JPS62286936A - Production of allyl chloride - Google Patents

Abstract

PURPOSE:To obtain the titled compound on an industrial scale at a low cost, by adding allyl alcohol to an aqueous solution of hydrochloric acid containing a catalyst selected from chlorides of transition metal, Mg, Al and Sn and immediately distilling out the product from the system by stripping. CONSTITUTION:Allyl alcohol is made to react in an aqueous solution of hydrochloric acid containing at least one kind of catalyst selected from the chlorides of transition metal, Mg, Al and Sn (e.g. cuprous chloride, cupric chloride, palladium chloride, cobalt chloride, etc.). The produced allyl chloride is distilled out by stripping to obtain allyl chloride having high quality in high yield. USE:Raw material for epichlorohydrin, glycerol, etc., raw material for agricultural chemicals, pharmaceuticals or perfumery, a soil improver, etc.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Application Field 1] The present invention is used as an important raw material for allyl compounds such as epichlorohydrin and glycerin, and also as a raw material for agricultural chemicals such as herbicides and insecticides, and as a sedative. This invention relates to a new method for producing allyl chloride from allyl alcohol, which is an important compound used in pharmaceutical raw materials such as agents and anesthetics, perfume raw materials, soil conditioners, etc.

[Prior Art and its Problems] Conventionally, allyl chloride has been produced by chlorinating propylene as shown in the following formula.

CH=CHCH3+ CI 2 -1 → However, in this production method, (a) the reaction temperature is high, many types of by-products are produced, and the yield of the target product is low; and (b) by-products are produced when propylene and chlorine come into contact. The reactor is clogged due to rough carbonization of the polymer, and clogging also occurs when the m compound adheres to the heat exchanger when the reaction product gas is rapidly cooled with a solvent (c) This method has serious drawbacks as an industrial manufacturing method, such as severe corrosion of the equipment due to the handling of hydrogen chloride at high temperatures.

In addition, similarly to the present invention, allyl alcohol is reacted with 1[9 at room temperature in the presence of a cuprous chloride catalyst to form allyl chloride with the following formula CH2=CH-CH2-OH+ HCICuCI CH2=CH-CI-(2- A synthesis method using CI +H20 has been reported in “Jacaues
:J,, But! ,Soc,Chim,, [5] 12
, 843 (1945) J.

According to a follow-up test of this method, the reaction solution after the reaction was separated into an organic layer and an aqueous layer, and when this Ti layer was analyzed, it was found that in addition to allyl chloride, a large amount of diallyl ether and a small amount of unreacted allyl alcohol were mixed together. I found out that it was. A small amount of allyl alcohol remained in the aqueous layer. Although it is possible to isolate allyl chloride by separating the i-layer, the yield of allyl chloride is not satisfactory due to the large amount of diallyl ether, which is a by-product.

This method has advantages such as being able to react at room temperature and using hydrochloric acid, which is easier to handle than chlorine, but it has the serious problem of not being able to obtain a satisfactory yield of allyl chloride because a large amount of diallyl ether is produced as a by-product. It has its drawbacks.

[Problems to be Solved by the Invention] The present invention improves the above-mentioned drawbacks associated with conventional methods, particularly in the production method of allyl chloride using allyl alcohol as a raw material, and provides a production method that is industrially more advantageous. The purpose is to provide.

[Means for Solving the Problems] The object of the present invention is to react at a reaction temperature of 4.5 m in an aqueous hydrochloric acid solution containing as a catalyst at least one member selected from the group consisting of transition metals, magnesium, aluminum, and tin chlorides.
This is achieved by a method in which allyl alcohol is reacted at 3°C (ordinary pressure) or above, and the produced allyl chloride is immediately distilled off from the reaction system by stripping (hereinafter referred to as stripping reaction).

The transition metals, magnesium, aluminum and tin used as catalysts can be introduced into the reaction system as long as they produce chlorides. When hydroxides, oxides or carbonates of the respective metals are introduced into the reaction system, they actually exist and act as chlorides in the reaction system and can be used as catalysts. The transition metals of the present invention refer to those with element numbers 21 to 30 and 39 to 48. Among them, copper and palladium are preferred.

Although the reaction of allyl chloride from hydrochloric acid and allyl alcohol proceeds without a catalyst, the reaction rate is quite slow and is not practical. For example, in a stripping reaction, 2
Using 0% by weight hydrochloric acid in 2 times the mole of allyl alcohol, 6
Even if allyl alcohol was added dropwise at 5°C over about 1 hour, the allyl chloride produced was stripped, and stripping was continued at the same temperature for about 1 hour, the yield of allyl chloride was only about 9%. No (Table 1).

