Pyridine-acetosulfonamide compounds, polyesters prepared therefrom, and methods of making and using the same

Abstract

This invention relates to the field of polyester preparation technology and discloses a pyridine-acetylsulfonamide compound having the structure shown in formula (I): In formula (I), R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 The substituted or unsubstituted linear or branched alkyl groups. The pyridine-acetylsulfonamide compound of the present invention can be used as a catalyst for the preparation of polyesters, catalyzing polymerization reactions through hydrogen bonding to achieve active and controllable ring-opening polymerization. Compared with previously reported catalysts, this catalyst has the characteristics of high catalytic efficiency, mild catalytic conditions, and no metal residue, and has important application prospects in the biomedical field.

Description

Technical Field

[0001] This invention relates to the field of polyester preparation technology, specifically to pyridine-acetylsulfonamide compounds, polyesters prepared therefrom, and methods for preparing the same. Background Technology

[0002] Aliphatic polyesters are an important class of polymer materials with good biocompatibility and biodegradability. They have broad application prospects in the biomedical field and have been widely used in areas such as absorbable surgical sutures, drug carriers, and tissue engineering scaffolds.

[0003] The main methods for synthesizing aliphatic polyesters include the condensation polymerization of fatty acids and fatty alcohols, and the ring-opening polymerization of cyclic lactones. The condensation polymerization of fatty acids and fatty alcohols suffers from drawbacks such as demanding reaction conditions, inability to precisely control the molecular weight of the product, low molecular weight of the prepared product, wide molecular weight distribution, and the generation of small molecule byproducts. Catalytic ring-opening polymerization is currently a research hotspot in the synthesis of aliphatic polyesters. Its catalytic systems include metal-ligand or metal alkane catalysis, enzyme catalysis, and organic small molecule catalysis. Among these, metal-ligands include metals such as iron, cobalt, aluminum, and zinc, and metal alkane compounds include zinc isopropoxide, alkyl aluminum, aryl aluminum, stannous octoate, and rare earth alkoxides. However, the residues of these catalysts in the polymer have varying degrees of potential toxicity to human cells, limiting the polymer's applications. Enzymatic catalysis exhibits high catalytic activity, but it is specific, only effective against certain lactones, and lacks versatility across monomer types. Compared to the previous two catalytic polymerization systems, organocatalytic ring-opening polymerization of lactones has advantages such as mild reaction conditions, controllable polymerization reaction, and narrow molecular weight distribution. Furthermore, the polymers produced do not contain metals, making them suitable as biocompatible materials for applications in food packaging, drug release, or delivery. However, current organocatalytic ring-opening polymerization reactions suffer from poor catalytic activity and low conversion rates. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of poor catalytic activity and low conversion rate in the existing organocatalytic ring-opening polymerization of lactones, and to provide a pyridine-acetylsulfonamide compound, polyesters prepared therefrom, and a method for their preparation. This pyridine-acetylsulfonamide compound, when used as a polyester catalyst, exhibits high catalytic activity and is metal-free; it also achieves high conversion of cyclic monomers, resulting in polymers with high yields and narrow molecular weight distributions.

[0005] To achieve the above objectives, a first aspect of the present invention provides a pyridine-acetylsulfonamide compound having the structure shown in formula (I):

[0006]

[0007] In equation (I), R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

[0008] A second aspect of the present invention provides a method for preparing a pyridine-acetylsulfonamide compound, the method comprising: reacting a pyridine derivative with an acetylsulfonamide compound to obtain a pyridine-acetylsulfonamide compound; wherein the pyridine-acetylsulfonamide compound has the structure shown in formula (I); the pyridine derivative has the structure shown in formula (II); and the acetylsulfonamide compound has the structure shown in formula (III).

[0009]

[0010] Among them, R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

[0011] A third aspect of the present invention provides a pyridine-acetylsulfonamide compound prepared by the aforementioned preparation method.

[0012] The fourth aspect of the present invention provides the use of the aforementioned pyridine-acetylsulfonamide compound in the preparation of polyesters.

[0013] The fifth aspect of the present invention provides a method for preparing a polyester, the method comprising: performing a ring-opening polymerization reaction on a cyclic monomer in the presence of a catalyst to obtain a polyester; wherein the catalyst is the aforementioned pyridine-acetylsulfonamide compound.

[0014] The sixth aspect of the present invention provides a polyester prepared by the aforementioned preparation method, wherein the polyester has a number-average molecular weight of 1,000-100,000 g / mol, a molecular weight distribution coefficient of 1-2, and a metal content of 0.

