JPH0479331B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing cinnamic acid esters by reacting styrenes, carbon monoxide, alcohol and oxygen. Cinnamic acid esters are widely used as fragrances or raw materials thereof because of their aromatic properties, and are also important compounds as raw materials for agricultural chemicals and photosensitive resins. (Prior Art) Conventionally, cinnamic acid has been produced on a small scale by a reaction using benzaldehyde and acetic acid derivatives as main raw materials. However, since this method uses expensive raw materials, it is not an industrially preferred method. As a method using cheaper raw materials, several methods have been proposed in which cinnamic acid esters are produced by reacting styrenes with carbon monoxide, alcohol, and oxygen in the presence of a catalyst (for example, 1987-70836, 1987-71039, 1987-71039, 1983-
15242 etc.). (Problems to be Solved by the Invention) However, none of these methods has achieved industrially satisfactory reaction results and catalytic activity. The purpose of the present invention is to provide a more advantageous industrial production method for cinnamic acid esters using styrenes, carbon monoxide, alcohol, and oxygen as raw materials, specifically to develop the activity of the main catalyst to a high degree and achieve high reaction results. An object of the present invention is to provide a method for producing cinnamic acid esters. (Means for Solving the Problem) In order to achieve the above object, the inventors of the present invention have continued to make intensive studies and found that conventional techniques, such as Japanese Patent Application Laid-open No. 57-70836 and Japanese Patent Application Laid-Open No. 56-15242, As shown in many examples, when using only cupric chloride as the cocatalyst copper salt, if the amount of copper atoms to be used is selected within a preferable range, the amount of chlorine atoms to be used should be within the same range. It was therefore found that this is one of the reasons why an industrially satisfactory catalyst system cannot be obtained, since the range is limited and it is not possible to arbitrarily select a preferable range. Further studies revealed that copper and chlorine are important co-catalysts when producing corresponding cinnamic acid esters by reacting carbon monoxide, alcohol and oxygen with palladium metal or its compounds as the main catalyst. and the need for each of these sources to be separate compounds, or at least in part separate compounds, and for the amounts used of each to be selected within a specific range, i.e., palladium metal or its compound as the main catalyst, and palladium metal or its compound as the main catalyst; An organic acid salt of copper, a dichlorine compound, and a compound of manganese or zinc are used as catalysts, the amount of copper atoms per liter of reaction mixture is set in a specific range, and the gram atomic ratio of chlorine atoms to copper atoms is The present inventors have discovered that by setting the amount within a specific range, high activity of the main catalyst can be obtained and cinnamic acid esters can be produced with high reaction results, and the present invention has been achieved. The present invention uses palladium metal or its compound as a main catalyst and 1 as a co-catalyst when producing corresponding cinnamic acid esters by reacting styrenes, carbon monoxide, alcohol and oxygen.
Using an organic acid salt of copper, a dichloride compound, and a manganese or zinc compound, the copper atoms in the reaction mixture are adjusted to 0.004 to 0.4 gram atom/g, and the chlorine atom to copper atom ratio is 2. This is a method for producing cinnamic acid esters, characterized in that the reaction is carried out as less than 100%. Specifically, the styrenes used in the method of the present invention include styrene, α-methylstyrene, β-methylstyrene, α-ethylstyrene, β-ethylstyrene, o-methylstyrene,
m-methylstyrene, p-methylstyrene, m-
Ethylstyrene, p-ethylstyrene, p-ter
Alkyl derivatives of styrene such as shari-butylstyrene and β-methyl-p-isopropylstyrene, or substituents on the aromatic ring that do not inhibit the reaction such as p-chlorostyrene, p-methoxystyrene, 3,4-dimethoxystyrene, etc. Examples include styrene derivatives. Alcohols include methanol, ethanol, propanol, butanol, pentanol,
Alcohols such as octanol, cyclopentanol, cyclohexanol, phenol, benzyl alcohol, ethylene glycol, polyethylene glycol, and propylene glycol, which may have substituents such as halogen or alkoxy groups that do not inhibit the reaction. . The amount of these alcohols used is 1 mole of styrene.
