Six-membered oxygen heterocyclic lactone, degradable polyether ester and preparation and degradation methods of six-membered oxygen heterocyclic lactone and degradable polyether ester

Abstract

The invention relates to six-membered oxygen heterocyclic lactone, degradable polyether ester and preparation and degradation methods of the six-membered oxygen heterocyclic lactone and the degradable polyether ester, and belongs to the technical field of organic chemistry and high polymer materials. According to the invention, low-cost bulk chemicals such as glycollate, glycollate derivatives, glycollic acid or glycollic acid derivatives and epoxy compounds are used as main raw materials to prepare six-membered oxygen heterocyclic lactones with different structures, and then degradable polyether esters with different structures and properties are prepared. The preparation method provided by the invention has the advantages of easily available raw materials, low cost, simple process and high efficiency, can realize high-efficiency preparation of degradable polyether esters with different structures and properties, and effectively overcomes the problem of lack of diversity and functionality of polyether esters caused by single structure of polyether ester monomers in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemistry and polymer materials, and in particular to a six-membered oxygen heterocyclic lactone, a degradable polyether ester and a preparation method and a degradation method thereof. Background Art

[0002] As a type of synthetic polymer material, polyether esters have shown unique advantages and broad application prospects due to their excellent physical properties, biocompatibility, biodegradability and recyclability. They have potential application value in disposable products, food packaging bags, medical implants, surgical sutures, agricultural supplies and other fields.

[0003] At present, the production method of polyether esters still requires expensive raw materials and complex synthesis steps, resulting in high production costs and difficulty in large-scale production. In addition, the types of monomers for the synthesis of polyether esters are very limited, resulting in a lack of diversity and functionality in polyether ester materials. These high production costs and limited monomer selection have become the main reasons restricting their industrial production and wide application.

[0004] The main chain structure, side chain groups, chiral structure, stereoregularity of the molecular chain and chain flexibility of the polymer will significantly affect the physical and mechanical properties of the polymer material. The introduction of different heteroatoms and substituents into the polymer can adjust the thermal properties and mechanical properties of the polymer, and finally prepare a polymer material with excellent comprehensive performance. Therefore, the synthesis of oxygen heterocyclic lactone monomers with diverse structures is the basis for the development of new polyetherester materials. Although some progress has been made in the research and development of new monomers and the optimization of the synthesis methods of polyetheresters in recent years, these methods are often difficult to meet the requirements of industrial production in terms of cost and efficiency, especially in terms of raw material procurement, production efficiency and environmental impact of monomer structure. There are obvious limitations.

[0005] Therefore, there is an urgent need to provide a six-membered oxygen heterocyclic lactone, a degradable polyether ester and a preparation and degradation method thereof, so as to solve the problem of the lack of diversity and functionality of polyether esters in the prior art due to the single structure of polyether ester monomers. Summary of the invention

[0006] In view of one or more technical problems existing in the prior art, the present invention provides a six-membered oxygen heterocyclic lactone, a degradable polyether ester and a preparation and degradation method thereof. The present invention uses low-cost bulk chemicals glycolate, glycolate derivatives, glycolic acid or glycolic acid derivatives and epoxy compounds as main raw materials to prepare six-membered oxygen heterocyclic lactones with different structures, and then efficiently prepares degradable polyether esters with different structures and properties, which can effectively overcome the problem of lack of diversity and functionality of polyether esters in the prior art due to the single structure of polyether ester monomers.

[0007] In a first aspect, the present invention provides a six-membered oxadiazole lactone having the following structure:

[0008]

[0009] wherein R' is hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0010] R 1 , R 2 , R 3 , R 4 R is independently selected from hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, fused aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imino, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphino, phosphoryl, silicon, nitro, cyano, aldehyde, keto, carboxyl or azido; 1 , R 2 , R 3 , R 4 Two or more of them may be connected to form a ring, connected to form an aromatic group or a C3-C8 heterocyclic group which may be optionally substituted;

[0011] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, cyano, propenyl, ether, and aromatic groups;

[0012] The heteroatom in the heterocyclic group is selected from oxygen, sulfur, nitrogen, boron and silicon.

[0013] Preferably, R' is a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, vinyl, allyl, ethynyl, propynyl, phenyl, tolyl, methoxy, ethoxy, amide, methyl, ethyl, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0014] R 1 , R 2 , R 3 , R 4each independently selected from a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, allyl, ethynyl, propynyl, phenyl, tolyl, naphthyl, conjugated alkenyl, conjugated alkynyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, methoxy, ethoxy, acyloxy, peroxy, amino, amide, thiol, thioether, imino, hydrazone, azo, phosphino, phosphoryl, trimethylsilyl, methyl, ethyl, vinyl, fluorine, chlorine, bromine, iodine, hydroxyl, aldehyde, keto, carboxyl, nitro, cyano, trifluoromethyl, pentafluoroethyl, azido, sulfonic acid, sulfinic acid, sulfone or sulfoxide group;

[0015] R 2 and R 3 The ring may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclopentynyl, cyclohexenyl, cyclohexynyl, cycloheptenyl, cycloheptynyl, phenyl which may be optionally substituted;

[0016] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, propenyl, ether, and phenyl.

[0017] The present invention provides in a second aspect a method for preparing the six-membered oxygen heterocyclic lactone described in the first aspect, the preparation method comprising: using a first monomer and an epoxy compound as reactants to obtain the six-membered oxygen heterocyclic lactone by a one-step method or a two-step method; the first monomer is one or more of glycolic acid, glycolic acid derivatives, glycolic esters, and glycolic ester derivatives.

[0018] Preferably, when the first monomer is glycolate or a glycolate derivative, the one-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a first reaction under the action of a first catalyst, and subjecting the first monomer to a first reaction ...

[0019] When the first monomer is glycolate or a glycolate derivative, the two-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a second reaction under the action of a first catalyst, separating and purifying to obtain an intermediate product, and heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone;

[0020] When the first monomer is glycolic acid or a glycolic acid derivative, the one-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a first reaction without a catalyst or under the action of a first catalyst, and subjecting the first monomer to a first reaction by vacuum distillation to obtain a six-membered oxygen heterocyclic lactone;

[0021] When the first monomer is glycolic acid or a glycolic acid derivative, the two-step method comprises the following steps: subjecting a mixture of the first monomer and the epoxy compound to a second reaction without a catalyst or under the action of the first catalyst, dissolving, filtering, washing and distilling the reaction mixture to obtain a crude product, separating and purifying the crude product to obtain an intermediate product; heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone;

[0022] When the first monomer is glycolic acid or a glycolic acid derivative, the two-step method comprises the following steps: mixing the first monomer, a solvent and an epoxy compound, and carrying out a second reaction without a catalyst or under the action of the first catalyst, concentrating, filtering, washing and distilling the mixture after the reaction to obtain a crude product, separating and purifying the crude product to obtain an intermediate product; heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone.

