A method for industrial production of N,N,N',N'-tetraoctyl-3-oxapentanamide

Abstract

The embodiment of the present application provides a kind of industrial preparation method of N,N,N',N'-tetraoctyl-3-oxypentanediamide, it is related to organic synthesis technical field.The method includes the following steps: 1) diethylene glycol acid, thionyl chloride and DMF are mixed and heated to obtain diethylene glycol chloride;2) di-n-octylamine, triethylamine, diethylene glycol chloride and tetrahydrofuran are mixed to obtain TODGA crude product at room temperature;3) TODGA crude product is subjected to primary vacuum distillation to obtain industrial grade TODGA product;4) industrial grade TODGA product is subjected to secondary vacuum distillation to obtain high-quality grade TODGA product;5) high-quality grade TODGA product is subjected to tertiary vacuum distillation to obtain high-purity grade TODGA product.The industrial preparation method of N,N,N',N'-tetraoctyl-3-oxypentanediamide of the embodiment of the present application, by strictly controlling reaction temperature, reaction rate and distillation parameter and other core conditions, develop a set of acyl chloride, amidation and refining process multistage coupling synergistic system technology.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to an industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide. Background Technology

[0002] N,N,N',N'-Tetraoctyl-3-oxopramethylenediamide (TODGA) is a highly efficient tripentate ligand. Its molecular structure contains three oxygen donor atoms, giving it excellent extraction ability and selectivity for trivalent lanthanides and actinides. This compound is composed entirely of carbon, hydrogen, oxygen, and nitrogen, following the "CHON" principle, and is environmentally friendly, being completely combustible and producing no secondary solid waste.

[0003] TODGA is widely used in high-level radioactive waste treatment processes in advanced nuclear fuel cycles and is one of the key extractants for separating actinides from lanthanides. However, industrial-scale production of TODGA has not yet been achieved in China. With the rapid development of my country's nuclear energy industry and the increasing demand for spent fuel reprocessing, the market demand for high-quality TODGA extractants is rising year by year. There is an urgent need to develop a stable and reliable industrial-scale production method for TODGA that offers significant advantages such as mild reaction conditions, easy-to-control reaction process, high yield, and controllable product purity.

[0004] Current methods for synthesizing TODGA mainly include one-step condensation, acyl chloride methods, and multi-step methods. These methods generally suffer from technical bottlenecks that hinder industrial production, such as poor process controllability, unstable yields, difficulties in purification, and significant environmental pressures, making it difficult to simultaneously achieve high product purity and yield. Furthermore, the acyl chloride method requires stringent anhydrous and oxygen-free operation, resulting in significant product loss during scale-up processes, high production costs, and difficulty in meeting the requirements of clean production and sustainable development. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides an industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide. The technical solution is as follows:

[0006] This invention provides an industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide, comprising the following steps:

[0007] S1: Add diethylene glycol, thionyl chloride and N,N-dimethylformamide to the synthesis reactor, stir and heat at 40-50℃ for 1-2 hours, then raise the temperature to 70-85℃ and heat for 2-3 hours to obtain the reaction solution;

[0008] S2: The reaction solution obtained in step S1 is subjected to vacuum distillation at 45-75℃ and a vacuum degree of 250-400Pa to obtain diethylene glycol chloride and tail gas.

[0009] S3: Add di-n-octylamine and triethylamine to a mixing tank, stir and mix, then pump into a synthesis reactor. Add diethylene glycol chloride and tetrahydrofuran obtained in step S2 to a mixing tank, stir and mix, then pump into a synthesis reactor. React at room temperature for 1-2 hours to obtain the mother liquor.

[0010] S4: Centrifuge the mother liquor from step S3 to obtain the supernatant, and then distill the supernatant under reduced pressure at 32-55℃ and a vacuum of 250-400Pa to obtain crude TODGA product.

[0011] S5: The crude TODGA product obtained in step S4 is leached with hydrochloric acid, and after centrifugation, an organic phase is obtained. The organic phase is mixed with an organic solvent, and after centrifugation, a liquid phase is obtained.

[0012] S6: The liquid phase from step S5 is transferred to a primary vacuum distillation vessel and subjected to primary vacuum distillation at 40-50°C and a vacuum of 250-400Pa to obtain industrial-grade TODGA product.

[0013] S7: The industrial-grade TODGA obtained in step S6 is transferred to a two-stage vacuum distillation vessel and subjected to two-stage vacuum distillation at 188-210℃ and a vacuum of 133-165 Pa to obtain a high-quality TODGA product.

