Preparation method of seven-membered cyclic lysine monomer and copolymerized polyamide

Abstract

The invention discloses a preparation method of a seven-membered cyclic lysine monomer and copolymerized polyamide, and relates to the field of organic synthesis. Alpha-amino-epsilon-caprolactam is obtained by taking lysine or lysine hydrochloride as an initial raw material, and then alpha-amino of an intermediate is alkylated by using alcohol under the catalysis of a catalyst to obtain a series of seven-membered cyclic lysine monomers. According to the preparation method provided by the invention, toxic and harmful reagents such as formaldehyde and halogenated hydrocarbon are not additionally introduced, and the green and environment-friendly requirements are met; meanwhile, the seven-membered cyclic lysine monomer can be copolymerized with lactam to obtain a series of copolymerized polyamides with various structures.

Description

Technical Field

[0001] The invention relates to the field of organic synthesis, and in particular to a method for preparing a seven-membered cyclic lysine monomer and a copolymer polyamide. Background Art

[0002] Amino acids have a variety of functional groups such as carboxyl and amino groups, and their application scenarios are diverse. With the rapid development of biotechnology, the amino acid industry has also made great strides. Taking lysine as an example, its production capacity has expanded to 4.33 million tons in 2023. However, lysine and other amino acids are currently mainly used in low-value applications such as feed additives, and there is an urgent need to increase added value. In order to achieve industrial upgrading of amino acid products, the development of new uses for amino acids such as lysine has become the research and development focus of the amino acid industry today.

[0003] Using amino acids and their salts as raw materials and developing new synthetic methods to prepare polymers can greatly reduce the dependence of the synthetic polymer industry on petroleum and alleviate environmental pollution caused by excessive use of fossil energy. It has become a frontier and hot spot in the field of polymer synthetic chemistry. Using biomass-derived lysine as raw material, various cyclic lysine monomers can be prepared. It has a similar structure to caprolactam and can be used to prepare polyamides by ring-opening polymerization. The obtained copolymer or homopolymer polyamide has alkylamine side groups and can be modified to give the polyamide excellent antibacterial properties. However, in the current preparation methods of cyclic lysine monomers, toxic and harmful hazardous reagents such as formaldehyde and halogenated hydrocarbons are often required for alkylation reactions, which do not meet the environmental protection requirements of green chemistry. The synthesis of cyclic lysine monomers through the alkylation strategy of safe and non-toxic reagents and their application in the preparation of copolymer polyamides are the key and difficult points of current related research. Summary of the invention

[0004] In view of this, the present invention provides a method for preparing a seven-membered cyclic lysine monomer and a copolymer polyamide. The seven-membered cyclic lysine monomer provided by the present invention uses lysine or its hydrochloride as a starting material, uses common solvents in the preparation process, and does not introduce additional toxic and harmful reagents, thereby meeting the requirements of green chemistry. At the same time, the present invention provides a method for copolymerizing such a seven-membered cyclic lysine monomer with lactam, thereby obtaining a variety of copolymer polyamide products.

[0005] The present invention first uses lysine or lysine hydrochloride as a starting material to prepare α-amino-ε-caprolactam through methyl esterification reaction and ring-closure reaction. The specific method is as follows:

[0006] Lysine or lysine hydrochloride, methanol and a catalyst are mixed to undergo a methyl esterification reaction, and then a solvent is added to the reaction solution, followed by a ring-closing reaction to obtain the α-amino-ε-caprolactam.

[0007] The present invention selects low-priced and easily available lysine or lysine hydrochloride as the starting raw material, which can greatly reduce the dependence of the synthetic polymer industry on petroleum and alleviate the environmental pollution caused by excessive use of fossil energy; at the same time, lysine or its hydrochloride is derived from biomass and is a renewable resource, which is beneficial to energy security and sustainable development.

[0008] The present invention firstly reacts lysine or its hydrochloride with methanol under the action of a catalyst to generate lysine methyl ester or a salt of lysine methyl ester. In some specific implementations, the reaction concentration of lysine or lysine hydrochloride is 0.5 mol / L to 10 mol / L.

[0009] In some specific implementations, the catalyst is an acidic substance or a chloride. The acidic substance may be one or more of carboxylic acid, sulfonic acid, sulfinic acid, thiocarboxylic acid, hydrochloric acid, phosphoric acid and sulfuric acid; the chloride may be one or more of chlorination agents such as N-chlorosuccinimide, zinc chloride, phosphorus trichloride, phosphorus pentachloride, thionyl chloride, benzoyl chloride, acetyl chloride and oxalyl chloride.