~100 mole parts, and may be used not only as a reaction raw material but also as a solvent. The partial pressure of carbon monoxide is from normal pressure to 50 kg/cm ² G, and if the partial pressure is higher than this, the corresponding by-products of phenylsuccinic acid diesters will increase. More preferably, the pressure is normal pressure to 40 kg/cm ² G. The partial pressure of oxygen is normal pressure to 50 Kg/cm ² , and as the partial pressure increases, by-products increase. More preferably, the pressure is normal pressure to 30 kg/cm ² G. The oxygen source may be pure oxygen or air. In order to avoid an explosive range, it is preferable to use the mixed gas of carbon monoxide and oxygen diluted with an inert gas such as nitrogen or argon. The required amount of the mixed gas of carbon monoxide, oxygen, and inert gas may be charged into the reactor all at once, or may be added intermittently. Further, a method of constantly circulating or a method of distributing intermittently may be used. In the reaction according to the method of the present invention, the alcohol as a raw material can essentially be used as a solvent, but any solvent can also be used as long as it does not inhibit the reaction. Examples of such solvents include ethers such as diethyl ether, dipropyl ether, methyl ethyl ether, phenylethyl ether, diphenyl ether, tetrahydrofuran, dioxane, ethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether, acetone, methyl ethyl ketone, and acetophenone. Ketones such as, esters such as methyl acetate, ethyl acetate, methyl propionate, benzene, toluene,
Aromatic hydrocarbons or substituted compounds thereof such as p-xylene, ethylbenzene, chlorobenzene, dichlorobenzene, aliphatic or alicyclic hydrocarbons such as n-hexane, n-pentane, cyclohexane, propylene carbonate, dimethyl carbonate, etc. carbonates, nitriles such as acetonitrile and benzonitrile, nitro compounds such as nitrobenzene and nitromethane, amide compounds such as dimethylformamide, and sulfone compounds such as sulfolane. Palladium metal or its compound which is the main catalyst of the present invention may be palladium black, metal palladium supported on a carrier such as activated carbon, asbestos or silica alumina, or zero-valent palladium complex such as dibenzylidene acetone complex.
Palladium metal or compound with a valence of Examples include divalent palladium compounds such as palladium complexes such as nitrile complexes, palladium chloride pyridine complexes, and palladium chloride ammine complexes. The amount of palladium metal or its compound used is in the range of 0.00001 to 0.1 gram atom, preferably 0.00005 to 0.01 gram atom, per mole of styrene as a raw material. Cocatalysts in the process of the invention are organic acid salts of copper, chlorine compounds and compounds of manganese or zinc. The first component, organic acid salts of copper, include copper aliphatic carboxylates such as copper acetate, copper propionate, and copper stearate, aromatic copper carboxylates such as copper benzoate, and copper acetylacetonate. Examples include salts of organic anions of copper such as . These organic acid salts of copper can be used alone or in combination of two or more. Further, it is preferable that these organic acid salts of copper be dissolved in the reaction mixture, but it is also possible for some of them to remain insoluble. The amount of these organic acid salts of copper used is 0.004 to 0.4 gram atoms of copper per liter of the reaction mixture. However, when copper chloride is used as the chlorine compound as a co-catalyst, the copper atom of this compound is also included in the above range and an organic acid salt of copper is used. When the amount of copper is less than this range, almost no reaction occurs, and when it is more than this range, by-products increase. More preferably,
0.008 to 0.3 gram atoms per liter of reaction mixture. The chlorine compound, which is the second component of the cocatalyst, is
Chlorine or its solution, hydrogen chloride or its solution,
