An apparatus system and method for synthesizing methyl ethylamine

Abstract

The application relates to a synthesis device system and a synthesis method of methyl ethylamine, wherein the synthesis device system comprises a formic acid ethylamide preparation unit, a reduction unit, a filtering unit and a rectification unit; the synthesis method corresponds to the synthesis device system; when the synthesis device system is used for synthesizing methyl ethylamine, no organic solvent needs to be added during the preparation of formic acid ethylamide; after the synthesis is completed, no other complicated post-treatment process is needed, and only simple rectification is needed to obtain the methyl ethylamine product with high efficiency, so that the synthesis device system can greatly improve the production efficiency and reduce the preparation cost of the methyl ethylamine.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and to a synthesis apparatus system and synthesis method, particularly to a synthesis apparatus system and synthesis method for methyl ethylamine. Background Technology

[0002] Semiconductor precursors are chemical substances used to manufacture semiconductor crystals during the semiconductor device manufacturing process. They are the foundation of semiconductor device manufacturing and have a crucial impact on the performance and quality of semiconductor devices.

[0003] Semiconductor precursor materials are represented by compounds of transition metals zirconium and hafnium, forming a series of precursor materials. Among them, zirconium oxide and hafnium oxide are the most important precursor materials due to their high dielectric constant and thermodynamic stability. However, the synthesis of zirconium oxide and hafnium oxide usually needs to be completed at extremely low temperatures, and the deposition process is irreversible and self-limiting. In order to make up for the shortcomings of zirconium oxide and hafnium oxide, researchers have developed tetramethylethylamino zirconium.

[0004] Compared to oxide forms of semiconductor precursor materials, tetramethylethylamino zirconium has significant advantages in its liquid form, particularly in terms of simplified synthesis conditions, purification, and post-processing. Furthermore, its vapor deposition process is more reproducible and avoids substrate contamination by dust or powder. Methylethylamine (N-ethylmethylamine, EMA) is one of the important ligands for the formation of tetramethylethylamino zirconium.

[0005] The Eschweiler-Clsanark reaction involves reacting carbonyl compounds such as aldehydes or ketones with amines, and heating with formic acid as a reducing agent to obtain alkylated products of the amines. The advantage of this method is its simplicity, but the alkylated products are mainly tertiary amines, and it is basically impossible or very difficult to control the conditions to make the product a single secondary amine.

[0006] Amines can react with aldehydes or ketones to form Schiff bases. Under pressure, using Ni or Pd as a catalyst, hydrogenation can reduce the carbon-nitrogen double bond, thereby efficiently generating monoalkyl-substituted secondary amines. However, the Schiff bases formed from simple amines and aldehydes or ketones are relatively unstable, and it is not easy to obtain stable products of Schiff bases formed from ethylamine and formaldehyde.

[0007] Introducing a benzyl protecting group into a primary amine followed by methylation, and then using Pd / C catalysis to remove the benzyl protecting group, can effectively prevent the formation of tertiary amines through multiple substitutions of the primary amine. This method results in a relatively high degree of product homogeneity. However, it involves many steps in mass production, and the methylation reagents are highly toxic and easily pollute the environment, which contradicts the company's principles of cost reduction, efficiency improvement, and environmental protection. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a synthesis apparatus system and synthesis method for methyl ethylamine. The synthesis method, in conjunction with the synthesis apparatus system, eliminates the need for adding organic solvents in the initial stage of methyl ethylamine preparation and eliminates the need for complex post-reaction processes. Therefore, it has high production efficiency and reduces production costs during the production process.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a synthesis apparatus system for methyl ethylamine, the synthesis apparatus system comprising a formic acid acetamide preparation unit, a reduction unit, a filtration unit, and a distillation unit;

[0011] The formate acetamide preparation unit includes an ethylamine supply device, a methyl formate supply device, a first reaction device, and an formate acetamide storage device; the outlets of the methyl formate supply device and the ethylamine supply device are respectively connected to the inlet of the first reaction device; the outlet of the first reaction device is connected to the formate acetamide storage device.

[0012] The reduction unit includes a reducing agent supply device, an acid supply device, an organic solvent supply device, and a second reaction device; the outlet of the formic acid acetamide storage device is connected to the inlet of the second reaction device; the outlets of the reducing agent supply device and the acid supply device are respectively connected to the inlet of the second reaction device; the outlet of the organic solvent supply device is respectively connected to the inlet of the reducing agent supply device and the acid supply device.

