JPS6230732A - Production of beta,gamma-unsaturated alkenyl-substituted phenol - Google Patents

Abstract

PURPOSE:To obtain the titled substance in high selectivity and yield, suppressing the side reaction, by carrying out the continuous Claisen rearrangement reaction of a beta,gamma-unsaturated alkenyl ether of a phenolic compound using a tank-type continuous reactor. CONSTITUTION:The titled substance can be produced by carrying out the Claisen rearrangement reaction of a beta,gamma-unsaturated alkenyl ether of a phenolic compound using a tank-type continuous reactor at 180-250 deg.C for 1-10hr. The tank-type continuous reactor is a reactor enabling the agitation and mixing of the raction liquid by a powered stirrer such as paddle blade, turbine blade, etc., placed in the reactor or with an exterior circulation line and circulation pump to take the reaction liquid out of the reactor and return the liqiud again to the reactor. The reactor may be used singly or two or more reactors may be connected in series. USE:Intermediate for the organic synthesis of fine chemicals, raw material of polymer, polymer modifier, etc.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing β, γ-unsaturated alkenyl group-substituted phenols by subjecting β, γ-unsaturated alkenyl ethers of phenols to Claisen rearrangement. .

More specifically, when β, γ-unsaturated alkenyl ethers of phenols are subjected to Claisen rearrangement, side reactions are suppressed and high selectivity is achieved by continuously performing Claisen rearrangement using a tank-type continuous reactor. Target β with high yield,
The present invention relates to a method for producing γ-unsaturated alkenyl group-substituted phenols.

β,γ-Unsaturated alkenyl group-substituted phenols are useful compounds as intermediates for organic synthesis of various fine chemicals, raw materials for polymer production, polymer modifiers, and the like.

(Prior art) By heating β, r-unsaturated alkenyl ether of phenol, phenol having β, γ-unsaturated alkenyl group at ortho position (in case both ortho positions are occupied) is known to rearrange to phenols having β, γ-unsaturated alkenyl groups at the para position, and this rearrangement reaction is called Claisen rearrangement (for example, Organic Reactions).
Reactions), Vol.

■, pp. 1-48).

The rearrangement reaction is usually carried out using N,N-dimethylaniline, N,N
- Easily progresses by heating to a high temperature of around 200°C in the presence or absence of a high boiling point solvent such as diethylaniline, tetralin, paraffin oil, etc. (e.g.
Ibid., pp. 29-47).

However, at such high temperatures, even β, γ-, and γ-alkenyl groups, which are much more difficult to polymerize than vinyl groups, tend to undergo thermal polymerization and other side reactions.
Undesirable by-products are formed.

Therefore, methods are known in which the rearrangement reaction is carried out under reduced pressure or in the presence of an inert gas such as carbon dioxide or nitrogen (for example, Ibid., p. 24), but the effect of suppressing side reactions is not sufficient. hard.

Furthermore, the method of using N,N-dialkylaniline as a solvent has the effect of suppressing the polymerization reaction and improving the selectivity and yield of the target substance (for example, Ibid., 24).
Page), but it is generally necessary to use a fairly large amount, and after the rearrangement reaction is completed, the solvent must be separated and removed by extraction with an aqueous mineral acid solution or distillation, so it is difficult to implement it industrially. This method is fraught with problems.

Incidentally, all conventional methods for producing β, γ-, γ-alkenyl group-substituted phenols by Claisen rearrangement described in the literature, including the above-mentioned method, have been carried out by batch reactions.

(Problems to be Solved by the Invention) An object of the present invention is to significantly suppress side reactions such as polymerization when β, γ-, γ-alkenyl ethers of phenols are subjected to Claisen rearrangement, and to , γ-, γ-alkenyl group-substituted phenols with high selectivity and high yield.

Another object of the present invention is to provide a simple and industrially advantageous method for producing highly pure β, γ-, γ-alkenyl group-substituted phenols.

(Means for Solving the Problems) In order to achieve the above object, the present inventors have investigated the reaction time and β and γ of phenols as raw materials regarding Claisen rearrangement.
−, conversion rate of γ-alkenyl ether, target product β
, production amount of γ-, γ-alkenyl group-substituted phenols,
The relationship between the amount of by-products and other factors was investigated. As a result, the amount of by-products, especially polymer by-products, increases quite rapidly at the initial stage of the rearrangement reaction, that is, at a low conversion rate, but increases only very slowly thereafter; In this case, when carrying out the Claisen rearrangement, the selectivity can be increased by coexisting in advance a certain amount or more of β-, γ-, γ-alkenyl group-substituted phenols with respect to the β-, γ-, γ-alkenyl ether of the phenol. In addition, by continuously carrying out Claisen rearrangement using a tank-type continuous reactor, conditions under which a considerable amount of β, γ-unsaturated alkenyl group-substituted phenols are always present. As the rearrangement reaction of β, γ-, and γ-alkenyl ethers of phenols is carried out below, side reactions are suppressed and the selectivity and yield can be improved, leading to the completion of the present invention.