[0010] On this basis, when the catalyst is an acidic substance, the methyl esterification reaction time is 2h~8h, and the reaction temperature is 60℃~180℃; when the catalyst is a chloride, the methyl esterification reaction time is 1h~6h, and the reaction temperature is 20℃~100℃.

[0011] After obtaining lysine methyl ester or the salt of lysine methyl ester, a solvent is added to the reaction system to cause a ring-closing reaction to obtain α-amino-ε-caprolactam.

[0012] In some specific implementations, the solvent is selected from one or more of diethyl ether, methyl tert-butyl ether, tetrahydrofuran, ethylene carbonate, propylene carbonate, acetonitrile, methyl ethyl ketone, acetone, methanol, ethanol, butanol, dichloromethane, carbon disulfide, chloroform, ethyl acetate, ethyl isovalerate, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and water, preferably one or more of methanol, dichloromethane and ethyl acetate.

[0013] In some specific implementations, the temperature of the ring-closing reaction is 20° C. to 180° C., preferably 40° C. to 180° C., and more preferably 60° C. to 180° C. In some specific implementations, the time of the ring-closing reaction is 0.5 h to 48 h, preferably 3 h to 48 h, and more preferably 6 h to 48 h.

[0014] After obtaining α-amino-ε-caprolactam, the present invention preferably purifies it to obtain a pure compound. The present invention has no restrictions on the purification method, and those skilled in the art can choose common means such as recrystallization and column chromatography for purification. The present invention uses recrystallization to purify the obtained α-amino-ε-caprolactam, and the recrystallization reagent is selected from one or more of ether, tetrahydrofuran, ethyl acetate, isopropyl acetate, isoamyl acetate, ethylene carbonate, propylene carbonate, acetonitrile, acetone, methanol, ethanol, isopropanol, dichloromethane, chloroform and carbon tetrachloride, preferably one or more of methanol, ethyl acetate, chloroform, and more preferably methanol or ethyl acetate.

[0015] In some specific implementations, the seven-membered cyclic lysine monomer of the present invention can be synthesized according to the following route:

[0016]

[0017] R1 and R2 are independently selected from C1 to C 10 Alkyl, halogen-substituted C1~C 10 Alkyl, C6~C 10 Aromatic or halogen-substituted C6~C 10 or R1, R2 and the N atom form a 3-10 membered heterocyclic ring.

[0018] Based on the above experiments, the present invention provides a series of preparation methods of seven-membered cyclic lysine monomers using α-amino-ε-caprolactam as raw material, specifically:

[0019] The present invention provides a method for preparing a dialkylamino-seven-membered cyclic lysine monomer, comprising:

[0020] Alpha-amino-ε-caprolactam, a monohydric alcohol compound and a catalyst are mixed and reacted to obtain a dialkylamino-seven-membered cyclic lysine monomer.

[0021] At the same time, the present invention also provides a method for preparing a nitrogen heterocycle-seven-membered cyclic lysine monomer, comprising:

[0022] Alpha-amino-ε-caprolactam, a diol compound and a catalyst are mixed in an alkaline solvent and reacted to obtain a nitrogen heterocyclic-seven-membered cyclic lysine monomer.

[0023] The present invention also provides a method for preparing a diaromatic amino-seven-membered cyclic lysine monomer, comprising: mixing α-amino-ε-caprolactam, an aromatic alcohol compound, an aromatic hydrocarbon compound and a catalyst and reacting the mixture to obtain a diaromatic amino-seven-membered cyclic lysine monomer.

[0024] The present invention improves the catalyst in the reaction process of alkylation of seven-membered cyclic lysine monomers, so that no toxic and harmful reagents such as formaldehyde and halogenated hydrocarbons are introduced into the entire reaction process, which meets the requirements of green environmental protection. The reagents used are all commonly used reagents in chemical production, with low production cost and little pollution, which is conducive to industrial promotion.