[0013] The filtration unit includes a reaction solution storage device, an alkali supply device, a filtration device, and a filtrate storage device; the outlet of the second reaction device and the outlet of the alkali supply device are respectively connected to the inlet of the reaction solution storage device; the filtration device is connected to the reaction solution storage device and the filtrate storage device.

[0014] The distillation unit includes a first distillation apparatus, a second distillation apparatus, a methyl ethylamine storage tank, a distillate liquid storage tank, a waste liquid storage tank, and a solvent recovery tank; the filtrate storage device is connected to the inlet of the first distillation apparatus; the light phase outlet of the first distillation apparatus is connected to the methyl ethylamine storage tank, and the heavy phase outlet is connected to the inlet of the distillate liquid storage tank; the outlet of the distillate liquid storage tank is connected to the inlet of the second distillation apparatus; the heavy phase outlet of the second distillation apparatus is connected to the waste liquid storage tank, and the light phase outlet is connected to the solvent recovery tank.

[0015] The methyl ethylamine synthesis apparatus system provided by this invention does not require the addition of organic solvents during the preparation of formic acid acetamide. After the synthesis is completed, no other complex post-processing is required; only simple distillation is needed to efficiently obtain the methyl ethylamine product. Therefore, the synthesis apparatus system provided by this invention can greatly improve production efficiency and reduce the preparation cost of methyl ethylamine.

[0016] Preferably, the formic acid acetamide preparation unit further includes a condensation device and a condensate storage device connected in sequence;

[0017] The feed inlet of the condensing device is connected to the gas outlet of the first reaction device;

[0018] The outlet of the condensate storage device is connected to the methyl formate supply device.

[0019] Preferably, the solvent recovery tank is connected to the organic solvent supply device via a pipeline.

[0020] Preferably, the filtration device comprises at least two filters connected in parallel.

[0021] Secondly, the present invention provides a method for synthesizing methyl ethylamine, the method comprising the following steps:

[0022] (1) Mix ethylamine and methyl formate, heat to reflux to react, and after the reaction is complete, separate the excess methyl formate to obtain acetamide formate;

[0023] (2) Mix the reducing agent solution, acid solution and the formic acid acetamide obtained in step (1), and heat to reflux to react and obtain the reaction solution;

[0024] The reducing agent solution is obtained by mixing a reducing agent with an organic solvent;

[0025] The acid solution is a mixture of organic acid and organic solvent;

[0026] (3) Adjust the pH of the reaction solution to ≥10, and then perform solid-liquid separation. The resulting filtrate is subjected to a first distillation. The light phase component obtained from the first distillation is the methyl ethylamine.

[0027] Preferably, the ratio of ethylamine to methyl formate in step (1) is:

[0028] Add 80-120g of ethylamine to every 1L of methyl formate.

[0029] Preferably, the reducing agent in the reducing agent solution in step (2) includes sodium borohydride.

[0030] Preferably, the molar ratio of sodium borohydride to ethylamine is 1:(0.8-1.2).

[0031] Preferably, the organic acid in the acid solution includes acetic acid.

[0032] Preferably, the concentration of organic acid in the acid solution is 8-12 mol / L.

[0033] Preferably, the molar ratio of acetic acid to ethylamine is 1:(0.8-1.2).

[0034] Preferably, the organic solvent comprises tetrahydrofuran.

[0035] Preferably, the amount of tetrahydrofuran used in the reducing agent solution is 0.45-0.55 L of tetrahydrofuran per 100 g of ethylamine.

[0036] Preferably, the synthesis method further includes the following steps after step (3):

[0037] (4) The heavy phase component obtained from the first distillation is subjected to a second distillation, and the light component obtained from the second distillation is an organic solvent;

[0038] Preferably, the light component obtained from the second distillation is reused to obtain a reducing agent solution and an acid solution;

[0039] Preferably, the methyl formate separated in step (1) is reused in the reaction of ethylamine with methyl formate.

[0040] As a further preferred technical solution, the synthesis method of the second aspect of the present invention is carried out in the synthesis apparatus system described in the first aspect.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) When the methyl ethylamine synthesis apparatus system provided by the present invention is used to synthesize methyl ethylamine, no organic solvent is required when preparing formic acid acetamide. After the synthesis is completed, no other complicated post-processing is required. Only simple distillation is needed to obtain methyl ethylamine product efficiently. Therefore, the synthesis apparatus system provided by the present invention can greatly improve production efficiency and reduce the preparation cost of methyl ethylamine.

