JPH0669986B2 - 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 catalytically reacting styrenes, carbon monoxide, alcohol 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 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. -152
42, JP 57-21342, JP 57-70836, JP 60-9224
2. JP-A-60-94940 and JP-A-60-126245 are proposed. However, these methods have not been sufficiently industrially satisfied in terms of reaction results and catalyst activity.

[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 styrene, carbon monoxide, alcohol and oxygen as raw materials, and Another object of the present invention is to provide a method for producing cinnamic acid esters by enhancing the catalytic activity of extremely expensive palladium and further enhancing the reaction results.

[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 component. Or its compound, a compound of copper or iron and a compound of an alkali metal, an alkaline earth metal or an aluminum group metal, as well as a compound of a halogen, play an important role, and a compound of a source of a copper or iron atom. And the halogen source compound are different from each other, or at least some of them are different compounds, the copper or iron atom source compound and the halogen atom source compound are the same compound. It was found that the catalytic activity and the reaction result were superior to those of the above. In addition, when the reaction is carried out in the presence of carbon dioxide using such a catalyst system, the activity of the catalyst is surprisingly higher than that in the case where carbon dioxide is not used, and the cinnamic acid has a high reaction result. The present invention has been reached by finding that esters can be obtained.

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. Or a cinnamic acid ester characterized by reacting in the presence of carbon dioxide using an iron compound, (3) a processed product of an alkali metal, an alkaline earth metal or an aluminum group metal and (4) a compound of a halogen Is a manufacturing method.

It should be noted that no example of carrying out the reaction by adding carbon dioxide to the reaction system as in the method of the present invention has been found yet. 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 have been described, and a report demonstrating the effects thereof 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.

As the alcohol, methanol, ethanol, propanol, butanol, pentanol, octanol, cyclopentanol, cyclohexanol, phenol,
Alcohols such as benzyl alcohol, ethylene glycol, polyethylene glycol and propylene glycol, which may have a substituent such as a halogen or an alkoxy group, which does not inhibit the reaction. 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 piroponate, 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 sulfolane or a sulfonic compound.

The palladium metal as the first component of the catalyst of the present invention or its compound is, for example, palladium metal supported on a carrier such as activated carbon, silica gel, alumina, silica-alumina, diatomaceous earth, magnesia, pumice, molecular sieves. , Or palladium metal such as palladium black, a divalentylideneacetone complex of palladium, or a zero-valent palladium complex such as tetrakis (triphenylphosphine) palladium, a palladium halide such as palladium chloride, palladium sulfate, palladium phosphate, nitric acid. Inorganic acid salts of palladium such as palladium, organic acid salts such as palladium acetate, propion palladium or palladium benzoate, bis (acetylacetonato) palladium, cyclooctadiene dichloropalladium, chloride Such as a compound of divalent palladium, such as palladium complexes such as radium benzonitrile complexes or palladium ammine complexes chloride.

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 per mol of the raw material styrene.
The range is ~ 1 x 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.

In addition, examples of iron compounds include iron halides such as iron chloride and iron bromide, inorganic salts of iron such as iron sulfate and iron nitrate, and iron oxalate, iron acetate, iron cinnamate, iron benzoate and the like. Examples include iron complex compounds such as organic acid salts and iron acetylacetonate, and the valence of iron in these compounds may be divalent or trivalent.

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. The same applies to iron compounds.

These copper or iron compounds are preferably dissolved in the reaction mixture, but it does not matter if some of them remain insoluble. The amount of the copper or iron compound used is in the range of 0.004 to 0.4 gram atom, preferably 0.008 to 0.3 gram atom, per reaction solution as copper or iron atom.

The third component of the catalyst of the present invention is a compound of alkali metal, alkaline earth metal or aluminum group metal,
Lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, gallium, indium, compounds of metals such as thorium are used, for example, hydroxides of these metals, halides, sulfuric acid, nitric acid, Salts of inorganic acids such as carbonic acid, salts of aliphatic or aromatic monovalent or polyvalent carboxylic acids such as acetic acid, propionic acid, butyric acid, caproic acid, cinnamic acid, benzoic acid and phthalic acid, or acetylacetone, benzezoyl Examples include β-diketones such as acetone, dibenzoylmethane, acetoacetic acid, and acetoacetic acid esters, β-keto acid or β-keto ester complexes, and the like.

