JP3242173B2 - Method for producing α, α'-diacetoxyazoalkanes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing α, α'-diacetoxyazoalkanes.

[0002]

2. Description of the Related Art The fact that α, α'-diacetoxyazoalkanes exhibit excellent ability as a polymerization initiation catalyst for compounds containing a polymerizable double bond such as styrene, methyl methacrylate, and vinyl acetate is, for example, as follows. USP 3,282,9
12, Mem. Fac. Eng., 1980, 21, 141-9. Further, α, α′-diacetoxyazoalkanes do not have the cyano group of azo compounds, which are one of the currently widely used polymerization initiation catalysts. Are even less toxic and are highly preferred in the current context of environmental concerns.

[0003] However, it is difficult to produce α, α'-diacetoxyazoalkanes, so that their use as polymerization initiation catalysts is limited.

That is, α, α ′ represented by the general formula [Formula 5]
-Diacetoxyazoalkanes have been conventionally produced by reacting α, α'-dihalogenoazoalkanes represented by the general formula [Chemical Formula 6] with sodium acetate in glacial acetic acid. However, the α, α′-dihalogenoazoalkanes are very unstable compounds, and decompose before reacting with sodium acetate.
The yield of α'-diacetoxyazoalkanes may be extremely low, or isolation and purification may be difficult due to the formation of by-products.

[0005]

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[Wherein R ¹ and R ² are the same or different and each represents a lower alkyl group or an aryl group. ]

[0007]

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Wherein R ¹ and R ² are the same as above. X represents a halogen atom. ]

[0009] 1,1'-azobis (1-acetoxy-1-) which is one of α, α'-diacetoxyazoalkanes
Taking phenylethane) as an example, the above USP 3,
In Example 14 of 282,912, the yield was 87.5%, which is an oily product containing a large amount of by-products, and no crystalline product of the azoalkane was obtained. In fact, according to Japanese Patent Application Laid-Open No. 50-157485, 30
% Yield. Further, since a large amount of a solvent such as glacial acetic acid, which is difficult to handle, is used, the reaction operation itself becomes complicated.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to make the reaction operation easy, and to produce α,
An object of the present invention is to provide a method for producing α′-diacetoxyazoalkanes.

[0011]

The present invention is characterized by reacting an amine with an α, α'-dihalogenoazoalkane represented by the general formula (1) in acetic acid. The present invention relates to a method for producing α, α′-diacetoxyazoalkanes represented by the formula (1).

[0012] Further, the present invention is a mixed solution of acetic acid and halogenated hydrocarbons, alpha represented by amine及beauty acetic acid sodium and general formula (1), is reacted α'- dihalogeno azo alkanes The present invention relates to a method for producing α, α′-diacetoxyazoalkanes represented by the general formula (2).

[0013]

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Wherein R ¹ and R ² are the same or different and represent a lower alkyl group or an aryl group. X represents a halogen atom. ]

[0015]

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Wherein R ¹ and R ² are the same as above. ]

The α, α′-dihalogenoazoalkanes of the general formula (1) used as a raw material in the present invention are known compounds, and their production methods are also known. For example, it can be produced by reacting ketone and hydrazine hydrate to obtain ketazine, and reacting ketazine with halogen such as chlorine or bromine. Preferred specific examples of the compound (1) include:
For example, 1,1′-azobis (1-chloro-1-phenylethane), 1,1′-azobis (1-bromo-1-phenylethane) and the like can be mentioned.

In the present invention, as the amine to be reacted with the azoalkane represented by the general formula (1), known amines can be widely used, for example, a primary amine represented by RNH ₂ such as ethylamine and propylamine, and dimethylamine. Secondary represented by (R) ₂ NH such as amine and diethylamine
Tertiary amines represented by (R) ₃ N such as tertiary amines, trimethylamine and triethylamine (R represents an alkyl group having 1 to 10 carbon atoms); heterocyclic amines such as piperidine, pyridine and pyrrole; Can be mentioned. The amount of the amine used in the present invention is not particularly limited and can be appropriately selected from a wide range, but is usually about 0.1 to 30 mol per 1 mol of the azoalkane of the general formula (1).
Preferably, it may be about 0.2 to 3 mol.

In the present invention, sodium acetate may be used together with the amine only when the azoalkane of the general formula (1) is reacted with the amine in a mixed solvent of acetic acid and a halogenated hydrocarbon. The amount of sodium acetate used is not particularly limited and can be appropriately selected from a wide range.
The amount is usually about 2 to 4 mol, preferably about 2 to 2.5 mol, per 1 mol of the azoalkane of the above general formula (1).