[0043] (2) The synthesis method provided by the present invention produces fewer byproducts, which will not cause difficulties in the purification of the product, and is conducive to obtaining high-purity methyl ethylamine, and can efficiently complete the production of methyl ethylamine. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the methyl ethylamine synthesis apparatus system provided in Example 1;

[0045] Wherein: 11, first reaction device; 12, ethylamine supply device; 13, methyl formate supply device; 14, condensation device; 15, condensate storage device; 16, formate acetamide storage device;

[0046] 21. Second reaction apparatus; 22. Reducing agent supply device; 23. Acid supply device; 24. Organic solvent supply device;

[0047] 31, reaction solution storage device; 32, alkali solution supply device; 33, first filter; 34, second filter; 35, filtrate storage device;

[0048] 41, First distillation unit; 42, Methyl ethylamine storage tank; 43, Distillate liquid storage tank; 44, Second distillation unit; 45, Solvent recovery tank; 46, Waste liquid storage tank. Detailed Implementation

[0049] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0050] An embodiment of the present invention provides a synthesis apparatus system for methyl ethylamine, the synthesis apparatus system comprising a formic acid acetamide preparation unit, a reduction unit, a filtration unit, and a distillation unit;

[0051] The formate acetamide preparation unit includes an ethylamine supply device, a methyl formate supply device, a first reaction device, and an formate acetamide storage device; the outlets of the methyl formate supply device and the ethylamine supply device are respectively connected to the inlet of the first reaction device; the outlet of the first reaction device is connected to the formate acetamide storage device.

[0052] The reduction unit includes a reducing agent supply device, an acid supply device, an organic solvent supply device, and a second reaction device; the outlet of the formic acid acetamide storage device is connected to the inlet of the second reaction device; the outlets of the reducing agent supply device and the acid supply device are respectively connected to the inlet of the second reaction device; the outlet of the organic solvent supply device is respectively connected to the inlet of the reducing agent supply device and the acid supply device.

[0053] The filtration unit includes a reaction solution storage device, an alkali supply device, a filtration device, and a filtrate storage device; the outlet of the second reaction device and the outlet of the alkali supply device are respectively connected to the inlet of the reaction solution storage device; the filtration device is connected to the reaction solution storage device and the filtrate storage device.

[0054] The distillation unit includes a first distillation apparatus, a second distillation apparatus, a methyl ethylamine storage tank, a distillate liquid storage tank, a waste liquid storage tank, and a solvent recovery tank; the filtrate storage device is connected to the inlet of the first distillation apparatus; the light phase outlet of the first distillation apparatus is connected to the methyl ethylamine storage tank, and the heavy phase outlet is connected to the inlet of the distillate liquid storage tank; the outlet of the distillate liquid storage tank is connected to the inlet of the second distillation apparatus; the heavy phase outlet of the second distillation apparatus is connected to the waste liquid storage tank, and the light phase outlet is connected to the solvent recovery tank.

[0055] The methyl ethylamine synthesis apparatus system provided by this invention does not require the addition of organic solvents during the preparation of formic acid acetamide. After the synthesis is completed, no other complex post-processing is required; only simple distillation is needed to efficiently obtain the methyl ethylamine product. Therefore, the synthesis apparatus system provided by this invention can greatly improve production efficiency and reduce the preparation cost of methyl ethylamine.

[0056] The synthesis apparatus system provided by the present invention also includes necessary temperature control devices, pressure control devices, and conveying devices, which will not be described in detail here. Those skilled in the art can make reasonable settings according to process requirements.

[0057] The synthesis of methyl ethylamine using the synthesis apparatus system provided by this invention includes the following steps:

[0058] (a) Ethylamine from the ethylamine supply device and methyl formate from the methyl formate supply device are injected into the first reaction device to mix the ethylamine and methyl formate. Then the mixture is heated under reflux to carry out the reaction. After the reaction is completed, the first reaction device is heated to evaporate the remaining methyl formate. Then the acetamide formate is introduced into the acetamide formate storage device.

[0059] (b) An organic solvent supply device provides organic solvent, disperses the reducing agent in the reducing agent supply device, and then flows into the second reaction device; formic acid acetamide in the formic acid acetamide storage device is introduced into the second reaction device, and after thorough stirring, acid solution is supplied by the acid solution supply device. After being mixed evenly, the mixture is heated and refluxed to carry out the reaction.

