CN119552085A - A kind of preparation method of N-ethylhexanediamine - Google Patents
A kind of preparation method of N-ethylhexanediamine Download PDFInfo
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- CN119552085A CN119552085A CN202411754905.8A CN202411754905A CN119552085A CN 119552085 A CN119552085 A CN 119552085A CN 202411754905 A CN202411754905 A CN 202411754905A CN 119552085 A CN119552085 A CN 119552085A
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- C07—ORGANIC CHEMISTRY
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- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/68—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton
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- C07—ORGANIC CHEMISTRY
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Abstract
The invention discloses a preparation method of N-ethylhexyl diamine, which takes acetaldehyde and 6-aminocapronitrile as raw materials, and carries out condensation hydrogenation reaction in the presence of a catalyst and an auxiliary agent to generate the N-ethylhexyl diamine, wherein the catalyst is a supported catalyst and/or a framework catalyst which comprises at least one of metals Ni, co, cu, fe, pd, pt, ru, rh as an active component, and the auxiliary agent is selected from inorganic alkali and/or quaternary ammonium alkali. The method takes acetaldehyde and 6-aminocapronitrile as raw materials to prepare N-ethylhexyl diamine through one-step condensation hydrogenation, has high reaction yield and simple post-treatment, and has industrial application prospect.
Description
Technical Field
The invention relates to a preparation method, in particular to a preparation method of N-ethylhexyl diamine.
Background
The main current source of N-ethylhexyl diamine (NET for English abbreviation) is the byproduct of the hydrogenation of adiponitrile to hexamethylenediamine. Ethanol is used as a solvent in the reaction, and the ethanol reacts with hexamethylenediamine under the action of a nickel catalyst to generate N-ethylated hexamethylenediamine. Because the boiling point of N-ethyl hexamethylenediamine is close to that of hexamethylenediamine, the N-ethyl hexamethylenediamine and the hexamethylenediamine are difficult to separate, and qualified products can be obtained by repeated rectification and purification, so that the energy consumption in the post-treatment process is high. Therefore, accurate determination of the content of N-ethylhexyl diamine in hexamethylene diamine is important for selection of proper separation methods and means, and further reduction of energy consumption.
The impurity content of hexamethylenediamine is generally determined by an external standard quantity method in industry. Providing a high purity N-ethylhexyl diamine standard is critical for accurate determination of the impurity content in the hexamethylenediamine. In addition, N-ethylhexyl diamine can also be used as an epoxy curing agent in the coating industry, an adhesive, a crosslinking agent in the paper industry, and the like.
Patent CN117550980a describes a process for the preparation of N-ethylhexyl diamine, using hexamethylenediamine and a haloethane under the action of sodium hydroxide and a phase transfer catalyst. However, the process flow of the method is complex, and because the substrate hexamethylenediamine has difunctional groups, and disubstituted N, N' -diethyl hexamethylenediamine and other impurities are easy to generate in the substitution reaction, a large excess of raw hexamethylenediamine is needed to ensure the higher selectivity of the N-ethyl hexamethylenediamine, and the production and post-treatment cost is increased.
Therefore, there is a need to develop a new reaction route, and it is desired to prepare N-ethylhexyl diamine in high yield.
Disclosure of Invention
In order to solve the technical problems, the invention provides a preparation method of N-ethylhexyl diamine, which takes acetaldehyde and 6-aminocapronitrile as raw materials to prepare the N-ethylhexyl diamine through one step of condensation hydrogenation, has high reaction yield and simple post-treatment, and has industrial application prospect.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the preparation process of N-ethyl hexanediamine includes condensation hydrogenation of acetaldehyde and 6-amino hexanenitrile in the presence of catalyst and assistant to produce N-ethyl hexanediamine, and the reaction process has the following expression:
the catalyst is a supported catalyst and/or a framework catalyst which comprises at least one of metals Ni, co, cu, fe, pd, pt, ru, rh as an active component, preferably comprises at least one of metals Ni and Co as an active component;
preferably, the catalyst can be a skeletal catalyst such as Grace 2800/Grace 2400/Grace 2724, and a supported catalyst such as XueKai 3100T and 6210P.