The amount of these alkali metal, alkaline earth metal or aluminum group metal compounds used is such that the ratio of these metal atoms to the atoms of copper or iron present in the reaction mixture is 0.01 to 50. It is 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,
Vanadium trichloride, molybdenum chloride, manganese chloride, iron chloride, iron iodide, platinum chloride, copper chloride, copper bromide, zinc chloride, tin chloride, antimony chloride, etc. Halides are mentioned, and further, phosgene, carbonic acid derivatives containing halogen such as methyl chloroformate, tertiary alkyl halides such as tert-butyl chloride and tert-butyl bromide, or acid halides such as acetyl chloride and benzoyl bromide. Examples thereof include organic halides that easily generate halogen 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 a palladium halide is used as the first component of the catalyst and / or an alkali metal, alkaline earth metal or aluminum group metal halide is used as the third component, the fourth component of the catalyst is added to these.
All or part of the halogen compound of the component may also be used, and when copper halide or iron halide is partially used as the second component of the catalyst, it may be added to the halogen compound of the fourth component of the catalyst. You may make it serve as all or one part.

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 argan.

The partial pressure of carbon monoxide is 50 atm (absolute pressure, the same shall apply hereinafter) 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 partial pressure of carbon dioxide with respect to the total pressure of the reaction is 10% (pressure ratio) to 98%, that is, the concentration of carbon dioxide in the reaction mixture gas is in the range of 10% by volume to 98%. If it is less than this, the effect of carbon dioxide will not appear, and if it is more than this, carbon monoxide and oxygen are diluted and the reaction is delayed. More preferably, it is in the range of 15% to 95%.

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 In a glass cylindrical container, 8.9 mg (0.050 mmol) of palladium chloride, 2.40 g (17.9 mmol) of copper (II) acetate monohydrate, 1.53 g (15.6 mmol) of potassium acetate, 0.32 g of phosphoryl chloride ( 2.1 mmol),
Then, 26.04 g (250 mmol) of styrene was taken and methanol was added to bring the total amount to 125 ml. This 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. Carbon monoxide with a partial pressure ratio of 8.4: 5.3: 86.3 to this autoclave,
A mixed gas of oxygen and carbon dioxide was stirred while being stirred so that the reaction pressure was 15 atm and the outlet gas amount was 1.5 l / min (standard state), and the mixture was reacted at 100 ° C. 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 it contained 83.0 mmol of styrene and 150.3 mmol of methyl cinnamate. The conversion of styrene was 66.8%, the selectivity of methyl cinnamate (yield based on styrene consumed) was 90.0%, and the yield of methyl cinnamate (yield based on charged styrene) was 60.1%. Palladium 1 which is a value showing the catalytic activity of palladium
The number of moles of cinnamic acid ester formed per gram atom (hereinafter referred to as Pd turnover ratio) was 3010.

Comparative Example-1 All were the same as in Example-1, except that the mixed gas in Example-1 was changed to a carbon dioxide-free mixed gas in which the partial pressure ratio of carbon monoxide: oxygen: nitrogen was 8.3: 5.2: 86.5. To react.

Styrene conversion 59.5%, methyl cinnamate selectivity and yield 81.2% and 48.3%, respectively, Pd turnover 24
The result was 20, which was inferior to Example-1.

Example 2 8.9 mg (0.050 mmol) of palladium chloride as a catalyst component, 1.88 g (9.4 mmol) of copper (II) acetate monohydrate, 3.0 g of basic aluminum acetate, and copper chloride (I
I) The same procedure as in Example 1 was carried out except that 0.42 g (3.1 mmol) was used.
%, The selectivity and yield of methyl cinnamate are 89.6 each.
% And 75.5%, and the Pd turnover ratio was 3780.

Comparative Example-2 All the same as in Example-1 except that the mixed gas in Example-2 was changed to a carbon dioxide-free mixed gas in which the partial pressure ratio of carbon monoxide: oxygen: nitrogen was 8.3: 5.2: 86.5. The conversion rate of styrene was 70.3%, and the selectivity and yield of methyl cinnamate were 82.8% and 58.2%, respectively.

Examples-3 to 5 The reaction was performed in the same manner as in Example-1 except that the catalyst shown in Table-1 was used instead of the catalyst in Example-1. The results are shown in Table-1.

Comparative Examples -3 to 4 All were reacted in the same manner as in Example-1 except that the catalyst shown in Table-1 was used instead of the catalyst in Example-1.

Comparative Example-3 is an example using a catalyst containing no halogen compound, and Comparative Example-4 is an example using a catalyst in which the same compound also serves as a halogen compound of a copper compound. The results are shown in Table-1.

Example-6 and Comparative Example-5 In place of the mixed gas in Example 1, a mixed gas having a partial pressure ratio of carbon monoxide: oxygen: carbon dioxide: nitrogen shown in Table 2 was used, except that the mixed gas was used as in Example 1. The same reaction was performed. The results are shown in Table 2 together with those of Example 1 and Comparative Example 1.

[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 to be used can be small, and the reaction results are extremely high, which is an advantageous scalp. It becomes an industrial production method of acid esters.

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. Or an iron compound,
(3) using an alkali metal, alkaline earth metal or aluminum group metal compound and (4) a halogen compound in the presence of carbon dioxide having a partial pressure ratio of 10% to 98% to the total pressure of the reaction. A method for producing cinnamic acid esters, which is characterized.