[0060] (c) After the reaction is completed, the reaction solution is introduced into the reaction solution storage device, and then the alkaline solution is supplied by the alkaline solution supply device to adjust the reaction solution in the reaction solution storage device to alkaline. Then, solid-liquid separation is performed by the filtration device, and the resulting filtrate is introduced into the filtrate storage device.

[0061] (d) The filtrate is distilled in the first distillation unit. The light phase obtained at the top of the first distillation unit is methyl ethylamine, which enters the methyl ethylamine storage tank. The heavy phase obtained at the bottom of the first distillation unit is introduced into the distillate storage tank. The distillate in the distillate storage tank is distilled in the second distillation unit. The light phase obtained is an organic solvent, which enters the solvent recovery tank. The heavy phase obtained enters the waste liquid storage tank.

[0062] The alkaline solution provided by the alkaline solution supply device of the present invention includes, but is not limited to, sodium bicarbonate and / or sodium hydroxide. As long as the alkalinity can be adjusted to meet the pH requirements, the present invention does not make any specific limitation.

[0063] In some embodiments, the formic acid acetamide preparation unit further includes a condensation device and a condensate storage device connected in sequence;

[0064] The feed inlet of the condensing device is connected to the gas outlet of the first reaction device;

[0065] The outlet of the condensate storage device is connected to the methyl formate supply device.

[0066] This invention, through the installation of a condensation device and a condensate storage device, allows excess methyl formate vapor in the first reaction device to be cooled by the condensation device and enter the condensate storage device, facilitating the reuse of methyl formate. This achieves the goal of reducing costs and increasing efficiency in the preparation of methyl ethylamine, and also plays a positive role in environmental protection.

[0067] In some embodiments, the solvent recovery tank is connected to the organic solvent supply device via a pipeline.

[0068] This invention achieves the recycling of organic solvents by connecting the solvent recovery tank and the organic solvent supply device through pipelines, thereby reducing costs and increasing efficiency in the preparation of methyl ethylamine and playing a positive role in environmental protection.

[0069] In some embodiments, the filtration device includes at least two filters connected in parallel.

[0070] This invention enables the continuous production of methyl ethylamine by using at least two filters connected in parallel, thus avoiding the production stoppage caused by filter blockage.

[0071] An embodiment of the present invention provides a method for synthesizing methyl ethylamine, the method comprising the following steps:

[0072] (1) Mix ethylamine and methyl formate, heat to reflux to react, and after the reaction is complete, separate the excess methyl formate to obtain acetamide formate;

[0073] (2) Mix the reducing agent solution, acid solution and the formic acid acetamide obtained in step (1), and heat to reflux to react and obtain the reaction solution;

[0074] The reducing agent solution is obtained by mixing a reducing agent with an organic solvent;

[0075] The acid solution is a mixture of organic acid and organic solvent;

[0076] (3) Adjust the pH of the reaction solution to ≥10, and then perform solid-liquid separation. The resulting filtrate is subjected to a first distillation. The light phase component obtained from the first distillation is the methyl ethylamine.

[0077] In this invention, the mixing temperature in step (1) and the mixing temperature in step (2) must be such that the reactants do not react during mixing. This invention does not specifically limit the mixing temperature.

[0078] In some embodiments, the ratio of ethylamine to methyl formate in step (1) is:

[0079] Add 80-120g of ethylamine to every 1L of methyl formate. For example, it can be 80g, 90g, 100g, 110g or 120g, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0080] In some embodiments, the reducing agent in the reducing agent solution of step (2) includes sodium borohydride.

[0081] In some embodiments, the molar ratio of sodium borohydride to ethylamine is 1:(0.8-1.2), for example, it can be 1:0.8, 1:0.9, 1:1, 1:1.1 or 1:1.2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0082] In some embodiments, the organic acid in the acid solution includes acetic acid.

[0083] In some embodiments, the concentration of organic acid in the acid solution is 8-12 mol / L, for example, it can be 8 mol / L, 9 mol / L, 10 mol / L, 11 mol / L or 12 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0084] In some embodiments, the molar ratio of acetic acid to ethylamine is 1:(0.8-1.2), for example, it can be 1:0.8, 1:0.9, 1:1, 1:1.1 or 1:1.2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0085] In some embodiments, the organic solvent includes tetrahydrofuran.