[0015] The seventh aspect of the present invention provides the application of the aforementioned polyester in biomedical materials or food packaging materials.

[0016] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0017] The pyridine-acetylsulfonamide compound of the present invention is prepared using industrially inexpensive and readily available pyridine derivatives and food additive acetylsulfonamide compounds as raw materials. The preparation method is simple, easy to operate, and the raw materials are widely available.

[0018] The pyridine-acetylsulfonamide compound of the present invention can be used as a catalyst for the preparation of polyesters. It catalyzes the polymerization reaction through hydrogen bonding to achieve active and controllable ring-opening polymerization. Compared with the catalysts reported in the prior art, this catalyst has the characteristics of high catalytic efficiency, mild catalytic conditions and no metal residue, and has important application prospects in the biomedical field.

[0019] The polyester prepared using the pyridine-acetylsulfonamide compound of the present invention as a catalyst has a narrow molecular weight distribution index, high product yield, no monomer residue, and snow-white color; moreover, the present invention utilizes organic hydrogen bonding catalysts to synthesize a variety of biodegradable polymers with precise molecular weights.

[0020] Compared with existing synthesis processes, this invention has the characteristics of being green and non-toxic, having good biocompatibility, novel structure, simple synthesis process and high yield, which meets the requirements of the biomedical and microelectronic fields for materials and the requirements of simple, mild and efficient synthesis of polymers with precise molecular weight. Attached Figure Description

[0021] Figure 1 Compound 20 prepared in Example 1 of this invention 1 H NMR spectrum;

[0022] Figure 2 The polylactide (PLA) prepared in Example 5 of this invention 1 H NMR spectrum;

[0023] Figure 3 The polytrimethylene carbonate (PTMC) prepared in Example 7 of this invention 1 HNMR image. Detailed Implementation

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] A first aspect of the present invention provides a pyridine-acetylsulfonamide compound having the structure shown in formula (I):

[0026]

[0027] In equation (I), R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

[0028] In this invention, C1-C 10 In the substituted or unsubstituted straight-chain or branched alkyl groups, the substituents include, but are not limited to, one or more of the following groups: halogen, hydroxyl, phenyl and substituted phenyl.

[0029] In this invention, R 2 Located in R 1 The adjacent and / or intermediate positions, i.e., R 2 It can be located in R 1 neighboring, R 2 It can be located in R 1 The position of R 2 It can also be located in R at the same time 1 Adjacent and intermediate positions. These can be adjusted according to specific needs.

[0030] In some embodiments of the present invention, R 1 Selected from dimethylamino, pyrrolidinyl, tert-butyl, or hydrogen; R 2 Selected from hydrogen, methyl, ethyl, butyl, isopropyl, or tert-butyl; R 4 Selected from hydrogen or methylphenyl, R 3 It is selected from hydrogen, methyl, butyl or phenyl.

[0031] In some embodiments of the present invention, the pyridine-acetylsulfonamide compound has at least one of the structures shown in Formula I-1 to Formula I-9:

[0032]

[0033] A second aspect of the present invention provides a method for preparing a pyridine-acetylsulfonamide compound, the method comprising: reacting a pyridine derivative with an acetylsulfonamide compound to obtain a pyridine-acetylsulfonamide compound; wherein the pyridine-acetylsulfonamide compound has the structure shown in formula (I); the pyridine derivative has the structure shown in formula (II); and the acetylsulfonamide compound has the structure shown in formula (III).

[0034]

[0035] Among them, R 1and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

[0036] In this invention, C1-C 10 In the substituted or unsubstituted straight-chain or branched alkyl groups, the substituents include, but are not limited to, one or more of the following groups: halogen, hydroxyl, phenyl and substituted phenyl.

[0037] In this invention, R 2 Located in R 1 The adjacent and / or intermediate positions, i.e., R 2 It can be located in R 1 neighboring, R 2 It can be located in R 1 The position of R 2 It can also be located in R at the same time 1 Adjacent and intermediate positions. These can be adjusted according to specific needs.

[0038] In some embodiments of the present invention, R 1 Selected from dimethylamino, pyrrolidinyl, tert-butyl, or hydrogen; R 2 Selected from hydrogen, methyl, ethyl, butyl, isopropyl, or tert-butyl; R 4 Selected from hydrogen or methylphenyl, R 3 It is selected from hydrogen, methyl, butyl or phenyl.