amine hydrochloride, and chlorine-containing compounds that tend to generate chlorine ions, such as tert-butyl chloride, phosgene, phosphorus pentachloride, phosphorus oxytrichloride, or titanium, vanadium, manganese, iron, copper, zinc, or Examples include chloride or oxychloride depending on the valence of metal such as aluminum. These chlorine compounds may be used alone or in combination of two or more. These chlorine compounds are used in an amount that is less than 2, ie, more than 0 and less than 2, in terms of the ratio of chlorine atoms to copper atoms present in the reaction mixture. However, when using palladium chloride as the main catalyst,
Although it is usually a trace amount, it is within the range of the amount including the chlorine atoms from palladium chloride. When the ratio of chlorine atoms to copper atoms is 0, that is, when no chlorine atoms are present, almost no reaction occurs. When this ratio increases to 2 or more, by-products increase and the selectivity and yield of cinnamate esters decrease. Preferably it is 0.02-1.99 gram atomic ratio. Examples of the manganese or zinc compound which is the third component of the cocatalyst in the method of the present invention include manganese or zinc chloride, acetate, propionate,
Other examples include salts of fatty acid carboxylic acids such as stearate, salts of aromatic carboxylic acids such as benzoate, and salts of organic anions such as acetylacetonate. It is preferable that these compounds are dissolved in the reaction mixture, but there is no problem even if some of them are insoluble. The amount of these manganese or zinc compounds used is such that the ratio of manganese or zinc metal atoms to copper atoms present in the reaction mixture is from 0.05 to 50, more preferably from 0.1 to 10. Two or more kinds of manganese or zinc compounds can also be used at the same time. The manganese or zinc chloride can simultaneously satisfy all or part of the chlorine compound as the second component of the cocatalyst and the manganese or zinc compound as the third component. The total pressure of the reaction according to the method of the present invention is from normal pressure to 500
Kg/cm ² G, preferably normal pressure to 300 Kg/cm ² G,
The reaction temperature is room temperature to 200°C, preferably 40 to 160°C. The reaction time varies depending on the reaction conditions, but is usually 0.01 to 24 hours, preferably 0.05 to 10 hours. After the reaction is completed, the cinnamic acid esters can be separated from the reaction product liquid by a commonly used separation method such as distillation or extraction. (Actions and Effects of the Invention) According to the method of the present invention, a preferable range of the amount of copper atoms serving as a cocatalyst and a preferable range of the ratio of chlorine atoms to copper atoms can be given to the reaction system, and the reaction can be carried out within these ranges. This makes it possible to produce cinnamic acid esters with surprisingly high reaction results using an extremely small amount of palladium main catalyst, making it an industrially extremely advantageous method for producing cinnamic acid esters. . (Example) Next, the method of the present invention will be explained in more detail by showing Examples and Comparative Examples. Example 1 Palladium acetate 11.23 in a glass cylindrical container
milligram (0.050 mmol), cupric acetate monohydrate 2.50 g (12.5 mmol), and manganous acetate tetrahydrate 3.82 g (15.6 mmol), add a small amount of methanol, and then styrene. Weigh out 26.04 grams (250.0 mmol) and add a solution of hydrogen chloride gas absorbed in methanol (concentration approximately 0.5 to 2N) whose concentration was measured just beforehand so that the amount of hydrogen chloride becomes 6.25 mmol. Then, methanol was further added to bring the total volume to 125 ml. The amount of copper atoms per liter of reaction mixture is 0.10
It is a gram atom, and the gram atomic ratio of chlorine atom to copper atom is 0.50. This glass container is 500ml
was placed in an autoclave. The stirring blades of the autoclave are made of glass, and the temperature measuring tube is also protected by glass. A mixed gas with a partial pressure ratio of carbon monoxide:oxygen:nitrogen of 10:5:85 was introduced into the autoclave at a total pressure of 50 kg/cm ² G at a rate of 1.2/min (standard condition) at the outlet while stirring was continued at 100°C. The reaction was allowed to proceed for 3 hours.