[0086] In some embodiments, the amount of tetrahydrofuran used in the reducing agent solution is 0.45-0.55 L of tetrahydrofuran per 100 g of ethylamine, for example, 0.45 L, 0.48 L, 0.5 L, 0.52 L or 0.55 L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0087] In some embodiments, the synthesis method further includes the following steps after step (3):

[0088] (4) The heavy phase component obtained from the first distillation is subjected to a second distillation, and the light component obtained from the second distillation is an organic solvent;

[0089] In some embodiments, the light component obtained from the second distillation is reused to obtain a reducing agent solution and an acid solution;

[0090] In some embodiments, the methyl formate separated in step (1) is reused in the reaction of ethylamine with methyl formate.

[0091] In some embodiments, the temperature at which the reaction is carried out by heating and reflux in step (1) is ≥35°C, for example, it can be 35°C, 36°C, 38°C, 40°C, 42°C or 45°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0092] In some embodiments, the temperature for the reaction in step (2) is ≥70°C, for example, 70°C, 71°C, 72°C, 73°C, 74°C or 75°C, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0093] As a further preferred technical solution, the synthesis method of the second aspect of the present invention is carried out in the synthesis apparatus system described in the first aspect.

[0094] Example 1

[0095] This embodiment provides a method such as Figure 1 The apparatus system for synthesizing methyl ethylamine shown includes a formic acid acetamide preparation unit, a reduction unit, a filtration unit, and a distillation unit.

[0096] The formate acetamide preparation unit includes an ethylamine supply device 12, a methyl formate supply device 13, a first reaction device 11, and a formate acetamide storage device 16; the outlets of the methyl formate supply device 13 and the ethylamine supply device 12 are respectively connected to the inlet of the first reaction device 11; the outlet of the first reaction device 11 is connected to the formate acetamide storage device 16.

[0097] The reduction unit includes a reducing agent supply device 22, an acid supply device 23, an organic solvent supply device 24, and a second reaction device 21; the outlet of the formic acid acetamide storage device 16 is connected to the inlet of the second reaction device 21; the outlets of the reducing agent supply device 22 and the acid supply device 23 are respectively connected to the inlet of the second reaction device 21; the outlet of the organic solvent supply device 24 is respectively connected to the inlet of the reducing agent supply device 22 and the acid supply device 23.

[0098] The filtration unit includes a reaction solution storage device 31, an alkali solution supply device 32, a filtration device, and a filtrate storage device 35; the outlet of the second reaction device 21 and the outlet of the alkali solution supply device 32 are respectively connected to the inlet of the reaction solution storage device 31; the filtration device is connected to the reaction solution storage device 31 and the filtrate storage device 35.

[0099] The distillation unit includes a first distillation apparatus 41, a second distillation apparatus 44, a methyl ethyl amine storage tank 42, a distillate liquid storage tank 43, a waste liquid storage tank 46, and a solvent recovery tank 45; the filtrate storage device 35 is connected to the inlet of the first distillation apparatus 41; the light phase outlet of the first distillation apparatus 41 is connected to the methyl ethyl amine storage tank 42, and the heavy phase outlet is connected to the inlet of the distillate liquid storage tank 43; the outlet of the distillate liquid storage tank 43 is connected to the inlet of the second distillation apparatus 44; the heavy phase outlet of the second distillation apparatus 44 is connected to the waste liquid storage tank 46, and the light phase outlet is connected to the solvent recovery tank 45.

[0100] The formic acid acetamide preparation unit further includes a condensation device 14 and a condensate storage device 15 connected in sequence; the inlet of the condensation device 14 is connected to the gas outlet of the first reaction device 11; the outlet of the condensate storage device 15 is connected to the methyl formic acid supply device 13.

[0101] The solvent recovery tank 45 is connected to the organic solvent supply device 24 via a pipeline; the filtration device includes a first filter 33 and a second filter 34 connected in parallel.

[0102] When using the synthesis apparatus system provided in this embodiment to synthesize methyl ethylamine, the following steps are included:

[0103] (a) Ethylamine from ethylamine supply device 12 and methyl formate from methyl formate supply device 13 are injected into the first reaction device 11 to mix ethylamine and methyl formate. Then, the mixture is heated under reflux to react. After the reaction is completed, the first reaction device 11 is heated to evaporate the remaining methyl formate. After cooling by condenser device 14, the condensate enters condensate storage device 15. Then, acetamide formate is introduced into acetamide formate storage device 16.

