JPS6222743A - Production of cinnamic acid ester - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as perfumery, etc., in high reaction result, economically, in improved yield, by reacting a styrene compound with carbon monoxide, an alcohol and oxygen using main catalyst consisting of metallic palladium and a cocatalyst composed of copper and chlorine at specific ratio. CONSTITUTION:The objective compound can be produced by reacting a styrene compound with carbon monoxide, an alcohol and oxygen in the presence of a catalyst consisting of (A) a main catalyst composed of metallic palladium or its compound and (B) a cocatalyst composed of (1) a copper compound, (2) a chlorine compound and (3) one or more compounds of metals selected from the group 4A, group 5A and iron group 8A of the periodic table. The content of the copper atom in the reaction mixture is 0.004-0.4g-atom/l, preferably 0.08-0.3g-atom/l, the g-atom ratio of Cl to Cu is <2, preferably 0.02-1.99, and the ratio of the third component metal compound to the copper atom is preferably 0.1-10.

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 for fragrances due to their aromatic properties, and are also important compounds as raw materials for agricultural chemicals and photosensitive resins.

(Prior Art) Cinnamic acid has conventionally 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, 1984-15242, JP-A-56-2274
9, JP-A-56-22750, JP-A-56-71039
, JP 57-21342, JP 57-21343,
JP-A-57-70836, JP-A-60-92242, JP-A-60-92243, JP-A-60-94940, JP-A-60-97935, etc.).

(Problems to be Solved by the Invention) However, these methods have not yet been industrialized because the catalyst activity is low and the reaction results are not satisfactory.

The purpose of this invention is to provide a method for advantageously producing cinnamic acid esters by reacting styrenes, carbon monoxide, alcohol and oxygen with high catalytic activity and high reaction performance.

(Means for solving the problem) In order to achieve the above object, the inventors of the present invention have continued to study intensively, and first, (1) conventional techniques, for example, Japanese Patent Application Laid-Open No. 57-70
As shown in many examples in Japanese Patent No. 836 and Japanese Patent No. 56-15242, when using only cupric chloride as a source compound for copper and chlorine as co-catalysts, the amount of copper atoms used is determined to be preferable. If one tries to select a range, the amount of chlorine atoms to be used is limited thereby, and it is not possible to arbitrarily select a preferable range, and this is one of the reasons why the catalyst system is not industrially satisfactory. , and (2) copper and chlorine are important cocatalysts in the reaction of carbon monoxide, alcohol, and oxygen to produce the corresponding cinnamic acid esters, and these sources can be used as separate compounds or in small quantities. They found that it is necessary to use palladium metal or its compound as the main catalyst, and copper, chlorine, and specified compounds as the co-catalyst. using
By setting the amount of copper atoms per liter of reaction mixture in a specific range and the gram atomic ratio of chlorine atoms to copper atoms in a specific range, high activity of the main catalyst can be obtained and cinnamic acid can be produced with high reaction performance. We have already filed an application after discovering that esters can be produced.

After that, we continued to study this reaction and found a new effective compound as the third component of the co-catalyst.If the reaction was carried out using the same specific range of copper atoms and chlorine atoms as mentioned above, the activity of the main catalyst could be increased. It was discovered that cinnamic acid esters could be produced with high reaction results, and the present invention was completed.

That is, the present invention provides a method for producing corresponding cinnamic acid esters by reacting styrenes, carbon monoxide, alcohol, and oxygen, using palladium metal or a compound thereof as a main catalyst and (1) a copper compound as a co-catalyst. ,(2)
chlorine compounds and (3) group 4A of the periodic table according to the International Union of Pure and Applied Chemistry (hereinafter simply referred to as the periodic table);
A compound of at least one metal selected from the group consisting of iron group 5A and iron group 8A is used, the copper atom in the reaction mixture is 0.004 to 0.4 g atom/l, and the copper atom of chlorine atom is used. This is a method for producing cinnamic acid esters, characterized in that the reaction is carried out at a gram atomic ratio of less than 2.