[0014] S8: The high-quality TODGA product obtained in step S7 is transferred to a three-stage vacuum distillation vessel and subjected to three-stage vacuum distillation at 227-250℃ and a vacuum degree of 52-65 Pa to obtain a high-purity TODGA product.

[0015] Optionally, in step S1, the molar ratio of diethylene glycol to thionyl chloride is 1:(2.5-8.0), and N,N-dimethylformamide accounts for 1%-5% of the mass of diethylene glycol.

[0016] Optionally, in step S2, the exhaust gas is absorbed with sodium carbonate solution to obtain a byproduct containing sodium sulfite and sodium chloride.

[0017] Optionally, in step S3, the molar ratio of di-n-octylamine to triethylamine is 1:(0.5-3.5), and the molar ratio of di-n-octylamine to diethylene glycol chloride is (2.2-4.5):1.

[0018] Optionally, in step S3, the molar ratio of diethylene glycol chloride to tetrahydrofuran is 1:(1.5-3.7).

[0019] Optionally, in step S5, the centrifugation speed after hydrochloric acid leaching is 8000-10000 r / min, and the centrifugation speed after mixing the organic phase and organic solvent is 3000-5000 r / min.

[0020] Optionally, in step S7, the residue obtained after secondary vacuum distillation is returned to step S4 and mixed with crude TODGA for recycling; in step S8, the residue obtained after tertiary vacuum distillation is returned to step S4 and mixed with crude TODGA for recycling.

[0021] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0022] (1) The present invention provides an industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide. By strictly controlling the core conditions such as reaction temperature, reaction rate, and distillation parameters, a systematic process with multi-stage coupling and synergy of acyl chloride, amidation, and purification steps has been developed. This process overcomes the technical defects of traditional synthesis methods, such as difficulty in process control, large yield fluctuations, and purification difficulties, and realizes reliable industrial-scale production of TODGA.

[0023] (2) An innovative three-stage vacuum distillation process was designed and efficiently integrated with the amide process. Through precise adjustment of distillation temperature and pressure, stable production of industrial-grade, premium-grade and high-purity TODGA products was successfully achieved, which can flexibly meet the differentiated product quality requirements of different application scenarios.

[0024] (3) The production process integrates a tail gas absorption and water recycling system to ensure that the exhaust gas meets emission standards and the wastewater is recycled and reused. This design not only reduces the consumption of raw and auxiliary materials and alleviates environmental pressure, but also fully meets the requirements of efficient and green development of modern chemical industry.

[0025] (4) Diethylene glycol is used as the starting material, which is readily available and the reaction conditions are mild. The entire process chain is fully controllable, which not only ensures the high purity and high yield of the product, but also provides a solid and reliable technical and economic guarantee for the large-scale industrial production of TODGA. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1This is a schematic flowchart of an industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] This invention provides an industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide, comprising an acyl chloride step, an amide step, and a refining step, as shown in the process route below. Figure 1 As shown, the preparation method includes the following steps:

[0030] S1: In the acyl chloride process, diethylene glycol acid from tank #1, thionyl chloride from tank #2, and N-dimethylformamide from tank #3 DMF are fed into reactor #4 and stirred and heated at 40-50°C for 1-2 hours. Then the temperature is raised to 70-85°C and heated for 2-3 hours to obtain the reaction solution.

[0031] S2: The reaction solution is fed into the No. 5 vacuum distillation kettle and distilled under reduced pressure at 45-75℃ and a vacuum degree of 250-400Pa to obtain diethylene glycol chloride and tail gas. The diethylene glycol chloride is transferred to the No. 6 diethylene glycol chloride tank. The gas enters the No. 7 spray gas absorption tower and is absorbed by the alkaline water spray liquid from the No. 8 alkaline water tower. The resulting absorbent is fed into the No. 9 spray water treatment equipment. After treatment, the solid obtained from the absorbent is stored in the No. 10 by-product tank, and the treated liquid is fed into the No. 8 alkaline water tank for recycling.

[0032] S3: In the amide process, diethylene glycol acid from tank #6 and tetrahydrofuran from tank #20 are fed into mixing tank #11 and mixed; di-n-octylamine from tank #12 and triethylamine from tank #13 are fed into mixing tank #14 and mixed; the mixture from mixing tank #11 and the mixture from mixing tank #14 are fed into reactor #15 and reacted at room temperature for 1-2 hours to obtain mother liquor;

[0033] S4: The mother liquor is fed into centrifuge #16 for centrifugation to separate the supernatant. The supernatant is transferred to liquid phase tank #18, and the solid after centrifugation is transferred to solid phase tank #17. The supernatant in liquid phase tank #18 is fed into vacuum distillation kettle #19 and distilled under vacuum conditions of 32-55℃ and 250-400 Pa. The remaining liquid is fed into crude TODGA tank #21 to obtain crude TODGA product. The fraction is fed into tetrahydrofuran tank #20. Tetrahydrofuran can be returned to step S3 for recycling.