[0104] (b) Organic solvent supply device 24 provides organic solvent to disperse the reducing agent in reducing agent supply device 22 and then flows into the second reaction device 21; formic acid acetamide in formic acid acetamide storage device 16 is introduced into the second reaction device 21, and after thorough stirring, acid solution supply device 23 provides acid solution. After mixing evenly, the mixture is heated and refluxed to carry out the reaction.

[0105] (c) After the reaction is completed, the reaction solution is introduced into the reaction solution storage device 31, and then the alkaline solution is supplied by the alkaline solution supply device 32 to adjust the reaction solution in the reaction solution storage device 31 to alkaline. Then, solid-liquid separation is performed using a filtration device, and the resulting filtrate is introduced into the filtrate storage device 35.

[0106] (d) The filtrate is distilled in the first distillation unit 41. The light phase obtained at the top of the first distillation unit 41 is methyl ethylamine, which enters the methyl ethylamine storage tank 42. The heavy phase obtained at the bottom of the first distillation unit 41 is introduced into the distillate storage tank 43. The distillate in the distillate storage tank 43 is distilled in the second distillation unit 44. The light phase obtained is an organic solvent, which enters the solvent recovery tank 45. The heavy phase obtained enters the waste liquid storage tank 46.

[0107] Application Example 1

[0108] This application example provides a method for synthesizing methyl ethylamine, which is carried out in the synthesis apparatus system provided in Example 1, and includes the following steps:

[0109] (1) Mix 100g of ethylamine with 1L of methyl formate, heat to 35℃ and reflux for 5h to carry out the reaction. After the reaction is completed, separate the excess methyl formate to obtain acetamide formate.

[0110] Excess methyl formate is collected in a condensate storage device via a condensation unit for reuse.

[0111] (2) Mix the reducing agent solution, acid solution and the formic acid acetamide obtained in step (1), heat to 70°C and reflux for 4 hours to react and obtain the reaction solution;

[0112] The reducing agent solution is obtained by mixing sodium borohydride as a reducing agent with the organic solvent tetrahydrofuran; the molar ratio of sodium borohydride to ethylamine is 1:1; the amount of tetrahydrofuran used in the reducing agent solution is 0.5L of tetrahydrofuran per 100g of ethylamine;

[0113] The acid solution is a mixture of the organic acid acetic acid and the organic solvent tetrahydrofuran, with the concentration of acetic acid being 10 mol / L and the molar ratio of acetic acid to ethylamine being 1:1.

[0114] (3) The pH of the reaction solution was adjusted to 10 using a 1 mol / L sodium hydroxide solution, and solid-liquid separation was performed. The filtrate was subjected to a first distillation. The light phase component obtained from the first distillation was methyl ethylamine. The heavy phase component obtained from the first distillation was subjected to a second distillation. The light component obtained from the second distillation was the organic solvent tetrahydrofuran, which was recycled into the solvent recovery tank. The remaining waste liquid was discharged from the bottom of the second distillation unit into the waste liquid storage tank.

[0115] The synthesis method provided in this embodiment can recover and reuse excess methyl formate and the solvent tetrahydrofuran. The waste is mainly in the form of solid sodium acetate and sodium metaborate or solution. The harmless treatment is simple and has little impact on the environment.

[0116] Application Example 2

[0117] This application example provides a method for synthesizing methyl ethylamine, which is carried out in the synthesis apparatus system provided in Example 1, and includes the following steps:

[0118] (1) Mix 80g of ethylamine with 1L of methyl formate, heat to 35℃ and reflux for 5h to carry out the reaction. After the reaction is completed, separate the excess methyl formate to obtain acetamide formate.

[0119] Excess methyl formate is collected in a condensate storage device via a condensation unit for reuse.

[0120] (2) Mix the reducing agent solution, acid solution and the formic acid acetamide obtained in step (1), heat to 70°C and reflux for 4 hours to react and obtain the reaction solution;

[0121] The reducing agent solution is obtained by mixing sodium borohydride as a reducing agent with the organic solvent tetrahydrofuran; the molar ratio of sodium borohydride to ethylamine is 1:0.8; the amount of tetrahydrofuran used in the reducing agent solution is 0.45L of tetrahydrofuran per 100g of ethylamine;

[0122] The acid solution is a mixture of the organic acid acetic acid and the organic solvent tetrahydrofuran, with the concentration of acetic acid being 8 mol / L and the molar ratio of acetic acid to ethylamine being 1:0.8.