[0039] In some preferred embodiments of the invention, the pyridine derivative has at least one of the structures shown in Formula II-1 to Formula II-12:

[0040]

[0041]

[0042] In some preferred embodiments of the present invention, the acetylsulamide compound has at least one of the structures shown in Formula III-1 to Formula III-6:

[0043]

[0044] In some preferred embodiments of the present invention, the pyridine-acetylsulfonamide compound has at least one of the structures shown in Formula I-1 to Formula I-9:

[0045]

[0046] In some embodiments of the present invention, the molar ratio of the pyridine derivative and the acesulfonamide compound is 0.5-2:1.

[0047] In this invention, the reaction is an organocatalytic ring-opening polymerization reaction.

[0048] In some embodiments of the present invention, the reaction temperature is 25°C-80°C and the time is 6-24 hours.

[0049] In some embodiments of the present invention, the reaction is carried out in a solvent, wherein the solvent is at least one selected from tetrahydrofuran, dichloromethane, trichloromethane, and toluene.

[0050] A third aspect of the present invention provides a pyridine-acetylsulfonamide compound prepared by the aforementioned preparation method.

[0051] In some embodiments of the present invention, the pyridine-acetylsulfonamide compound has one of the structures shown in Formula I-1 to Formula I-9:

[0052]

[0053]

[0054] The fourth aspect of the present invention provides the use of the aforementioned pyridine-acetylsulfonamide compound in the preparation of polyesters.

[0055] This invention uses industrially inexpensive and readily available pyridine derivatives and food additive acesulfonamide compounds as raw materials to synthesize pyridine-acesulfonamide compounds. These pyridine-acesulfonamide compounds can be used as catalysts for the preparation of polyesters. Compared with existing catalytic systems, this invention has significant advantages, including mildness, high efficiency, wide availability, simple synthesis, diverse types, broad range, metal-free composition, structural stability, ease of use, and easy control of the polymerization process. It has important application prospects in the biopharmaceutical field.

[0056] The fifth aspect of the present invention provides a method for preparing a polyester, the method comprising: performing a ring-opening polymerization reaction on a cyclic monomer in the presence of a catalyst to obtain a polyester; wherein the catalyst is the aforementioned pyridine-acetylsulfonamide compound.

[0057] The method of the present invention uses the aforementioned pyridine-acetylsulfonamide compound as a catalyst to catalyze the polymerization reaction through hydrogen bonding. Compared with the catalysts reported previously, this catalyst has the characteristics of high catalytic efficiency and milder reaction.

[0058] In some embodiments of the present invention, the cyclic monomer is a monomer having the structure shown in formula (IV) or a monomer having the structure shown in formula (V);

[0059]

[0060] In equation (IV), A represents the general formula [-(CR1R2)-]. n In the structure shown, n is an integer from 2 to 10; R1 and R2 are each independently selected from hydrogen, C1-C5 substituted or unsubstituted straight-chain or branched alkyl groups; X is selected from oxygen;

[0061] In equation (V), A and B are each independently represented by the general formula [-(CR1R2)-]. m In the structure shown, m is an integer from 2 to 10; R1 and R2 are each independently selected from hydrogen, C1-C5 substituted or unsubstituted straight-chain or branched alkyl groups; X is selected from oxygen.

[0062] In some embodiments of the present invention, the cyclic monomer is β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, or undecylactone.

[0063] In this invention, undecylactone refers to macrocyclic undecylactone.

[0064] In some embodiments of the present invention, the cyclic monomer is glycolide, lactide, butylidene lactide, decyl lactide, decalide, O-carboxyanhydride (OCA), or N-carboxyanhydride (NCA).

[0065] In this invention, decacyclic lactone refers to macrocyclic decacyclic lactone.

[0066] In this invention, the conversion rate of cyclic monomers is 90%-99%.

[0067] In some embodiments of the present invention, the amount of catalyst added is 0.05-10 mol% of the cyclic monomer.

[0068] In some embodiments of the present invention, the ring-opening polymerization reaction is carried out at a temperature of 80-140°C for a time of 0.2-24 hours.

[0069] This invention prepares polyesters by pyridine-acetylsulfonamide catalytic ring-opening polymerization under solvent-containing or solvent-free conditions. The polyesters include, but are not limited to: polybutyrolactone, polyvalerolactone, polycaprolactone, polylactide, polyglycolic acid, and polytrimethylene carbonate.

