JPS60169437A - Hydrolysis of cinnamic acid ester - Google Patents

Abstract

PURPOSE:To carry out the hydrolysis of a cinnamic acid ester to cinnamic acid economically in an industrial scale, in high yield at a low cost, by using an acidic substance as the catalyst, and removing at least a part of alcohol from the system during the reaction. CONSTITUTION:For example, the cinnamic acid ester used as the raw material is charged through the top inlet port 2 of a plate column reactor containing an acidic cation exchange resin as the catalyst, and the raw material is transferred through the hydrolysis reactor 1 while introducing steam to the lower part 3 of the column to effect the hydrolysis. The alcohol produced by the reaction is distilled out from the column top opening 5 together with water and the produced cinnamic acid is taken out of the column through the bottom outlet port 4. When the acid catalyst is benzenesulfonic acid, etc., it is introduced into the column together with the raw material from the top inlet port 2 or together with steam from the steam injection port 3.

Description

Detailed Description of the Invention The present invention relates to a method for hydrolyzing cinnamic acid esters, and more specifically, the present invention relates to a method for hydrolyzing cinnamic acid esters, and more specifically, a hydrolysis reaction for obtaining cinnamic acids from cinnamic acid esters using an acidic substance as a catalyst. The object of the present invention is to provide a method for carrying out the reaction while removing at least a portion of the alcohol from the reaction system.

Cinnamic acids are used as raw materials for perfumes, medicines, pressure-sensitive papers, and other useful industrial chemicals, and conventional methods for producing cinnamic acids include the Perkin reaction or the condensation of benzaldehyde and ketene.

The present inventors first conducted an oxidative carbonylation (alkoxycarbonylation) reaction of styrenes in the presence of palladium metal or a compound thereof, a salt of copper or iron, and a compound containing an alkali metal or alkaline earth metal. It was discovered that cinnamic acid esters can be produced industrially advantageously.

In other words, today, if it is not possible to hydrolyze efficiently and economically using these cinnamic acid esters as a raw material, it is possible to produce cinnamic acids at a lower cost and with higher quality than the conventional method of directly producing cinnamic acids. It is possible to obtain it.

Therefore, an object of the present invention is to provide an industrially advantageous method for carrying out a hydrolysis reaction for obtaining cinnamic acids from cinnamic acid esters.

As a result of intensive studies on the hydrolysis reaction, the present inventors have discovered a method for advantageously producing cinnamic acids in the presence of an acid catalyst, and have arrived at the present invention.

That is, the present invention provides a method for hydrolyzing cinnamic acid esters in the presence of an acid catalyst, in which the cinnamic acid esters and water or steam are introduced into a reaction zone, and at least a part of the produced alcohols is removed from the reaction zone. This is a method for hydrolyzing cinnamic acid esters, which is characterized in that the reaction is carried out while the reaction is carried out.

The present invention will be explained in detail below.

The raw materials used in the method of the present invention have the general formula (in the formula
Hl represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; t represents hydrogen or an alkyl group having 1 to 6 carbon atoms; R
3 represents an alkyl group having 1 to 4 carbon atoms. ), specifically methyl cinnamate, ethyl cinnamate, butyl cinnamate, α-methyl-
Ethyl β-phenylacrylate, methyl α-propyl-β-chlorophenylacrylate, and the like.

The hydrolysis reaction according to the method of the invention is carried out in the presence of an acid catalyst.

As acid catalysts, mineral acids such as hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, nitric acid, sulfuric acid, hexafluorophosphoric acid, fluorosulfonic acid, chlorosulfonic acid, trifluoroacetic acid, methanesulfonic acid, Organic acids such as benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid; heteropolyacids such as phosphomolybdic acid and silicotungstic acid; Lewis acids such as boron trifluoride, phosphorus trifluoride, and antimony trifluoride; Alternatively, so-called solid acids such as acidic cation exchange resins, clay minerals, and zeolites may be mentioned.

In the method of the present invention, a simple mechanical separation of the catalyst and reaction medium from the reaction product is possible, resulting in rapid recovery of the reaction target cinnamic acids, omission of the catalyst removal step, and ease of operation. For promotion it is preferred to use insoluble particulate acidic catalysts.

In this context, "insoluble" means that the catalyst is substantially insoluble in both the mixture of reactants and the mixture of reaction products under the reaction conditions in the practice of this invention, e.g., substantially all of the catalyst is separated. means that it exists in a solid phase. Moreover, the term "granular" as used in the catalyst means that the particle size is small enough to allow separation from the reaction medium by simple mechanical means.