That is, the present invention provides a method for producing β, γ-, γ-alkenyl group-substituted phenols by subjecting β, γ-, γ-alkenyl ethers of phenols to Claisen rearrangement, which uses a tank-type continuous reactor. This is a process for producing β-, γ-, γ-alkenyl group-substituted phenols, characterized in that Claisen rearrangement is carried out continuously using

Next, the present invention will be explained in detail.

β of the phenol as a raw material for producing the β, γ-unsaturated alkenyl group-substituted phenol used in the method of the present invention,
The γ-, γ-alkenyl ether is not particularly limited as long as it has a structure in which at least one position ortho or para to the β, r-unsaturated alkenyl ether group is unsubstituted.

Specific examples of β, γ-, γ-alganyl ethers of these phenols include phenol, 0-cresol, m-cresol, p-cresol, O-chlorophenol, p-chlorophenol, 0- ditrophenol, p-nitrophenol, p-aminophenol,
0-methoxyphenol, p-methoxyphenol, p
-acetoxyphenol, p-acetylphenol, 2
-Allylphenol, 2,4-dimethylphenol, 2
．． Monohydric phenols such as 5-dimethylphenol, 6,4-dimethylphenol, and 2,6-dimethylphenol. -hydroxyphenyl)methane (bisphenol F), 4.4'-dihydroxybenzophenone, 4.4'-dihydroxydiphenylsulfone, 4.
Examples include so-called β, γ-unsaturated alkenyl ethers such as allyl ether, β-methallyl ether, and crotyl ether of phenols represented by polyhydric phenols such as 4'-dihydroxydiphenyl ether and 4.4'-dihydroxydiphenyl. can.

These β, γ-unsaturated alkenyl ethers of phenols can be easily produced by a method of reacting phenols and β, γ-unsaturated alkenyl halides in the presence of an alkali metal hydroxide, etc. .

Next, when carrying out the method of the present invention, a tank-type continuous reactor is used.

The tank-type continuous reactor referred to in the present invention includes paddle blades, turbine blades, Faudler blades, pull margin blades,
By equipping a powered agitator represented by an anchor blade, screw blade, ribbon blade, etc. and/or a circulation pump outside the reactor with a circulation line that extracts the reaction liquid in the reactor and returns it to the reactor. A reactor for stirring and mixing a reaction solution, in which β, γ-unsaturated alkenyl ether of phenols as a starting material is continuously supplied to the reactor, and the reaction product is continuously supplied from the reactor. This refers to a reactor equipped with a device for taking out the reactor.

Incidentally, a baffle plate, a draft tube, etc. for improving the stirring and mixing effect, a jacket for heating/cooling, a serpentine coil, an external heat exchanger, etc. can be provided as appropriate.

The tank-type continuous reactor described above may be used alone, or two or more may be used in series. In addition, when two or more reactors are connected in series and used, the second and subsequent reactors do not necessarily have to be tank-type continuous reactors, and a pipe reactor or the like can also be used.

In addition, when using two or more reactors connected in series,
The starting material, β, γ-unsaturated alkenyl ether of phenols, is usually supplied only to the first reactor,
The second and subsequent reactors are preferably used as ripening reactors to complete the rearrangement reaction. In this case, the first
The reaction conditions are set so that the conversion rate of β, r-unsaturated alkenyl ether of phenols in the primary reactor is at least 5%, preferably 30% or more, most preferably 50% or more. good.

The reaction temperature and reaction time vary depending on the type and reactivity of the β-, γ-unsaturated alkenyl ether of the phenol, so they cannot be specified as a rule, but usually 150-3
It is appropriate to carry out the reaction at a temperature of 0.000C for about 0.5 to 20 hours (as an average residence time), preferably for about 1 to 10 hours (as an average residence time) at a temperature of 180 to 250C.

There are no particular restrictions on the reaction pressure, and the reaction can be carried out under reduced pressure, normal pressure, or increased pressure.

Reaction solvents are generally not required in the method of the invention, but
It is also possible to use solvents such as N,N-dialkylaniline, hydrocarbons, mono- or dialkyl ethers of ethylene glycol and diethylene glycol, which are used in thermal theory and Claisen rearrangement reactions.

When carrying out a continuous reaction, the β, γ-unsaturated alkenyl ether of the phenol as a starting material and/or the β, γ-product as a starting material is usually placed in a horizontal continuous reactor in advance.
After charging the unsaturated alkenyl group-substituted phenol, a method is adopted in which the starting material is continuously supplied to the reactor and the product is continuously taken out.

The continuous rearrangement reaction can be carried out by filling the reactor with liquid, or by controlling the liquid level of the reactor at a constant level, or the like.

In the method of the present invention, target substances β and γ in the reaction product are
-Since the content of unsaturated alkenyl group-substituted phenols is extremely high, the reaction product can be used as it is for many purposes, but if a product with even higher purity is required,
It may be purified by methods such as vacuum distillation.

(Example) The present invention will be explained in more detail below using Examples.

