JPS6027662B2 - Nitrile manufacturing method - Google Patents

Description

Detailed Description of the Invention The present invention produces nitrile by reacting an organic halide and an alkali metal cyanide in the presence of a specific polyoxyalkylene ether in a liquid phase heterogeneous system consisting of an aqueous phase and an organic phase. Relating to a method of manufacturing.

Conventionally, when conducting an organic reaction, an aqueous phase and an organic liquid have been separated in order to simplify the separation of products after the reaction and/or to make the reactants and catalysts that are too thick to dissolve in the organic liquid to act effectively. The use of liquid-phase heterogeneous systems consisting of phases is well known.

In order to effectively advance a reaction between different phases consisting of an aqueous phase and an organic phase, it is necessary to devise ways to facilitate the interaction between the components present in the aqueous phase and the components present in the organic phase. Methods include a method using a surfactant and a method using a phase transfer catalyst. Examples of applications of methods using surfactants can be found, for example, in emulsion polymerization and ester hydrolysis reactions in the field of biochemistry. The purpose of using this surfactant is to increase the contact interface between the organic phase and the aqueous phase, to facilitate the transfer of organic substances to the aqueous phase, or to facilitate the transfer of components in the aqueous phase to the organic phase. Except in limited cases such as reactions, they generally do not produce a sufficiently satisfactory reaction promoting effect. In the method using a phase transfer catalyst, a metal compound is dissolved in an aqueous phase, and the active anion from the metal compound is removed by the phase transfer catalyst.
Anion) is transported into the organic phase, and the organic ion reaction between the organic reactant and the active anion proceeds in the organic phase. Quaternary ammonium salts and phosphonium salts having a moderate carbon chain have been conventionally used as phase transfer catalysts, but these are generally expensive and their production methods are complicated. Desired phase transfer catalysts are not easily available. Furthermore, since these quaternary ammonium salts and phosnium salts are thermally unstable, they easily decompose when separating each component from the reaction mixture, resulting in loss of these salts and side reactions caused by decomposition products. , which may lead to a decrease in product purity. Furthermore, since quaternary ammonium salts and phosnium salts are cationic compounds, there are limits to the range of reactions in which they can be used. On the other hand, reaction examples using /ionic phase transfer catalysts are also already known. It has been demonstrated in several cases that macrocyclic polyethers, named crownethers, can be used as phase transfer catalysts. However, compared to the quaternary ammonium salts and phosnium salts mentioned above, crown ethers are more difficult to manufacture and purify and are extremely expensive. It is very difficult to choose. Over the past few years, the following polyoxyethylene derivatives (octopus-shaped molecules, oct
Research has also begun on the catalytic ability of the operational vessel Molec Yamae).

These polyoxyethylene derivatives are compounds characterized by having two or more di- or triethylene glycol chains located very close to each other or attached to the same atom, which can be used as a transfer catalyst. When used as a crown ether, it has been reported that in some cases it exhibits catalytic activity comparable to that of crown ethers.

In these polyoxyethylene derivatives, weak bonds (e.g. hydrogen bonds) form a more rigid cyclic structure between adjacent di- or triethylene glycol chains, and catalytic activity is expressed by trapping metal cations in the cyclic structure. It is considered a thing. As is clear from their unique structure, these polyoxyethylene derivatives are not easy to manufacture and are extremely expensive. In particular, the above compound {c}' is said to exhibit a fairly high catalytic ability as a phase transfer catalyst, but like the nonionic surfactants used for the hydrolysis of esters in the field of biochemistry, it is Since one end of the oxyethylene chain is a hydroxyl group, it often undergoes a reaction itself in the coexistence of an alkali metal compound, which limits its applicability. The inventors of the present invention have conducted intensive research to resolve the problems of the secondary method described above and more advantageously conduct organic ion reactions in a liquid phase heterogeneous system consisting of an aqueous phase and an organic phase. In addition, it was discovered that certain polyoxyalkylene ethers have extremely excellent catalytic ability (reaction promoting effect) despite their completely linear polyether structure, leading to the present invention.

That is, according to the present invention, between different phases consisting of an aqueous phase and an organic phase, the following general formula [where x and y are the sum of both (x+y
) is a number of 0 or more with an average of 6 to 30, and RI and R2 are substituted or unsubstituted with a total number of carbons of n/2 or more (RI and R2) is a hydrocarbon group or a trialkylsilyl group, and x of -CQCH20 and y of -CQCH20 may be arranged arbitrarily]. Nitriles can be effectively produced by reacting them with compounds.

The polyoxyalkylene ether of general formula (1) used in the present invention has an average number of oxyalkylene units (
It is most important that n) is from 6 to 30 (preferably from 7 to 15); in the case of ethers with di-, tri-, and tetraethylene glycol chains where n is 5 or less, especially 4 or less, the catalytic activity is If n exceeds 30 and is not substantially expressed, the catalyst activity will not only decrease, but also catalyst synthesis will become difficult, and solubility and other properties will deteriorate, making it impractical.