[0034] S5: In the refining process, the crude TODGA in tank #21 and the hydrochloric acid solution in tank #23 are mixed in tank #22. The mixture in tank #22 is then centrifuged in centrifuge #24. The resulting solid is transferred to tank #25 and the liquid phase is transferred to tank #26. In tank #26, the liquid phase separates into an aqueous phase and an organic phase. The aqueous phase is transferred to tank #27 and the organic phase is transferred to tank #28. The organic phase in tank #28 and the petroleum ether in tank #34 are mixed in tank #29. The resulting suspension is then centrifuged in centrifuge #30. The resulting solid is transferred to tank #31 and the resulting organic phase is transferred to tank #32.

[0035] S6: Transfer the organic phase in the 32# organic phase tank to the 33# primary vacuum distillation vessel and perform primary vacuum distillation at 40-50℃ and a vacuum degree of 250-400Pa. The distillate is fed into the 35# industrial-grade TODGA tank to obtain industrial-grade TODGA product with a purity of 82.1-89.4% and a yield of 75.5-82.3%. The fraction is fed into the 34# petroleum ether tank. The petroleum ether can be returned to step S5 for recycling.

[0036] S7: Transfer the industrial-grade TODGA product from the 35# industrial-grade TODGA tank to the 36# secondary vacuum distillation kettle and perform secondary vacuum distillation at 188-210℃ and a vacuum degree of 133-165 Pa. The fraction is transferred to the 38# premium-grade TODGA tank to obtain premium-grade TODGA product with a purity of 90.2-95.6% and a yield of 81.5-85.7%. The distillation residue is transferred to the 37# residue tank, and the distillation residue in the 37# residue tank is transferred to the 21# crude TODGA tank for recycling.

[0037] S8: Transfer the premium TODGA product from tank #38 to tank #39 for three-stage vacuum distillation at 227-250℃ and a vacuum of 52-65 Pa. The fraction is then transferred to tank #41 for high-purity TODGA to obtain high-purity TODGA product with a purity of 96.1-99.6% and a yield of 84.5-87.9%. The distillation residue is transferred to tank #40 for residue, and then transferred to tank #21 for crude TODGA for recycling. The solids from tanks #17, #25, and #31 are transferred to tank #42 for by-products.

[0038] In step S1, the molar ratio of diethylene glycol to thionyl chloride is 1:(2.5-8.0), and N,N-dimethylformamide accounts for 1%-5% of the mass of diethylene glycol.

[0039] In step S3, the molar ratio of di-n-octylamine to triethylamine is 1:(0.5-3.5), the molar ratio of di-n-octylamine to diethylene glycol chloride is (2.2-4.5):1, and the molar ratio of diethylene glycol chloride to tetrahydrofuran is 1:(1.5-3.7).

[0040] In step S5, the centrifugation speed after hydrochloric acid leaching is 8000-10000 r / min, and the centrifugation speed after mixing the organic phase and organic solvent is 3000-5000 r / min.

[0041] The following specific examples provide further details.

[0042] Example 1

[0043] This invention provides an industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide, comprising the following steps:

[0044] 1) Preparation of diethylene glycol chloride:

[0045] 20.0 kg (148.3 mol) of diethylene glycol acid, 26.9 L (370.75 mol) of thionyl chloride, and 400 g of DMF were weighed and added to reactor #4. The mixture was stirred and refluxed at 40 °C for 1.8 hours, then heated to 75 °C and reacted for 2.5 hours. After the reaction was completed, the reaction solution was transferred to a vacuum distillation vessel #5 for distillation at 45 °C and a vacuum of 300 Pa. Diethylene glycol chloride (21.7 kg) was obtained after distillation, with a purity of 99.1% and a yield of 87.7%.