The auxiliary agent is selected from one or more of inorganic base and/or quaternary ammonium base, preferably LiOH, naOH, KOH, tetramethyl ammonium hydroxide and tetraethyl ammonium hydroxide.
In some examples of the invention, the molar ratio of acetaldehyde to 6-aminocapronitrile is (0.5-1.1): 1, preferably (0.9-1): 1.
In some examples of the invention, the catalyst is used in an amount of 0.1 to 50%, preferably 1 to 10% by mass of acetaldehyde.
In some examples of the invention, the auxiliary is used in an amount of 0.1 to 50%, preferably 1 to 20% by mass of the catalyst.
In some examples of the invention, the reaction is carried out using a batch or semi-batch process at a reaction temperature of 60-150 ℃, preferably 80-120 ℃, and the reaction pressure is maintained at 2-10MPaG, preferably 3-6MPaG, by continuous hydrogen feed.
In some examples of the invention, the solvent is selected from a protic solvent and/or an aprotic solvent, preferably an aprotic solvent, more preferably one or both of tetrahydrofuran, dioxane;
Preferably, the solvent is used in an amount of 0.5 to 5 times, preferably 0.5 to 2 times the total mass of acetaldehyde and 6-aminocapronitrile.
In some examples of the invention, after the reaction is completed, the product is refined;
The refining comprises desolventizing and rectifying, light component removing and product rectifying, wherein the desolventizing and rectifying is carried out for the first time according to the selection of the reaction solvent, the light component removing and rectifying is carried out for the second time on the reaction light component, and the product rectifying is used for obtaining the N-ethylhexyl diamine product with the purity of more than 99.0 percent.
Preferably, a rectifying tower with the number of plates of 30 is adopted for solvent removal, light removal and product rectification, and solvent removal rectifying conditions are, for example, tetrahydrofuran system rectifying pressure is 48-58kPaA, tower top temperature is 45-50 ℃, reflux ratio is 1-5:1, dioxane system rectifying pressure is 13-16kPaA, tower top temperature is 45-50 ℃, and reflux ratio is 1-5:1. The light component removal and rectification conditions are rectification pressure of 1-3kPaA, tower top temperature of 141-169 ℃ and reflux ratio of 1-10:1. The product rectifying condition is that the rectifying pressure is 0.5-2kPaA, the tower top temperature is 135-158kPaA, and the reflux ratio is 1-10:1.
The invention has the beneficial effects that:
The novel process route is adopted, the high conversion rate of the reaction and the high selectivity of the N-ethylhexyl diamine can be ensured without greatly excessive raw material proportion, the N-ethylhexyl diamine can be prepared by condensation hydrogenation through a one-step process, the operation efficiency is high, the post-treatment is simple, and the high-purity N-ethylhexyl diamine can be obtained.
Detailed Description
The invention will now be further illustrated by means of specific examples which are given solely by way of illustration of the invention and do not limit the scope thereof.
The raw materials and reagents in the following examples of the present invention are commercially available unless otherwise specified. Wherein, grace2800 skeleton nickel catalyst, grace2724 skeleton cobalt catalyst manufacturer is GRACE CATALYSTS Technologies, coCAT-3100T cobalt-based supported catalyst, SNCAT-6210P nickel-based supported catalyst manufacturer is XueKai catalyst.
The reaction liquid composition in the following examples was analyzed by gas chromatography under conditions of Agilent DB-5 column, sample inlet temperature 280℃and FID detector temperature 300℃with column flow rate of 1.5ml/min, hydrogen flow rate of 30ml/min, air flow rate of 400ml/min, temperature programming of 50℃for 2min, temperature of 5℃to 80℃and then 15℃to 280℃for 10min.
The parameters of the reaction kettle are 1L in volume, and the self-priming stirring paddle adopts an electric heating sleeve for heating.
[ Example 1]
200G of 6-aminocapronitrile, 139.3g of tetrahydrofuran, 7.9g of Grace2800 skeletal nickel catalyst and 0.16g of tetramethylammonium hydroxide pentahydrate are added into a reaction kettle, hydrogen is supplemented to 3MPaG after nitrogen substitution, stirring is started and the temperature is raised to 80 ℃, and then 78.6g of acetaldehyde is added into the reaction kettle by a advection pump. After the end of the feed, the 3MPaG pressure was maintained until the hydrogen consumption was zero (i.e., the flow meter showed an instantaneous feed flow of hydrogen of 0) and the reaction was stopped. And then cooling and filtering to obtain reaction mother liquor. The conversion of acetaldehyde is 99.5% and the selectivity of N-ethylhexyl diamine is 99.7% as detected by GC.