During this time, the outlet gas was discharged through a reflux condenser. After the reaction was completed, the reaction solution was cooled and depressurized, and the taken out reaction solution was analyzed by liquid chromatography and found to contain 12.25 mmol of styrene, 217.8 mmol of methyl cinnamate, and 8.25 mmol of by-product dimethyl phenylsuccinate. Styrene conversion rate 95.1%,
The selectivity of methyl cinnamate (yield based on consumed styrene) was 91.6%, the yield of methyl cinnamate (yield based on charged styrene) was 87.1%, and the selectivity of dimethyl phenylsuccinate was 3.5%. The yield is
It was 3.3%. The number of moles of cinnamic acid ester produced per gram atom of palladium of the main catalyst (hereinafter abbreviated as Pd turnover) was 4,360. Example 2 Palladium chloride 8.87 mg (0.050 mmol), cupric acetate monohydrate 2.19 g (10.97 mmol), cupric chloride 0.206 g (1.53 mmol)
After taking 3.82 g (15.6 mmol) of manganous acetate tetrahydrate and adding some methanol, 26.04 g (250.0 mmol) of styrene was added, and methanol was further added to bring the total volume to 125 ml. The total amount of copper atoms per reaction mixture is 0.10
gram atoms, and the gram atomic ratio of total chlorine atoms to total copper atoms is 0.25. Example 1
When the reaction was carried out in the same manner as above, the conversion rate of styrene was 94.3.
%, selectivity and yield of methyl cinnamate are respectively
They were 92.8% and 87.5%. The Pd rotation rate was 4380. Below, the range of the amount of copper atoms per reaction mixture is shown based on comparative examples and examples. Comparative Examples 1 and 2, Examples 3, 4 and 5 All the same as Example 2 except that the amounts of cupric acetate monohydrate and cupric chloride used in Example 2 were changed to the amounts shown in Table 1. The reaction was carried out in the same manner.
The ratio of chlorine atoms to copper atoms is all 1.0.
The results are shown in Table 1. Next, the range of the gram atomic ratio of chlorine atoms to copper atoms will be shown based on comparative examples and examples. Comparative Examples 3 and 4 and Examples 6 to 9 All the same procedures as in Example 2 were carried out except that the amounts of cupric acetate monohydrate and cupric chloride and the type of palladium compound were changed as shown in Table 2. The reaction was carried out in the same manner as in Example 2. All amounts of copper atoms per liter of reaction mixture are 0.1 gram atoms. The results are shown in Table 2 together with the results of Examples 2 and 4 mentioned above.

【table】

[Table] Example 10 5% instead of palladium chloride in Example 2
Using 180 mg (0.085 milligram atom of palladium) of Pd/C (5% by weight of palladium supported on activated carbon), 1.89 grams (9.47 mmol) of cupric acetate monohydrate, and cupric chloride. The reaction was carried out in the same manner as in Example 2, except that the amount was changed to 419 milligrams (3.12 mmol). The amount of copper atoms per liter of reaction mixture is 0.1 gram atoms and the ratio of chlorine atoms to copper atoms is 0.50. The styrene conversion rate was 86.4%, the selectivity of methyl cinnamate was 79.6%, and the yield was 68.8%. Example 11 Everything was the same as in Example 2, except that parachlorostyrene was used instead of styrene, ethanol was used instead of methanol, and the amount of palladium chloride was changed to 0.1 mmol. Ethyl 4-chloroinnamate was produced in a yield of 60.2%. Example 12 The amount of palladium acetate in Example 1 was changed to 9.0 milligrams (0.04 millimoles), and instead of hydrogen chloride gas, a liquid obtained by absorbing chlorine gas in methanol was used, so that the number of chlorine atoms was 6.26 milligram atoms. Everything else was the same as in Example 1. The copper atoms per liter of reaction mixture are 0.10 gram atoms, and the gram atomic ratio of chlorine atoms to copper atoms is
It is 0.50. The conversion rate of styrene was 94.8%, the selectivity of methyl cinnamate was 82.3%, and the yield was 78.0%. Pd rotation rate is
It is 4880. Examples 13 to 17 The reaction was carried out in the same manner as in Example 2, except that 0.04 mmol of the palladium compound shown in Table 3 was used, and the type and amount of each cocatalyst component was changed as shown in Table 3. The results are shown in Table 3 below those of Example 12.