[0023] Preferably, the glycolic acid derivative is one or more of 2-hydroxypropionic acid, 2-hydroxypropionic acid, 2-hydroxybutyric acid, 2-hydroxyvaleric acid, 2-hydroxyhexanoic acid, sodium glycolate, potassium glycolate, lactic acid, and mandelic acid;

[0024] The glycolate derivative is one or more of methyl glycolate, ethyl glycolate, tert-butyl glycolate, benzyl glycolate, methyl lactate, ethyl lactate, tert-butyl lactate, and benzyl lactate; and / or

[0025] The epoxy compound is selected from one or more of the following structures.

[0026]

[0027] Preferably, the molar ratio of the first monomer to the epoxy compound is 30 / 1 to 1 / 10;

[0028] The molar ratio of the first catalyst to the first monomer is 1 / 100000 to 1 / 2;

[0029] The temperature of the first reaction is -10 to 200°C;

[0030] The temperature of the second reaction is -20 to 220°C, preferably 65 to 140°C; and / or

[0031] The temperature of the heated reduced pressure distillation is 0-250°C.

[0032] Preferably, the first catalyst is selected from one or more of an inorganic acid catalyst, an organic acid catalyst, an inorganic base catalyst, an organic base catalyst, a metal chloride catalyst, a metal oxide catalyst, a metal salt catalyst, and an ionic liquid catalyst;

[0033] Preferably, the inorganic acid catalyst is selected from one or more of sulfuric acid, hydrochloric acid, hydrobromic acid, tungstic acid, titanic acid, boric acid, acidic zirconium sulfate, and aluminosilicate;

[0034] The organic acid catalyst is selected from one or more of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, boron trifluoride, tri(pentafluorophenyl)boron, triethylboron, camphorsulfonic acid, benzoic acid, salicylic acid, oxalic acid, malic acid, and ion exchange resin;

[0035] The inorganic base catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, lithium hydroxide, magnesium hydroxide, zinc hydroxide, copper hydroxide, iron hydroxide, and ammonium hydroxide;

[0036] The organic base catalyst is selected from one or more of triethylamine, pyridine, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and hexamethyldisilazane;

[0037] The metal chloride catalyst is selected from one or more of ferric chloride, ferric chloride, zinc chloride, tin chloride, magnesium chloride, titanium chloride, aluminum chloride, indium chloride, and Schiff alkali metal complex catalysts;

[0038] The metal oxide catalyst is selected from one or more of iron oxide, ferroferric oxide, copper oxide, magnesium oxide, zinc oxide, aluminum oxide, calcium oxide, and titanium oxide; the metal salt catalyst is selected from one or more of copper tetrafluoroborate, bismuth trifluoride, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, cesium carbonate, sodium glycolate, sodium acetate, lithium diisopropylamide, sodium methoxide, sodium tert-butoxide, potassium tert-butoxide, n-butyl lithium, and isobutyl lithium; and / or

[0039] The ionic liquid catalyst is selected from one or more of imidazole ionic liquids, pyridine ionic liquids, quaternary ammonium salt ionic liquids, and quaternary phosphonium salt ionic liquids.

[0040] In a third aspect, the present invention provides a degradable polyether ester, wherein the degradable polyether ester has the following structure:

[0041]

[0042] wherein R' is hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0043] R 1 , R 2, R 3 , R 4 R is independently selected from hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, fused aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imino, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphino, phosphoryl, silicon, nitro, cyano, aldehyde, keto, carboxyl or azido; 1 , R 2 , R 3 , R 4 Two or more of them may be connected to form a ring, connected to form an aromatic group or a C3-C8 heterocyclic group which may be optionally substituted;

[0044] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, cyano, propenyl, ether, and aromatic groups;

[0045] The heteroatom in the heterocyclic group is selected from oxygen, sulfur, nitrogen, boron and silicon.

[0046] Preferably, R' is a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, vinyl, allyl, ethynyl, propynyl, phenyl, tolyl, methoxy, ethoxy, amide, methyl, ethyl, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0047] R 1 , R 2 , R 3 , R 4 each independently selected from a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, allyl, ethynyl, propynyl, phenyl, tolyl, naphthyl, conjugated alkenyl, conjugated alkynyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, methoxy, ethoxy, acyloxy, peroxy, amino, amide, thiol, thioether, imino, hydrazone, azo, phosphino, phosphoryl, trimethylsilyl, methyl, ethyl, vinyl, fluorine, chlorine, bromine, iodine, hydroxyl, aldehyde, keto, carboxyl, nitro, cyano, trifluoromethyl, pentafluoroethyl, azido, sulfonic acid, sulfinic acid, sulfone or sulfoxide group;

[0048] R 2 and R 3 The ring may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclopentynyl, cyclohexenyl, cyclohexynyl, cycloheptenyl, cycloheptynyl, phenyl which may be optionally substituted;

[0049] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, propenyl, ether, and phenyl.

[0050] The present invention provides in a fourth aspect a method for preparing the degradable polyether ester according to the third aspect, the preparation method comprising:

[0051] The six-membered oxygen heterocyclic lactone is subjected to solvent ring-opening polymerization or bulk ring-opening polymerization and purification treatment to obtain a degradable polyether ester;

[0052] Preferably, the solvent ring-opening polymerization is to mix the six-membered oxalolactone with an organic solvent and perform ring-opening polymerization under the action of an initiator and a second catalyst; and / or

[0053] The solvent ring-opening polymerization is the ring-opening polymerization of the six-membered oxygen heterocyclic lactone under the action of an initiator and a second catalyst.

[0054] Preferably, the temperature of the ring-opening polymerization is -60°C to 200°C.

[0055] Preferably, the second catalyst is selected from stannous octoate (SnOct2), diethyl zinc (DEZ), zinc chloride (ZC), dibutyltin oxide (DBTO), dioctyltin oxide (DOTO), trimethylaluminum (TMA), triethylaluminum (TEA), tetrabutyl titanate (TBT), a metal complex containing a Schiff base ligand, diphenyl phosphate (DPP), 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), 4-dimethylaminopyridine (DMAP), 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) One or more;

[0056] The initiator is selected from one or more of methanol, ethanol, isopropanol, n-butanol, tert-butanol, benzyl alcohol, tert-butyl alcohol, ethylene glycol, glycerol, benzyl alcohol, pentaerythritol, preferably benzyl alcohol; and / or

[0057] The organic solvent is selected from one or more of dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, benzene and toluene.

[0058] The fifth aspect of the present invention provides a method for degrading the degradable polyether ester described in the third aspect, the degradation method comprising: subjecting the degradable polyether ester to a degradation reaction under the action of a third catalyst, heating and distilling under reduced pressure to obtain a six-membered oxygen heterocyclic lactone.