The reaction mother liquor adopts the column plate number of 30 to carry out desolventizing, light removal and product rectification. The solvent removal rectification pressure is 48kPaA, the tower top temperature is 45 ℃, the reflux ratio is 1:1, the light removal rectification pressure is 3kPaA, the tower top temperature is 161 ℃, the reflux ratio is 5:1, the product rectification pressure is 1kPaA, the tower top temperature is 148 ℃, and the reflux ratio is 10:1, so that the product is obtained. The product was analyzed by GC and had an N-ethylhexyl diamine content of 99.8%.
[ Example 2]
100G of 6-aminocapronitrile, 137.3g of dioxane, 3g of Grace2724 framework cobalt catalyst and 0.11g of tetraethylammonium hydroxide are added into a reaction kettle, after nitrogen replacement, hydrogen is supplemented to 5MPaG, stirring is started, the temperature is raised to 110 ℃, and then 37.3g of acetaldehyde is introduced into the reaction kettle by a advection pump. After the end of the feed, the 5MPaG pressure was maintained until the hydrogen consumption was zero, and the reaction was stopped. And then cooling and filtering to obtain reaction mother liquor. The conversion of acetaldehyde is 99.8% and the selectivity of N-ethylhexyl diamine is 99.8% as detected by GC.
The reaction mother liquor adopts the column plate number of 30 to carry out desolventizing, light removal and product rectification. The solvent removal rectification pressure is 16kPaA, the tower top temperature is 50 ℃, the reflux ratio is 5:1, the light removal rectification pressure is 1kPaA, the tower top temperature is 161 ℃, the reflux ratio is 1:1, the product rectification pressure is 2kPaA, the tower top temperature is 158 ℃, and the reflux ratio is 10:1, so that the product is obtained. The product was analyzed by GC and had an N-ethylhexyl diamine content of 99.7%.
[ Example 3]
150G of 6-aminocapronitrile, 322.2g of dioxane, 6gCoCAT-3100T of cobalt-based supported catalyst and 0.31g of lithium hydroxide are added into a reaction kettle, after nitrogen is replaced, hydrogen is supplemented to 4MPaG, stirring is started, the temperature is raised to 100 ℃, and then 64.8g of acetaldehyde is introduced into the reaction kettle by a advection pump. After the end of the feed, the 4MPaG pressure was maintained until the hydrogen consumption was zero, and the reaction was stopped. And then cooling and filtering to obtain reaction mother liquor. The conversion of acetaldehyde is 99.1% and the selectivity of N-ethylhexyl diamine is 99.2% by GC detection.
The reaction mother liquor adopts the column plate number of 30 to carry out desolventizing, light removal and product rectification. The solvent removal rectification pressure is 13kPaA, the tower top temperature is 45 ℃, the reflux ratio is 1:1, the light removal rectification pressure is 2kPaA, the tower top temperature is 155 ℃, the reflux ratio is 2:1, the product rectification pressure is 0.5kPaA, the tower top temperature is 135 ℃, and the reflux ratio is 1:1, so that the product is obtained. The product was analyzed by GC and had an N-ethylhexyl diamine content of 99.1%.
[ Example 4]
180G of 6-aminocapronitrile, 487.3g of tetrahydrofuran, 1gSNCAT-6210P nickel-based supported catalyst and 0.6g of sodium hydroxide are added into a reaction kettle, hydrogen is supplemented to 6MPaG after nitrogen replacement, stirring is started, the temperature is raised to 90 ℃, and then 63.6g of acetaldehyde is introduced into the reaction kettle by using a advection pump. After the end of the feed, the 6MPaG pressure was maintained until the hydrogen consumption was zero, and the reaction was stopped. And then cooling and filtering to obtain reaction mother liquor. The conversion of acetaldehyde is 99.9% and the selectivity of N-ethylhexyl diamine is 99.8% as detected by GC.