[0046] 2) Preparation of crude TODGA:

[0047] 64.0 kg (265.1 mol) of di-n-octylamine and 13.5 kg (133.4 mol) of triethylamine were weighed into mixing tank #14 and mixed thoroughly by mechanical stirring. 20.0 kg (117.0 mol) of diethylene glycol chloride and 12.7 kg (176.1 mol) of tetrahydrofuran were transferred to mixing tank #11 and mixed thoroughly by mechanical stirring. 32.7 kg of the mixture from mixing tank #11 was slowly pumped into reactor #15, and 77.5 kg of the mixture from mixing tank #14 was slowly added to reactor #15. The reaction was carried out at room temperature (20-25℃) for 1.5 hours. After the reaction, a mother liquor was obtained and transferred to a vacuum distillation vessel #19. Distillation was performed at 35℃ and a vacuum of 280 Pa. After distillation, 82.4 kg of crude TODGA was obtained with a purity of 58.1% and a yield of 71.2%.

[0048] 3) Preparation of industrial-grade TODGA products:

[0049] 80.0 kg of crude TODGA was mixed thoroughly with 80.0 kg of 10% HCl solution and then centrifuged in centrifuge #24 at 9000 r / min. The organic phase was collected and transferred to organic phase tank #28. The organic phase in organic phase tank #28 was mixed thoroughly with 70.0 kg of petroleum ether at 60°C and then centrifuged in centrifuge #30 at 4000 r / min. The organic phase was collected and transferred to organic phase tank #32. The organic phase in organic phase tank #32 was transferred to a single-stage vacuum distillation vessel #33 for distillation. The distillation temperature was 48°C and the vacuum degree was 380 Pa. After distillation, 44.0 kg of industrial-grade TODGA product was obtained with a purity of 86.5% and a yield of 81.8%.

[0050] 4) Preparation of high-quality TODGA products:

[0051] 40.0 kg of industrial-grade TODGA product from tank #35 was transferred to a secondary vacuum distillation vessel #36 for distillation. The distillation temperature was 205℃ and the vacuum degree was 162 Pa. After distillation, 30.8 kg of premium-grade TODGA product was obtained with a purity of 93.8% and a yield of 83.5%.

[0052] 5) Preparation of high-purity TODGA products:

[0053] 30.0 kg of premium TODGA product from tank #38 was transferred to a three-stage vacuum distillation vessel #39 for distillation. The distillation temperature was 248℃ and the vacuum degree was 58 Pa. After distillation, 24.5 kg of high-purity TODGA product was obtained, with a purity of 99.4% and a yield of 86.6%.

[0054] Example 2

[0055] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0056] Step 1): Preparation of diethylene glycol acyl chloride: Weigh 20.0 kg (148.3 mol) of diethylene glycolic acid, measure 26.9 L (370.75 mol) of thionyl chloride, and weigh 1.0 kg of DMF. Add these to reactor #4 and reflux at 50°C for 1.0 h, then raise the temperature to 85°C and react for 3.0 h. After the reaction is complete, transfer the reaction solution to a vacuum distillation vessel #5 for distillation at 75°C and a vacuum degree of 390 Pa. After distillation, 22.0 kg of diethylene glycol acyl chloride is obtained with a purity of 98.8% and a yield of 88.2%.

[0057] Finally, 44.0 kg of industrial-grade TODGA product was obtained with a purity of 86.5% and a yield of 81.8%. 30.8 kg of premium-grade TODGA product was obtained with a purity of 93.8% and a yield of 83.5%. 24.5 kg of high-purity TODGA product was obtained with a purity of 99.4% and a yield of 86.6%.

[0058] Example 3

[0059] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0060] Step 2): Preparation of crude TODGA: Weigh 64.0 kg (265.1 mol) of di-n-octylamine and 13.5 kg (133.4 mol) of triethylamine into mixing tank #14 and mix thoroughly by mechanical stirring. Transfer 20.0 kg (117.0 mol) of diethylene glycol chloride and 31.2 kg (432.9 mol) of tetrahydrofuran to mixing tank #11 and mix thoroughly by mechanical stirring. Slowly pump 51.2 kg of the mixture from tank #11 into reactor #15, and slowly add 77.5 kg of the mixture from mixing tank #14 into reactor #15. The reaction is carried out at room temperature for 2.0 hours. After the reaction, 82.4 kg of crude TODGA was obtained with a purity of 58.1% and a yield of 71.2%.

[0061] Finally, 44.0 kg of industrial-grade TODGA product was obtained with a purity of 86.5% and a yield of 81.8%. 30.8 kg of premium-grade TODGA product was obtained with a purity of 93.8% and a yield of 83.5%. 24.5 kg of high-purity TODGA product was obtained with a purity of 99.4% and a yield of 86.6%.