[0059] Preferably, the third catalyst is selected from one or more of stannous octoate, zinc chloride, zinc oxide, sodium glycolate, and tin chloride; and / or

[0060] The temperature of the degradation reaction is 0-300°C.

[0061] Compared with the prior art, the present invention has at least the following beneficial effects:

[0062] The present invention uses low-cost bulk chemicals such as glycolic acid esters, glycolic acid ester derivatives, glycolic acid or glycolic acid derivatives and epoxy compounds as main raw materials to prepare six-membered oxygen heterocyclic lactones with different structures, providing a universal synthesis method for expanding the types of oxygen heterocyclic lactone monomers. When glycolic acid esters or glycolic acid ester derivatives are used as raw materials to prepare six-membered oxygen heterocyclic lactones, bulk reaction can be achieved under the action of a catalyst at room temperature, and high-purity six-membered oxygen heterocyclic lactones can be obtained with simple purification. This is a green, environmentally friendly, low-energy six-membered oxygen heterocyclic lactone preparation process that can be applied to industrial mass production. When glycolic acid or glycolic acid derivatives are used as raw materials to prepare six-membered oxygen heterocyclic lactones, no catalyst is used, and the reaction system is pure and easy to operate.

[0063] The present invention uses low-cost bulk chemicals glycolate, glycolate derivatives, glycolic acid or glycolic acid derivatives and epoxy compounds as main raw materials to prepare six-membered oxygen heterocyclic lactones with different structures. Under the action of a catalyst, the six-membered oxygen heterocyclic lactone can realize the preparation of degradable polyether esters with different structures, high molecular weight and excellent performance under mild conditions, which can effectively overcome the problem of lack of diversity and functionality of polyether esters due to the single structure of polyether ester monomers in the prior art. The preparation method of the present invention has easy-to-obtain raw materials, simple and efficient processes, can realize the efficient preparation of polyether esters with different structures and properties, significantly reduce the production cost of polyether esters, improve production efficiency, make industrial production of polyether esters with different structures and properties possible, and broaden its application range.

[0064] The degradable polyether ester provided by the present invention can be degraded or depolymerized under the action of a catalyst to obtain the six-membered oxadiazole lactone as its preparation monomer. The six-membered oxadiazole lactone obtained by degradation can be subjected to ring-opening polymerization to obtain the degradable polyether ester again, and closed-loop recovery can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0066] Figure 1 This is the NMR spectrum of the six-membered heterocyclic lactone with a benzene ring as the side group prepared in Example 1;

[0067] Figure 2 This is the NMR spectrum of a six-membered heterocyclic lactone with a methyl side group prepared in Example 6;

[0068] Figure 3 This is the NMR spectrum of another six-membered heterocyclic lactone with a methyl side group prepared in Example 6;

[0069] Figure 4 This is the NMR spectrum of the six-membered heterocyclic lactone with geminal dimethyl side groups prepared in Example 7;

[0070] Figure 5 This is the NMR spectrum of the six-membered heterocyclic lactone with a cyclohexyl side group prepared in Example 8;

[0071] Figure 6 is the H NMR spectrum of the polyether ester prepared in Example 10;

[0072] Figure 7 This is the H-NMR spectrum of the polyether ester prepared in Example 12. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0074] In a first aspect, the present invention provides a six-membered oxadiazole lactone having the following structure:

[0075]

[0076] wherein R' is hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0077] R 1 , R 2 , R 3 , R 4 R is independently selected from hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, fused aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imino, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphino, phosphoryl, silicon, nitro, cyano, aldehyde, keto, carboxyl or azido; 1 , R 2, R 3 , R 4 Two or more of them may be connected to form a ring, connected to form an aromatic group or a C3-C8 heterocyclic group which may be optionally substituted;

[0078] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, cyano, propenyl, ether, and aromatic groups;

[0079] The heteroatom in the heterocyclic group is selected from oxygen, sulfur, nitrogen, boron and silicon.

[0080] It should be noted that the above-mentioned substituted substituents refer to optionally substituted straight-chain or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imine, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphine, phosphoryl, and silicon substituents.

[0081] The six-membered oxygen heterocyclic lactone provided by the present invention can realize the preparation of degradable polyether esters with different structures, high molecular weight and excellent performance under mild conditions under the action of a catalyst, effectively overcoming the problem of lack of diversity and functionality of polyether esters due to the single structure of polyether ester monomers in the prior art, realizing the economical and efficient synthesis of polyether esters with different structures, significantly reducing the production cost of polyether esters, improving production efficiency, making it possible to industrialize the production of polyether esters with very different structures and properties, and broadening their application range.

[0082] According to some preferred embodiments, R' is a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, vinyl, allyl, ethynyl, propynyl, phenyl, tolyl, methoxy, ethoxy, amide, methyl, ethyl, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0083] R 1 , R 2 , R 3 , R 4 each independently selected from a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, allyl, ethynyl, propynyl, phenyl, tolyl, naphthyl, conjugated alkenyl, conjugated alkynyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, methoxy, ethoxy, acyloxy, peroxy, amino, amide, thiol, thioether, imino, hydrazone, azo, phosphino, phosphoryl, trimethylsilyl, methyl, ethyl, vinyl, fluorine, chlorine, bromine, iodine, hydroxyl, aldehyde, keto, carboxyl, nitro, cyano, trifluoromethyl, pentafluoroethyl, azido, sulfonic acid, sulfinic acid, sulfone or sulfoxide group;

[0084] R 2 and R 3 The ring may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclopentynyl, cyclohexenyl, cyclohexynyl, cycloheptenyl, cycloheptynyl, phenyl which may be optionally substituted;

[0085] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, propenyl, ether, and phenyl.

[0086] The present invention provides in a second aspect a method for preparing the six-membered oxygen heterocyclic lactone described in the first aspect, the preparation method comprising: using a first monomer and an epoxy compound as reactants to obtain the six-membered oxygen heterocyclic lactone by a one-step method or a two-step method; the first monomer is one or more of glycolic acid, glycolic acid derivatives, glycolic esters, and glycolic ester derivatives.

[0087] Glycolic acid and its derivatives, glycolic acid esters and their derivatives and epoxy compounds are important basic chemicals in the chemical industry. The annual output of compounds such as glycolic acid, glycolic acid esters, lactic acid, lactic acid esters reaches hundreds of thousands of tons, and the output of epoxy compounds is as high as tens of millions of tons. The ring-opening reaction of epoxy compounds using hydroxyl groups has become the most used organic reaction in industry, and the rich variety of epoxy compounds provides a huge substrate range for these reactions. Therefore, the present invention has economy and diversity by adopting low-cost and diversified bulk chemicals (glycolic acid and its derivatives, glycolic acid esters and their derivatives and epoxy compounds) as the synthetic raw materials of polyether ester monomers, can provide a rich monomer library for the synthesis of polyether esters, and finally realize the economical and efficient synthesis of polyether esters with different structures, which can not only significantly reduce the production cost of polyether esters and improve production efficiency, but also make the industrial production of polyether esters with different structures and properties possible, and broaden its scope of application.