In general, materials capable of forming Lewis or Brønsted type acids are useful catalysts, but materials with acid functionality available on the surface of the solid without releasing acidity into the liquid reaction medium are particularly preferred.

Specific catalyst forms include acidic cation exchange resins and inorganic solid acids.

The acidic cation exchange resin is a strong acid type resin with sulfonic acid functionality such as Ashi, Diaion 0PK20.
8, Diamond ion ■PK-228, Diamond ion (Bl
HPK-25° (manufactured by Mitsubishi Chemical Industries, Ltd.), Amberlite 200 (manufactured by Rohm and Haas), which have a skeleton of styrene-divinylbenzene copolymer, Nafion 501 (manufactured by DuPont) Examples include those having a skeleton of a tetrafluoroethylene polymer such as fluorine.It is preferable that the inorganic solid acid has a hydrogen ion exchange ability exceeding 1 milliequivalent/f. Natural or synthetic materials such as zeolites have acidic properties that are useful in the method of this invention; clay minerals and zeolites include montmorillonite, kaolinite, bentonite, halloysite,
Examples include smectite, illite, chloride, and sepiolite.

Other examples include heteropolyacids supported on inorganic carriers.

Next, the hydrolysis reaction system will be explained, but it is not limited to the following example.

First, a plated column reactor system in which an acidic cation exchange resin is present as a catalyst will be described.

That is, cinnamic acid esters or a solution containing them are introduced from the upper part of a column reactor in which an acidic cation exchange resin is present, water vapor is introduced from the lower part of the column, and dialcohols are also introduced from the upper part of the column. This is a method of hydrolysis of cinnamic acid esters in which cinnamic acids are obtained from the bottom of the column, and there is an acidic cation exchange resin layer and water vapor rises from the bottom! This is a method in which cinnamic acid esters are brought into contact with

In addition, the above-mentioned water vapor can also be supplied as water and converted into steam within the reaction system, depending on the case.

In the method of the present invention, each ridge of a tray column reactor is filled with an acidic cation exchange resin. The tray for supporting the resin is
The outflow of the resin can be prevented by using a perforated plate (preferably with a hole diameter of 0.5 mm or less) or a valve-shaped tray, and installing a wire mesh in a part of the upper part of the overflow pipe.

This plated column reactor system can be explained by the schematic diagram shown in FIG. That is, cinnamic acid esters are continuously introduced through the raw material inlet 2 opened in the main part of the tower. In this case, the cinnamic acid ester does not necessarily have to be pure, and may contain the cinnamic acid, a solvent described below, or water.

On the other hand, steam is introduced through a steam inlet 3 opened in the lower part of the column. The cinnamic acid esters introduced through the feed port 2 are hydrolyzed by water vapor introduced from the lower part of the tower as they move downward through the hydrolysis reaction tower 1 in which an acidic ion exchange resin is supported on the tray 6. Ru. The alcohols produced during this time are collected together with water through an opening 5 provided at the top of the tower.
It is distilled from more. On the other hand, cinnamic acids produced by hydrolysis can be taken out through the outlet 4 provided at the bottom of the tower.

Next, when using an inorganic acid such as sulfuric acid, hydrochloric acid, or an organic acid such as benzenesulfonic acid as an acid catalyst, these acid catalysts are added to the raw material inlet 2 together with the cinnamic acid ester or It can also be introduced together with water vapor from the water vapor inlet 3.

Next, we will discuss the multi-vessel continuous reactor system, but the basic principle is the same as the plate tower system. The multi-vessel continuous reactor system can be explained with the schematic diagram shown in FIG.

Hydrolysis reaction tank 7 filled with acidic cation exchange resin,
7', ? 'Use a reactor connected to Cinnamic acid esters are introduced through a raw material inlet 8 opened into the reaction tank 7, and steam is introduced through a steam injection port 9 opened into the reaction tank 7''.The hydrolysis reaction liquid passes through a pipe 12 to react. It moves through the tanks 7' and 7'' while increasing the hydrolysis rate, and is finally taken out as cinnamic acids through the outlet 10 in multiple stages. On the other hand, alcohols produced by the reaction can be distilled out of the p-system through the opening 11 through the pipe 13.

However, although the number of reaction tanks is assumed to be three here, it is not limited to this, and the number can be selected as appropriate.

In addition, when using an inorganic acid such as sulfuric acid or hydrochloric acid or an organic acid such as benzenesulfonic acid as an acid catalyst, these acid catalysts may be used together with the cinnamic acid ester through the raw material inlet 8 or by steam blowing. It can also be introduced from the inlet 9 together with water vapor.