[0070] In this invention, the ring-opening polymerization reaction is carried out in the presence of a solvent or in the absence of a solvent; when polymerization is carried out in the presence of a solvent, the solvent includes, but is not limited to, one or more of the following: acetone, cyclohexanone, dioxane, tetrahydrofuran, benzene, toluene, xylene, dichloromethane, chloroform, tetrachloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and acetonitrile; preferably tetrahydrofuran, toluene, dichloromethane, chloroform, or N,N-dimethylformamide.

[0071] In this invention, the ring-opening polymerization reaction is carried out in the presence of an initiator or in the absence of an initiator; when the ring-opening polymerization reaction is carried out in the presence of an initiator, the initiator is not limited to, but includes, one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, benzyl alcohol, phenethyl alcohol, ethylene glycol, 5-hexen-1-ol, and water.

[0072] In this invention, the molar ratio of the initiator to the catalyst pyridine phenol salt is 0.01-10:1.

[0073] In this invention, the ring-opening polymerization reaction is carried out under vacuum with a vacuum degree of 1-500 Pa; or under a protective gas (inert gas, such as Ar) with a pressure of 100-101325 Pa.

[0074] In the solution prior to the ring-opening polymerization reaction, the initial reaction concentration of the cyclic monomer is 0.1 mol / L-100 mol / L. After the ring-opening polymerization reaction is completed, a terminator, namely triethylamine, is added. A precipitation solvent, such as methanol, ethanol, diethyl ether, or n-hexane, is added after the terminator.

[0075] The sixth aspect of the present invention provides a polyester prepared by the aforementioned preparation method, wherein the polyester has a number-average molecular weight of 1,000-100,000 g / mol, a molecular weight distribution coefficient of 1-2, and a metal content of 0.

[0076] Using the pyridine-phenol compound of the present invention as a catalyst, the conversion rate of cyclic monomers is high (90-99%), and the corresponding polyester dispersion index (PDI) is low.

[0077] The catalyst prepared by this invention has controllable activity and no chain transesterification reaction. The polyester produced by it has the characteristics of narrow molecular weight distribution index, high product yield, no monomer residue, and snow-white color.

[0078] The polyester obtained by this invention is a high molecular weight biodegradable material with a large molecular weight, narrow molecular weight distribution, and no metal impurities. It has important industrial application prospects and great commercial application potential in the fields of biomedicine and microelectronics.

[0079] The seventh aspect of the present invention provides the application of the aforementioned polyester in biomedical materials or food packaging materials.

[0080] The polyester obtained by the method of the present invention can be used as a biomedical material or a food packaging material, especially a biodegradable food packaging material. For example, polycaprolactone (PCL) and polylactide (PLA) can be used as biodegradable surgical sutures. Polycaprolactone can also be used as a medical surgical splint, and polylactide can also be used as a food packaging bag, straw, lunch box, etc.

[0081] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited to the following description.

[0082] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0083] The 1H NMR spectra involved in the following examples were measured using a Bruker Ascend™-400 1H NMR spectrometer, and the deuterated reagents used were deuterated chloroform (CDCl3) and deuterated dimethyl sulfoxide (DMSO-d6).

[0084] Preparation Example 1

[0085] The preparation method of the compound with the structure shown in Formula I-2 specifically includes the following steps:

[0086] (1) Dissolve 5g of the compound with the structure shown in Formula III-1 in 10mL of water, add 6mL of concentrated hydrochloric acid, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0087] (2) The compound with the structure shown in Formula II-7 (0.5 g, 4.09 mmol) and the acidified acesulfame potassium obtained in step (1) (0.667 g, 4.09 mmol) were added to a 100 mL round-bottom flask. Using 20 mL of THF as solvent, the mixture was reacted overnight at 60 °C. After the reaction, the solvent was removed under vacuum. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent diffused at room temperature for a period of time, producing white crystals, thus obtaining the compound with the structure shown in Formula I-2. The separation yield was 80%. Figure 1 The product is shown. 1 HNMR spectrum, from Figure 1 It is evident that the catalyst has high purity.

[0088] Preparation Example 2

[0089] The preparation method of the compound with the structure shown in Formula I-1 specifically includes the following steps:

[0090] (1) Dissolve 5g of the compound with the structure shown in Formula III-1 in 10mL of water, add 6mL of concentrated hydrochloric acid, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0091] (2) The compound with the structure shown in Formula II-1 (0.43 g, 4.09 mmol) and the acidified acesulfame potassium obtained in step (1) (0.667 g, 4.09 mmol) were added to a 100 mL round-bottom flask. The reaction was carried out overnight at 60 °C with 20 mL THF as solvent. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL n-hexane was added. The solvent diffused at room temperature for a period of time to produce white crystals, and the compound with the structure shown in Formula I-1 was obtained. The separation yield was 81%.

