JP2944793B2 - Amine production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for industrially producing N, N-dialkylethylenediamine by catalytic hydrogenation of N, N-dialkylaminoacetonitrile. N, N-dialkylethylenediamine is a compound useful as a raw material for a pharmaceutical / pesticide intermediate, a surfactant, a paper strength enhancer, and the like.

[0002]

2. Description of the Related Art As a method for producing N, N-dialkylethylenediamine, for example, the following methods are known. That is, as the so-called ethyleneimine method,
A method for producing an N, N-dialkylalkylenediamine by reacting an alkylimine with a monoalkylamine (Japanese Patent Application Laid-Open No. 58-46041), wherein amines are obtained by reductive amination of primary alcohols with ammonia and hydrogen Production method (JP-A-60-104043), production of N, N-dialkylalkylenediamine by treating β- (dialkylamino) propionamide obtained from acrylamide and alkylamine with hypochlorite (JP-A-57-18650), as a method for catalytically hydrogenating the corresponding nitrile, hydrogenating N, N-dimethylaminoacetonitrile using a Raney nickel catalyst,
Method for producing N, N-dimethylethylenediamine (J.
Am. Chem. Soc., 68 , p. 1607, (1946)).

[0003]

However, according to the above method, the target N, N-dialkylalkylenediamine is converted to 8
Although it is obtained in a yield of 0 to 85 mol%, ethyleneimine as a main raw material has very strong toxicity. Therefore, a step of recovering ethyleneimine is required in order to avoid mixing into the target substance. In the above method, the conversion of the primary alcohol as the raw material is 90 mol%, but the selectivity to the target N, N-dialkylalkylenediamine is poor, and the yield is only 25 mol%. The yield of N, N-dialkylalkylenediamine according to the above method is about 45 mol%. Further, since the intermediate is treated with an alkali, there is a disadvantage that the process is lengthened. In the method (1), the secondary amination reaction proceeds to produce about 20 mol% of a by-product. The yield of the target product, N, N-dimethylethylenediamine, is 47 mol%.

[0004] Therefore, in the present invention, the catalytic hydrogenation of N, N-dialkylaminoacetonitrile can be carried out in high yield,
And, by suppressing the generation of secondary amine as a by-product,
It is intended to produce N, N-dialkylethylenediamine.

[0005]

In the catalytic hydrogenation of nitriles, the starting nitriles and the hydrogen cyanide produced by decomposition thereof become catalyst poisons, and the yield of primary amines as the target product is reduced. Lower. Also, the generated primary amines are deammonified to form secondary amines. The inventors of the present invention have conducted intensive studies on the above problems, and as a result, in order to minimize the generation of the above-mentioned catalyst poisons and secondary amines, the raw material N, N-dialkylaminoacetonitrile was supplied at a specific feed rate. It was found that charging into the reactor was effective, and the present invention was completed.
That is, the present invention relates to a compound represented by the general formula (1):

[0006]

Embedded image (Wherein, R ₁ and R ₂ represent a methyl group or an ethyl group) by catalytic hydrogenation of an N, N-dialkylaminoacetonitrile represented by the general formula (2)

[0007]

Embedded image (Wherein, R ₁ and R ₂ represent a methyl group or an ethyl group.) In producing N, N dialkylethylenediamine represented by the formula, Raney cobalt or Raney nickel is used as a catalyst, and N, N-dialkylaminoacetonitrile is used. A process for producing N, N-dialkylethylenediamine, characterized in that it is fed to a reactor at a rate of 0.5 to 3.0 g / hr / g-cat.

In the present invention, N, N-dialkylaminoacetonitrile used as a raw material is a colorless liquid,
It can be easily synthesized from dialkylamine and glycolonitrile. As N, N-dialkylaminoacetonitrile,
Specific examples include N, N-dimethylaminoacetonitrile (hereinafter, abbreviated as DAN), N, N-diethylaminoacetonitrile, and N, N-methylethylaminoacetonitrile.