[0062] Example 4

[0063] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0064] Step 1): Weigh 20.0 kg (148.3 mol) of diethylene glycol acid, measure 26.9 L (370.75 mol) of thionyl chloride, and weigh 400 g of DMF. Add these to reactor #4 and reflux at 50°C for 1 hour with stirring. Then, raise the temperature to 70°C and react for 2.5 hours. After the reaction is complete, transfer the reaction solution to a vacuum distillation vessel #5 for distillation at 65°C and a vacuum of 250 Pa. Diethylene glycol acyl chloride is obtained after distillation with a purity of 98.7% and a yield of 88.1%.

[0065] Example 5

[0066] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0067] Step 1): Weigh 20.0 kg (148.3 mol) of diethylene glycol acid, measure 26.9 L (370.75 mol) of thionyl chloride, and weigh 400 g of DMF. Add these to reactor #4 and reflux at 45°C for 2 hours with stirring. Then, raise the temperature to 80°C and react for another 2 hours. After the reaction is complete, transfer the reaction solution to a vacuum distillation vessel #5 for distillation at 55°C and a vacuum of 400 Pa. Diethylene glycol acyl chloride is obtained after distillation with a purity of 98.9% and a yield of 88.2%.

[0068] Example 6

[0069] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0070] Step 2): Weigh 64.0 kg (265.1 mol) of di-n-octylamine and 13.5 kg (133.4 mol) of triethylamine into mixing tank #14 and mix thoroughly by mechanical stirring. Transfer 20.0 kg (117.0 mol) of diethylene glycol chloride and 12.7 kg (176.1 mol) of tetrahydrofuran to mixing tank #11 and mix thoroughly by mechanical stirring. Slowly pump 32.7 kg of the mixture from mixing tank #11 into reactor #15, and slowly add 77.5 kg of the mixture from mixing tank #14 into reactor #15. React at room temperature (20-25℃) for 1 hour. After the reaction, the mother liquor is obtained and transferred to vacuum distillation vessel #19. Distill at 55℃ and a vacuum of 250 Pa. After distillation, crude TODGA is obtained with a purity of 60.7% and a yield of 69.8%.

[0071] Example 7

[0072] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0073] Step 2): Weigh 64.0 kg (265.1 mol) of di-n-octylamine and 13.5 kg (133.4 mol) of triethylamine into mixing tank #14 and mix thoroughly by mechanical stirring. Transfer 20.0 kg (117.0 mol) of diethylene glycol chloride and 12.7 kg (176.1 mol) of tetrahydrofuran to mixing tank #11 and mix thoroughly by mechanical stirring. Slowly pump 32.7 kg of the mixture from mixing tank #11 into reactor #15, and slowly add 77.5 kg of the mixture from mixing tank #14 into reactor #15. React at room temperature (20-25℃) for 1 hour. After the reaction, the mother liquor is obtained and transferred to vacuum distillation vessel #19. Distill at 32℃ and a vacuum of 400 Pa. After distillation, crude TODGA is obtained with a purity of 57.4% and a yield of 72.3%.

[0074] Example 8

[0075] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0076] Step 3): Mix 80.0 kg of crude TODGA with 80.0 kg of 10% HCl solution until homogeneous, then transfer to centrifuge #24 at 9000 r / min. Collect the organic phase and transfer it to organic phase tank #28. Mix the organic phase from organic phase tank #28 with 70.0 kg of petroleum ether at 60°C until homogeneous, then transfer to centrifuge #30 at 4000 r / min. Collect the organic phase and transfer it to organic phase tank #32. Transfer the organic phase from organic phase tank #32 to a single-stage vacuum distillation vessel #33 for distillation. Distillation temperature is 40°C, and vacuum degree is 250 Pa. After distillation, industrial-grade TODGA product is obtained with a purity of 88.5% and a yield of 78.9%.

[0077] Example 9

[0078] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0079] Step 3): Mix 80.0 kg of crude TODGA with 80.0 kg of 10% HCl solution until homogeneous, then transfer to centrifuge #24 at 9000 r / min. Collect the organic phase and transfer it to organic phase tank #28. Mix the organic phase from organic phase tank #28 with 70.0 kg of petroleum ether at 60°C until homogeneous, then transfer to centrifuge #30 at 4000 r / min. Collect the organic phase and transfer it to organic phase tank #32. Transfer the organic phase from organic phase tank #32 to a single-stage vacuum distillation vessel #33 for distillation. Distillation temperature is 50°C, and vacuum degree is 400 Pa. After distillation, industrial-grade TODGA product is obtained with a purity of 85.7% and a yield of 82.3%.

[0080] Example 10

[0081] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0082] Step 4): Transfer 40.0 kg of industrial-grade TODGA product from the 35# industrial-grade TODGA tank to a 36# two-stage vacuum distillation vessel for distillation. The distillation temperature was 188℃, and the vacuum degree was 133 Pa. After distillation, a high-quality TODGA product was obtained with a purity of 94.1% and a yield of 82.5%.