[0092] Preparation Example 3

[0093] The preparation method of the compound with the structure shown in Formula I-3 specifically includes the following steps:

[0094] (1) Dissolve 5g of the compound with the structure shown in Formula III-1 in 10mL of water, add 6mL of concentrated hydrochloric acid, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0095] (2) The compound with the structure shown in Formula II-11 (4.09 mmol) and the acidified acesulfame potassium obtained in step (1) (4.09 mmol) were added to a 100 mL round-bottom flask. 20 mL of THF was used as solvent, and the mixture was reacted at 60 °C overnight. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent was allowed to diffuse at room temperature for a period of time to produce white crystals, thus obtaining the compound with the structure shown in Formula I-3. The separation yield was 87%.

[0096] Preparation Example 4

[0097] The preparation method of the compound with the structure shown in Formula I-4 specifically includes the following steps:

[0098] (1) Dissolve 5g of the compound with the structure shown in Formula III-2 in 10mL of water, add 6mL of concentrated hydrochloric acid dropwise, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0099] (2) The compound with the structure shown in Formula II-2 (4.09 mmol) and the acidified acesulfame potassium obtained in step (1) (4.09 mmol) were added to a 100 mL round-bottom flask. 20 mL of THF was used as solvent, and the mixture was reacted overnight at 60 °C. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent was allowed to diffuse at room temperature for a period of time to produce white crystals, thus obtaining the compound with the structure shown in Formula I-4. The separation yield was 83%.

[0100] Preparation Example 5

[0101] The preparation method of the compound with the structure shown in Formula I-5 specifically includes the following steps:

[0102] (1) Dissolve 5g of the compound with the structure shown in Formula III-3 in 10mL of water, add 6mL of concentrated hydrochloric acid, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0103] (2) The compound with the structure shown in Formula II-8 (4.09 mmol) and the acidified acesulfame potassium obtained in step (1) were added to a 100 mL round-bottom flask. 20 mL of THF was used as the solvent, and the mixture was reacted overnight at 60 °C. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent was allowed to diffuse at room temperature for a period of time to produce white crystals, thus obtaining the compound with the structure shown in Formula I-5. The separation yield was 90%.

[0104] Preparation Example 6

[0105] The preparation method of the compound with the structure shown in Formula I-6 specifically includes the following steps:

[0106] (1) Dissolve 5g of the compound with the structure shown in Formula III-4 in 10mL of water, add 6mL of concentrated hydrochloric acid, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0107] (2) The compound with the structure shown in Formula II-9 (4.09 mmol) and the acidified acesulfame potassium obtained in step (1) were added to a 100 mL round-bottom flask. 20 mL of THF was used as the solvent, and the mixture was reacted overnight at 60 °C. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent was allowed to diffuse at room temperature for a period of time to produce white crystals, thus obtaining the compound with the structure shown in Formula I-6. The separation yield was 90%.

[0108] Preparation Example 7

[0109] The preparation method of the compound with the structure shown in Formula I-7 specifically includes the following steps:

[0110] (1) Dissolve 5g of the compound with the structure shown in Formula III-2 in 10mL of water, add 6mL of concentrated hydrochloric acid dropwise, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0111] (2) The compound with the structure shown in Formula II-5 (4.09 mmol) and the acidified acesulfame potassium obtained in step (1) were added to a 100 mL round-bottom flask. 20 mL of THF was used as the solvent, and the mixture was reacted at 60 °C overnight. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent was allowed to diffuse at room temperature for a period of time to produce white crystals, thus obtaining the compound with the structure shown in Formula I-7. The separation yield was 90%.

[0112] Preparation Example 8

[0113] The preparation method of the compound with the structure shown in Formula I-8 specifically includes the following steps:

[0114] (1) Dissolve 5g of the compound with the structure shown in Formula III-5 in 10mL of water, add 6mL of concentrated hydrochloric acid, stir, and extract with 20mL of ethyl acetate. After the solvent evaporates in air, a colorless solid is obtained. After the solvent evaporates slowly in air, recrystallize twice from ethyl acetate to form needle-shaped colorless crystals, thus obtaining acidified acesulfame.