[0025] In the preparation method of the seven-membered cyclic lysine monomer provided by the present invention, when the reaction raw material is a monohydric alcohol compound, the monohydric alcohol compound is used as both the reactant and the solvent of the reaction; when the reaction raw material is a dihydric alcohol compound, the solvent of the reaction is an alkaline solvent, and the alkaline solvent can be triethylamine, pyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), N,N-diisopropyl One or more of ethylamine and 4-dimethylaminopyridine, preferably one or more of triethylamine, pyridine, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) and 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD), more preferably triethylamine; when the reaction raw material is an aromatic alcohol compound, the solvent of the reaction is an aromatic hydrocarbon compound, and the aromatic hydrocarbon compound can be one or more of toluene, xylene and trimethylbenzene, preferably trimethylbenzene. In some specific implementations, the mass ratio of the α-amino-ε-caprolactam to the monohydric alcohol compound is 1:1-25, preferably 1:1-24, and more preferably 1:1-23. In some specific implementations, the molar ratio of the α-amino-ε-caprolactam to the dihydric alcohol compound is 1:1-3, preferably 1:1.2-3, and more preferably 1:1.2-2.8. In some specific implementations, the molar ratio of the α-amino-ε-caprolactam to the alkaline solvent is 1:10 to 30, preferably 1:10 to 28, and more preferably 1:10 to 26. In some specific implementations, the molar ratio of the α-amino-ε-caprolactam to the aromatic alcohol compound is 1:2 to 6, preferably 1:2 to 5, and more preferably 1:2 to 4. In some specific implementations, the molar ratio of the α-amino-ε-caprolactam to the aromatic hydrocarbon compound is 1:30 to 50, preferably 1:30 to 45, and more preferably 1:30 to 40.

[0026] In the above-mentioned preparation method of dialkylamino, nitrogen heterocyclic and diaromatic amino seven-membered cyclic lysine monomers, the catalyst is selected from at least one of oxides of Group VIII metals, borohydrides of Group VIII metals, complexes of Group VIII metals, supported metal catalysts, phosphorus-containing compounds, alkali metal catalysts and chloride metal catalysts; the ligand of the complex of Group VIII metal is selected from at least one of water, ammonia, halogen, tetrahydrofuran, DME, acetonitrile, cyclopentadiene, cyclooctadiene, cyclooctatetraene, 4-isopropyltoluene, trimethylphosphine, tributylphosphine, triphenylphosphine, DPEphos, JosiPhos, BINAP, XantPhos, DPPF, BrettPhos, RuPhos, XPhos, SPhos, BippyPhos, acac and p-cymene.

[0027] In some specific implementations, the carrier of the supported metal catalyst is a metal oxide. In some specific implementations, the catalyst is selected from Pd / TiO2, Cu(OH) x / Al2O3, Co(acac)2, [RuCp*Cl2]2, RuCl2(PPh3)3, [Ru(p-cymene)Cl2]2, Pd / Fe2O3, AlCl 3、 At least one of triphenylphosphine, K3PO4, DPEphos, LiOtBu and Hβ-zeolite supported metal catalyst.

[0028] In some specific implementations, the molar ratio of the α-amino-ε-caprolactam to the catalyst is 1:0.1-40, preferably 1:0.2-37, and more preferably 1:0.3-35.

[0029] The preparation method of the seven-membered cyclic lysine monomer provided by the present invention can be carried out under light irradiation, preferably ultraviolet light irradiation; it can also be carried out under heating conditions, the reaction temperature is 25°C to 200°C, preferably 50°C to 200°C, more preferably 80°C to 200°C; the reaction time is 3h to 24h, preferably 5h to 24h, more preferably 7h to 24h.

[0030] After obtaining the dialkylamino-seven-membered cyclic lysine monomer, the nitrogen heterocycle-seven-membered cyclic lysine monomer and the diaromaticamino-seven-membered cyclic lysine monomer, the invention uses them to synthesize copolymerized polyamide.

[0031] The present invention provides a method for preparing a copolymer polyamide, comprising the following steps:

[0032] The seven-membered cyclic lysine monomer prepared by the above preparation method, lactam, a catalyst and an activator are mixed and reacted to obtain a copolymer polyamide;

[0033] The activator has the following structure:

[0034]

[0035] Wherein, x is selected from an integer of 1 to 8;

[0036] R is selected from methyl, ethyl, phenyl, 4-tert-butylphenyl or 4-trifluoromethylphenyl.

[0037] The present invention uses the seven-membered cyclic lysine monomer prepared by the above preparation method to prepare copolymer polyamide, aiming to obtain copolymer polyamide with diverse structures and non-toxic and harmless production process in a simple, safe and efficient manner.

[0038] In some specific implementations, the copolyamide of the present invention has the following structure:

[0039]

[0040] wherein n is selected from an integer of 20 to 200, x is selected from an integer of 1 to 8, and 0<m<1;

[0041] R1 and R2 are independently selected from C1 to C 10 Alkyl, halogen-substituted C1~C 10 Alkyl, C6~C 10 Aromatic or halogen-substituted C6~C 10 or R1, R2 and the N atom form a 3-10 membered heterocyclic ring.

