JPS6092243A - Preparation of cinnamic ester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for producing cinnamic acid esters, and particularly relates to a method for producing cinnamic acid esters by oxidatively carbonylating styrenes in the presence of alcohol. be.

[Prior art]

Cinnamic acid is cinnamaldehyde, cyclamenaldehyde, β-
It is not only used as a raw material for fragrances together with amyl cinnamaldehyde, etc., but also useful as a raw material for agricultural chemicals, and can be produced by the perkin reaction on a laboratory scale.

Examples of obtaining cinnamic acid esters by oxidative carbonylation reaction of styrene include JP-A-53-40709, JP-A-56-15242, JP-A-56-22749, JP-A-5
6-22750, JP-A-56-71039, JP-A-15-1989
7-21342, JP 157-21343, JP 5
7-70836 and the like.

Most of these conventional examples use palladium and copper or iron as catalysts, and it has been suggested that the presence of halogen is essential in the reaction system.

Therefore, when the present inventors carried out the reaction using the reaction system containing the halogen, stainless steel (SvS316'
/fF) or titanium metal reactors will corrode extremely rapidly, and even when using Hastelloy C reactors, the inner surface of the reactor will gradually corrode, and if the reactor has been used for a long time, the reaction will deteriorate. It was found that the reproducibility deteriorated significantly.

This corrosion of the reactor also occurred when a zirconium reactor was used, and it was found that the tantalum reactor exhibited some degree of corrosion resistance.

However, for the purpose of industrially advantageous production of cinnamic acid esters, using a reactor made of high-grade materials such as Hastelloy C1 or tantalum thicken is unsuitable because the fixed costs included in the production unit cost are additionally high. Economically, it is extremely disadvantageous.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to prevent corrosion of the reactor due to the reaction system,
The object of the present invention is to provide a method for producing cinnamic acid ester, which can economically advantageously produce cinnamic acid ester with high yield and selectivity.

[Structure of the invention]

In order to achieve this objective, the present inventors conducted intensive research on a method for producing cinnamic acid esters by oxidative carbonylation of styrenes, and as a result, developed a method for producing cinnamic acid esters by oxidative carbonylation of styrenes. When a reaction was carried out using this compound, a new fact was discovered that not only the corrosion of the reactor by the reaction system was prevented, but also the selectivity of the reaction was increased, leading to the present invention.

That is, the present invention uses (a) palladium metal or its compound, (b) copper or iron salts, and (c) alkali metal or alkaline earth metal salts as catalyst components, and at least one of the catalyst components is a halogen. A glass-lined or glass-lined cylindrical reactor is used to produce a cinnamic acid ester by reacting styrene with an aliphatic alcohol having 1 to 4 carbon atoms, carbon oxide, and oxygen in the presence of a compound catalyst. The gist of the present invention is a method for producing a cinnamic acid ester, characterized in that the reaction is carried out in a cinnamic acid ester.

When a metal reactor is used as in the conventional method, it is important to consider how the metal components eluted from the surface of the reactor due to corrosion by the reaction system are involved in the reaction, and how the metal surface itself interacts with the activity of the substrate. Although it is not clear exactly what kind of influence it will have on the reaction, when the reaction is carried out in a glass-lined or glass-inner cylindrical reactor as in the present invention, the metal base of the reactor and the reaction liquid may contact can be avoided and cinnamic acid esters can be obtained with high selectivity.

The present invention will be explained in detail below.

In the process of the invention, styrenes are reacted with an aliphatic alcohol having 1 to 4 carbon atoms, carbon oxide and oxygen in the presence of a specific catalyst.

Styrenes are represented by the general formula (wherein R' represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and R1 represents hydrogen or a C1 to 6 alkoxy group). represents an alkyl group), specifically styrene, β-methylstyrene, p-methylstyrene, p-methoxystyrene, p-chlorostyrene, β-methyl-p-isopropylstyrene, β- Examples include amylstyrene.

Specific examples of aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, and acetals, ketals, orthoesters of carboxylic acids, Compounds that can dissociate within the reaction system to release the above-mentioned alcohol, such as dialkoxycycloalkanes and orthoboric acid esters, can also be used.