[0088] The present invention uses low-cost bulk chemicals such as glycolic acid esters, glycolic acid ester derivatives, glycolic acid or glycolic acid derivatives and epoxy compounds as main raw materials to prepare six-membered oxygen heterocyclic lactones with different structures, providing a universal synthesis method for expanding the types of oxygen heterocyclic lactone monomers. When glycolic acid esters or glycolic acid ester derivatives are used as raw materials to prepare six-membered oxygen heterocyclic lactones, bulk reaction can be achieved under the action of a catalyst at room temperature, and high-purity six-membered oxygen heterocyclic lactones can be obtained with simple purification. This is a green, environmentally friendly, low-energy six-membered oxygen heterocyclic lactone preparation process that can be applied to industrial mass production. When glycolic acid or glycolic acid derivatives are used as raw materials to prepare six-membered oxygen heterocyclic lactones, no catalyst is used, and the reaction system is pure and easy to operate.

[0089] The synthetic route of the six-membered oxygen heterocyclic lactone of the present invention is as follows:

[0090] One-step synthesis route:

[0091]

[0092] Two-step synthesis route:

[0093] It should be noted that I in the above formula corresponds to the intermediate product. The present invention can choose to add a catalyst or not according to the type of the first monomer. When the first monomer is glycolic acid ester or glycolic acid ester derivative, the first catalyst needs to be added. When the first monomer is glycolic acid or glycolic acid derivative, the catalyst can be added or not.

[0094] According to some preferred embodiments, when the first monomer is glycolate or a glycolate derivative, the one-step method includes the following steps: subjecting the first monomer and the epoxy compound to a first reaction under the action of a first catalyst, and obtaining a six-membered oxygen heterocyclic lactone by reduced pressure distillation; the entire process does not require any organic solvent.

[0095] When the first monomer is glycolate or a glycolate derivative, the two-step method includes the following steps: subjecting the first monomer and the epoxy compound to a second reaction under the action of a first catalyst, separating and purifying to obtain an intermediate product, and heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone; the entire process is carried out in an air atmosphere without the need for any organic solvent.

[0096] When the first monomer is glycolic acid or a glycolic acid derivative, the one-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a first reaction without a catalyst or with a first catalyst, and subjecting the first monomer to a first reaction by vacuum distillation to obtain a six-membered oxygen heterocyclic lactone.

[0097] When the first monomer is glycolic acid or a glycolic acid derivative, the two-step method comprises the following steps: subjecting a mixture of the first monomer and the epoxy compound to a second reaction without a catalyst or under the action of the first catalyst, dissolving, filtering, washing and distilling the reaction mixture to obtain a crude product, separating and purifying the crude product to obtain an intermediate product; heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone;

[0098] When the first monomer is glycolic acid or a glycolic acid derivative, the two-step method comprises the following steps: mixing the first monomer, a solvent and an epoxy compound, and performing a second reaction without a catalyst or under the action of the first catalyst, concentrating, filtering, washing and distilling the reaction mixture to obtain a crude product, separating and purifying the crude product to obtain an intermediate product; heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone. It should be noted that the process of dissolving glycolic acid or a glycolic acid derivative as a raw material in a solvent can be heated, and the heating temperature is 0 to 100°C, preferably 25 to 65°C.

[0099] According to some preferred embodiments, the glycolic acid derivative is one or more of 2-hydroxypropionic acid, 2-hydroxypropionic acid, 2-hydroxybutyric acid, 2-hydroxyvaleric acid, 2-hydroxyhexanoic acid, sodium glycolate, potassium glycolate, lactic acid, and mandelic acid;

[0100] The glycolate derivative is one or more of methyl glycolate, ethyl glycolate, tert-butyl glycolate, benzyl glycolate, methyl lactate, ethyl lactate, tert-butyl lactate, and benzyl lactate; and / or

[0101] The epoxy compound is selected from one or more of the following structures.

[0102]

[0103] According to some preferred embodiments, the molar ratio of the first monomer to the epoxy compound is 30 / 1 to 1 / 10.

[0104] According to some preferred embodiments, the molar ratio of the first catalyst to the first monomer is 1 / 100000 to 1 / 2.

[0105] It should be noted that when a catalyst is used, the molar ratio of the glycolate derivative or glycolic acid derivative to the epoxy compound is 10 / 1 to 0.1 / 1, preferably 8 / 1 to 0.8 / 1.

[0106] According to some preferred embodiments, the temperature of the first reaction is -10 to 200°C.

[0107] According to some preferred embodiments, the temperature of the second reaction is -20 to 220°C, preferably 65 to 140°C.

[0108] According to some preferred embodiments, the temperature of the heated reduced pressure distillation is 0 to 250°C.

[0109] It should be noted that in the above-mentioned method for preparing six-membered oxygen heterocyclic lactone, when the first monomer is glycolic acid ester or glycolic acid ester derivative, the reaction temperature is -50 to 200°C, preferably room temperature; when the first monomer is glycolic acid or glycolic acid derivative, the reaction temperature is -50 to 220°C, preferably 65 to 140°C.

[0110] According to some preferred embodiments, the first catalyst is selected from one or more of an inorganic acid catalyst, an organic acid catalyst, an inorganic base catalyst, an organic base catalyst, a metal chloride catalyst, a metal oxide catalyst, a metal salt catalyst, and an ionic liquid catalyst;

[0111] Preferably, the inorganic acid catalyst is selected from one or more of sulfuric acid, hydrochloric acid, hydrobromic acid, tungstic acid, titanic acid, boric acid, acidic zirconium sulfate, and aluminosilicate;

[0112] The organic acid catalyst is selected from one or more of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, boron trifluoride, tri(pentafluorophenyl)boron, triethylboron, camphorsulfonic acid, benzoic acid, salicylic acid, oxalic acid, malic acid, and ion exchange resin;

[0113] The inorganic base catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, lithium hydroxide, magnesium hydroxide, zinc hydroxide, copper hydroxide, iron hydroxide, and ammonium hydroxide;

[0114] The organic base catalyst is selected from one or more of triethylamine, pyridine, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and hexamethyldisilazane;

[0115] The metal chloride catalyst is selected from one or more of ferric chloride, ferric chloride, zinc chloride, tin chloride, magnesium chloride, titanium chloride, aluminum chloride, indium chloride, and Schiff alkali metal complex catalysts;

[0116] The metal oxide catalyst is selected from one or more of iron oxide, ferroferric oxide, copper oxide, magnesium oxide, zinc oxide, aluminum oxide, calcium oxide, and titanium oxide; the metal salt catalyst is selected from one or more of copper tetrafluoroborate, bismuth trifluoride, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, cesium carbonate, sodium glycolate, sodium acetate, lithium diisopropylamide, sodium methoxide, sodium tert-butoxide, potassium tert-butoxide, n-butyl lithium, and isobutyl lithium; and / or

[0117] The ionic liquid catalyst is selected from one or more of imidazole ionic liquids, pyridine ionic liquids, quaternary ammonium salt ionic liquids, and quaternary phosphonium salt ionic liquids.