[0042] The invention firstly mixes the seven-membered cyclic lysine monomer, lactam and an activator under an inert atmosphere, and then adds a catalyst to carry out polymerization reaction to obtain a copolymerized polyamide product.

[0043] In some specific implementations, the catalyst is selected from one or more of carbene reagents, guanidine reagents, amidine reagents, phosphazene reagents, alkali metals, alkali metal oxides, alkali metal hydroxides, alkali metal hydrides, and alkali metal alkoxides, preferably one or more of potassium bis(trimethylsilyl)amide, sodium hydride, potassium hydride, phosphazene base (t-BuP4), potassium tert-butoxide, sodium methoxide, potassium methoxide, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene), sodium and potassium.

[0044] In some specific implementations, the molar ratio of the seven-membered cyclic lysine monomer to the lactam is 0.01 to 0.9:1, preferably 0.05 to 0.2:1. In some specific implementations, the molar ratio of the total amount of the seven-membered cyclic lysine monomer to the lactam, the activator, and the catalyst is 10 to 200:1:1, preferably 50 to 100:1:1.

[0045] The polymerization reaction temperature is 40° C. to 250° C., preferably 145° C. to 185° C.; the polymerization reaction time is 1 h to 48 h, preferably 3 h to 12 h.

[0046] After obtaining the copolymer polyamide product, the present invention mixes it with a good solvent and a poor solvent to obtain a pure copolymer polyamide. In some specific implementations, the good solvent is one or more of trifluoroethanol, hexafluoroisopropanol, trifluoroacetic acid and formic acid. In some specific implementations, the poor solvent is one or more of ethyl acetate, ether, petroleum ether and dichloromethane.

[0047] The present invention uses lysine or lysine hydrochloride from biomass as a starting material to prepare a series of seven-membered cyclic lysine monomers, and applies them to the synthesis of copolymerized polyamide. The seven-membered cyclic lysine monomer provided by the present invention does not introduce toxic and harmful reagents, such as formaldehyde, halogenated hydrocarbons, etc., during the preparation process, and is synthesized using common laboratory reagents, which meets the requirements of green chemistry, has low production costs, and has little environmental pollution, and realizes the strategy of using safe and non-toxic reagents to perform alkylation reactions on caprolactam. DETAILED DESCRIPTION

[0048] It should be understood that the expression "one or more of..." includes each of the items recited after the expression individually and in various different combinations of two or more of the recited items, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited items should be understood to have the same meaning, unless otherwise understood from the context.

[0049] The use of the terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, for example not excluding other unrecited elements or steps, unless otherwise specifically stated or otherwise understood from the context.

[0050] It should be understood that the order of steps or the order in which certain actions are performed is not important as long as the present invention remains operable. In addition, two or more steps or actions may be performed simultaneously.

[0051] The use of any and all examples or exemplary language, such as "for example" or "including", herein is intended only to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating that any non-claimed element is essential to the practice of the invention.

[0052] In addition, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise expressly stated, it should be understood that all ranges, quantities, values ​​and percentages used in this disclosure are modified by "about". Here, "about" generally means that the actual value is within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range.

[0053] The present invention is further described below in conjunction with the following examples. The protection scope of the present invention is not limited by the following examples.

[0054] Example 1

[0055] Weigh 914g (5mol) of lysine hydrochloride, add 2.5L of methanol, and then slowly add 515g (5.25mol) of concentrated sulfuric acid. After the addition is complete, continue to stir and reflux for 8h, transfer to a large reactor, continue to add methanol, and add a methanol solution containing 640g (16mol) of sodium hydroxide, continue to stir and react for 10h, evaporate the methanol, add 30L of ethyl acetate for recrystallization, and filter to obtain a white solid α-amino-ε-caprolactam weighing 320g with a yield of 48%. 1 H NMR (D2O, 400MHz) δ3.25-3.35(m,1H), 3.15-3.25(m,2H), 1.50-2.15(m,4H).

[0056] Example 2

[0057] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add 50ml of methanol and 100mg of Pd / TiO2 to the reaction system in sequence, replace the air with argon, and ensure that the entire reaction process is carried out under an argon atmosphere, and react for 15h under ultraviolet (365nm LED) irradiation conditions. After the reaction is completed, filter and vacuum evaporation to obtain a crude product, and the crude product is recrystallized from ethyl acetate to obtain an α-dimethylamino-ε-caprolactam product with a yield of 65%. 1H NMR (300MHz, CDCl3) δ6.56(s,1H),3.54(d,1H),3.05-2.78(m,2H),2.26(s,6H),1.97-1.80(m,1H),1.80-1.65(m,2H),1.65-1.31(m,3H).