The reaction mother liquor adopts the column plate number of 30 to carry out desolventizing, light removal and product rectification. The solvent removal rectification pressure is 58kPaA, the tower top temperature is 50 ℃, the reflux ratio is 1:1, the light removal rectification pressure is 1kPaA, the tower top temperature is 141 ℃, the reflux ratio is 5:1, the product rectification pressure is 0.5kPaA, the tower top temperature is 135 ℃, and the reflux ratio is 5:1, so that the product is obtained. The product was analyzed by GC and had an N-ethylhexyl diamine content of 99.5%.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and additions may be made to those skilled in the art without departing from the method of the present invention, which modifications and additions are also to be considered as within the scope of the present invention.
Claims (7)
1. The preparation method of N-ethylhexyl diamine is characterized in that acetaldehyde and 6-aminocapronitrile are used as raw materials, and condensation hydrogenation reaction is carried out in the presence of a catalyst and an auxiliary agent to generate N-ethylhexyl diamine;
The catalyst is a supported catalyst and/or a framework catalyst which comprises at least one of metals Ni, co, cu, fe, pd, pt, ru, rh as an active component;
The auxiliary agent is selected from one or more of inorganic base and/or quaternary ammonium base, preferably LiOH, naOH, KOH, tetramethyl ammonium hydroxide and tetraethyl ammonium hydroxide.
2. The process for the preparation of N-ethylhexyl diamine according to claim 1, wherein the molar ratio of acetaldehyde to 6-aminocapronitrile is from (0.5 to 1.1): 1, preferably from (0.9 to 1): 1.
3. The process for the preparation of N-ethylhexyl diamine according to claim 1, wherein the catalyst is used in an amount of 0.1 to 50% by mass of acetaldehyde, preferably 1 to 10%.
4. A process for the preparation of N-ethylhexyl diamine according to any one of claims 1 to 3, wherein the auxiliary is used in an amount of 0.1 to 50% by mass of the catalyst, preferably 1 to 20%.
5. The process for the preparation of N-ethylhexyl diamine according to any one of claims 1 to 4, wherein the reaction is carried out using a batch or semi-batch process, the reaction temperature is between 60 and 150℃and preferably between 80 and 120℃and the reaction pressure is maintained between 2 and 10MPaG and preferably between 3 and 6MPaG by continuous hydrogen feed.
6. Process for the preparation of N-ethylhexyl diamine according to any one of claims 1 to 5, wherein the solvent is selected from a protic solvent and/or an aprotic solvent, preferably an aprotic solvent, more preferably one or both of tetrahydrofuran, dioxane;
Preferably, the solvent is used in an amount of 0.5 to 5 times, preferably 0.5 to 2 times the total mass of acetaldehyde and 6-aminocapronitrile.
7. The process for producing N-ethylhexyl diamine according to any one of claims 1 to 6, wherein after the completion of the reaction, the product is purified;
the refining comprises desolventizing rectification, light component removal rectification and heavy component removal rectification.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1207797A (en) * | 1981-11-02 | 1986-07-15 | Ferdinand Dengel | Substituted 2,5-diaminopentanes, their preparation and drugs containing these compounds |
| US20110281908A1 (en) * | 2008-10-06 | 2011-11-17 | Emory University | Aminoquinoline Derived Heat Shock Protein 90 Inhibitors, Methods Of Preparing Same, And Methods For Their Use |
| CN115772085A (en) * | 2022-09-28 | 2023-03-10 | 河南省化工研究所有限责任公司 | A kind of method for preparing hexamethylenediamine by hydrogenation of 6-aminocapronitrile |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1207797A (en) * | 1981-11-02 | 1986-07-15 | Ferdinand Dengel | Substituted 2,5-diaminopentanes, their preparation and drugs containing these compounds |
| US20110281908A1 (en) * | 2008-10-06 | 2011-11-17 | Emory University | Aminoquinoline Derived Heat Shock Protein 90 Inhibitors, Methods Of Preparing Same, And Methods For Their Use |
| CN115772085A (en) * | 2022-09-28 | 2023-03-10 | 河南省化工研究所有限责任公司 | A kind of method for preparing hexamethylenediamine by hydrogenation of 6-aminocapronitrile |
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