JPH07242633A - Production of 5-aminoethylaminomethyl-2-chloropyridine - Google Patents

Abstract

PURPOSE:To provide an industrially advantageous method for producing 5- aminoethylaminomethyl-2-chloropyridine useful as an intermediate of agrochemicals. CONSTITUTION:In a method for producing 5-aminoethylaminomethyl-2- chloropyridine by reacting 2-chloro-5-chloromethylpyridine with ethylenediamine, the characteristic of this method for production of 5-aminoethylaminomethyl-2- chloropyridine is that this reaction is conducted in the presence of water by using ethylenediamine in an amount of 2 to 10 equivalent based on 1 equivalent 2-chloro-5-chloromethylpyridine.

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention relates to a method for producing 5-aminoethylaminomethyl-2-chloropyridine which is useful as an intermediate for agricultural chemicals.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 60-218386 discloses a 2-
A method for producing 5-aminoethylaminomethyl-2-chloropyridine by reacting chloro-5-chloromethylpyridine with ethylenediamine is disclosed. Therein, it is described that the method can be preferably carried out using a solvent or a diluent, and water and other solvents are exemplified as the solvent or the diluent, but 2-chloro-5-chloromethylpyridine and There is no description of an example in which water is specifically used in the reaction of ethylenediamine.

[0003]

In the reaction between 2-chloro-5-chloromethylpyridine and ethylenediamine in the above-mentioned conventional method, 2-chloro-5-chloromethylpyridine reacts with two amino groups of ethylenediamine. N, N'-bis (2-chloro-5-pyridylmethyl)
The production of ethylenediamine (hereinafter abbreviated as DPEDA) is not preferable. The production of DPEDA can be suppressed to some extent by using an excess amount of ethylenediamine, but while suppressing the production of such by-products,
It is desired to improve the selectivity of the reaction in order to produce the target 5-aminoethylaminomethyl-2-chloropyridine in a large amount.

[0004]

Means for Solving the Problems As a result of intensive studies to improve the selectivity of such a reaction, the present inventors have surprisingly found that this object can be achieved by the presence of water in the reaction. With the knowledge obtained, the present invention has been completed.

That is, according to the present invention, 2-chloro-5-chloromethylpyridine (hereinafter abbreviated as CMC) and ethylenediamine (hereinafter abbreviated as EDA) are reacted to give 5
In the method for producing -aminoethylaminomethyl-2-chloropyridine (hereinafter abbreviated as PEDA), CM
2 to 10 equivalents of EDA are used with respect to C1 equivalents, and
The present invention relates to a method for producing PEDA, which comprises reacting in the presence of water.

The present invention can generally be implemented by the following method. CMC is, for example, JP-A-5-221986.
Those manufactured by the method disclosed in the publication can be used, but those manufactured by other methods may be used. According to the method disclosed in JP-A-5-221986, CMC can be easily produced by reducing 2-chloro-5-trichloromethylpyridine with a proton donor such as sulfuric acid and a reducing agent such as zinc. be able to. There, if appropriate reaction conditions are selected, the production of 2-chloro-5-dichloromethylpyridine as a reaction product is suppressed as much as possible, while the production of CMC is increased as much as possible, and some 2-chloro-5-methylpyridine is also contained. A mixture is obtained. CMC can be easily obtained by subjecting this reaction product to usual purification and separation operations. When the CMC obtained by this method is used as a starting material for the method of the present invention, a crude CMC solution can be obtained by adding water and a solvent to the reaction product, and thus the crude CMC solution can be directly obtained without distillation. The use of the method of the invention facilitates the preparation of raw materials, and is therefore preferable in industrial practice. Coarse CMC
The solution is preferably a solution containing 10 to 40% by weight of CMC. As the extraction solvent, benzene, toluene,
Aromatic hydrocarbons such as xylene, halogenated hydrocarbons such as ethylene dichloride, and aliphatic hydrocarbons such as hexane are used. Among them, if a solvent having a low polarity such as toluene is used, the reaction product is It is preferable because the tar content can be removed. Coarse CM obtained in this way
In addition to CMC, the C solution contains 5 to 20% by weight of 2-chloro-5-methylpyridine based on CMC.

EDA is usually obtained as ethylenediamine itself, but in the present invention, it is desirable to use an aqueous solution of EDA as it is. The amount of EDA used varies depending on the reaction raw material, solvent and the like and cannot be specified unconditionally, but is usually 2 to 10 equivalents, preferably 4 to 6 equivalents relative to 1 equivalent of CMC. It is preferable to use an excess amount of EDA with respect to 1 equivalent of CMC, because the above-mentioned production of DPEDA can be suppressed.

The amount of water present in the reaction system of the method of the present invention is usually 0.5 to 35 equivalents, preferably 1 to 25 equivalents, more preferably 5 to 10 equivalents, relative to 1 equivalent of CMC. When EDA is used as the aqueous solution, the concentration of the EDA aqueous solution is 20 to 90% by weight, preferably 50 to 80%.
A weight percent EDA aqueous solution, more preferably 60-80 weight percent EDA aqueous solution is used.