[0058] Example 3

[0059] Weigh 2 g (15.6 mmol) of α-amino-ε-caprolactam (prepared in Example 1), dissolve it in 60 ml of trimethylol, add benzyl alcohol (60 mmol), catalyst Cu(OH) x / Al2O3 (480mmol), stir and react at 135℃ for 12h, filter after the reaction is completed, and evaporate under reduced pressure to obtain a crude product, which is recrystallized from ethyl acetate to obtain α-dibenzylamino-ε-caprolactam product with a yield of 80%. 1 H NMR(300MHz, CDCl3)δ7.41-7.32(m,10H),5.83(s,1H),

[0060] 4.07-3.92(dd,4H),3.45(d,1H),3.09-2.90(m,2H),1.99(d,2H),1.70(m,2H),1.45(s,2H).

[0061] Example 4

[0062] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add Co(acac)2 (0.5mmol), PPh3 (0.5mmol), K3PO4 (10mmol) and 30mL of methanol to the reaction system in sequence under N2 atmosphere, and stir and react at 140°C for 24h. After the reaction is completed, the system is cooled to room temperature for suction filtration, and the crude product is obtained by rotary evaporation under reduced pressure. The crude product is recrystallized from ethyl acetate to obtain α-dimethylamino-ε-caprolactam product with a yield of 87%. 1 H NMR (300MHz, CDCl3) δ6.47(s,1H),3.54(d,1H),3.04-2.78(m,2H),2.26(s,6H),1.99-1.80(m,1H),1.80-1.64(m,2H),1.64-1.34(m,3H).

[0063] Example 5

[0064] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add 10ml of methanol, 7.8mmol [RuCp*Cl2]2, 18.7mmol DPEphos, and 78mmol LiOtBu to the reaction system in sequence, and stir and react at 100°C for 24h. After the reaction is completed, the system is cooled to room temperature, filtered, and vacuum rotary distilled to obtain a crude product, which is recrystallized from ethyl acetate to obtain α-dimethylamino-ε-caprolactam product with a yield of 92%. 1 H NMR (300MHz, CDCl3) δ6.43(s,1H),3.55(d,1H),3.04-2.80(m,2H),2.27(s,6H),2.01-1.81(m,1H),1.81-1.64(m,2H),1.64-1.28(m,3H).

[0065] Example 6

[0066] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add 15.6mmol [RuCl2(PPh3)3] and 31.2mmol butanol to the reaction system in sequence, and stir the reaction at 180°C for 10h. After the reaction is completed, the system is cooled to room temperature, filtered after the reaction is completed, and the crude product is obtained by vacuum rotary evaporation. The crude product is recrystallized from ethyl acetate to obtain α-dibutylamino-ε-caprolactam product, and the yield is 88%. 1 H NMR (300MHz, CDCl3) δ5.74(t,1H),3.48-3.41(m,1H),3.41-3.05(m,2H),2.75-2. 56(m,4H),2.02-1.92(m,1H),1.85-1.59(m,4H),1.54-1.20(m,9H),0.90(t,6H).

[0067] Example 7

[0068] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add [Ru(p-cymene)Cl2]2 (46.8mmol), DPEphos (93.6mmol), NEt3 (187.2mmol), butanediol (23.4mmol) to the reaction system in sequence, and reflux for 24h at 90°C. After the reaction, the system is cooled to room temperature, and the crude product is obtained by rotary evaporation under reduced pressure. The crude product is recrystallized from ethyl acetate to obtain α-tetrahydropyrrolyl-ε-caprolactam product with a yield of 82%. 1H NMR(300MHz, CDCl3)δ6.41(t,1H),3.50-3.42(m,1H),3.42-3.11(m,2H),3 .03-2.59(m,4H),2.03-1.95(m,1H),1.89-1.57(m,4H),1.54-1.20(m,3H).