[0118] The present invention provides a degradable polyether ester in a third aspect, wherein the degradable polyether ester has the following structure:

[0119]

[0120] wherein R' is hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0121] R 1 , R2 , R 3 , R 4 R is independently selected from hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, fused aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imino, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphino, phosphoryl, silicon, nitro, cyano, aldehyde, keto, carboxyl or azido; 1 , R 2 , R 3 , R 4 Two or more of them may be connected to form a ring, connected to form an aromatic group or a C3-C8 heterocyclic group which may be optionally substituted;

[0122] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, cyano, propenyl, ether, and aromatic groups;

[0123] The heteroatom in the heterocyclic group is selected from oxygen, sulfur, nitrogen, boron and silicon.

[0124] It should be noted that the raw materials for preparing the degradable polyether ester (having the structure of Formula III) provided by the present invention include the six-membered oxygen heterocyclic lactone (having the structure of Formula II) described in the first aspect.

[0125] The degradable polyether ester provided by the present invention can be degraded or depolymerized under the action of a catalyst to obtain the six-membered oxadiazole lactone as its preparation monomer, and the six-membered oxadiazole lactone obtained by degradation can be polymerized by ring-opening to obtain the degradable polyether ester again, and closed-loop recycling can be achieved. The degradable polyether ester provided by the present invention is expected to reduce the cost of degradable polyether ester, expand its application scenarios, and accelerate the commercialization process of new degradable and recyclable polyether esters.

[0126] According to some preferred embodiments, R' is a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, vinyl, allyl, ethynyl, propynyl, phenyl, tolyl, methoxy, ethoxy, amide, methyl, ethyl, nitro, cyano, trifluoromethyl or pentafluoroethyl;

[0127] R 1 , R 2 , R 3 , R 4each independently selected from a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, allyl, ethynyl, propynyl, phenyl, tolyl, naphthyl, conjugated alkenyl, conjugated alkynyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, methoxy, ethoxy, acyloxy, peroxy, amino, amide, thiol, thioether, imino, hydrazone, azo, phosphino, phosphoryl, trimethylsilyl, methyl, ethyl, vinyl, fluorine, chlorine, bromine, iodine, hydroxyl, aldehyde, keto, carboxyl, nitro, cyano, trifluoromethyl, pentafluoroethyl, azido, sulfonic acid, sulfinic acid, sulfone or sulfoxide group;

[0128] R 2 and R 3 The ring may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclopentynyl, cyclohexenyl, cyclohexynyl, cycloheptenyl, cycloheptynyl, phenyl which may be optionally substituted;

[0129] The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, propenyl, ether, and phenyl.

[0130] The present invention provides in a fourth aspect a method for preparing the degradable polyether ester according to the third aspect, the preparation method comprising:

[0131] The six-membered oxygen heterocyclic lactone is subjected to solvent ring-opening polymerization or bulk ring-opening polymerization and purification treatment to obtain a degradable polyether ester;

[0132] It should be noted that the six-membered oxadiazole lactone used in the preparation process of the above-mentioned degradable polyether ester is the six-membered oxadiazole lactone (having the structure of Formula II) in the first aspect above.

[0133] The invention uses six-membered oxygen heterocyclic lactones with different structures prepared from low-cost bulk chemicals such as glycolic acid esters, glycolic acid ester derivatives, glycolic acid or glycolic acid derivatives and epoxy compounds as main raw materials as main raw materials, and under the action of a catalyst, can realize the preparation of degradable polyether esters with different structures, high molecular weight and excellent performance under mild conditions, effectively overcomes the problem of lack of diversity and functionality of polyether esters due to the single structure of polyether ester monomers in the prior art, can realize the economical and efficient synthesis of polyether esters with different structures, can significantly reduce the production cost of polyether esters, improve production efficiency, make the industrial production of polyether esters with different structures and properties possible, and broaden their application range.

[0134] The preparation reaction formula of degradable polyether ester is as follows:

[0135]

[0136] It should be noted that in the process of preparing the degradable polyether ester by solvent ring-opening polymerization or bulk ring-opening polymerization, a quencher needs to be added to terminate the reaction, and the mixture after the reaction is purified by washing with methanol.

[0137] According to some preferred embodiments, the solvent ring-opening polymerization is to mix the six-membered oxalolactone with an organic solvent, and perform ring-opening polymerization under the action of an initiator and a second catalyst.

[0138] Specifically, the preparation of degradable polyether ester by solution ring-opening polymerization includes the following steps: dissolving an initiator and a second catalyst in an organic solvent, stirring at a certain temperature for a period of time, then adding a six-membered oxygen heterocyclic lactone, reacting at a predetermined temperature for a period of time, adding a quencher to terminate the reaction, and washing the reaction mixture with methanol to obtain a degradable polyether ester.

[0139] According to some preferred embodiments, the solvent ring-opening polymerization is the ring-opening polymerization of the six-membered oxalocyanate lactone under the action of an initiator and a second catalyst.

[0140] Specifically, the preparation of degradable polyether ester by bulk ring-opening polymerization includes the following steps: adding an initiator and a catalyst to a six-membered oxygen heterocyclic lactone compound, reacting at a predetermined temperature for a period of time, adding a quencher to terminate the reaction, and washing the reaction mixture with methanol to obtain a degradable polyether ester.

[0141] According to some preferred embodiments, the temperature of the ring-opening polymerization is -60°C to 200°C; when bulk ring-opening polymerization is adopted, the temperature of the ring-opening polymerization is -20°C to 200°C; when solution ring-opening polymerization is adopted, the temperature of the ring-opening polymerization is -60°C to 200°C.

[0142] According to some preferred embodiments, the second catalyst is selected from stannous octoate (SnOct2), diethyl zinc (DEZ), zinc chloride (ZC), dibutyltin oxide (DBTO), dioctyltin oxide (DOTO), trimethylaluminum (TMA), triethylaluminum (TEA), tetrabutyl titanate (TBT), a metal complex containing a Schiff base ligand, diphenyl phosphate (DPP), 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), 4-dimethylaminopyridine (DMAP), 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) One or more;

[0143] The initiator is selected from one or more of methanol, ethanol, isopropanol, n-butanol, tert-butanol, benzyl alcohol, tert-butyl alcohol, ethylene glycol, glycerol, benzyl alcohol, pentaerythritol, preferably benzyl alcohol; and / or

[0144] The organic solvent is selected from one or more of dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, benzene and toluene.