[0083] Example 11

[0084] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0085] Step 4): Transfer 40.0 kg of industrial-grade TODGA product from the #35 industrial-grade TODGA tank to a #36 two-stage vacuum distillation vessel for distillation. The distillation temperature is 210℃ and the vacuum degree is 165 Pa. After distillation, a high-quality TODGA product is obtained with a purity of 92.1% and a yield of 84.2%.

[0086] Example 12

[0087] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0088] Step 5): Transfer 30.0 kg of premium TODGA product from tank #38 to a three-stage vacuum distillation vessel #39 for distillation. The distillation temperature is 227℃ and the vacuum degree is 52 Pa. After distillation, high-purity TODGA product is obtained with a purity of 99.1% and a yield of 86.9%.

[0089] Example 13

[0090] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0091] Step 5): Transfer 30.0 kg of premium TODGA product from tank #38 to a three-stage vacuum distillation vessel #39 for distillation. The distillation temperature is 250℃ and the vacuum degree is 65 Pa. After distillation, high-purity TODGA product is obtained with a purity of 98.2% and a yield of 87.3%.

[0092] Example 14

[0093] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0094] In step 1), the molar ratio of diethylene glycol to thionyl chloride is 1:8.0, and N,N-dimethylformamide accounts for 1% of the mass of diethylene glycol. After distillation, diethylene glycolyl chloride is obtained with a purity of 99.4% and a yield of 87.9%.

[0095] Example 15

[0096] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0097] In step 1), the molar ratio of diethylene glycol to thionyl chloride is 1:8.0, and N,N-dimethylformamide accounts for 5% of the mass of diethylene glycol. After distillation, diethylene glycolyl chloride is obtained with a purity of 98.8% and a yield of 88.3%.

[0098] Example 16

[0099] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0100] In step 2), the molar ratio of di-n-octylamine to triethylamine is 1:3.5, the molar ratio of di-n-octylamine to diethylene glycol chloride is 2.2:1, and the molar ratio of diethylene glycol chloride to tetrahydrofuran is 1:1.5. After distillation, crude TODGA is obtained with a purity of 61.6% and a yield of 64.7%.

[0101] Example 17

[0102] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0103] In step 2), the molar ratio of di-n-octylamine to triethylamine is 1:0.5, the molar ratio of di-n-octylamine to diethylene glycol chloride is 4.5:1, and the molar ratio of diethylene glycol chloride to tetrahydrofuran is 1:1.5. After distillation, crude TODGA is obtained with a purity of 57.5% and a yield of 72.8%.

[0104] Example 18

[0105] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0106] In step 3), after leaching with hydrochloric acid, the centrifugation speed was 8000 r / min, and after mixing the organic phase with petroleum ether, the centrifugation speed was 5000 r / min. After distillation, industrial-grade TODGA product was obtained with a purity of 85.2% and a yield of 82.1%.

[0107] Example 19

[0108] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this embodiment of the invention is the same as that in Example 1, except that:

[0109] In step 3), after leaching with hydrochloric acid, the centrifugation speed was 10000 r / min, and after mixing the organic phase with petroleum ether, the centrifugation speed was 3000 r / min. After distillation, industrial-grade TODGA product was obtained with a purity of 88.6% and a yield of 79.5%.

[0110] Comparative Example 1

[0111] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that:

[0112] Step 1): Preparation of diethylene glycol acyl chloride: Weigh 20.0 kg (148.3 mol) of diethylene glycolic acid, measure 26.9 L (370.75 mol) of thionyl chloride, and weigh 400 g of DMF, and add them to reactor #4. The mixture is stirred and refluxed at 55 °C for 1.8 hours, then heated to 88 °C and reacted for 2.5 hours. After the reaction is complete, the reaction solution is transferred to a vacuum distillation vessel #5 for distillation at 45 °C and a vacuum degree of 300 Pa. After distillation, 1.36 kg of diethylene glycol acyl chloride is obtained with a purity of 30.2% and a yield of 5.5%.

[0113] Comparative Example 2

[0114] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that:

[0115] Step 2): Preparation of crude TODGA: Weigh 64.0 kg (265.1 mol) of di-n-octylamine and 13.5 kg (133.4 mol) of triethylamine into mixing tank #14 and mix thoroughly by mechanical stirring. Transfer 20.0 kg (117.0 mol) of diethylene glycol chloride and 12.7 kg (176.1 mol) of tetrahydrofuran to mixing tank #11 and mix thoroughly by mechanical stirring. Slowly pump 32.7 kg of the mixture from mixing tank #11 into reactor #15, and slowly add 77.5 kg of the mixture from mixing tank #14 into reactor #15. Control the reaction temperature at 35℃ and the reaction time at 1.5 hours. After the reaction, 1.2 kg of crude TODGA was obtained with a purity of 12.8% and a yield of 8.4%.