[0069] Example 8

[0070] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add octanol (60mmol) and 200mg Pd / Fe2O3 to the reaction system in sequence, replace the air with nitrogen, and then replace the nitrogen with hydrogen, and ensure that the entire reaction process is carried out under a hydrogen atmosphere, and heat reflux at 170°C for 24h. After the reaction is completed, filter and vacuum rotary evaporation to obtain a crude product, and the crude product is recrystallized from acetone to obtain the α-dioctylamino-ε-caprolactam product monomer, with a yield of 95%. 1 H NMR(300MHz, CDCl3)δ5.85(t,1H),3.49-3.42(m,1H),3.42-3.04(m,2H),2.75-2.56(m,4 H),2.01-1.88(m,1H),1.88-1.58(m,4H),1.58-1.33(m,5H),1.27(m,20H),0.87(t,6H).

[0071] Example 9

[0072] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), dissolve it in 60ml of trimethylol, add 60mmol of phenylpropanol and 20mmol of AlCl3 in sequence, react at 170°C for 8h, add 200ml of ethyl acetate to dilute after the reaction, then wash with 300ml of 1mol / L NaOH and 300ml of saturated NaCl, and obtain a crude product after reduced pressure rotary evaporation. The crude product can be recrystallized from acetone to obtain α-diphenylpropylamino-ε-caprolactam product with a yield of 81%. 1 H NMR (300MHz, CDCl3) δ7.39-7.15(m,10H),6.23(s,1H),3.48(m,1H),3.13-2.92(m, 2H),2.73-2.52(m,8H),1.99(d,2H),1.70(m,6H),1.67-1.48(m,3H),1.41(m,1H).

[0073] Example 10

[0074] 1 g of Hβ-zeolite (Si / Al=25 molar ratio) with a pore size of 6.6 angstroms was added to an aqueous solution containing 5 wt% Ru, stirred at room temperature for 2 h, then dried at 80°C for 12 h, and calcined at 400°C for 2 h to obtain the catalyst required for the subsequent reaction.

[0075] Weigh 2g (15.6mmol) of α-amino-ε-caprolactam (prepared in Example 1), add 31.2mmol of octanol and the above-mentioned catalyst, replace the air with argon, and then replace the argon with hydrogen, and ensure that the entire reaction process is carried out under a hydrogen atmosphere, heat to 180°C, react for 16h, filter after the reaction is completed, and obtain a crude product after reduced pressure rotary evaporation. The crude product is recrystallized from acetone to obtain an α-dioctylamino-ε-caprolactam product monomer with a yield of 79%. 1 H NMR(300MHz, CDCl3)δ5.81(t,1H),3.51-3.43(m,1H),3.43-3.01(m,2H),2.77-2.56(m,4H),2.03- 1.89(m,1H),1.89-1.56(m,4H),1.56-1.31(m,5H),1.58-1.33(m,5H),1.26(m,20H),0.88(t,6H).

[0076] Embodiment 11

[0077] 310 mg (2 mmol) of the activator with the structure shown in the figure below, 1.56 g (10 mmol) of α-dimethylamino-ε-caprolactam (prepared in Example 2), and 10.17 g (90 mmol) of caprolactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of KHMDS was added after evacuation at 40°C for 30 min, and the mixture was protected by nitrogen and reacted in an oil bath at 65°C for 3 h. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 62%. The number average molecular weight measured by GPC was 10.4 kDa. 1 H NMR (300MHz TFA / DMSO-d6,8:92,v:v)δ3.70-3.61(m,1H),3.13-3.02(m,4H),2.76-2.72(m,6H),2.56-2.55(m,2H),1.83-1.18(m,12H).

[0078]

[0079] The activator structure of this embodiment

[0080] Example 12

[0081] 338 mg (2 mmol) of the activator with the structure shown in the figure below, 2.40 g (10 mmol) of α-dibutylamino-ε-caprolactam (prepared in Example 6), and 10.17 g (90 mmol) of caprolactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of sodium hydride (NaH) was added after evacuation at 40°C for 30 min, and the mixture was protected by argon and reacted in an oil bath at 80°C for 3 h. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 67%. The number average molecular weight measured by GPC was 9.2 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ3.65-3.58(m,1H),3.42-3.35(m,4H),2.45-2.42(m,4H),1.88-1.20(m,16H)0.92(t,6H).

[0082]

[0083] The activator structure of this embodiment

[0084] Example 13

[0085] 546 mg (2 mmol) of the activator with the structure shown in the figure below, 3.08 g (10 mmol) of α-dibenzylamino-ε-caprolactam (prepared in Example 3), and 7.66 g (90 mmol) of butyrolactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of phosphazene base (t-BuP4) was added after evacuation at 40°C for 30 min, and the mixture was protected by nitrogen and reacted in an oil bath at 165°C for 3 h. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 53%. The number average molecular weight measured by GPC was 13.5 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ7.55-7.42(m,10H),4.08-3.90(m,4H),3.71-3.63(m,1H),3.15-3.04(m,4H),2.51(m,2H),1.87-1.17(m,8H).