[0145] The fifth aspect of the present invention provides a method for degrading the degradable polyether ester described in the third aspect, the degradation method comprising: subjecting the degradable polyether ester to a degradation reaction under the action of a third catalyst, heating and distilling under reduced pressure to obtain a six-membered oxygen heterocyclic lactone.

[0146] The degradable polyether ester (having a structure of formula III) provided by the present invention can achieve closed-loop recovery through catalytic degradation, and its specific degradation method comprises the following steps: adding polyether ester and a catalyst to a reaction device, performing a degradation reaction at a predetermined temperature, and after the reaction is completed, performing reduced pressure distillation on the mixed heat after the reaction, and further purifying by washing, recrystallization or secondary distillation after vacuum distillation according to demand to obtain a six-membered oxygen heterocyclic lactone (having a structure of formula II), and the six-membered oxygen heterocyclic lactone (having a structure of formula II) obtained after degradation can be subjected to ring-opening polymerization again to prepare a polyether ester (having a structure of formula III) having the same structure and molecular weight as before degradation, and realizing the entire closed-loop recovery. The process is shown in the following formula.

[0147]

[0148] According to some preferred embodiments, the third catalyst is selected from one or more of stannous octoate, zinc chloride, zinc oxide, sodium glycolate, and tin chloride; and / or

[0149] The temperature of the degradation reaction is 0-300°C.

[0150] In order to more clearly illustrate the technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the examples. The present invention does not specifically limit the sources of the reagents used in the examples and comparative examples, and the reagents can be directly purchased or synthesized by themselves.

[0151] Preparation of six-membered oxygen heterocyclic lactone:

[0152] Example 1

[0153] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0154] At room temperature, add 168 mL of methyl glycolate to a 500 mL flask with a magnet, then add 50 mL of styrene oxide, keep stirring, add 0.6 mL of concentrated sulfuric acid to the mixed solution, react at room temperature for 1 hour, wait for the solution temperature to drop to room temperature naturally, add saturated sodium bicarbonate aqueous solution until the pH value is neutral, distill off the excess methyl glycolate at 70°C under reduced pressure, distill off the crude product at 140°C under reduced pressure, add 100 mL of dichloromethane to dissolve, and wash with saturated sodium bicarbonate aqueous solution 3 times, each time with 100 mL of saturated sodium bicarbonate aqueous solution, wash with saturated brine 2 times, each time with 50 mL of saturated brine. Take the organic phase, add anhydrous magnesium sulfate and stir, filter out the insoluble matter, remove dichloromethane by rotary evaporation, dissolve the obtained product in 60 mL of tetrahydrofuran, and recrystallize at a volume ratio of n-hexane and tetrahydrofuran of 10:1, and finally recrystallize twice with anhydrous solvent to obtain 45 g of colorless crystals. The nuclear magnetic spectrum of the colorless crystals is as follows Figure 1 As shown, the obtained colorless crystals are known to be six-membered heterocyclic lactones with a benzene ring as the side group.

[0155] Example 2

[0156] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0157] At room temperature, add 168 mL of methyl glycolate to a 500 mL flask with a magnetic son, then add 40 mL of phenyl glycidyl ether, keep stirring, add 435 mg of sodium hydroxide to the mixed solution, and react at room temperature for 2 hours. Add dilute hydrochloric acid to a pH value of 6-7, distill off the excess methyl glycolate at 70 ° C, distill off the crude product at 140 ° C, add 100 mL of dichloromethane to dissolve, wash with saturated sodium bicarbonate aqueous solution 3 times, each time with 100 mL of saturated sodium bicarbonate aqueous solution, wash with saturated brine 2 times, each time with 50 mL of saturated brine. Take the organic phase, add anhydrous magnesium sulfate and stir, filter out the insoluble matter, remove dichloromethane by rotary evaporation, dissolve the obtained product in 56 mL of tetrahydrofuran, and recrystallize it according to the volume ratio of n-hexane and tetrahydrofuran of 10:1, and finally recrystallize it twice with anhydrous solvent to obtain 36 g of colorless crystals.

[0158] Example 3

[0159] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0160] Add 63g glycolic acid to a 500mL flask containing 165mL tetrahydrofuran, heat to dissolve at 50℃, and then add 19mL styrene oxide to react for 10h. After the reaction is completed, distill tetrahydrofuran to obtain an oily liquid, add dichloromethane to wash, filter out insoluble matter, adjust the pH value of the filtrate to neutral with saturated sodium bicarbonate solution, and wash twice with saturated brine, each time with 50mL saturated brine. Add anhydrous magnesium sulfate and stir, filter out insoluble matter, and distill out dichloromethane to obtain an oily liquid. Distill out some impurities under reduced pressure at 120℃, distill out the crude product under reduced pressure at 140℃, and then separate and purify by column chromatography (the volume ratio of petroleum ether to ethyl acetate is 8:1), and finally recrystallize twice with an anhydrous solvent (the volume ratio of n-hexane to tetrahydrofuran is 10:1), and the final product is 8g colorless crystals.

[0161] Example 4

[0162] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0163] Add 60g glycolic acid to a 300mL flask, heat to a molten state at 75℃, then add 30mL styrene oxide and stir for 6 hours. After the reaction is completed, let it cool naturally to room temperature, add dichloromethane to wash, and then filter. Use saturated sodium bicarbonate solution to adjust the pH value of the filtrate to neutral, wash with saturated brine twice, each time with 100mL saturated brine, add anhydrous magnesium sulfate and stir, filter out insoluble matter, and evaporate to remove dichloromethane to obtain an oily liquid. The crude product is distilled out under reduced pressure at 140℃, and then separated and purified by column chromatography (the volume ratio of petroleum ether to ethyl acetate is 8:1), and finally recrystallized twice using an anhydrous solvent (the volume ratio of n-hexane to tetrahydrofuran is 10:1), and the final product is 11g of colorless crystals.

[0164] Example 5

[0165] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0166] Add 17 g of glycolic acid and 30 mL of styrene oxide to a 100 mL flask, heat at 85 ° C for 6 hours, then heat at 140 ° C for two hours, cool naturally to room temperature, add ether to wash, then filter, wash with saturated sodium bicarbonate solution and saturated brine, add anhydrous magnesium sulfate and stir, filter out insoluble matter, evaporate and remove the solvent to obtain an oily liquid, distill off the crude product under reduced pressure at 155 ° C, then recrystallize twice using an anhydrous solvent (the volume ratio of n-hexane to tetrahydrofuran is 10:1), and recrystallize once with anhydrous ether at -20 ° C. The final product is 13 g of colorless crystals.