[0116] Comparative Example 3

[0117] This comparative example provides a method for preparing N,N,N',N'-tetraoctyl-3-oxopramethylenediamide, comprising the following steps:

[0118] 1) 134 g of diglycine and 476 g of thionyl chloride were added to a round-bottom flask and refluxed for 3 hours. After the reaction was completed, excess thionyl chloride was removed by vacuum distillation to obtain diglycyl chloride.

[0119] 2) Add 200 mL of dichloromethane to diglycyl chloride. Dissolve 202 g of triethylamine and 482 g of di-n-octylamine in 200 mL of dichloromethane and slowly add the solutions to the diglycyl chloride solution. React at room temperature for 5 hours. After the reaction is complete, add dilute hydrochloric acid, stir for 1 hour, and then filter. Concentrate the filtrate to obtain crude TODGA. Purify the crude product by column chromatography to obtain 250 g of pure TODGA.

[0120] 3) The filter cake was washed with water to remove triethylamine hydrochloride. The filter cake was recrystallized from a 3 / 1 (v / v) mixture of petroleum ether and ethyl acetate to obtain 200 g of monooxaamide carboxylic acid. The monooxaamide carboxylic acid was further reacted according to existing methods (e.g., the TODGA preparation method described in Solvent Extraction and Ion Exchange, 2007, 25, 205) to obtain 105 g of TODGA, with an overall TODGA yield of 61%.

[0121] Comparative Example 4

[0122] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that:

[0123] Step 3) Preparation of industrial-grade TODGA product: 90.0 kg of crude TODGA was mixed thoroughly with 80.0 kg of 15% HCl solution and centrifuged in centrifuge #24 at 10000 r / min. The organic phase was collected and transferred to organic phase tank #28. The organic phase in organic phase tank #28 was mixed thoroughly with 100.0 kg of petroleum ether at 65°C and centrifuged in centrifuge #30 at 5000 r / min. The organic phase was collected and transferred to organic phase tank #32. Without primary vacuum distillation, 149.0 kg of industrial-grade TODGA product was obtained with a purity of 28.7% and a yield of 81.9%.

[0124] Comparative Example 5

[0125] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that:

[0126] Step 3) Preparation of industrial-grade TODGA product: 80.0 kg of crude TODGA was mixed thoroughly with 80.0 kg of 5% HCl solution and then centrifuged in centrifuge #24 at 9000 r / min. The organic phase was collected and transferred to organic phase tank #28. The organic phase in organic phase tank #28 was mixed thoroughly with 70.0 kg of petroleum ether at 25°C and then centrifuged in centrifuge #30 at 4000 r / min. The organic phase was collected and transferred to organic phase tank #32. The organic phase in organic phase tank #32 was transferred to a single-stage vacuum distillation vessel #33 for distillation. The distillation temperature was 48°C and the vacuum degree was 380 Pa. After distillation, 22.0 kg of industrial-grade TODGA product was obtained with a purity of 31.2% and a yield of 41.6%.

[0127] Comparative Example 6

[0128] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that:

[0129] Step 4) Preparation of premium-grade TODGA product: 40.0 kg of industrial-grade TODGA product from the 35# industrial-grade TODGA tank was transferred to a 36# two-stage vacuum distillation vessel for distillation. The distillation temperature was 150℃ and the vacuum degree was 195 Pa. After distillation, 18.4 kg of premium-grade TODGA product was obtained, with a purity of 89.7% and a yield of 58.3%.

[0130] Comparative Example 7

[0131] The industrial-scale preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that:

[0132] Step 5) Preparation of high-purity TODGA product: 30.0 kg of high-quality TODGA product from the 38# high-quality TODGA tank was transferred to the 39# three-stage vacuum distillation vessel for distillation. The distillation temperature was 214℃ and the vacuum degree was 96 Pa. After distillation, 19.6 kg of high-purity TODGA product was obtained, with a purity of 93.7% and a yield of 61.4%.

[0133] Comparative Example 8

[0134] The industrial preparation method of N,N,N',N'-tetraoctyl-3-oxopramethylenediamide provided in this comparative example is the same as that in Example 1, except that: after step 3), step 5) is performed first, followed by step 4), and the purity of the final TODGA product is 93.8%, and the yield is 29.2%.