Furthermore, the present invention can also be applied to batch reactions. In that case,
This is usually carried out by heating a reactor into which cinnamic acid esters, water and a catalyst have been introduced, and at least a portion of the alcohol produced at this time is removed from the system by distillation.

Water does not necessarily need to be taken out of the system, but if the alcohol has a higher boiling point than water, the alcohol is distilled out of the reaction system together with water, and the required amount of water is added to the reactor.

In the present invention, the rate of hydrolysis can be increased by removing at least a portion of the alcohol produced by hydrolysis out of the reaction system.

Although the use of a solvent is not essential in the method of the present invention,
In order to proceed with the reaction more smoothly, it is preferable to use a solvent.

Examples of such solvents include diethyl ether, diisopropyl ether, dibutyl ether, dioxane,
Ethers such as tetrahydrofuran and ethylene glycol dimethyl ether, acetone, methyl ethyl ketone,
Examples include ketones such as dibutyl ketone and acetophenone, nitriles such as acetonitrile, propionitrile, and benzonitrile, and aromatic carbonized limescale such as benzene, toluene, xylene, and ethylbenzene, but methanol,
Alcohols such as ethanol and phthanol can be used.

The appropriate amount of water relative to the cinnamic acid ester substrate is 2 to 200 times in terms of moles, but when hydrolysis is carried out continuously in the method of the present invention, the amount of water in units of moles is 5 to 200 times.
It is sufficient to use ~20 times the amount of water vapor.

The reaction temperature is suitably 80 to 140°C, more preferably 100 to 130°C. At temperatures as low as 90° C., not only will the reaction rate be slow, but it will also be difficult to drive out the alcohols produced, making it impossible to carry out the process advantageously. Furthermore, although the operation is normally carried out at normal pressure, it may be advantageous to operate at slight gradual vacuums or increases.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 As an acid hydrolysis reactor, a plate column type reactor as shown in FIG. 1 was used. However, the reactor has a diameter of 0.5 mm.
It is a perforated plate column with a diameter of 14 m, which has 20 stages of perforated plates with 20 holes.The fourth stage from the top has a raw material inlet, that is, the inlet for cinnamic acid esters, and the main part at the bottom of the column has a steamer inlet. has. Diamond ion PK-208 below 94 steps from the top
(Mitsubishi Chemical Industries, Ltd.) was filled in each stage.

2431 tons of methyl cinnamate per hour from the raw material inlet.

4050 tons of steam was introduced per hour through the steam inlet. As a result, 2109 F of the product cinnamic acid was obtained per hour from the bottom of the column, and in addition, 1 F of unreacted methyl cinnamate was obtained per hour.
21.5 f and 3932 water flowed per hour. on the other hand,
From the top of the column, 456 tons of methanol and 3400 F of steam were obtained per hour.

The reaction temperature was set at 110° C. at the raw material inlet and 120° C. at the bottom of the column.

Example 2 200 ml containing 1Of Diamondion PK-208,
Methyl cinnamate was fed as a methanol solution at a rate of 3 F per hour and water was fed at a rate of 501 F per hour to a glass Mitsuro flask using a microfeeder. The hydrolysis reaction was carried out while maintaining the Mitsuro flask at 120° C. in an oil bath and evaporating the dimetator and water from one outlet of the Mitsuro flask.

Two hours after the start of the reaction, the amount of methyl cinnamate and the amount of cinnamic acid produced were analyzed, and the conversion rate of methyl cinnamate was 1-1.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a plate column reactor system applied to the method of the present invention, and FIG. 2 is a schematic diagram of a multi-tank continuous reactor system. 1...Hydrolysis reaction tower 2...Raw material inlet 3...
Steam inlet 4...Cinnamic acids outlet 5...Alcohol distillation opening 7.7', 7''...Hydrolysis reaction tank 8...Raw material inlet 9...Steam inlet 10 ...Cinnamic acids outlet 11...Alcohol distillate opening

Claims (2)

[Claims] (1) In a method of hydrolyzing cinnamic acid esters in the presence of an acid catalyst, the cinnamic esters and water or steam are introduced into the reaction zone, and at least a part of the alcohol produced is removed from the reaction zone. A method for hydrolyzing cinnamic acid esters, characterized by carrying out a reaction. (2) The method according to claim (1), wherein the reaction zone is a plate column reactor or a multi-vessel continuous reactor.