JPS5920240A - Preparation of organic compound - Google Patents

Abstract

PURPOSE:To prepare vinylbenzaldehyde in high yield, by using easily available vinylbenzyl chloride or bromide as a raw material, reacting the compound with hexamethylenetetramine in water or in a hydrophilic solvent, and heating the product in the presence of water. CONSTITUTION:Vinylbenzyl chloride or vinylbenzyl bromide is made to react with hexamethylenetetramine in a hydophilic solvent such as ethanol, acetic acid, acetonitrile, etc. or in water, preferably in the presence of a polymerization inhibitor such as t-butylcatechol to obtain an ionic addition product as an intermediate, which is hydrolyzed under heating in the presence of water to afford the objective vinylbenzaldehyde. EFFECT:The reaction can be carried out easily without separating the intermediate. USE:Raw material of functional polymers.

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide monomers useful as raw materials for functional polymers. Specifically, it is an object of the present invention to provide a method for easily producing vinylbenzaldehyde.

Conventionally, several reports have been made regarding methods for producing vinylbenzaldehyde, and the outline thereof is as follows. That is, R, H, Wiley +P, H, H
method by decarboxylation of formylcinnamic acid by J. obson [J'ownal of American Ch.
em, Soc, 71 +2429 (1949) and Journal of Polymer Science
, 5.4.483 (1950) :),
Methods include dehydration of formyl alcohol, hydrolysis of dimethoxymethylstyrene, and reaction of vinylphenylmagnesium chloride with dimethylformamide. However, these conventional methods require long steps to produce each raw material to obtain vinylbenzaldehyde, have a low overall yield, or are difficult to recover. The problem was that I couldn't get it.

The inventors conducted various voltage tests in order to solve the problems in the conventional manufacturing method, and as a result, they arrived at the present invention.

That is, the present invention provides t6 H=/l/H/S/l which is obtained by separating vinylpentyl chloride in a hydrophilic bath medium or water.
This is a method for producing vinylbenzaldehyde by reacting /bromide with hexamethere/tetramine, followed by a thermal reaction in the presence of water. The feature of the present invention is that the reaction is continuous without separating intermediates. It is possible to easily produce vinylbenzaldehyde in high yield. Another feature is the use of easily obtained vinylbenzyl chloride or bromide as a raw material.

The raw material vinylbenzyl chloride or bromide is
It is a well-known fact to those skilled in the art that vinylbenzaldehyde can be easily obtained from ethylbenzene.In the method for producing vinylbenzaldehyde of the present invention, it is thought that a two-step reaction proceeds based on the reaction mechanism. In the first step, vinylbenzyl chloride or bromide and hexamethyltetramine react to form an ionic adduct as an intermediate. In the second step, the intermediate is heated in the presence of water and undergoes oral decomposition to produce the target vinylbenzaldehyde.

Therefore, in the production method of the present invention, vinylbenzyl chloride or vinylpenzyl bromide, hexamethylene ketolami, and water or a hydrophilic solvent are required.

Vinylbenzyl chloride or bromide may be in the meta or para form, or a mixture of these isomers. Usually, it can be used as long as it has a purity of 80% or more, but preferably has a purity of 90% or more. Vinylbenzyl chloride-covered bromide is produced from ethylbenzene as described above, but commercially available products may also be used.

Hexamethylene ketorami/ can be used as a commercially available product. Although there is no particular limitation, the amount used is preferably 0.8 mol to 10 mol, preferably 1 mol to 6 mol, per 1 mol of vinylbenzyl chloride or bromide. In the present invention, it is necessary to use a monohydrophilic bath medium or water as a solvent. A hydrophilic solvent is 20'U
It refers to a liquid that can melt water at 5wt or more, 0% or more. Examples of hydrophilic solvents that can be used include alcohols having 1 to 7 carbon atoms, aliphatic carboxylic acids having 1 to 5 carbon atoms, aceto/, methyl ethyl keto/, keto/s such as cyclohexanone, tetrahydrofura/, Ethers such as dioxa/, nitriles such as acetonitrile and propionitrile, dimethylformamide, dimethylacetamide, N-
Examples include amines V such as methylpyrrolisif, dimethylforpogicide, sulfolane, etc., and solvents containing two or more of these functional groups in the molecule, such as cellosolve, diglyme, dimethoxyethane, and the like. Among these, solvents that are inert to the raw materials and products under the reaction conditions are preferred. In order to improve the yield, a highly preferred solvent has a boiling point of 60° C. or more in order to allow the second stage reaction to proceed sufficiently.

In addition, in order to easily separate vinylbenzaldehyde when performing post-reaction treatment and purification steps such as distillation, boiling point 1
Solvents below 50°C are advantageous.