[0115] (2) The compound with the structure shown in Formula II-12 (4.09 mmol) and the acidified acesulfame potassium obtained in step (1) were added to a 100 mL round-bottom flask. 20 mL of THF was used as the solvent, and the mixture was reacted at 60 °C overnight. After the reaction was completed, the solvent was removed by vacuum method. The product was recrystallized from methanol to form a hot saturated solution. 10 mL of n-hexane was added, and the solvent was allowed to diffuse at room temperature for a period of time to produce white crystals, thus obtaining the compound with the structure shown in Formula I-8. The separation yield was 95%.

[0116] Preparation of Comparative Example 1

[0117] Following the method of Preparation Example 1, except that the compound with the structure shown in Formula II-2 was replaced with chloropyridine, the compound with the structure shown in Formula D-1 was obtained.

[0118]

[0119] Example 1

[0120] In a 10 mL reaction tube, butyrolactone (0.3856 g, 2.88 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-2 (0.027 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 80 °C for 2 h. After the reaction was complete, the crude product was dissolved in a small amount of dichloromethane, and then added to a cold methanol solution, resulting in the precipitation of a polymer. Centrifugation yielded 0.26 g of a white solid, which was then dried in a vacuum drying oven. The structure of the polymer was identified by NMR, and the molecular weight and dispersion of the polymer were determined by GPC. The conversion rate of butyrolactone was determined to be 92%, the number-average molecular weight was 2700 g / mol, and the molecular weight distribution coefficient was 1.29.

[0121] Example 2

[0122] In a 10 mL reaction tube, ε-caprolactone (0.3168 mL, 2.88 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-1 (0.023 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 100 °C for 3 h. After the reaction was complete, the crude product was dissolved in a small amount of DCM, and then added to a cold methanol solution, resulting in polymer precipitation. Centrifugation yielded 0.25 g of a white solid, which was then transferred to a vacuum drying oven for drying. The structure of the polymer was identified by NMR, and the molecular weight and dispersion of the polymer were determined by GPC. The conversion rate of ε-caprolactone was determined to be 95%, the number-average molecular weight was 3600 g / mol, and the molecular weight distribution coefficient was 1.33.

[0123] Example 3

[0124] In a 10 mL reaction tube, valerolactone (0.288 g, 2.88 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-3 (0.030 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 90 °C for 4 h. After the reaction was complete, the crude product was dissolved in a small amount of DCM, and then added to a cold methanol solution, resulting in polymer precipitation. Centrifugation yielded 0.22 g of a white solid, which was then transferred to a vacuum drying oven for drying. The structure of the polymer was identified by NMR, and the molecular weight and dispersion of the polymer were determined by GPC. The conversion rate of valerolactone was determined to be 95%, the number-average molecular weight was 3000 g / mol, and the molecular weight distribution coefficient was 1.24.

[0125] Example 4

[0126] In a 10 mL reaction tube, glycolide (0.6682 g, 5.76 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-4 (0.026 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 140 °C for 5 h. After the reaction was complete, the crude product was dissolved in a minimal amount of dichloromethane, and then added to a cold methanol solution, resulting in polymer precipitation. Centrifugation yielded 0.47 g of a white solid, which was then dried in a vacuum drying oven. The structure of the polymer was identified by NMR, and the molecular weight and dispersion were determined by GPC. The conversion rate of glycolide was determined to be 94%, the number-average molecular weight was 6400 g / mol, and the molecular weight distribution coefficient was 1.23.

[0127] Example 5

[0128] In a 10 mL reaction tube, lactide (1.244 g, 8.64 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-5 (0.026 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 140 °C for 6 h. After the reaction was complete, the crude product was dissolved in a minimal amount of dichloromethane, and then added to a cold methanol solution, resulting in the precipitation of a polymer. Centrifugation yielded 0.90 g of a white solid, which was then dried in a vacuum drying oven. The structure of the polymer was identified by NMR, as shown below. Figure 2 shown 1 H NMR spectrum, from Figure 2 It is evident that the purity of lactide is high. The molecular weight and dispersity of the polymer were determined by GPC. The conversion rate of lactide was found to be 96%, the number-average molecular weight was 12000 g / mol, and the molecular weight distribution coefficient was 1.29.