[0123] (3) Adjust the pH of the reaction solution to 10 using 1 mol / L sodium hydroxide solution, and perform solid-liquid separation. The resulting filtrate is subjected to first distillation. The light phase component obtained from the first distillation is methyl ethylamine. The heavy phase component obtained from the first distillation is subjected to second distillation. The light component obtained from the second distillation is the organic solvent tetrahydrofuran, which is recycled into the solvent recovery tank. The remaining waste liquid enters the waste liquid storage tank from the bottom of the second distillation unit.

[0124] The synthesis method provided in this embodiment can recover and reuse excess methyl formate and the solvent tetrahydrofuran. The waste is mainly in the form of solid sodium acetate and sodium metaborate or solution. The harmless treatment is simple and has little impact on the environment.

[0125] Application Example 3

[0126] This application example provides a method for synthesizing methyl ethylamine, which is carried out in the synthesis apparatus system provided in Example 1, and includes the following steps:

[0127] (1) Mix 120g of ethylamine with 1L of methyl formate, heat to 35℃ and reflux for 5h to carry out the reaction. After the reaction is completed, separate the excess methyl formate to obtain acetamide formate.

[0128] Excess methyl formate is collected in a condensate storage device via a condensation unit for reuse.

[0129] (2) Mix the reducing agent solution, acid solution and the formic acid acetamide obtained in step (1), heat to 70°C and reflux for 4 hours to react and obtain the reaction solution;

[0130] The reducing agent solution is obtained by mixing sodium borohydride as a reducing agent with the organic solvent tetrahydrofuran; the molar ratio of sodium borohydride to ethylamine is 1:1.2; the amount of tetrahydrofuran used in the reducing agent solution is 0.55L of tetrahydrofuran per 100g of ethylamine;

[0131] The acid solution is a mixture of the organic acid acetic acid and the organic solvent tetrahydrofuran, with the concentration of acetic acid being 12 mol / L and the molar ratio of acetic acid to ethylamine being 1:1.2.

[0132] (3) Adjust the pH of the reaction solution to 10 using 1 mol / L sodium hydroxide solution, and perform solid-liquid separation. The resulting filtrate is subjected to first distillation. The light phase component obtained from the first distillation is methyl ethylamine. The heavy phase component obtained from the first distillation is subjected to second distillation. The light component obtained from the second distillation is the organic solvent tetrahydrofuran, which is recycled into the solvent recovery tank. The remaining waste liquid enters the waste liquid storage tank from the bottom of the second distillation unit.

[0133] The synthesis method provided in this embodiment can recover and reuse excess methyl formate and the solvent tetrahydrofuran. The waste is mainly in the form of solid sodium acetate and sodium metaborate or solution. The harmless treatment is simple and has little impact on the environment.

[0134] Application Example 4

[0135] This application example provides a method for synthesizing methyl ethylamine, which is the same as application example 1 except that the organic solvent is replaced by an equal volume of anhydrous ethanol.

[0136] In this application example, the use of anhydrous ethanol as an organic solvent poses a risk of sodium borohydride reacting with ethanol to produce a large amount of hydrogen gas, which could prevent the synthesis from proceeding smoothly.

[0137] The purity and yield of methyl ethylamine obtained in corresponding examples 1-3 were determined. The purity was determined by gas chromatography, and the yield was calculated by comparing the actual yield of the product with the theoretical yield. The results are shown in Table 1.

[0138] Table 1

[0139] Purity (wt%) Yield (%) Application Example 1 99.1 92 Application Example 2 99.2 83 Application Example 3 99.1 90

[0140] In summary, the methyl ethylamine synthesis apparatus system provided by this invention does not require the addition of organic solvents during the preparation of formic acid acetamide. After synthesis, no other complex post-processing is required; simple distillation is sufficient to efficiently obtain the methyl ethylamine product. Therefore, the synthesis apparatus system provided by this invention can greatly improve production efficiency and reduce the preparation cost of methyl ethylamine. The synthesis method provided by this invention produces fewer byproducts, which does not cause purification difficulties and is conducive to obtaining high-purity methyl ethylamine, enabling efficient production of methyl ethylamine.