[0135] Step 4) Preparation of high-quality TODGA product: 40.0 kg of the high-purity TODGA product obtained in Step 5) of Comparative Example 9 was transferred to a No. 36 two-stage vacuum distillation vessel for distillation. The distillation temperature was 205℃ and the vacuum degree was 162 Pa. After distillation, 11.8 kg of high-quality TODGA product was obtained with a purity of 93.8% and a yield of 29.2%.

[0136] Step 5) Preparation of high-purity TODGA product: 30.0 kg of industrial-grade TODGA product from the 35# industrial-grade TODGA tank was transferred to a 39# three-stage vacuum distillation vessel for distillation. The distillation temperature was 248℃ and the vacuum degree was 58 Pa. After distillation, 18.3 kg of high-purity TODGA product was obtained, with a purity of 94.7% and a yield of 66.8%.

[0137] As can be seen from the above examples and comparative examples, the industrial-scale preparation process of the present invention, through the synergistic design of "acyl chloride-amidation-gradient purification", can stably produce gradient products that meet different application requirements, and the product purity and yield are significantly better than those of traditional synthesis methods.

[0138] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An industrial-scale preparation method for N,N,N',N'-tetraoctyl-3-oxopramethylenediamide, characterized in that, Includes the following steps: S1: Add diethylene glycol, thionyl chloride and N,N-dimethylformamide to the synthesis reactor, stir and heat at 40-50℃ for 1-2 hours, then raise the temperature to 70-85℃ and heat for 2-3 hours to obtain the reaction solution; S2: The reaction solution obtained in step S1 is subjected to vacuum distillation at 45-75℃ and a vacuum degree of 250-400Pa to obtain diethylene glycol chloride and tail gas. S3: Add di-n-octylamine and triethylamine to a mixing tank, stir and mix, then pump into a synthesis reactor. Add diethylene glycol chloride and tetrahydrofuran obtained in step S2 to a mixing tank, stir and mix, then pump into a synthesis reactor. React at room temperature for 1-2 hours to obtain the mother liquor. S4: Centrifuge the mother liquor from step S3 to obtain the supernatant, and then distill the supernatant under reduced pressure at 32-55℃ and a vacuum of 250-400 Pa to obtain crude TODGA product. S5: The crude TODGA product obtained in step S4 is leached with hydrochloric acid, and after centrifugation, an organic phase is obtained. The organic phase is mixed with an organic solvent, and after centrifugation, a liquid phase is obtained. S6: The liquid phase from step S5 is transferred to a primary vacuum distillation vessel and subjected to primary vacuum distillation at 40-50°C and a vacuum of 250-400Pa to obtain industrial-grade TODGA product. S7: The industrial-grade TODGA obtained in step S6 is transferred to a two-stage vacuum distillation vessel and subjected to two-stage vacuum distillation at 188-210℃ and a vacuum of 133-165 Pa to obtain a high-quality TODGA product. S8: The high-quality TODGA product obtained in step S7 is transferred to a three-stage vacuum distillation vessel and subjected to three-stage vacuum distillation at 227-250℃ and a vacuum degree of 52-65 Pa to obtain a high-purity TODGA product.

2. The method according to claim 1, characterized in that, In step S1, the molar ratio of diethylene glycol to thionyl chloride is 1:(2.5-8.0), and N,N-dimethylformamide accounts for 1%-5% of the mass of diethylene glycol.

3. The method according to claim 1, characterized in that, In step S2, the exhaust gas is absorbed with sodium carbonate solution to obtain byproducts containing sodium sulfite and sodium chloride.

4. The method according to claim 1, characterized in that, In step S3, the molar ratio of di-n-octylamine to triethylamine is 1:(0.5-3.5), and the molar ratio of di-n-octylamine to diethylene glycol chloride is (2.2-4.5):

1.

5. The method according to claim 1, characterized in that, In step S3, the molar ratio of diethylene glycol chloride to tetrahydrofuran is 1:(1.5-3.7).

6. The method according to claim 1, characterized in that, In step S5, the centrifugation speed after hydrochloric acid leaching is 8000-10000 r / min, and the centrifugation speed after mixing the organic phase and organic solvent is 3000-5000 r / min.

7. The method according to claim 1, characterized in that, In step S7, the residue obtained after secondary vacuum distillation is returned to step S4 and mixed with crude TODGA for recycling; in step S8, the residue obtained after tertiary vacuum distillation is returned to step S4 and mixed with crude TODGA for recycling.

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