Particularly in such cases, examples of preferable solvents include alcohols having 1 to 5 carbon atoms (e.g., ethanol, impropatol, n-butanol, n-amyl alcohol, etc.).
, acetic acid, propionic acid, tetrahydrofuran, dioxa/, cellosolve, dimethoxyethane, methyl ethyl keto/, cyclohexanone, acetonitrile, etc.

These solvents may be used alone or in a mixture of two or more without any problem. Further, the hydrophilic solvent may be used in the form of a mixed solvent with water. The amount of hydrophilic solvent or water used is 1 to 50 times, preferably 2 to 20 times, the volume of vinylbenzyl logenide.

Such a hydrophilic solvent or water is a hydrophilic solvent that has the property of being capable of decomposing not only the raw materials vinylbenzyl chlorinide and hexamethylene tetodymium, but also the intermediate. The reason why aqueous solvents or water are effective is not clear at first glance, but it is thought to be due to the above-mentioned dissolving power and hydrophilic washing for intermediates of aqueous solvents or water. That is, since the intermediate can be bath-dissolved, the first stage of the reaction proceeds at a high conversion rate, and furthermore, in the second stage, which requires reaction with water, the water and the hydrophilic solvent are homogeneous or equivalent to that. VC first because it forms a vinegar solution and the reaction takes place in it.
Similar to Yoshikaa, it is thought that a high rate of conversion will occur.

In the production method of the present invention, in the second stage of the reaction,
The presence of water is essential. Water may be used as a solvent or a part thereof in the first stage of the reaction, or may be added after the first stage is completed. Total amount of water that should be used
is theoretically 6 mol per 1 mol of vinylbenzyl chloride or promyr, and usually 10 to 2
00 mol, preferably 15 to 150 mol.

The reason why hydrophilic solvents or water are particularly effective during the synthesis of vinylbenzaldehyde is that in addition to their characteristics such as high reaction yields, they can be placed in a much more advantageous position in the vinylbenzaldehyde method. . That is, after reaction in the presence of a hydrophilic solvent or water 1, the i! Vinylbenzaldehyde forms adducts with hydrogen sulfite etc. in a high yield in the same system, and this adduct directly or by adding an appropriate solvent becomes a precipitate suitable for vinylbenzaldehyde recovery. It is from. Although vinylbenzaldehyde is not extremely sensitive, it is thermally polymerizable, so the effect of recovering and purifying it without applying heat is great.
In addition to the above-mentioned essential components, polymerization inhibitors and the like may be added. Military @ Inhibitor and 17, Hydrokino/, 1. -butylcatechol, t-butylhydroquino/, t-butyladei)F
Including phenolics such as -4-hydroxy-anisole and 2,6-di-t-bunalhydrogycitoluene, diphenylamine, diphenylvicrylhydrazine, P-benzoquinone, N-methyl-N-nitrosoanili/, and cuperone. , n-butylnitrile, etc. Among these, phenolic combination inhibitors are particularly preferred 1. The time of addition of the combination inhibitor is not limited to %, but is at the beginning of the combination reaction. Further, if necessary, the addition may be performed in two or more times at different times.

The degree of use of the polymerization inhibitor is lJ, 01 to 20 mol, preferably 0.05 mol, relative to vinylbenzyl halobide.
~5 mol%.

The manufacturing method of the present invention is embodied in the Examples described below, and the outline thereof is as follows.

Dissolve vinylbenzyl chloride or bromide in a solvent! Or emulsify. At this time, a polymerization inhibitor may be added if necessary. Add the required amount of hexamethylenetetramine to it while stirring.

The reaction temperature is between room temperature and 60°C, which is sufficient to complete the first stage of the reaction, but the reaction temperature may be increased from room temperature to a temperature between 6°C and 110°C for the second stage. After raising the temperature to 60 to 110'C, if water is still not present in the solvent or if the amount of water is insufficient, it is necessary to add a predetermined amount of water. Then,
After stirring with oil for 1 to 8 hours σ), the reaction is terminated. In order to hasten the completion of the reaction, hydrochloric acid may be present during the second stage heating reaction. After the reaction, it can be treated and purified according to conventional methods. For example, the solvent is distilled off under reduced pressure and then vacuum distilled to obtain vinylbenzaldehyde.

Alternatively, steam distillation may be performed directly after the reaction. If necessary, an appropriate extraction operation or the like may be performed at the processing stage.

In addition, the second stage reaction and purification may be carried out by steam distillation without adding water in advance. It is 1.95% or more. s＜L
The monomers obtained can be used in the synthesis of one-dimensional polymers. If desired, it is possible to further improve the purity through vacuum distillation.