[0141] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A system for synthesizing methyl ethylamine, characterized in that, The synthesis apparatus system includes a formic acid acetamide preparation unit, a reduction unit, a filtration unit, and a distillation unit; The formate acetamide preparation unit includes an ethylamine supply device, a methyl formate supply device, a first reaction device, and an formate acetamide storage device; the outlets of the methyl formate supply device and the ethylamine supply device are respectively connected to the inlet of the first reaction device; the outlet of the first reaction device is connected to the formate acetamide storage device. The reduction unit includes a reducing agent supply device, an acid supply device, an organic solvent supply device, and a second reaction device; the outlet of the formic acid acetamide storage device is connected to the inlet of the second reaction device; the outlets of the reducing agent supply device and the acid supply device are respectively connected to the inlet of the second reaction device; the outlet of the organic solvent supply device is respectively connected to the inlet of the reducing agent supply device and the acid supply device. The filtration unit includes a reaction solution storage device, an alkali supply device, a filtration device, and a filtrate storage device; the outlet of the second reaction device and the outlet of the alkali supply device are respectively connected to the inlet of the reaction solution storage device; the filtration device is connected to the reaction solution storage device and the filtrate storage device. The distillation unit includes a first distillation apparatus, a second distillation apparatus, a methyl ethylamine storage tank, a distillate liquid storage tank, a waste liquid storage tank, and a solvent recovery tank; the filtrate storage device is connected to the inlet of the first distillation apparatus; the light phase outlet of the first distillation apparatus is connected to the methyl ethylamine storage tank, and the heavy phase outlet is connected to the inlet of the distillate liquid storage tank; the outlet of the distillate liquid storage tank is connected to the inlet of the second distillation apparatus; the heavy phase outlet of the second distillation apparatus is connected to the waste liquid storage tank, and the light phase outlet is connected to the solvent recovery tank.

2. The synthesis apparatus system according to claim 1, characterized in that, The formic acid acetamide preparation unit also includes a condensation device and a condensate storage device connected in sequence. The feed inlet of the condensing device is connected to the gas outlet of the first reaction device; The outlet of the condensate storage device is connected to the methyl formate supply device.

3. The synthesis apparatus system according to claim 1, characterized in that, The solvent recovery tank is connected to the organic solvent supply device via pipeline.

4. The synthesis apparatus system according to claim 1, characterized in that, The filtration device includes at least two filters connected in parallel.

5. A method for synthesizing methyl ethylamine, characterized in that, The method for synthesizing methyl ethylamine is carried out in the apparatus system for synthesizing methyl ethylamine according to any one of claims 1-4, and the method comprises the following steps: (1) Mix ethylamine and methyl formate, heat to reflux and react. After the reaction is complete, separate the excess methyl formate to obtain acetamide formate; (2) Mix the reducing agent solution, acid solution and the formic acid acetamide obtained in step (1), and heat to reflux to react and obtain the reaction solution; The reducing agent solution is obtained by mixing a reducing agent with an organic solvent; The acid solution is a mixture of organic acid and organic solvent; (3) Adjust the pH of the reaction solution to ≥10, and then perform solid-liquid separation. The resulting filtrate is subjected to a first distillation. The light phase component obtained from the first distillation is the methyl ethylamine.

6. The synthesis method according to claim 5, characterized in that, The ratio of ethylamine to methyl formate in step (1) is as follows: Add 80-120g of ethylamine to every 1L of methyl formate.

7. The synthesis method according to claim 5, characterized in that, The reducing agent in the reducing agent solution in step (2) is sodium borohydride.

8. The synthesis method according to claim 7, characterized in that, The molar ratio of sodium borohydride to ethylamine is 1:(0.8-1.2).

9. The synthesis method according to claim 5, characterized in that, The organic acid in the acid solution is acetic acid.

10. The synthesis method according to claim 5, characterized in that, The concentration of organic acid in the acid solution is 8-12 mol / L.

11. The synthesis method according to claim 9, characterized in that, The molar ratio of acetic acid to ethylamine is 1:(0.8-1.2).

12. The synthesis method according to claim 5, characterized in that, The organic solvent is tetrahydrofuran.

13. The synthesis method according to claim 12, characterized in that, The amount of tetrahydrofuran used in the reducing agent solution is 0.45-0.55 L of tetrahydrofuran per 100 g of ethylamine.

14. The synthesis method according to claim 5, characterized in that, The synthesis method further includes steps after step (3): (4) The heavy phase component obtained from the first distillation is subjected to a second distillation, and the light component obtained from the second distillation is an organic solvent.

15. The synthesis method according to claim 14, characterized in that, The light fraction obtained from the second distillation is reused to obtain reducing agent solution and acid solution.

16. The synthesis method according to claim 5, characterized in that, The methyl formate separated in step (1) is reused in the reaction of ethylamine and methyl formate.

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