Styrenes used in the method of the present invention include:
Specifically, styrene, α-methylstyrene, β-methylstyrene, α-ethylstyrene, β-ethylstyrene, 0-methylstyrene, m~methylstyrene, p-methylstyrene, m-ethylstyrene, p-ethyl Styrene, p-tert-butylstyrene, β-methyl-p-
alkyl derivatives of styrene such as isopropylstyrene;
Or p-chlorostyrene, p-methoxystyrene,
Examples include styrene derivatives having a substituent on the aromatic ring that does not inhibit the reaction, such as 3.4-dimethoxystyrene.

Alcohols include methanol, ethanol, propatool, butanol, pentanol, octatool, cyclopentanol, cyclohexanol, phenol,
Alcohols such as benzyl alcohol, ethylene glycol, polyethylene glycol, and propylene glycol may have a substituent such as a halogen or an alkoxy group that does not inhibit the reaction. The amount of these alcohols used is 1 to 100 per mole of styrene.
It is expressed in molar parts and can be used not only as a reaction raw material but also as a solvent.

Carbon monoxide and oxygen used in the method of the present invention are preferably diluted with an inert gas such as nitrogen or argon in order to avoid explosion.

Air can also be used as the oxygen source. The partial pressure of carbon monoxide is 50 atm (absolute pressure or below) or less, preferably in the range of 0.005 to 40 atm. The partial pressure of oxygen is 50 atmospheres or less, preferably 0.002 to 30
is within the range of

These carbon monoxide, oxygen, and inert gases may be charged into the reactor in the required amounts all at once, or by adding the necessary gases continuously or intermittently, or by adding a mixture of these gases continuously or intermittently. It may also be possible to distribute the information publicly.

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. Such solvents include ethers such as diethyl ether, dipropyl ether, methyl ethyl ether, phenylethyl ether, diphenyl ether, tetrahydrofuran, dioxane, ethylene glycol diethyl ether, tetraethylene glycol dimethyl ethyl, acetone, methyl ethyl ketone, Ketones such as acetophenone, esters such as methyl acetate, ethyl acetate, methyl propionate, aromatic hydrocarbons or substituted compounds thereof such as benzene, toluene, p-xylene, ethylbenzene, chlorobenzene, dichlorobenzene, n-hexane, Aliphatic or alicyclic hydrocarbons such as n-penkune and cyclohexane, carbonates such as propylene carbonate and dimethyl carbonate, acetonitrile, benzonitrile, etc.
Examples include IJ compounds, aromatic nitro compounds such as nitrobenzene, amide compounds such as dimethylformamide, and sulfone compounds such as sulfolane.

The main catalyst of the present invention, palladium metal or its compound, includes palladium black, metal palladium supported on a carrier such as activated carbon, asbestos, or silica alumina, dibenzylidene acetone complex, or tetrakis (
zero-valent palladium metals or compounds such as zero-valent palladium complexes such as (triphenylphosphine) palladium; inorganic acid salts of palladium such as palladium chloride and palladium nitrate; organic acid salts such as palladium acetate or palladium benzoate; Examples include divalent palladium compounds such as palladium complexes such as bis(acetylacetonato)palladium, cyclooctadiene dichloropalladium, palladium chloride benzonitrile complex, palladium chloride pyridine complex, or palladium chloride ammine complex.

The amount of palladium metal or its compound used is in the range of 1XIF6 to IX1'O' gram atom per mole of raw material styrene as palladium metal atom,
Preferably 5 X 10'' to 1X10-2 gram atoms.

The copper compound that is the first component of the promoter of the present invention is as follows:
Salts of inorganic acids of copper such as copper carbonate, copper chloride or copper nitrate, salts of aliphatic carboxylic acids of copper such as copper acetate, copper propionate, copper stearate, copper cinnamate, aromatic carboxylic acids such as copper benzoate Salts of acids, salts of organic anions of copper such as copper acetylacetonate, and the like. These copper compounds can be used alone or in combination of two or more.