[0086]

[0087] The activator structure of this embodiment

[0088] Embodiment 14

[0089] 434 mg (2 mmol) of the activator with the structure shown in the figure below, 3.65 g (10 mmol) of α-diphenylpropylamino-ε-caprolactam (prepared in Example 9), and 11.45 g (90 mmol) of enantholactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of potassium tert-butoxide (t-BuOK) was added after evacuation at 40°C for 30 min, and the mixture was protected by argon and reacted in an oil bath at 95°C for 3 h. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 41%. The number average molecular weight measured by GPC was 7.8 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ7.39-7.15(m,10H),3.65-3.42(m,1H),3.14-3.01(m,4H),2.76-2.72(m,10H),2.53-2.50(m,2H),1.81-1.19(m,16H).

[0090]

[0091] The activator structure of this embodiment

[0092] Embodiment 15

[0093] 338 mg (2 mmol) of the activator with the structure shown in the figure below, 1.56 g (10 mmol) of α-dimethylamino-ε-caprolactam (prepared in Example 4), and 14.12 g (90 mmol) of capryllactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of sodium methoxide (MeONa) was added after evacuation at 40°C for 30 min, and nitrogen was protected and the reaction was carried out in an oil bath at 185°C for 3 h. Trifluoroethanol was added to dissolve, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 35%. The number average molecular weight measured by GPC was 11.6 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ3.73-3.59(m,1H),3.10-2.95(m,4H),2.75-2.66(m,6H),2.50(m,2H),1.85-1.22(m,16H).

[0094]

[0095] The activator structure of this embodiment

[0096] Example 16

[0097] 570 mg (2 mmol) of the activator with the structure shown in the figure below, 2.40 g (10 mmol) of α-dibutylamino-ε-caprolactam (prepared in Example 6), and 7.66 g (90 mmol) of butyrolactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was added after evacuation at 40°C for 30 min, and the mixture was reacted in an oil bath at 120°C for 3 h under argon protection. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 55%. The number average molecular weight measured by GPC was 8.5 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ3.78-3.63(m,1H),3.04-2.95(m,4H),2.57(m,2H),1.79-1.23(m,14H),0.87(t,6H).

[0098]

[0099] The activator structure of this embodiment

[0100] Embodiment 17

[0101] 310 mg (2 mmol) of the activator with the structure shown in the figure below, 3.08 g (10 mmol) of α-dibenzylamino-ε-caprolactam (prepared in Example 3), and 11.45 g (90 mmol) of enantholactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was added after evacuation at 40°C for 30 min, and the mixture was reacted in an oil bath at 105°C for 3 h under argon protection. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 52%. The number average molecular weight measured by GPC was 7.8 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ7.53-7.22(m,10H),4.10-3.95(m,4H),3.72-3.61(m,1H),3.23-3.05(m,4H),2.49-2.47(m,2H),1.77-1.15(m,14H).

[0102]

[0103] The activator structure of this embodiment

[0104] Embodiment 18

[0105] 546 mg (2 mmol) of the activator with the structure shown in the figure below, 3.53 g (10 mmol) of α-dioctylamino-ε-caprolactam (prepared in Example 10), and 14.12 g (90 mmol) of capryllactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of sodium (Na) was added after evacuation at 40°C for 30 min, and nitrogen was protected and reacted in an oil bath at 150°C for 3 h. Trifluoroethanol was added to dissolve, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 43%. The number average molecular weight measured by GPC was 10.4 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ3.70-3.65(m,1H),2.75-2.58(m,4H),3.15-3.03(m,4H),2.53(m,2H),

[0106] 1.85-1.07(m,28H),0.85(t,6H).

[0107]

[0108] The activator structure of this embodiment

[0109] Embodiment 19

[0110] 338 mg (2 mmol) of the activator with the structure shown in the figure below, 3.53 g (10 mmol) of α-dioctylamino-ε-caprolactam (prepared in Example 8), and 8.92 g (90 mmol) of valerolactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of sodium hydride (NaH) was added after evacuation at 40°C for 30 min, and nitrogen was protected and reacted in an oil bath at 185°C for 3 h. Trifluoroethanol was added to dissolve, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 61%. The number average molecular weight measured by GPC was 15.0 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ3.87-3.77(m,1H),3.12-3.02(m,4H),2.78-2.72(m,4H),2.55-2.50(m,2H),1.81-1.18(m,22H),0.87(t,6H).