Although a solvent may or may not be used in the reaction of the process of the present invention, it is generally desirable to use a solvent. Solvents used are CMC and EDA
Any substance which is inert to the reaction with and which dissolves CMC may be used. For example, aromatic hydrocarbons such as benzene, toluene, xylene, halogenated hydrocarbons such as ethylene dichloride, hexane, etc. And aliphatic hydrocarbons thereof. CMC is prepared and used as a solution having a concentration of 10 to 40% by mixing CMC with these solvents. In addition, the above-mentioned JP-A-5
C manufactured by the method disclosed in JP-A-221986.
As described above, the crude CMC solution obtained from MC is preferably prepared and used at the same concentration.

The reaction temperature in the method of the present invention is the reaction raw material,
The temperature is usually 10 to 50 ° C., preferably 20 to 40 ° C., and the reaction time in this case is 1 to 5 hours, although it varies depending on the solvent and the like and cannot be specified unconditionally.

After completion of the reaction, PEDA can be easily obtained by subjecting the reaction product to conventional purification and separation operations. For example, an aqueous solution of sodium hydroxide having a concentration of 10 to 45% (CM
A toluene solution of PEDA is obtained by adding (1 equivalent to 1 equivalent of C) and distilling to remove a mixture of EDA, water and a solvent.

The preferred embodiments of the present invention will be described below. (1) 6 to 10 to 40% by weight of crude CMC in toluene solution
0-80% by weight EDA aqueous solution (4 equivalents to 1 equivalent of CMC)
(~ 6 eq.) Slowly with stirring and within a temperature range of 30-40 ° C. After the dropping, the reaction is continued by further stirring for a while within the same temperature range. (2) After completion of the reaction, an aqueous sodium hydroxide solution having a concentration of 10 to 45% (1 equivalent to 1 equivalent of CMC) is added to the reaction product to neutralize the reaction liquid. Excess ethylenediamine is distilled off as a mixture with water and toluene by distilling the reaction mixture. The residue is a toluene solution containing PEDA, and water is added to the residue for extraction, and the solution is separated into P
An aqueous solution of EDA can be obtained. Further, toluene is recovered by distilling the organic layer after separation. (3) The mixture of EDA, water, and toluene distilled from the reaction mixture is separated to collect an aqueous solution of EDA and toluene.

Examples of the present invention will be described below.

【Example】

Example 1 The effect of the presence of water during the reaction between CMC and EDA was examined. A solution of CMC in ethylenedichloride having a concentration of 25.0% by weight was added dropwise to a 70% aqueous solution of EDA in an amount of 10 equivalents per 1 equivalent of CMC over 1 hour, and the reaction was further performed for 1 hour with stirring. The reaction product was analyzed by liquid chromatography, and PEDA selectivity was determined by the following formula. PEDA selectivity = A / (A + B + C) A: PEDA production ratio (%) B: DPEDA production ratio (%) C: Other components unknown (%) (hereinafter abbreviated as UK)

On the other hand, in the same manner as in the case of using an ethylene dichloride solution of EDA prepared at various concentrations instead of a 70% aqueous solution of EDA (the amount of EDA used is 5 equivalents relative to 1 equivalent of CMC), the PEDA selectivity is the same. I asked. The respective results are shown in Table 1. Contrast 1 in Table 1
Under the conditions of ˜4, that is, in the absence of water, a large amount of UK (unidentified structure) was produced. Under the conditions of Example 1, that is, in the presence of water, the production of UK could be suppressed.

[0015]

[Table 1]

Examples 2 to 16 and 17 to 36 CMCs produced by the method disclosed in JP-A-5-221986, and extracted with ethylene dichloride or toluene after the reduction reaction are crude CMCs.
Used as a solution. The ratio of components other than the solvent in the crude CMC solution was 90% for CMC and 10% for 2-chloro-5-methylpyridine. (1) Examples 2 to 16: 25% by weight of a crude CMC ethylene dichloride solution was added dropwise to an EDA aqueous solution over 1 hour, and the mixture was further reacted for 1 hour under stirring. The reaction product was analyzed in the same manner as in Example 1 above to determine the PEDA selectivity. The results are shown in Table 2. (2) Examples 17 to 36: Table 3 shows the results of replacing the ethylene dichloride solution of 25% by weight of crude CMC with a toluene solution. In addition, as a comparative example, the one using a toluene solution of EDA is also shown.

[0017]

[Table 2]

[0018]

[Table 3]

All of the results in Tables 2 and 3 using crude CMC showed similar results as when using pure CMC.