In the production method of the present invention, in order to obtain a higher yield of cinnamic acid ester, the dissolved molar ratio of styrene to the aliphatic alcohol in the reaction system must be 0.5 to 1.
．． It is preferable to keep it at 5.

- Carbon oxide and oxygen can be used in their pure state, but they can also be used diluted with an inert gas such as phoneme or argon. In order to obtain a higher yield of cinnamic acid ester, the carbon monoxide partial pressure in the reaction system should be adjusted to 0.1 kg/
The ratio of carbon monoxide partial pressure to oxygen partial pressure in the reaction system is kept at 1.
It is preferable to keep it between 0 and 2.5.

In the method of the invention, the reaction comprises (a) palladium metal or a compound thereof, (b) a salt of copper or iron, and (e) an alkali metal or an alkaline earth metal, and (a)
, (b), ((((1) is carried out in the presence of a catalyst containing a halogen compound.

Examples of palladium metal or its compounds include palladium black, metal palladium with a carrier, or zero-valent palladium complexes such as tetrakis(triphenylphosphine)palladium; inorganic salts of divalent palladium such as palladium chloride and palladium nitrate; Examples include palladium compounds such as divalent palladium carboxylates such as palladium acetate and palladium benzoate; divalent palladium complexes such as bis(acetylacetonato)palladium and bis(triphenylphosphine)dichloropalladium.

When these palladium metals or their compounds are supported on a carrier, silica, alumina, silica alumina, magnesia, titania, diatomaceous earth, activated carbon, graphite, barium carbonate, calcium carbonate, etc. are used as the carrier.

Examples of copper or iron salts include inorganic salts such as hydrochlorides, nitrates, sulfates, phosphates, and borates, and organic acid salts such as acetates and benzoates.

The valence of copper or iron in the salts may be monovalent or divalent.

Examples of salts of alkali metals or alkaline earth metals include inorganic salts such as their hydrochlorides; organic acid salts such as acetates, propionates, butyrates, pivalates, and stearates.

(a), (b) in the catalyst used in the method of the present invention,
(C) The mixing ratio of the three components is such that the atomic ratio of (a) palladium metal or its compound and (b) copper or iron salt is 1:0.1 to 500, preferably 1:10 to 300. Also, the molar ratio of (b) copper or iron salts to (e) alkali metal or alkaline earth metal salts is 1:0.1 to 100, preferably 1:0.1. It is suitable to adjust it so that it may be in the range of ~50.

In the present invention, there is no problem even if no reaction solvent is used, but in some cases, an appropriate inert solvent may be used to facilitate the operation. Examples of solvents include ethers such as diethyl ether, diphenyl ether, dioxane, tetrahydrofuran, and ethylene glycol dimethyl ether; acetone, methyl ethyl ketone, dibutyl ketone, and acetophenone; methyl acetate, ethyl acetate, ethyl propionate, benzyl benzoate, and phenyl. Esters such as dimethyl succinate; Aromatic hydrocarbons such as benzene, toluene, p-xylene, and ethylbenzene; Aliphatic or alicyclic hydrocarbons such as n-hexane, n-octane, and cyclohexane; , N-methylpyrrolidone-based amides; carbonates such as ethylene carbonate and propylene carbonate.

The glass-lined or glass-inner cylinder reactor used in the method of the present invention is preferably made of inexpensive materials such as general silicate glass or borosilicate glass.

Although there are no particular restrictions on the reaction pressure, it is preferable that the carbon monoxide partial pressure is higher than the oxygen partial pressure in order to increase the reaction rate. In addition, the total pressure of the reaction system is 20 kg/cn in the case of a glass-lined reactor. G or less is preferable, but in the case of a glass-inner cylinder type reactor, it is also possible to set the pressure to an even higher pressure.

In the production method of the present invention, the yield of cinnamic acid ester can be improved by raising the reaction temperature by υ, but increasing the reaction temperature by 10° will cause side reactions such as the production of carbon dioxide, resulting in the production of cinnamic acid ester. selectivity decreases. Therefore, the reaction temperature is usually normal m~200℃, preferably 50~1
It is appropriate that the temperature be within the range of 50°C.

The desired cinnamic acid ester can be easily separated and obtained from the reaction product liquid obtained by the reaction of the present invention by employing ordinary separation means such as distillation and extraction.