Note that n represents the average number of units and is not necessarily an integer. RI and R2 in general formula (1) are
Since the desired reaction takes place between the aqueous and organic phases,
The reaction rate is inevitably limited to some extent by the above-mentioned n, and the reaction rate increases significantly when the total number of carbon atoms (m) of RI and R2 is n/2 or more. RI and R2,n
The reaction system may apparently form an emulsion depending on the alkali metal cyanide concentration in the aqueous phase, the reaction temperature, the organic reactant, the reaction product, the medium, the ratio of the aqueous phase to the organic phase, etc. Such appearance (state of the system) is essentially unrelated to the catalytic action of the polyoxyalkylene ether in the present invention. However, industrially, when separating the reaction product after the reaction by a method known per se, it is desirable that the aqueous phase and the organic phase be easily separated into two layers, so the desirable relationship between n and m is Although it varies depending on the type of reaction and reaction conditions, one empirical rule holds true. This and RI and R
Considering the ease of industrial introduction of 2, the solubility of the synthesized polyoxyalkylene ether in the organic reaction medium, and the physical properties (physical constants) such as melting point and boiling point, n and m are n
It is preferable to satisfy the relationship: /2<m<60, particularly nSm<40. Typical examples of RI and R2 include methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, cetyl, stearyl, allyl, bentenyl, decenyl, oleyl, etc. saturated or unsaturated aliphatic hydrocarbon groups, alicyclic hydrocarbon groups such as cyclohexyl, methylcyclohexyl, ethylcyclohexyl,
Substituted phenyl groups such as phenyl group, butylphenyl, /nylphenyl, te'sylphenyl, unde-sylphenyl, dodecylphenyl, substituted penzyl groups such as benzyl group, methyl-substituted penzyl, nonyl-substituted penzyl, and trialkylsilyl such as trimethylsilyl. Examples include groups. However, RI and R2 are selected from among these substituted or unsubstituted hydrocarbon groups and trialkylsilyl groups, with n/2<m, preferably n/2<m<60,
Particularly preferably, the bond is selected so as to satisfy nSm<40. The above general formula used in the present invention (
The polyoxyalkylene ether represented by 1) is generally produced industrially by a polyaddition reaction of the corresponding alcohol or phenol with ethylene oxide or (and) propylene oxide, and is generally produced by the following general formula [where x and y are have the same meaning as those in formula (1), and R is the same as RI or R2 in general formula (1)]
Since it can be easily produced by etherifying or silyl etherifying the compound represented by by a method known per se, it is extremely inexpensive and can be widely used for R1, R2.
and (=x10y), and the optimum polyoxyalkylene ether can be easily selected depending on the type of reaction.

Furthermore, when the polyoxyalkylene ether of general formula (1) is used as a reaction promoter (or catalyst) according to the present invention, since the polyoxyalkylene ether is extremely stable chemically and thermally, A wide range of reactions can be carried out under a wide range of conditions. In addition, since the polyoxyalkylene ether serves as a high boiling point solvent when distilling each component from the organic phase after the reaction, the overall distillation yield can be improved. An additional advantage also arises. When the method of the present invention is carried out industrially, the amount of polyoxyalkylene ether of general formula (1) to be added is:
Although not particularly limited, the so-called catalyst amount (ca
In general, the amount is preferably in the range of about 0.001 to 1.0 mol, particularly about 0.01 to about 0.3 mol, per 1 mol of the organic reactant.

In the method of the present invention, the use of an organic solvent that is chemically stable under the reaction conditions is often advantageous in terms of process engineering and economics.

The solvent that can be used should be appropriately selected depending on the type of reaction, but typical solvents that can be used over a relatively wide range include hydrocarbons such as hexane, octane, cyclohexane, benzene, and toluene, dibutyl ether, Ethers such as tetrahydrofuran and anisole,
Examples include nitrile agents such as acetonitrile and benzonitrile. Depending on the type of organic ion reaction, esters such as ethyl acetate, butyl acetate, methyl propionate, and phenyl acetate, and alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol can also be used. There is no original limit on the amount of these solvents used. However, the ratio of the organic phase to the aqueous phase in the reaction system is generally 10:1 to 1 by volume.
:10 is preferably in the range of 3:1 to 1:3. In order to carry out the reaction in a non-emulsion state, to increase the reaction rate or to facilitate phase separation after the reaction, it is desirable to have a relatively high salt concentration in the aqueous phase;
For this purpose, various harmless salts may be added to the reaction system or to the mixture after the reaction. The reaction temperature should be selected appropriately depending on the individual reaction, but for example, conducting the reaction at the boiling temperature of the solvent, organic reactant, reaction product, etc. is not practical from the viewpoint of removing the reaction heat. is also useful. When carrying out the method of the present invention, the general method for treating the mixed liquid after the reaction is to separate the reaction mixed liquid into an aqueous layer and an organic layer, and to separate each component from the organic layer by distillation. . Although there are many organic halides that can be used in the process of the present invention, organic chlorides and organic bromides are preferred industrially.