The amount of acetic acid used in this reaction is not particularly limited and can be appropriately selected from a wide range.
Is usually about 0.1 to 3 l, preferably about 0.5 to 1.5 l, per 1 mol of the azoalkane.

In this reaction, a halogenated hydrocarbon may be used together with acetic acid as a solvent. The use of halogenated hydrocarbons has the advantage that not only can the desired product be obtained in high yield, but also the amount of acetic acid used can be considerably reduced, and the reaction operation can be simplified. The halogenated hydrocarbon is not particularly limited, and a wide variety of known ones can be used. Examples thereof include dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, tricrene, and perchrene. The use amount of the halogenated hydrocarbon is not particularly limited and can be appropriately selected from a wide range. The amount is usually about 0.5 to 5 l, preferably about 1 to 3 l, per 1 mol of the azoalkane of the above general formula (1). . A large excess of amine can be used together with acetic acid to combine the functions of a reaction substrate and a solvent.

This reaction is carried out usually at 0 to 40 ° C., preferably at 10 to 40 ° C.
The reaction is performed at a temperature of about 30 ° C., and is usually completed in about 1 to 12 hours, preferably about 1 to 4 hours.

The α, α′-diacetoxyazoalkanes of the above general formula (2) obtained by this reaction can be easily separated and purified from the reaction system by ordinary separation means such as liquid separation, dehydration and concentration.

[0024]

The following examples are provided to further clarify the present invention.

Example 1 30.7 g (0.1 mol) of 1,1'-azobis (1-chloro-1-phenylethane), 16.4 g (0.2 mol) of sodium acetate and 4.0 g (0.05 mol) of pyridine were mixed with 100 ml of acetic acid and 200 ml of chloroform. , And reacted at room temperature for 2 hours. After completion of the reaction, the reaction solution was poured into 1 liter of water, and the chloroform layer was separated. The chloroform layer was washed with 5% aqueous sodium bicarbonate (200 ml), dried over anhydrous magnesium sulfate, concentrated to dryness, and 1,1′-azobis (1-acetoxy-1-).
33.7 g (yield 95.2%) of white crystals of phenylethane) were obtained. mp. 105-107 ° C.

EXAMPLE 2 30.7 g (0.1 mol) of 1,1'-azobis (1-chloro-1-phenylethane), 16.4 g (0.2 mol) of sodium acetate and 5.1 g (0.05 mol) of triethylamine were added to acetic acid 30
In addition to 0 ml, the reaction and treatment were performed in the same manner as in Example 1,
32.7 g (92.4% yield) of white crystals of 1,1′-azobis (1-acetoxy-1-phenylethane) were obtained.

Example 3 30.7 g (0.1 mol) of 1,1'-azobis (1-chloro-1-phenylethane) and 18.3 g (0.2 mol) of diethylamine
5 mol) was added to a mixed solvent of 100 ml of acetic acid and 200 ml of dichloroethane, and the reaction and treatment were carried out in the same manner as in Example 1.
33.5 g (yield: 94.6%) of white crystals of 1'-azobis (1-acetoxy-1-phenylethane) was obtained.

Example 4 30.7 g (0.1 mol) of 1,1'-azobis (1-chloro-1-phenylethane) and 15 g (0.25 mol) of acetic acid were added to 300 ml of pyridine, and the reaction and treatment were carried out in the same manner as in Example 1. As a result, 32.2 g (yield 91.0%) of white crystals of 1,1′-azobis (1-acetoxy-1-phenylethane) were obtained.

[0029]

According to the present invention, the desired α, α′-
Diacetoxyazoalkanes can be obtained in high yield, and thus have an excellent effect that almost no by-products are produced.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-228449 (JP, A) JP-A-7-206798 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 245/04

Claims (2)

(57) [Claims] 1. A compound represented by the general formula [2] characterized by reacting an amine with an α, α'-dihalogenoazoalkane represented by the general formula [1] in acetic acid. α,
A method for producing α'-diacetoxyazoalkanes. Embedded image [In the formula, R ¹ and R ² are the same or different and represent a lower alkyl group or an aryl group. X represents a halogen atom. [Chemical formula 2] Wherein R ¹ and R ² are the same as above. ] At wherein acetic acid and a mixed solution of halogenated hydrocarbons, alpha represented by amine及beauty acetic acid sodium and general formula [3], reacting the α'- dihalogeno azo alkanes Α, represented by the general formula [Formula 4],
A method for producing α'-diacetoxyazoalkanes. Embedded image [In the formula, R ¹ and R ² are the same or different and represent a lower alkyl group or an aryl group. X represents a halogen atom. [Formula 4] Wherein R ¹ and R ² are the same as above. ]