The catalyst used in the present invention is commercially available Raney cobalt or Raney nickel, and Raney cobalt or Raney nickel modified with various metals can also be used. Metals include iron, chromium, molybdenum,
Vanadium, tungsten, manganese, lead, copper, silver, tin, platinum, palladium, and the like are mentioned, and are often used for modification. A catalyst in which ruthenium or platinum is supported on carbon or alumina has a very low activity and cannot be used in the present invention.

The feed rate of the raw material N, N-dialkylaminoacetonitrile is 0.5 to 3.0 g / hr / g-cat.
Is preferably within the range. Feed rate 0.5 g / hr /
If it is less than g-cat, not only the production efficiency will be reduced, but also the secondary reaction of the primary amine, which is the target substance, will be accelerated. If it exceeds 3.0 g / hr / g-cat, , The amount of unreacted substances increases, and the yield of the primary amine, which is the target, decreases.

Further, in order to suppress the secondary amine reaction of the primary amine, generally used liquid ammonia or aqueous ammonia may be supplied to the reactor together with the supply of the raw material liquid.

The reaction temperature in the present invention is usually 50 to 100 ° C.
And preferably 70 to 90 ° C. Reaction temperature is 50 ℃
If it is less than 1, there is a disadvantage that the production rate is low because the reaction rate is low, and if it exceeds 100 ° C., there is a disadvantage that the secondary amine reaction of the primary amine is accelerated. The reaction pressure with hydrogen is usually 50 to 150 Kg / cm ² · G, preferably 80 to 120 Kg / cm ² · G. Pressure is 50 Kg / c
When it is m ² · G or less, the hydrogenation reaction has a disadvantage that not proceed sufficiently, even beyond the 150 Kg / cm ² · G, not reduce the by-products to the split, the hydrogen supply equipment is large-scale And is industrially inconvenient.

In the present invention, an inert solvent can be used to maintain the activity of the catalyst. Examples of the solvent include methyl alcohol, ethyl alcohol, propyl alcohol, and monohydric lower alcohols of isopropyl alcohol; butane, isobutane, pentane,
Aliphatic and aromatic hydrocarbons such as cyclopentane, hexane, cyclohexane, isopentylbenzene, ethylbenzene, xylene, toluene, etc .; tertiary amines such as triethanolamine, triethylamine, etc .; pyridine, piperazine, ethylene glycol, propylene Diols such as glycol, diethylene glycol, tetraethylene glycol, 1,3-propanediol, 1,4-butanediol; methyl ether, diethyl ether,
Ethers such as methyl ether, methyl ethyl ether, tetrahydrofuran and the like can be mentioned.

As the N, N-dialkylethylenediamine produced by the present invention, specifically, N, N-dimethylethylenediamine (hereinafter abbreviated as DEDA), N, N-dialkylethylenediamine
Examples include N-diethylethylenediamine and N, N-methylethylethylenediamine.

After completion of the reaction in the present invention, the obtained N,
The insoluble catalyst is separated from the N-dialkylethylenediamine solution by filtration, and the inert solvent and by-products are removed by distillation to obtain a high-purity target product.

[0016]

The present invention will be described below in detail with reference to examples. In the following, “%” is on a molar basis unless otherwise specified. In addition, as an analysis method, the raw materials, the target product, and by-products in the reaction solution were quantified by gas chromatography, and the structure was determined by NMR and IR.

Example 1 A pressure-resistant reactor (capacity 100 ml, equipped with a heater) was charged with
5.93 g and Raney cobalt (trade name, manufactured by Nikko Rica Co., Ltd.)
KCR-400) 8.705 g was charged. The internal temperature of the reactor was raised to 80 ° C by a heater and the pressure was increased to 110 Kg / cm ² · G by hydrogen.
g was fed to the reactor. At this time, the supply speed of the DAN is
It was 1.5 g-DAN / hr / g-cat. During this time, the internal temperature of the reactor was maintained at 80 ° C., and the pressure was maintained at 110 Kg / cm ² · G. After feeding the DAN, it was kept for 1 hour to complete the reaction. Thereafter, the catalyst in the reaction solution was separated by filtration, and the obtained reaction solution was analyzed. The results are shown in Tables 1 and 2.