[Table] Example 18 Weigh out 8.87 milligrams (0.050 millimoles) of palladium chloride, 2.50 grams (12.5 millimoles) of cupric acetate monohydrate, and 3.82 grams (15.6 millimoles) of manganese acetate tetrahydrate. After adding a small amount of methanol, 26.04 grams (250.0 mmol) of styrene was taken, and the hydrogen chloride gas, whose concentration had been measured just beforehand, was absorbed into methanol.
1.07N) was added to make the amount of hydrogen chloride 6.4 mmol, and methanol was further added to make the total amount 125 ml. The amount of copper atoms per liter of reaction mixture is 0.10
gram atoms, and the total chlorine to copper gram atomic ratio is 0.52. Everything was the same as in Example 1 except that the same reactor as in Example 1 was used, the total pressure was 35 Kg/cm ² G, and a mixed gas with a carbon monoxide:oxygen:nitrogen partial pressure ratio of 9.9:5.1:85.0 was used. and reacted. Styrene conversion is 93.7%, methyl cinnamate yield and selectivity are 89.1% and 83.5%, respectively
The Pd rotation rate was 4180. Example 19 All preparations were the same as in Example 18, except that 6.0 ml of a solution in which hydrogen chloride gas was absorbed in methanol (concentration 1.11N) was added so that the amount of hydrogen chloride was 6.7 mmol. The amount of copper atoms per liter of reaction mixture remains unchanged at 0.10 gram atoms, and the total chlorine to copper gram atomic ratio is 0.54. Using the same reactor as in Example 1, the total pressure was set to 35
Kg/cm ² G and the partial pressure ratio of carbon monoxide:oxygen:nitrogen is
The reaction was carried out in the same manner as in Example 1 except that a mixed gas of 8.9:5.5:85.6 was used. The conversion rate of styrene was 94.2%, and the selectivity and yield of methyl cinnamate were 91.3% and 86.0, respectively.
It was %. The Pd rotation rate was 4300. Example 20 All preparations were the same as in Example 18, except that 5.0 ml of a solution in which hydrogen chloride gas was absorbed in methanol (concentration 1.07N) was added so that the amount of hydrogen chloride was 5.4 mmol. The amount of copper atoms per liter of reaction mixture remains unchanged at 0.10 gram atoms, and the total chlorine to copper gram atomic ratio is 0.44. Using the same reactor as in Example 1, the total pressure was 20Kg/
cm ² G, and the partial pressure ratio of carbon monoxide:oxygen:nitrogen is
The reaction was carried out in the same manner as in Example 1 except that a mixed gas of 8.9:5.5:85.6 was used. The conversion rate of styrene was 89.3%, and the selectivity and yield of methyl cinnamate were 90.5% and 80.8%, respectively. Pd rotation rate is
It was 4040.

Claims (1)

[Claims] 1. When producing the corresponding cinnamic acid esters by reacting styrenes, carbon monoxide, alcohol and oxygen, palladium metal or its compound is used as the main catalyst, and a copper organic acid salt dichloride compound and a cocatalyst are used as the co-catalyst. 3 Manganese or zinc compounds are used to reduce the copper atoms in the reaction mixture to 0.004
1. A method for producing cinnamic acid esters, characterized in that the reaction is carried out at ~0.4 gram atom/g and the gram atomic ratio of chlorine atoms to copper atoms is less than 2.