Further, it is preferable that these copper compounds be dissolved in the reaction mixture, but a portion thereof may remain insoluble. The amount of these copper compounds used is 0.004 to 0.4 gram atoms per liter of reaction mixture as copper atoms. However, when a copper chloride is used as the chlorine compound as the second component of the co-catalyst, the above range includes the copper atom of this compound. 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, reaction mixture 1
o,oos to 0.3 gram atoms per liter.

Examples of the chlorine compound which is the second component of the promoter include chlorine or its solution, hydrogen chloride or its solution, amine hydrochloride, and tertiary-butyl chloride,
Chlorine-containing compounds that tend to generate chlorine ions, such as phosgene, phosphorus pentachloride, and phosphorus oxytrichloride, or chlorides or oxychlorides depending on the valence of metals such as titanium, vanadium, iron, copper, or aluminum. Can be mentioned.

These chlorine compounds may be used alone or in combination of two or more. These chlorine compounds have a ratio of chlorine atoms to copper atoms present in the reaction mixture, which is less than 2;
That is, use an amount greater than 0 and less than 2. However, if other catalyst components contain chlorine atoms, the range includes the amount including the chlorine atoms. When the ratio of chlorine atoms to copper atoms is O, 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 cinnamic acid esters decrease. Preferably it is 0.02-1.99 gram atomic ratio.

The metal as a compound of metals selected from the group consisting of iron groups 4A, 5A and 8A of the periodic table, which is the third component of the promoter, is titanium, zirconium, hafnium, vanadium, niobium, tantalum, iron, Cobalt, nickel, and compounds of these metals include chlorides, oxychlorides, oxides, hydroxides, carbonates or acetic acids, aliphatic carboxylic acids such as propionic acid, stearic acid, cinnamic acid, and succinic acid. Examples include salts, aromatic carboxylates such as benzoic acid or phthalic acid, and complex compounds such as acetylacetonate complexes, cyclopentagenyl complexes, and carbonyl complexes. Among these, the chloride and oxychloride may also serve as part or all of the chlorine compound of the second cocatalyst component. Two or more kinds of these metal compounds can also be used simultaneously. The amount of these metal compounds used as the third component of the cocatalyst is such that the ratio of these metal atoms to the copper atoms present in the reaction mixture is 0.05 to 50;
Preferably it is from 01 to ]0.

The method of the present invention may be carried out using either a batch method or a continuous flow method.

The total pressure of the reaction in the method of the present invention depends on the partial pressures of carbon monoxide and oxygen or inert gas used, but is usually 5.
00 atm or less, preferably 1 to 300 atm. The reaction temperature is room temperature to 200°C, preferably 40 to 16
It is 0°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, resulting in 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 11.23 mg of palladium acetate in a glass cylindrical container
(0,050 mmol), cupric acetate monohydrate 250P
(12.5 mi!7 moles), cobaltous acetate tetrahydrate 3
．． Take 7'47 (15.0 mmol), add a small amount of methanol to it, and then add 26.04 P of styrene.
Weigh out (250.0 mmol) and add 5.0 ml of a solution (concentration 1.25 N) in which hydrogen chloride gas was absorbed into methanol, the concentration of which was measured just beforehand, and the amount of hydrogen chloride is 6.3 It was made to be millimoles. Furthermore, a portion of methane was added to make the total amount 125 mA'. Reaction mixture 11
The amount of copper atoms per unit is 0.10 gram atoms, and the gram atomic ratio of chlorine atoms to copper atoms is 0.50. This glass container was inserted into a 500 ml autoclave. The autoclave's stirring blades are made of glass, and the temperature measuring tube is also protected by glass. The total pressure in the autoclave was 51 atm, and the partial pressure ratio of carbon monoxide:oxygen:nitrogen was 8.5:
A mixed gas of 5.3:86.2 was passed through the outlet at a rate of 1.2 liters/min (standard condition), stirring was continued, and the reaction was carried out at 100° C. for 3 hours. The partial pressures of carbon monoxide and oxygen in the reactor are 4.3 and 2.7 atmospheres, respectively. The reaction loggas was discharged through a water-cooled reflux condenser.