Example 2 The procedure of Example 1 was repeated except that Raney cobalt was replaced by Raney nickel (trade name: KCR-200, manufactured by Nikko Rika Co., Ltd.). Table 1 shows the results.

Example 3 14.38 g of methyl alcohol and Raney cobalt (Nikko Rika Co., Ltd.) were placed in a pressure-resistant reactor (capacity: 100 ml, equipped with a heater).
8.705 g was manufactured. Subsequent operations were performed in exactly the same manner as in Example 1. Table 1 shows the results.
Shown in

Comparative Example 1 In a pressure-resistant reactor (capacity 100 ml, with heater),
5.0g and Raney Cobalt (Nikko Rica Co., Ltd., trade name KC
(R-400) 12.86 g was charged. The internal temperature of the reactor was raised to 80 ° C. by a heater, and the pressure was raised to 110 Kg / cm ² · G by hydrogen. The internal temperature of the reactor was maintained at 80 ° C., and the pressure was increased to 110 Kg / cm ² · G as needed when the hydrogen was consumed by the reaction and the pressure reached 90 Kg / cm ² · G. After reacting for 4 hours, the catalyst in the reaction solution was separated by filtration, and the obtained reaction solution was analyzed. Table 1 shows the results.

Comparative Example 2 The procedure of Comparative Example 1 was repeated, except that Raney cobalt was replaced by Raney nickel (trade name: KCR-200, manufactured by Nikko Rika Co., Ltd.). Table 1 shows the results.

Comparative Examples 3 and 4 In Example 1, the supply rate of the DAN was set to 3.7
And 0.4 g-DAN / hr / g-cat, except that the operation was the same. Table 1 shows the results.

Comparative Example 5 The procedure was the same as in Example 1 except that Raney cobalt was replaced by a 5% by weight ruthenium-alumina-supported catalyst (trade name: 5% -Al ₂ O ₃ manufactured by NE Chemcat Co., Ltd.). Operated. Table 1 shows the results.

Example 4 The procedure of Example 1 was repeated, except that the starting material, DAN, was changed to N, N-diethylaminoacetonitrile.
Table 2 shows the results.

Example 5 The procedure of Example 1 was repeated, except that the starting material, DAN, was changed to N, N-methylethylaminoacetonitrile. Table 2 shows the results.

[0026]

According to the present invention, the target N, N-dialkylethylenediamine can be produced in a high yield, which was not achieved by the prior art, and by suppressing the generation of by-products. That is, in Comparative Examples 1 to 4, in which the feed rate of the raw material nitrile is out of the range of the present invention, the yield of the primary amine as the target product is low and / or the amount of the secondary amine as a by-product is low. Many. In Comparative Example 5 in which the type of the catalyst is out of the range of the present invention, the catalytic activity is very low, and most of the starting nitrile remains. On the other hand, in Examples 1 to 5 in which the feed rate of the starting nitrile and the type of the catalyst were within the scope of the present invention, the yield of the target product was clearly higher, the amount of by-products was smaller, and Is significant.

[0027]

[Table 1]

[0028]

[Table 2]

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Claims (1)

(57) [Claims] 1. A compound of the general formula (1) (Wherein, R ₁ and R ₂ represent a methyl group or an ethyl group) by catalytic hydrogenation of an N, N-dialkylaminoacetonitrile represented by the general formula (2). (Wherein, R ₁ and R ₂ represent a methyl group or an ethyl group.) In producing N, N-dialkylethylenediamine represented by the formula, Raney cobalt or Raney nickel is used as a catalyst, and N, N-dialkylaminoacetonitrile is used. Is supplied to the reactor at a rate of 0.5 to 3.0 g / hr / g-cat.