those of Example-1.

Examples-2, 3 and Comparative Examples-2, 3 are all Examples-except for using the mixed gas shown in Table-1.
Same as 1. The results are shown in Table 1 together with Example-1 and Comparative example-1.

Example-4 8.9 mg of palladium (II) chloride (0.050
), Copper (II) acetylacetonate 3.27 g (12.5 mmol), lanthanum acetate 4.93 g (15.6 mmol), hydrogen chloride in methanol (concentration 1.25 N) 5.0.
ml (6.3 mmol as hydrogen chloride), the total reaction pressure was 2
All were the same as in Example 1 except that the pressure was 0 atm, and the conversion of styrene was 86.2%, the selectivity and the yield of methyl cinnamate were 90.4% and 77.9%, respectively, and the Pd turnover ratio was 3900. .

Comparative Example-4 When a partial pressure ratio of carbon monoxide: oxygen: nitrogen was 8.2: 5.2: 86.6 and a mixed gas containing no carbon dioxide was used, the reaction was performed in the same manner as in Example-4. The conversion was 70.3%, the methyl cinnamate selectivity and yield were 82.5% and 58.0%, respectively, and the Pd turnover was 2900, which were inferior to those of Example-4.

Example-5 A reaction was conducted in the same manner as in Example-1 except that 0.2 g of 5% palladium carbon was used in place of palladium acetate in Example-1, and the conversion of styrene was 85.2% and that of methyl cinnamate was 8%. The selectivity and yield were 85.7% and 73.0%, respectively.

Examples-6 to 9 The reaction was performed in the same manner as in Example-1 except that the catalysts shown in Table-2 were used instead of the catalyst in Example-1. The results are shown in Table-2.

Comparative Examples-5 to 6 All were reacted in the same manner as in Example-1 except that the catalysts shown in Table-2 were used instead of the catalyst in Example-1.

Comparative Example-5 is an example in which a catalyst not containing a compound of a rare earth element and a halogen compound is used, and Comparative Example-6 is an example in which a catalyst in which the same compound serves as a copper compound and a halogen compound is used. The results are shown in Table-2.

[Effects of the Invention] According to the method of the present invention, since a high catalytic activity of palladium can be obtained under mild conditions, the amount of expensive palladium used can be small, and the reaction results are extremely high, which is extremely advantageous. It becomes an industrial production method of cinnamic acid esters.

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Claims (1)

[Claims] 1. A method for producing a corresponding cinnamic acid ester by catalytically reacting styrenes, carbon monoxide, alcohol and oxygen, wherein (1) palladium metal or its compound and (2) copper are used as catalysts. Using a compound, (3) a compound of a rare earth element and (4) a compound of a halogen,
The concentration of carbon dioxide in the reaction mixture gas is 15% by volume or
A method for producing cinnamic acid esters, which comprises reacting by adding carbon dioxide to 95% by volume.