Example 4 A mixture of 32.4 g of 2-chloro-5-chloromethylpyridine and 183.6 g of toluene was added dropwise with stirring to 85.86 g of an aqueous ethylenediamine solution having a concentration of 70% at 35 ° C. over 1 hour. After completion of the dropping, the mixture was stirred at 35 ° C. for 1 hour, and then, under water cooling, a 40% concentration aqueous sodium hydroxide solution 2
0.0 g was added. The reaction mixture was distilled while adding 450 g of toluene to distill off excess ethylenediamine.
The residue was extracted with 90 g of water, the organic layer was further extracted with 30 g of water, and the both were combined to give 5-aminoethylaminomethyl-2.
-Aqueous solution 168.0 containing 35.92 g of chloropyridine
9 g was obtained. (Yield 96.7%)

On the other hand, an aqueous solution of ethylenediamine is recovered by separating the fraction obtained by distilling off excess ethylenediamine. Toluene is also recovered by washing the organic layer with water. Further, toluene is recovered by distilling the organic layer obtained by the final liquid separation.

[0022]

【The invention's effect】

(1) According to the method of the present invention, since the byproduct of DPEDA is suppressed in the reaction between CMC and EDA and the selectivity of the PEDA production reaction is high, PEDA can be obtained in high yield and high purity. Therefore, a complicated post-treatment operation was conventionally required after the reaction, but it is not necessary or can be simplified, which is advantageous for industrial implementation. (2) In the present invention, CMC as a raw material having a wide range of purity can be used. For example, JP-A-5-221986
By using an appropriate CMC reaction product produced by the method disclosed in the publication, the reduction reaction product can be directly extracted as a raw material without distillation after extraction with a solvent such as toluene. . Therefore, complicated purification and separation operations for increasing the purity of CMC in the reduction reaction product can be omitted. (3) Furthermore, in the method of the present invention, even if EDA is used in an excessive amount,
EDA can be easily recovered as an aqueous solution and can be recycled and used. Since the reaction between CMC and EDA is a two-phase system reaction, the reaction proceeds sufficiently,
In particular, it is not necessary to use a phase transfer catalyst.

Claims (11)

[Claims] 1. A method for producing 5-aminoethylaminomethyl-2-chloropyridine by reacting 2-chloro-5-chloromethylpyridine with ethylenediamine, wherein 1 equivalent of 2-chloro-5-chloromethylpyridine is used. On the other hand, ethylenediamine is used in an amount of 2 to 10 equivalents, and the reaction is carried out in the presence of water, which is a method for producing 5-aminoethylaminomethyl-2-chloropyridine. 2. The method according to claim 1, wherein the reaction is carried out in the presence of 0.5 to 35 equivalents of water with respect to 1 equivalent of 2-chloro-5-chloromethylpyridine. 3. The method according to claim 1, wherein ethylenediamine is used as a 20 to 90% by weight aqueous solution. 4. The method according to claim 1, wherein ethylenediamine is used as a 50-80% by weight aqueous solution. 5. A toluene solution of 10 to 40% by weight of 2-chloro-5-chloromethylpyridine is added to 2-chloro-5.
-The reaction is carried out by adding dropwise to an aqueous solution of 60 to 80% by weight of ethylenediamine containing 4 to 6 equivalents of ethylenediamine to 1 equivalent of chloromethylpyridine while stirring and in the temperature range of 10 to 50 ° C. The method described in. 6. A temperature range of 20 to 40 ° C. 5.
the method of. 7. A toluene solution of 10-40% by weight of 2-chloro-5-chloromethylpyridine is 2-chloro-5.
In addition to -chloromethylpyridine, 5 for the compound
6. The method of claim 5, comprising .about.50% by weight 2-chloro-5-methylpyridine. 8. A toluene solution of 15% by weight of 2-chloro-5-chloromethylpyridine in a 70% by weight aqueous solution of ethylenediamine containing 5 equivalents of ethylenediamine with respect to 1 equivalent of 2-chloro-5-chloromethylpyridine. To
While stirring, add dropwise in a temperature range of 30 to 40 ° C,
The method according to claim 5, wherein the reaction is performed. 9. A reaction product of 2-chloro-5-chloromethylpyridine and ethylenediamine is added with 1 equivalent of an aqueous sodium hydroxide solution having a concentration of 10 to 45% with respect to 1 equivalent of 2-chloro-5-chloromethylpyridine, The method according to claim 5, wherein a toluene solution containing 5-aminoethylaminomethyl-2-chloropyridine is obtained by distilling to remove a mixture of ethylenediamine, water and toluene. 10. 5-Aminoethylaminomethyl-2-
The method according to claim 9, wherein water is added to a toluene solution containing chloropyridine to separate the solution, thereby obtaining an aqueous solution containing 5-aminoethylaminomethyl-2-chloropyridine and recovering toluene. 11. The method according to claim 9, wherein the aqueous solution of ethylenediamine and toluene are recovered by separating a mixture of ethylenediamine, water and toluene. [0001]