[0129] Example 6

[0130] In a 10 mL reaction tube, carboxylic acid anhydride (0.415 g, 5.76 mmol), benzyl alcohol (10 μL, 0.096 mmol), and a compound with the structure shown in Formula I-6 (0.028 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 130 °C for 8 h. After the reaction was complete, the crude product was dissolved in a minimal amount of dichloromethane, and then added to a cold methanol solution, resulting in polymer precipitation. Centrifugation yielded 0.30 g of a white solid, which was then dried in a vacuum drying oven. The structure of the polymer was identified by NMR, and the molecular weight and dispersion were determined by GPC. The conversion rate of carboxylic acid anhydride was determined to be 95%, the number-average molecular weight was 4300 g / mol, and the molecular weight distribution coefficient was 1.22.

[0131] Example 7

[0132] In a 10 mL reaction tube, trimethylene carbonate (0.490 g, 4.80 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-7 (0.027 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 90 °C for 4 h. After the reaction was complete, the crude product was dissolved in a minimal amount of dichloromethane, and then added to a cold methanol solution, resulting in the precipitation of a polymer. Centrifugation yielded 0.32 g of a white solid, which was then transferred to a vacuum drying oven for drying. The structure of the polymer was identified by NMR, as shown below. Figure 3 shown 1 H NMR spectrum, from Figure 3 It is evident that the polymer exhibits high purity and low monomer residue. The molecular weight and dispersity of the polymer were determined using GPC. The conversion rate of trimethylene carbonate was found to be 97%, the number-average molecular weight was 6300 g / mol, and the molecular weight distribution coefficient was 1.21.

[0133] Example 8

[0134] In a 10 mL reaction tube, lactide (0.415 g, 2.88 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-8 (0.026 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 120 °C for 4 h. After the reaction was complete, the crude product was dissolved in a minimal amount of dichloromethane, and then added to a cold methanol solution, resulting in polymer precipitation. Centrifugation yielded 0.30 g of a white solid, which was then transferred to a vacuum drying oven for drying. The structure of the polymer was identified by NMR, and the molecular weight and dispersion of the polymer were determined by GPC. The conversion rate of lactide was determined to be 97%, the number-average molecular weight was 4300 g / mol, and the molecular weight distribution coefficient was 1.15.

[0135] Example 9

[0136] In a 10 mL reaction tube, lactide (0.415 g, 2.88 mmol), benzyl alcohol (10 μL, 0.096 mmol), and the compound with the structure shown in Formula I-8 (0.038 g, 0.096 mmol) were added, and the mixture was magnetically stirred at 130 °C for 4 h. After the reaction was complete, the crude product was dissolved in a minimal amount of dichloromethane, and then added to a cold methanol solution, resulting in polymer precipitation. Centrifugation yielded 0.29 g of a white solid, which was then transferred to a vacuum drying oven for drying. The structure of the polymer was identified by NMR, and the molecular weight and dispersion of the polymer were determined by GPC. The conversion rate of lactide was determined to be 96%, the number-average molecular weight was 4300 g / mol, and the molecular weight distribution coefficient was 1.20.

[0137] Comparative Example 1

[0138] The method of Preparation Example 1 was followed, except that the compound with the structure shown in Formula I-2 was replaced with the compound with the structure shown in D-1 obtained in Comparative Example 1. The conversion rate of lactide was 30%, the number-average molecular weight was 1200 g / mol, and the molecular weight distribution coefficient was 1.40.

[0139] Table 1

[0140]

[0141] As can be seen from the results in Table 1, the catalyst of the present invention achieves a monomer conversion rate of over 90%, which is higher than that of Comparative Example 1. Compared with Comparative Example 1, the present application has significantly better performance.

[0142] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. The application of a pyridine-acetylsulfonamide compound in the preparation of polyesters, characterized in that, The pyridine-acetylsulfonamide compound has the structure shown in formula (I): ，（I）； In equation (I), R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

2. The application according to claim 1, wherein, R 1 Selected from dimethylamino, pyrrolidinyl, tert-butyl, or hydrogen; R 2 Selected from hydrogen, methyl, ethyl, butyl, isopropyl, or tert-butyl; R 4 Selected from hydrogen, R 3 It is selected from hydrogen, methyl or butyl.

3. The application according to claim 1, wherein, The method for preparing the pyridine-acetylsulfonamide compound includes: reacting a pyridine derivative with an acetylsulfonamide compound to obtain the pyridine-acetylsulfonamide compound; wherein the pyridine-acetylsulfonamide compound has the structure shown in formula (I); the pyridine derivative has the structure shown in formula (II); and the acetylsulfonamide compound has the structure shown in formula (III). ,(I); ,(II); , (III); Among them, R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

4. The application according to claim 3, wherein, R 1 Selected from dimethylamino, pyrrolidinyl, tert-butyl, or hydrogen; R 2 Selected from hydrogen, methyl, ethyl, butyl, isopropyl, or tert-butyl; R 4 Selected from hydrogen, R 3 It is selected from hydrogen, methyl or butyl.