Organic halides with a halogen atom bonded to a tertiary carbon may also cause elimination reactions, so it is recommended to use an organic halide with a halogen atom bonded to a primary or secondary carbon. good. Preferred organic halides include, for example, methyl chloride, methyl bromide, ethyl chloride, ethyl bromide, n-butyl bromide, and n-butyl bromide.
- Primary alkyl halides (chloride and bromide) such as butyl chloride, n-octyl chloride, and n-octyl bromide; secondary alkyl halides represented by isopropyl chloride, isopropyl bromide, sec-butyl chloride, sec-butyl bromide, etc. (chloride and bromide), cyclohexyl chloride, cyclohexylb. Cycloalkyl halides (chloride and glomid) such as mido, 1,2-dichloroethane, 1
・2-dipromoethane, 1.4-dichloroethane, 1.
4-dibromoethane, 1,3-dichloroproban, 1.
Alkane dihalides (chloride and bromide) represented by 6-dichlorohexane, dichloromethane, etc., allyl chloride, allyl bromide, prenyl chloride, 1
- Examples include allylic halides (chloride and bromide) such as 4-dichloro-2-ptene, geranyl chloride, and crotyl bromide, and aralkyl halides (chloride and bromide) represented by benzyl chloride and benzyl bromide. .
Alkali metal cyanides include LjCN, NaCN,
Examples include KCN, but NaCN and KCN are industrially particularly preferred in view of reaction rate, economy, and post-treatment of the reaction mixture. There is no particular limit to the amount of these metal cyanides used, but usually 2
It is used in the reaction as a 0-7% by weight aqueous solution. The reaction temperature is generally selected within the range of about 00°C to about 150°C. Allyl halide and pendyl halide have a faster reaction rate than other organic halides, so they can be reacted at a lower temperature. Industrially, one simple method is to remove the heat generated by the reaction using a solvent or the latent heat of distillation of the organic halide. Of course, external heating or cooling is also possible. Generally, the reaction is carried out under atmospheric pressure, but it is also possible to carry out the reaction under increased pressure or slightly reduced pressure. Hereinafter, the present invention will be explained with reference to examples, but these only illustrate one part of the present invention.
The present invention is not limited by these examples.

M% in the examples means weight%. Example 1 A 6% aqueous solution of sodium cyanide (20%) is placed in a 100' four-necked flask equipped with a thermometer, a box frame apparatus and a reflux condenser.
I, benzyl chloride 80 mmol, and C8 days, 7
0 (C2 days 40) 7C8 days, 71.0 mmol was added, and the mixture was allowed to react at 10 pC for 8 hours while stirring vigorously.

After the reaction, mesitylene was added to the organic layer as an internal standard and analyzed by gas chromatography. 75 mmol of pendyl cyanide was produced. As a result of distilling the obtained organic layer under reduced pressure, 8# of pendyl cyanide was obtained as a crab fraction on the 60:00/1 side Hg. Example 2 In the same reactor as in Example 1, 6 x % of potassium cyanide was added.
Aqueous solution 20 I, n-octyl bromide 100 mmol,
and mole, and while stirring vigorously, 100oo
The reaction was carried out for 9 hours.

After the reaction, the organic layer was analyzed by gas chromatography, and it was found that n-octyl cyanide was produced in a yield of 98% based on the added n-octyl bromide.

Examples 3 to 9 and Comparative Example 1 In Example 2, an organic compound was prepared from an organic halide by the same reaction conditions and operations as in Example 2 except that one or both of the organic halide and the polyoxyalkylene ether were changed. Performed nitrile synthesis.

The results obtained are shown in Table 1 below. In addition, in Table 1,
All yields are the yields of each product based on the added organic halide. Table I

Claims (1)

[Claims] 1 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. between different phases consisting of an aqueous phase and an organic phase ▼ [In the formula, x and y are such that n is The average is 6-30. is a number greater than or equal to 0, and R^1 and R^2 are those (R
A substituted or unsubstituted hydrocarbon group or trialkylsilyl group in which the total number of carbon atoms in ^1 and R^2) is n/2 or more, and x -CH_2CH_2O- and y ▲ mathematical formula, chemical formula , tables, etc. are available. ▼ may be arranged arbitrarily.] A method for producing a nitrile, which is characterized by reacting an organic halide and an alkali metal cyanide in the presence of a polyoxyalkylene diether represented by the following.