The amount m of these catalysts used in the present invention is preferably in the range of 1.0 to 100 mol % based on allyl alcohol. If the amount is less than this, the reaction rate is slow and disadvantageous. If a larger amount is used, the speed will increase, but the catalyst will precipitate, increasing the slurry turbidity and making the operation complicated, which is not preferable.

Further, even if the catalyst is added in an amount exceeding the solubility of the catalyst, it is disadvantageous because the reaction container must be made larger as the amount of reaction liquid increases.

The second feature of the present invention is to perform a stripping reaction. However, when the allyl chloride produced without performing a stripping reaction is completely refluxed, the reaction solution after the reaction is separated into two layers, and the upper layer is In addition to allyl chloride, a large amount of diallyl ether is preserved in the n-layer.

The raw material allyl alcohol in the present invention does not need to be anhydrous since the reaction is carried out in an aqueous solution, and the allyl alcohol aqueous solution can be used as it is as a reaction raw material without further purification.

The reaction temperature in the present invention is the temperature required for the stripping reaction, that is, the azeotropic point of allyl chloride and water of 43°C or higher (azeotropic composition water: 2.2% by weight), and practically, about 50°C or higher. Temperature is preferred.

The upper limit of the reaction temperature is not particularly limited, but since it is a reaction in an aqueous solution under normal pressure, it is 100°C considering the presence of inorganic salts.
The front and back are i-high. The boiling point of the reaction solution also depends on the amount of hydrochloric acid, the amount of catalyst, and the amount of allyl compound in the solution.

As mentioned above, the reaction can be carried out between 43 and 100°C, but as the reaction temperature increases, the amount of allyl alcohol and diallyl ether mixed into allyl chloride increases, so rectification in a stripping column is necessary. The load increases (the azeotropic point of allyl alcohol and water is 87.
5℃). On the other hand, as an advantage on the high temperature side, the reaction rate can be increased, the concentration of allyl compound in the liquid can be lowered, and the stripping yield of allyl chloride can be improved.

Although the reaction can be carried out in either a batch or a flow system, it is industrially reasonable to carry out the reaction in a flow system. At this time, raw materials (allyl alcohol, hydrochloric acid, catalyst) are continuously supplied, and the produced allyl chloride is stripped from the reaction system in an INR manner. At this time, a certain amount of the reaction liquid is continuously extracted from the system so as to maintain a constant liquid level.

Hydrogen chloride used in the present invention has the same mole as allyl alcohol, and the amount of hydrochloric acid introduced into the reaction system may be at least 1.05 times the mole of allyl alcohol, but if it is less than this, the reaction rate will decrease. This is disadvantageous because the yield of allyl chloride also decreases. Preferably it is 1.2 times or more.

Furthermore, when a large amount is used, the amount of reaction liquid increases, the capacity of the reaction container increases, and productivity decreases. Therefore, it is preferably about 1.2 to 10 times.

The optimum reaction time (residence time in the continuous method) for the present invention varies depending on the amount of hydrochloric acid and the catalyst m, but is about 10 minutes to 5 hours within the above range.

When the flow reaction is carried out according to the conditions and method of the present invention, the purity of allyl chloride distilled by stripping is 99% or more, giving a yield of 90 to 96%.

The organic impurities in allyl chloride obtained by stripping are allyl alcohol and diallyl ether, and almost no other components are observed. Therefore, the yield of allyl chloride can be improved by increasing the rectification efficiency of the stripping column, and further by recovering allyl chloride from the extracted liquid or returning the allyl compound to the reaction system.

The present invention is not restricted in any way by the selection of either method.

In addition, the component obtained by stripping has an azeotropic composition of allyl chloride and water, and also contains a small amount of hydrogen chloride, which can be removed by rectification of the organic layer after washing with weakly alkaline water such as sodium hydrogen carbonate. This will yield high quality allyl chloride.

The extracted reaction solution is recovered from hydrogen chloride by recovering the furyl compound, and by distilling off the water produced in the reaction and, if water-containing allyl alcohol is used, to maintain the water balance and returning it to the reactor. The majority and all 8 of the catalyst can be recycled and used.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples unless it departs from the gist of the present invention.