5. The application according to claim 4, wherein, The pyridine derivative has at least one of the structures shown in Formula II-1, Formula II-3, Formula II-4, Formula II-5, Formula II-7, Formula II-8, Formula II-11 and Formula II-12: ,II-1; ,II-3; ,II-4; ,II-5; ,II-7; ,II-8; ,II-11; ,II-12; And / or, the acesulfame potassium compounds have at least one of the structures shown in Formula III-1, Formula III-4, and Formula III-6: ,III-1; ,III-4; ,III-6。 6. The application according to claim 3, wherein, The molar ratio of the pyridine derivative to the acetylsulamide compound is 0.5-2:

1.

7. The application according to claim 3, wherein, The reaction is carried out at a temperature of 25℃-80℃ for a time of 6-24 hours. And / or, the reaction is carried out in a solvent, wherein the solvent is at least one of tetrahydrofuran, dichloromethane, trichloromethane, and toluene.

8. The application of a pyridine-acetylsulfonamide compound in the preparation of polyesters, characterized in that, The pyridine-acetylsulfonamide compound has at least one of the structures shown in Formulas I-1 to I-5 and I-7 to I-8: ,I-1; ,I-2; ,I-3; ,I-4; ,I-5; ,I-7; ,I-8。 9. A method for preparing polyester, characterized in that, The preparation method includes: performing a ring-opening polymerization reaction on a cyclic monomer in the presence of a catalyst to obtain a polyester; wherein the catalyst is a pyridine-acetylsulfonamide compound; The pyridine-acetylsulfonamide compound has the structure shown in formula (I): ，（I）； In equation (I), R 1 and R 2 Each is independently selected from dimethylamino, pyrrolyl, hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups; R 3 and R 4 Each is independently selected from hydrogen, C1-C 10 Substituted or unsubstituted straight-chain or branched alkyl groups.

10. The preparation method according to claim 9, wherein, R 1 Selected from dimethylamino, pyrrolidinyl, tert-butyl, or hydrogen; R 2 Selected from hydrogen, methyl, ethyl, butyl, isopropyl, or tert-butyl; R 4 Selected from hydrogen, R 3 It is selected from hydrogen, methyl or butyl.

11. The preparation method according to claim 9 or 10, wherein, The cyclic monomer is a monomer having the structure shown in formula (IV) or a monomer having the structure shown in formula (V); In formula (IV), A is the general formula [ (CR1R2) ] n In the structure shown, n is an integer from 2 to 10; R1 and R2 are each independently selected from hydrogen, C1-C5 substituted or unsubstituted straight-chain or branched alkyl groups; X is selected from oxygen; In formula (V), A and B are each independently general formulas. (CR1R2) ] m In the structure shown, m is an integer from 2 to 10; R1 and R2 are each independently selected from hydrogen, C1-C5 substituted or unsubstituted straight-chain or branched alkyl groups; X is selected from oxygen.

12. The preparation method according to claim 9 or 10, wherein, The cyclic monomer is β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, or undecylactone. And / or, the cyclic monomer is glycolide, lactide, butylene lactide, decylene lactide, or decalide.

13. The preparation method according to claim 9 or 10, wherein, The catalyst is added at an amount of 0.05-10 mol% of the cyclic monomer. And / or, the ring-opening polymerization reaction is carried out at a temperature of 80-140°C for a time of 0.5-24 h; And / or, the ring-opening polymerization reaction is carried out in the presence of an initiator selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, benzyl alcohol, phenethyl alcohol, ethylene glycol, 5-hexen-1-ol, and water.

14. The preparation method according to claim 13, wherein, The molar ratio of the initiator to the catalyst is 0.01-10:

1.

15. A method for preparing polyester, characterized in that, The preparation method includes: performing a ring-opening polymerization reaction on a cyclic monomer in the presence of a catalyst to obtain a polyester; wherein the catalyst is a pyridine-acetylsulfonamide compound; The pyridine-acetylsulfonamide compound has at least one of the structures shown in Formulas I-1 to I-5 and I-7 to I-8: ,I-1; ,I-2; ,I-3; ,I-4; ,I-5; ,I-7; ,I-8。

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