The manufacturing method of the present invention will be concretely described below with detailed examples, but the scope of the present invention and its scope is not limited thereto.

Example 1 Vinylbenzyl chloride (m-form/p-form = 6; 4)
30.51 iF and t-butylcatechol 1. OF was dissolved in 1501d of ethanol, and a solution prepared by dissolving 65g of hexamethylenetetramine in 6Qme of water was added thereto. The temperature was raised to 50'C, stirred for 60 minutes, and then further heated to 80'0.
I 1. Ta. After stirring at a temperature of 80°C for 6 hours, the reaction was terminated. After the reaction, 30F sodium chloride was added, and methylene chloride 150111 was added and stirred at high strength to separate the layers. 150 ml of methylene chloride was added to the aqueous layer again, and the same treatment was carried out. The solvent was distilled off from the diluted methylene chloride extract.

The residue was vacuum distilled to obtain product 20.1F (71
~73°C/4% Hg).

Yield/6% (Gl, C), elemental analysis: c; 81.47%
, t+; 6.01%, O; 1206qb.

The results of infrared (IR) analysis are shown in FIG. The purity (gold side of m-form, 1-form) measured by gas chromatography (GLC) is 97%. IR Gara-CH2(J(C-
czl 27 Q cln-”) completely disappeared,
On the other hand, absorption of aldehyde (C=0 1700c+I+-
1) appears strongly, indicating that the raw material is not present and the target is present.
No 0 also) IMR, vinyl group (δ(Il, l
b-2~6.2 and 6.6~7.15), formyl group (δ value; 9.5), be/zene nucleus (δ value; /, 4~8.
15) was observed, and the integral ratio of the valley signal also indicated that it was vinylbenzaldehyde.

Fruits/Decorations 2 to 6 (and Comparative Examples 1 to 2) Anti-ffL was prepared in the same manner as in Example 1, except that instead of ethanol, the same amount of the following solvent with <7ffi was used.
1. When silk production was carried out, the results shown in Table 1 were obtained.

Table 1 Example 7 P-vinylbenzylchloride y 30. ! 5 g'cD
0.3 g of 2.6-di-L-butylhydroquinone and 742 g of hexametere/detrami were sequentially added to the solution dissolved in 120 ml of 1-acid while stirring. 9000 ml of this mixture
At the point where the mixture was heated to 70ml, 70ml of water was added and the mixture was stirred for 2 hours to complete the reaction. After distilling off the solvent (water and acetic acid) from the reaction mixture, product 19.69 was obtained (90
~93°C/4mmHg).

Yield 73%, purity 96% (GLC analysis).

Example 8 To a solution of n]-vinylbenzyl bromide 39.4 F in dioxane 20 Q mt, hexamethylene tetrami 728 F was added portionwise over 5 minutes.

After stirring at room temperature for 1 hour, 1501 d of water was added.

After heating and stirring for 11 hours at 958C, 2N hydrochloric acid 10
After addition of Yc, heating and stirring were continued for 10 minutes to complete the reaction. After distilling off the solvent under reduced pressure at 50'C, pm-vinylbenzaldehyde 17.2F was obtained by simple distillation.
/ obtained (87-90'C/ 5mrnHI/')
.

Yield 65%, purity 96% (GLC).

Elemental analysis: C; 82.2 o%, H; 6.12%
, O: 11.64%.

Example 9 A reaction was carried out exactly as in Example 8, except that P-vinylbenzyl bromide 39.4 N was used in place of Il monomer. P-vinylbenzaldehyde 16.4&(
90-93 °C/4 mp HCl) was obtained. Yield 6
3%, purity 96% ((1L C').

Example 10 Vinylbenzyl chloride 3 [J, 5, ? and 5 g of diphenylene/L=7 amine (J) were added to 300 rnt of water containing 1 g of sodium lauryl sulfate and dispersed with stirring.

5 og of hexamethylenetetramine was added thereto. 5
The reaction was completed by stirring at 0° C. for 2 hours and then under reflux for 2 hours. The reaction solution was extracted with chloroborum, chloroform was distilled off, and the residue was distilled after distillation to obtain 14.8 g of vinylbenzaldehyde (72-b 5 g). It was pi. Yield 56% (OL, C
).

[Brief explanation of the drawing]

FIG. 1 shows the infrared absorption spectrum of the reaction product in Example IK. Special applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] A method for producing vinylbenzaldehyde by reacting vinylbenzyl chloride i ft with vinylbenzylpromer and hexamethylenetetrami in a hydrophilic solvent or water, and then heating the reaction in the presence of water.