As support catalysts, cuprous chloride, cupric chloride, palladium chloride, cobalt chloride, titanium tetrachloride, vanadium trichloride, nickel chloride, ferric chloride, aluminum chloride,
Using magnesium chloride and tin tetrachloride, 20% by weight
218 t of salt to allyl alcohol (15Q)
Allyl chloride was stripped by dropping allyl alcohol over a period of about 1 hour at the temperature specified in each Example using the molar value, and stripping was further continued at the same temperature for about 1 hour.

Hot water at 45° C. was circulated outside the distillation column. The fraction consisted of an organic layer and an aqueous layer, and the yield was calculated from the extrusion of the active layer and the allyl chloride purity determined by GO analysis. The yield and fraction composition are shown in Table 1.

Comparative Examples 1-2 The same procedures as Examples 1-12 were carried out except that no catalyst was used. The conditions and results are shown in Table-1.

Example 13 11t-1-1, Flas et al. (200
ml) was continuously supplied with a hydrochloric acid aqueous solution of cupric chloride and a 70% allyl alcohol aqueous solution, and the reaction solution was drawn out while keeping the liquid level constant by overflowing through a side pipe from the bottom of the flask. .

The distillation column has an inner diameter of 18Φ and holds 20m1 of 4Φ glass beads.
It was filled and 45°C hot water was circulated outside.

A stripping reaction was performed using this apparatus.

Cupric chloride (15,'5% by weight), hydrogen chloride (22,0
In acid aqueous solution of cupric chloride consisting of water <62.5%) and water <62.5%) at 114.60 C1/Hr, and 70fflf1% allyl alcohol aqueous solution at 24.96
The oil bath was heated so that the temperature of the reaction solution was 75°C. The liquid level was kept constant so that 5 ml of reaction solution was 131°. The residence time is approximately 1 hour.

Stripping and overflow were continued for 3 hours, and after the system stabilized, 1 hour of data was recorded.

Fraction is 22.150/Hr, overflow liquid is 118
．． 9q/Hr: 1(-0) The fraction consists of 21.68g of organic layer and 0.470g of aqueous layer, the organic layer contains 99.2% allyl chloride, and allyl alcohol is 0.3ffiffi. %, diallyl ether was 0.51ft1%.

The yield of allyl chloride reached 93.4%.

The overflow liquid is 0.8q1 allyl chloride, 0.5c+ allyl alcohol, and 0.020 diallyl ether.
It contained.

Example 14 Same as Example 1'! Copper Jn oxide (1
0.9% by weight), hydrogen chloride (23.3%) and water (65.9% by weight) at 108.710/Hr, and 70% allyl alcohol. A stripping reaction was carried out continuously under the same conditions and method as in Example 1 by supplying an aqueous solution at a rate of 24.810/Hr.

Stripping and overflow were continued for 3 hours, and after the system stabilized, data was recorded for 1 hour. As a result, the fraction was 22.08q/1-1r, and the overflow liquid was 110.
30/Hr, and the analysis results were as follows.

The fraction consists of an organic layer of 21.6G and an aqueous layer of 0.46G, which contains 99.31% allyl chloride and 0.
．． It contained double weight percent allyl alcohol and 0.5 weight percent diallyl ether.

The yield of allyl chloride was 93.8%.

In addition, the overflow liquid is 0.6 g of 7lyl chloride,
Allyl alcohol 0.4g, diallyl ether 0.02
It contained 0.

Example 15 Palladium chloride (13,4
φ hanging%), hydrogen chloride (22.8% by weight) and water (64% by weight)
, 6% by weight) in an aqueous solution of palladium chloride in hydrochloric acid.
Example 1
The stripping reaction was carried out continuously under the same conditions and method as described above.

Stripping and overflow were continued for 3 hours, and data was recorded for 1 hour after the system stabilized.

As a result, the fraction consisted of an organic layer of 20.15a and an aqueous layer of 0°42Q, which organic layer contained 98.5% by weight allyl chloride, 0.6% allyl alcohol, and 0.8% by weight allyl chloride. It contained heavy fft% diallyl ether. The yield of allyl chloride was 87.9%.

In addition, the overflow liquid is allyl chloride 0°60,
It contained 1.1Q of allyl alcohol, J'j and 0.2q of diallyl ether.

[Advantageous Effect 1 of the Invention] An industrial method for producing allyl chloride with higher quality and higher yield than conventional methods is provided.

Claims (1)

[Claims] It is characterized in that allyl alcohol is reacted with an aqueous hydrochloric acid solution containing as a catalyst at least one selected from the group consisting of transition metal, magnesium, aluminum and tin chlorides, and the produced allyl chloride is distilled off from the reaction system. A method for producing allyl chloride.