Example 1 Equipped with a stirrer, thermometer, pressure gauge, starting material supply piping (with small metering pump for raw material supply), and reaction product extraction piping (manually operated needle valve, cooler, receiver) o, o'-diallyl bisphenol A3 was placed in a stainless steel autoclave with an internal volume of 5 oooil in advance.
0019 was charged, and while stirring and controlling the internal temperature at 200°C, the diallyl ether of bisphenol A, which was the starting material, was added to 701! It was supplied continuously at a flow rate of time i.

From the time when the autoclave was filled with liquid and overflow of the reaction product started, continuous reaction was carried out while maintaining the internal temperature at 200°C and the internal pressure at 5 kg/i (controlled by manual operation of the dollar valve). .

After 24 hours had passed since the start of overflow, when a steady state was reached, one hour's worth of reaction products were sampled (7019).

The reaction product was analyzed using gas chromatography (
Using bisphenol A as an internal standard, quantitative analysis after trimethylsilyl etherification treatment revealed that the composition was 96% o,o'-diallylbisphenol.
6% by weight and 1.9% by weight of unreacted diallyl ether of bisphenol A, and the conversion rate calculated based on this was 98.1% and the selectivity was 98.5%.

Example 2 The autoclave used in Example 1 was used as the first reactor, and the second reactor was a separable flask equipped with a stirrer, thermometer, reflux condenser, and a side pipe for overflow (overflow during stirring). The internal volume up to the side pipe is 200 mA! The overflowing reaction product from the second reactor is cooled in a cooler and then taken to a receiver. Note that there is a needle valve sealed between the first reactor and the second reactor. (Connected by piping)
The continuous Claisen rearrangement of diallyl ether of bisphenol A was carried out using the following method.

After charging 30,019,120 g of 0,0'-diallylbisphenol A into the first reactor and the second reactor, respectively,
The diallyl ether of bisphenol A, which is a starting material, was continuously supplied to the first reactor at a flow rate of 10,019/hour (the internal temperatures of both the first and second reactors were 210° C.).

The first reactor (internal pressure 5 kg/crIG), followed by the second reactor
24 hours have passed since the overflow of the reaction product started from the reactor (under atmospheric pressure), and when a steady state has been reached, one hour's worth of reaction product (100!i) is collected,
As a result of analysis using the same method as in Example 1, the composition was 0.
．． 98.1% by weight of 0'-diallyl bisphenol A and 0.3% by weight of unreacted diallyl ether of bisphenol A, and the conversion rate calculated based on this was 99.7%.
, the selectivity was 98.4%.

Comparative Example 1 The same reactor as in Example 1 was charged with diallyl ether 300II of bisphenol A, and Claisen rearrangement was performed at a temperature of 200°C for 7 hours using a batch method.The reaction product was analyzed in the same manner as in Example 1. As a result, the composition was o,o'-diallylbisphenol A 92
．． 8% by weight, and 0.7% by weight of unreacted diallyl ether of bisphenol A (conversion rate = 99.3%, selectivity: 93.5%).

Example 3 A continuous isomerization reaction of allyl phenyl ether was carried out in the same manner and under the same conditions as in Example 1, except that allyl phenyl ether was used instead of o,0'-diallylbisphenol A in Example 1. As a result, The composition of the reaction product is 2-
The content was 95.0% by weight of allylphenol and 2.11% of unreacted allyl phenyl ether (conversion rate = 9).
Z9%, selectivity: 97.0%).

Comparative Example 2 300 g of allyl phenyl ether was charged into the same autoclave as in Example 1, and a rearrangement reaction was carried out at a temperature of 200°C for 7 hours using a batch method. As a result, the composition of the reaction product was as follows.
The content was 91.5% by weight of 2-allylphenol and 0.5% by weight of unreacted allyl phenyl ether (conversion rate: 99%).
．． 5%, selectivity: 92.0%).

(Effects of the Invention) As described in detail above, the method for producing β, γ-unsaturated alkenyl group-substituted phenols of the present invention uses a continuous tank type reactor to produce phenols with θ, γ-substituted phenols. By continuously performing Claisen rearrangement of unsaturated alkenyl ether,
It suppresses side reactions, particularly polymerization reactions, and makes it possible to produce β, γ-unsaturated alkenyl group-substituted phenols with high selectivity and high yield.

Incidentally, such excellent effects cannot be achieved in batch reactions or continuous reactions using continuous reactors other than slow-tank type reactors, and are unique to single-type reactors.

Furthermore, the method of the present invention produces highly pure β,γ-unsaturated alkenyl group-substituted phenols without using solvents such as N,N-dialkylaniline or special additives to suppress side reactions. Therefore, the reaction product can be used as it is for various purposes without any particular refinement.

Therefore, the method for producing β, γ-unsaturated alkenyl group-substituted phenols of the present invention is extremely advantageous and has high industrial utility value.

Claims (1)

[Claims] (1) In a method for producing β, γ-unsaturated alkenyl group-substituted phenols by subjecting β, γ-unsaturated alkenyl ethers of phenols to Claisen rearrangement, a tank type continuous reactor is used to continuously produce phenols substituted with β, γ-unsaturated alkenyl groups. A method for producing β, γ-unsaturated alkenyl group-substituted phenols, characterized by carrying out Claisen rearrangement.