After the reaction was completed, the reaction solution was cooled and depressurized, and the reaction solution taken out was analyzed by liquid chromatography to find that it contained 16.7 mmol of styrene, 214.8 mmol of methyl cinnamate, and 7.14 mmol of dimethyl phenylsuccinate. The conversion rate of styrene was 93.3%, the selectivity of methyl cinnamate (yield based on consumed styrene) was 92.1%, and the yield of methyl cinnamate (yield based on charged styrene) was 85.9%. The number of moles of cinnamic acid ester produced per gram atom of main catalyst palladium (hereinafter referred to as Pd turnover rate) was 4,300.

Example 2 Palladium acetate, 23 mg (0,050 mmol)
, cupric acetate monohydrate 1.87 fi' (9.37 mmol), cupric chloride 0.419 P (3.12 mmol), cobaltous acetate tetrahydrate 3.74! i'(1
After adding a small amount of methanol, 26.04 fI of styrene (250.0 mmol) was taken, and methanol was added to bring the total volume to 125 ml. The total amount of copper atoms per reaction mixture 11 is 0.10 gram atoms, and the gram atomic ratio of chlorine atoms to total copper atoms is 0.5. The reaction was carried out in the same manner as in Example 1 except that the reaction time was 35 hours. The conversion of styrene was 90.2%, the selectivity and yield of methyl cinnamate were 91.5% and 825%, respectively, and the Pd turnover was 41%.
It was 30.

Example 3 The same procedure as in Example 2 was carried out except that the total reaction pressure was 10 atm. The conversion of styrene was 864%, the selectivity and yield of methyl cinnamate were 90.9 and 78.5%, respectively, and the Pd turnover was 3930.

Example 4 The reaction was carried out in the same manner as in Example 2 except that the total reaction pressure was 6 atm. The conversion of styrene was 85.1%, and the selectivity and yield of methyl cinnamate were 90.0. % and 76.6%, and the Pd rotation rate was 3830.

Comparative Example 1 The amount of cupric acetate monohydrate used in Example 2 was reduced to 2.5
05' (12.5 mmol), and all the preparations were the same as in Example 2 except that cupric chloride was not used. The amount of copper atoms per reaction mixture 11 is 0.10 gram atoms, and the ratio of chlorine atoms to copper atoms is O. The same procedure as in Example 2 was carried out except that the total reaction pressure was 10 atm. The styrene conversion was 4.3% and the methyl cinnamate yield was less than 0.1%.

Comparative Example 2 The amount of cupric chloride in Example 2 was s, oo159.5
(mmol), and all the preparations were the same as in Example 2 except that cupric acetate monohydrate was not used. Reaction mixture 1
The amount of copper atoms per unit is 0.482 atoms, and the gram atomic ratio of chlorine atoms to copper atoms is 2. The same procedure as in Example 2 was carried out except that the total reaction pressure was 10 atm. The conversion rate of styrene was 64.2%, the selectivity and yield of methyl cinnamate were 5.7% and 3.7%, respectively, and the Pd
The rotation rate was 190.

Example 5 5% Pd/in place of palladium acetate in Example 2
C (5% by weight of palladium supported on activated carbon)
The same procedure as in Example 2 was carried out except that 170■ was used. The styrene conversion rate was 84.4%, and the selectivity and yield of methyl cinnamate were 77.3% and 65.2%, respectively.

Examples 6 to 9 Using 0.04 mmol of the palladium compound shown in Table 1,
The same procedures as in Example 2 were carried out except that the type and amount of the co-catalyst component were changed as shown in Table 1. The results are shown in Table 1.

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 (1) a copper compound, (2) as the co-catalyst. Using a chlorine compound and (3) a compound of at least one metal selected from the group consisting of iron groups 4A, 5A, and 8A of the periodic table, the copper atoms in the reaction mixture are
A method for producing cinnamic acid esters, characterized in that the reaction is carried out at 0.4 gram atom/l and at a gram atomic ratio of chlorine atoms to copper atoms of less than 2.