[0167] Example 6

[0168] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0169] Add 176 mL of methyl glycolate to a 500 mL flask with a magnet at room temperature, then add 50 mL of propylene oxide and keep stirring. Add 2.3 g of ferric chloride to the mixed solution, react at room temperature for 2 hours, distill off the excess methyl glycolate under reduced pressure at 55°C, distill off the crude product under reduced pressure at 90°C, add 300 mL of dichloromethane to dissolve, wash with saturated sodium bicarbonate aqueous solution 3 times, each time with 200 mL of saturated sodium bicarbonate aqueous solution, and use saturated brine 2 times, each time with 50 mL of saturated brine. Take the organic phase, add anhydrous magnesium sulfate and stir, filter out the insoluble matter, remove dichloromethane by rotary evaporation, and distill the resulting product under reduced pressure at 65°C to obtain 35 g of colorless liquid. The NMR spectrum of the colorless liquid is shown as follows Figure 2-3 As shown, it can be seen that the obtained colorless liquid is a mixture of two six-membered heterocyclic lactones with methyl side groups.

[0170] Example 7

[0171] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0172] At room temperature, add 187 mL of methyl glycolate to a 500 mL flask with a magnet, then add 40 mL of methyl propylene oxide, keep stirring, add 1.5 g of ferric chloride to the mixed solution, react at room temperature for 2 hours, first distill off the excess methyl glycolate under reduced pressure at 55 °C, then distill off the crude product under reduced pressure at 110 °C, add 300 mL of dichloromethane to dissolve, wash with saturated sodium bicarbonate aqueous solution 3 times, each time with 200 mL of saturated sodium bicarbonate aqueous solution, wash with saturated brine 2 times, each time with 50 mL of saturated brine. Take the organic phase, add anhydrous magnesium sulfate and stir, filter out the insoluble matter, remove dichloromethane by rotary evaporation, and distill the resulting product under reduced pressure at 85 °C to obtain 26 g of colorless liquid. The NMR spectrum of the colorless liquid is as follows Figure 4 As shown, it can be seen that the obtained colorless liquid is a six-membered heterocyclic lactone with a geminal dimethyl side group.

[0173] Example 8

[0174] A method for preparing a six-membered oxygen heterocyclic lactone, comprising:

[0175] At room temperature, add 153 mL of methyl glycolate to a 500 mL flask with a magnet, then add 40 mL of cyclohexene oxide, keep stirring, add 1.2 g of ferric chloride to the mixed solution, react at room temperature for 2 hours, first distill off the excess methyl glycolate under reduced pressure at 55°C, then distill off the crude product under reduced pressure at 110°C, add 300 mL of dichloromethane to dissolve, wash with saturated sodium bicarbonate aqueous solution 3 times, each time with 200 mL of saturated sodium bicarbonate aqueous solution, wash with saturated brine 2 times, each time with 50 mL of saturated brine. Take the organic phase, add anhydrous magnesium sulfate and stir, filter out the insoluble matter, remove dichloromethane by rotary evaporation, and distill the resulting product under reduced pressure at 100°C to obtain 35 g of colorless liquid. The NMR spectrum of the colorless liquid is as follows Figure 5 As shown, it can be seen that the obtained colorless liquid is a six-membered heterocyclic lactone with a cyclohexyl side group.

[0176] Preparation of biodegradable polyether ester:

[0177] Example 9

[0178] A method for preparing a degradable polyether ester, comprising:

[0179] In a glove box, benzyl alcohol (6.1 mg, 0.056 mmol) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (7.8 mg, 0.056 mmol) were added to a Schlenk tube filled with 2.8 mL of tetrahydrofuran, and then 1 g of the six-membered oxygen heterocyclic lactone in Example 1 was added, and the mixture was reacted at -40°C for 2 hours under nitrogen protection, and then two drops of acetic acid were added to terminate the reaction, and the mixture was dripped into 100 mL of ice methanol, and the precipitate was separated by centrifugation to obtain a degradable polyether ester. The number average molecular weight measured by gel permeation chromatography (GPC) was 9.5 kg·mol -1 , the molecular weight distribution is 1.68.

[0180] Example 10

[0181] A method for preparing a degradable polyether ester, comprising:

[0182] In a glove box, benzyl alcohol (6.1 mg, 0.056 mmol) and a complex of N,N'-1,3-bis(3,5-di-tert-butyl salicylidene)propylenediamine and trimethylaluminum (Schiff base ligand metal complex) (30.6 mg, 0.056 mmol) were added to a Schlenk tube containing 2.8 mL of tetrahydrofuran, and then 1 g of the six-membered oxygen heterocyclic lactone in Example 1 was added. The reaction was carried out at -40°C for 5 hours under nitrogen protection, and then two drops of acetic acid were added to terminate the reaction. The mixture was dropped into 100 mL of ice methanol, and the precipitate was separated by centrifugation to obtain a degradable polyether ester, whose nuclear magnetic resonance spectrum is shown as follows. Figure 6 As shown, it can be seen that the Figure 6 The number average molecular weight measured by GPC is 12.0 kg·mol -1 , the molecular weight distribution is 1.08.

[0183] Embodiment 11

[0184] A method for preparing a degradable polyether ester, comprising:

[0185] In a glove box, benzyl alcohol (1.2 mg, 0.011 mmol) and a complex of N,N'-1,3-bis(3,5-di-tert-butyl salicylidene)propylenediamine and trimethylaluminum (Schiff base ligand metal complex) (6.1 mg, 0.011 mmol) were added to a Schlenk tube containing 2.8 mL of tetrahydrofuran, and then 1 g of the six-membered oxygen heterocyclic lactone in Example 1 was added. The mixture was reacted at -40°C for 5 hours under nitrogen protection, and then two drops of acetic acid were added to terminate the reaction. The mixture was dripped into 100 mL of ice methanol, and the precipitate was separated by centrifugation to obtain a degradable polyether ester. The number average molecular weight measured by GPC was 54.0 kg·mol -1 , the molecular weight distribution is 1.05.

[0186] Example 12

[0187] A method for preparing a degradable polyether ester, comprising:

[0188] In a glove box, benzyl alcohol (6.1 mg, 0.056 mmol) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (7.8 mg, 0.056 mmol) were added to a Schlenk tube containing 0.87 mL of tetrahydrofuran and stirred at -40°C for 5 minutes. Then, 650 mg of the six-membered oxadiazole lactone in Example 6 was injected into the Schlenk tube using a syringe. After reacting at -40°C for 7 hours under nitrogen protection, two drops of acetic acid were added to terminate the reaction. The mixture was dropped into 100 mL of ice methanol and centrifuged to separate the precipitate to obtain a degradable polyether ester, whose nuclear magnetic resonance spectrum is shown in FIG. Figure 7 As shown, it can be seen that the Figure 7 The number average molecular weight measured by GPC is 9.3 kg·mol -1 , the molecular weight distribution is 1.24.