Oxidative carbonylation reaction 1 of styrenes represented by the general formula (wherein R' and R8 are the same as defined above) according to the method of the present invention (wherein R1 and R1 are the same as defined above, (Rs represents a carbon atom!A1-4 alkyl group.) A cinnamic acid ester is obtained.

[Embodiments of the invention]

The present invention will be explained in more detail below using examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 A Hastelloy CM autoclave with a spinner agitation type glass inner cylinder having an internal volume of 90 resistant and 7 ml of styrene.

Mefi/-le 3 ml-, 5% pd/A-C0(
5-fold fIts 2-dium supported on activated carbon)
o, o s mmoJ (pa conversion), cupric acetate 0
．． 5 mmol-s Barium chloride 0.5 mmol was charged, and after sealing, -carbon oxide 8 kg/c1r? G was press-fitted. Then, 6% Ot/N* (phoneme containing 6 volumes of oxygen) was injected to make the total pressure 103 kg/crl G.

The autoclave was heated to 100°C and reaction was carried out for 30 minutes. After the reaction was completed, the autoclave was water-cooled and depressurized, and the composition of the reaction gas and the reaction product liquid were analyzed by gas chromatography.

As a result, the produced methyl cinnamate was 6.98 mm 01°, and the selectivity of methyl cinnamate was 9477 mm. Note that the selectivity of methyl cinnamate was determined by the following formula.

Methyl cinnamate selectivity = Methyl cinnamate ÷ (Methyl cinnamate +
2 and 3 methyl propionate + acetophenone + dimethyl phenylsuccinate) .

As a result of ±, the generated methyl cinnamate was 6.20 rran
The selectivity for oJ methyl cinnamate was o 1.24'A.

〔Effect of the invention〕

As detailed above, the method for producing cinnamic acid ester of the present invention uses a glass-lined or glass-inner cylindrical reactor, and can prevent corrosion of the reactor in the reaction system. At the same time, cinnamic acid esters can be produced with extremely high selectivity and yield.

Furthermore, since the reactor is inexpensive, manufacturing costs can be kept low, which is extremely advantageous industrially.

Agent Patent Attorney Tsuyoshi Shigeno Procedural Support Device Indication of the case 1982 Patent Application No. 198819 2 Name of the invention Process for producing cinnamic acid ester 3 Relationship with the case of the person making the amendment Name of the patent applicant (596) Mitsubishi Kasei Kogyo Co., Ltd. 4 Agent address 502 Akasaka Omotemachi Building, 107, 4-8-19 Akasaka, Minato-ku, Tokyo Sponsored by 6 Column for detailed explanation of the invention in the specification to be amended.

7. Contents of the amendment (1) rt on page 9, line 7 of the specification); Category 1 ΦΦ participation may also be used. '' is corrected to ``The valence of copper in salts may be monovalent or divalent, and the valence of iron may be divalent or trivalent.''

that's all

Claims (1)

[Claims] (1) (a) Palladium metal or its compound, (b)
In the presence of a catalyst containing copper or iron salts and (C) alkali metal or alkaline earth metal salts as catalyst components, and at least one of the catalyst components being a halogen compound, styrenes having 1 to 4 carbon atoms are heated. of aliphatic alcohol, carbon oxide and oxygen to produce the cinnamic acid ester, the reaction is carried out in a glass-lined or glass-lined cylindrical reactor. Manufacturing method. (2. In the method for producing a cinnamic acid ester according to claim 1, styrenes are of the general formula (wherein R is hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, or -4 alkoxy group, and R represents hydrogen or an alkyl group having 1 to 6 carbon atoms. (3) Claim 1. or the method for producing a cinnamic acid ester according to item 2, wherein the styrene is styrene. (4) Any one of claims 1 to 3.
The method for producing a cinnamic acid ester described in paragraph 1 is characterized in that the ratio of (a) palladium metal or its compound to (b) copper or iron salts is in an atomic ratio of 1:0.1 to 500. Manufacturing method. (5) In the method for producing a cinnamic acid ester according to any one of claims 1 to 4, (b)
A production method characterized in that the molar ratio of copper or iron salts to (C) alkali metal or alkaline earth metal salts is 1:01 to 100.