[0111]

[0112] The activator structure of this embodiment

[0113] Embodiment 20

[0114] 570 mg (2 mmol) of the activator with the structure shown in the figure below, 1.82 g (10 mmol) of α-tetrahydropyrrolyl-ε-caprolactam (prepared in Example 7), and 8.92 g (90 mmol) of valerolactam were weighed into a 250 mL baked round-bottom flask, and 2 mmol of sodium hydride (NaH) was added after evacuation at 40°C for 30 min, and the mixture was protected by argon and reacted in an oil bath at 135°C for 3 h. Trifluoroethanol was added to dissolve the mixture, and the polymer solution was precipitated in ethyl acetate / ether (v:v=1:1), centrifuged, and dried to obtain a copolymerized polyamide product with a yield of 55%. The number average molecular weight measured by GPC was 7.1 kDa. 1 H NMR(300MHz TFA / DMSO-d6,8:92,v:v)δ3.70-3.62(m,1H),3.15-3.02(m,8H),2.51-2.50(m,2H),1.88-1.38(m,14H).

[0115]

[0116] The activator structure of this embodiment

[0117] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a dialkylamino-seven-membered cyclic lysine monomer, characterized in that: include: Alpha-amino-ε-caprolactam, a monohydric alcohol compound and a catalyst are mixed and reacted to obtain a dialkylamino-seven-membered cyclic lysine monomer.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the α-amino-ε-caprolactam to the monohydric alcohol compound is 1:1-25.

3. A method for preparing a nitrogen heterocycle-seven-membered cyclic lysine monomer, characterized in that: include: Alpha-amino-ε-caprolactam, a diol compound and a catalyst are mixed in an alkaline solvent and reacted to obtain a nitrogen heterocyclic-seven-membered cyclic lysine monomer.

4. The preparation method according to claim 3, characterized in that: The molar ratio of the α-amino-ε-caprolactam to the diol compound is 1:1 to 3; The molar ratio of the α-amino-ε-caprolactam to the alkaline solvent is 1:10-30.

5. A method for preparing a diaromatic amino-seven-membered cyclic lysine monomer, characterized in that: include: Alpha-amino-ε-caprolactam, aromatic alcohol compounds, aromatic hydrocarbon compounds and a catalyst are mixed and reacted to obtain a diaromatic amino-seven-membered cyclic lysine monomer.

6. The preparation method according to claim 5, characterized in that: The molar ratio of the α-amino-ε-caprolactam to the aromatic alcohol compound is 1:2-6; The molar ratio of the α-amino-ε-caprolactam to the aromatic hydrocarbon compound is 1:30-50.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The catalyst is selected from at least one of oxides of Group VIII metals, borohydrides of Group VIII metals, complexes of Group VIII metals, supported metal catalysts, phosphorus-containing compounds, alkali metal catalysts and chloride metal catalysts; the ligand of the complex of Group VIII metals is selected from at least one of water, ammonia, halogen, tetrahydrofuran, DME, acetonitrile, cyclopentadiene, cyclooctadiene, cyclooctatetraene, 4-isopropyltoluene, trimethylphosphine, tributylphosphine, triphenylphosphine, DPEphos, JosiPhos, BINAP, XantPhos, DPPF, BrettPhos, RuPhos, XPhos, SPhos, BippyPhos, acac and p-cymene.

8. The preparation method according to claim 7, characterized in that: The catalyst is selected from Pd / TiO2, Cu(OH) x / Al2O3, Co(acac)2, [RuCp*Cl2]2, RuCl2(PPh3)3, [Ru(p-cymene)Cl2]2, Pd / Fe2O3, AlCl 3、 At least one of triphenylphosphine, K3PO4, DPEphos, LiOtBu and Hβ-zeolite supported metal catalyst.

9. The preparation method according to any one of claims 1 to 6, characterized in that: The reaction is carried out under light; Alternatively, the reaction temperature is 25°C to 200°C, and the reaction time is 3h to 24h.

10. A method for preparing a copolymer polyamide, characterized in that: The following steps are involved: Prepare a seven-membered cyclic lysine monomer according to the preparation method according to any one of claims 1 to 6; The seven-membered cyclic lysine monomer, lactam, catalyst and activator are mixed and reacted to obtain a copolymer polyamide having the following structure: The activator has the following structure: Wherein, x is selected from an integer of 1 to 8; R is selected from methyl, ethyl, phenyl, 4-tert-butylphenyl or 4-trifluoromethylphenyl.

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