[0189] Embodiment 13

[0190] A method for preparing a degradable polyether ester, comprising:

[0191] In a glove box, benzyl alcohol (6.1 mg, 0.056 mmol) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (7.8 mg, 0.056 mmol) were added to a Schlenk tube containing 2 mL of tetrahydrofuran and stirred at -40°C for 5 minutes. Then, 1 g of the six-membered oxygen heterocyclic lactone in Example 1 was dissolved in 0.8 mL of tetrahydrofuran and injected into the Schlenk tube using a syringe. Under nitrogen protection, the mixture was reacted at -40°C for 2 hours. Then, two drops of acetic acid were added to terminate the reaction. The mixture was dripped into 100 mL of ice methanol and centrifuged to separate the precipitate to obtain a degradable polyether ester. The number average molecular weight measured by GPC was 8.6 kg·mol -1 , the molecular weight distribution is 1.65.

[0192] Degradation method of degradable polyether ester:

[0193] Embodiment 14

[0194] A method for degrading a degradable polyether ester, comprising:

[0195] 1 g of the degradable polyether ester obtained in Example 10 and stannous octoate (113.7 mg, 0.281 mmol) were added to a dry bottle, and the reaction was stirred at 140° C. for 3 hours, and then distilled under reduced pressure at 140° C. to obtain a crude product, which was recrystallized twice using an anhydrous solvent (the volume of n-hexane and tetrahydrofuran was 10:1). The final product was 0.7 g of colorless crystals, which were identified by nuclear magnetic resonance as a six-membered oxygen heterocyclic lactone for preparing the degradable polyether ester.

[0196] Embodiment 15

[0197] A method for degrading a degradable polyether ester, comprising:

[0198] 1 g of the degradable polyether ester obtained in Example 10 and zinc chloride (38 mg, 0.281 mmol) were added to a dry bottle, and the reaction was stirred at 140° C. for 2 hours, and then the crude product was distilled under reduced pressure at 140° C., and recrystallized twice using an anhydrous solvent (the volume of n-hexane and tetrahydrofuran was 10:1). The final product was 0.6 g of colorless crystals, which were identified by nuclear magnetic resonance as a six-membered oxygen heterocyclic lactone for preparing the degradable polyether ester.

[0199] Example 16

[0200] A method for degrading a degradable polyether ester, comprising:

[0201] 1 g of the degradable polyether ester obtained in Example 10 and stannous octoate (74.1 mg, 0.183 mmol) were added to a dry bottle, stirred at 150°C for 2 hours, and then distilled under reduced pressure to obtain a crude product. 10 mL of dichloromethane was added to dissolve, and washed with saturated brine for 3 times, each time with 10 mL of saturated brine, then dried with anhydrous magnesium sulfate, rotary evaporated, and finally distilled under reduced pressure at 55°C to obtain a final product of 0.57 g of a colorless liquid, which was identified by nuclear magnetic resonance as a six-membered oxygen heterocyclic lactone for preparing the degradable polyether ester.

[0202] The above is only a preferred embodiment of the present invention. It should be pointed out that although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that several improvements and modifications may be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention and do not deviate from the scope defined by the claims of the present invention.

[0203] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A six-membered oxygen heterocyclic lactone, characterized in that The six-membered oxygen heterocyclic lactone has the following structure: wherein R' is hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, nitro, cyano, trifluoromethyl or pentafluoroethyl; R 1 , R 2 , R 3 , R 4 R is independently selected from hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, fused aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imino, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphino, phosphoryl, silicon, nitro, cyano, aldehyde, keto, carboxyl or azido; 1 , R 2 , R 3 , R 4 Two or more of them may be connected to form a ring, connected to form an aromatic group or a C3-C8 heterocyclic group which may be optionally substituted; The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, cyano, propenyl, ether, and aromatic groups; The heteroatom in the heterocyclic group is selected from oxygen, sulfur, nitrogen, boron and silicon.

2. The six-membered oxygen heterocyclic lactone according to claim 1, characterized in that R' is a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, vinyl, allyl, ethynyl, propynyl, phenyl, tolyl, methoxy, ethoxy, amide, methyl, ethyl, nitro, cyano, trifluoromethyl or pentafluoroethyl; R 1 , R 2 , R 3 , R 4 each independently selected from a substituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, allyl, ethynyl, propynyl, phenyl, tolyl, naphthyl, conjugated alkenyl, conjugated alkynyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, methoxy, ethoxy, acyloxy, peroxy, amino, amide, thiol, thioether, imino, hydrazone, azo, phosphino, phosphoryl, trimethylsilyl, methyl, ethyl, vinyl, fluorine, chlorine, bromine, iodine, hydroxyl, aldehyde, keto, carboxyl, nitro, cyano, trifluoromethyl, pentafluoroethyl, azido, sulfonic acid, sulfinic acid, sulfone or sulfoxide group; R 2 and R 3 The ring may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclopentynyl, cyclohexenyl, cyclohexynyl, cycloheptenyl, cycloheptynyl, phenyl which may be optionally substituted; The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, propenyl, ether, and phenyl.

3. A method for preparing a six-membered oxygen heterocyclic lactone according to claim 1 or 2, characterized in that: The preparation method comprises: using a first monomer and an epoxy compound as reactants to obtain a six-membered oxacyclic lactone through a one-step method or a two-step method; the first monomer is one or more of glycolic acid, glycolic acid derivatives, glycolic acid esters, and glycolic acid ester derivatives.

4. The preparation method according to claim 3, characterized in that: When the first monomer is glycolate or a glycolate derivative, the one-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a first reaction under the action of a first catalyst, and subjecting the first monomer to a first reaction ... When the first monomer is glycolate or a glycolate derivative, the two-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a second reaction under the action of a first catalyst, separating and purifying to obtain an intermediate product, and heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone; When the first monomer is glycolic acid or a glycolic acid derivative, the one-step method comprises the following steps: subjecting the first monomer and the epoxy compound to a first reaction without a catalyst or under the action of a first catalyst, and subjecting the first monomer to a first reaction by vacuum distillation to obtain a six-membered oxygen heterocyclic lactone; When the first monomer is glycolic acid or a glycolic acid derivative, the two-step method comprises the following steps: subjecting a mixture of the first monomer and the epoxy compound to a second reaction without a catalyst or under the action of the first catalyst, dissolving, filtering, washing and distilling the reaction mixture to obtain a crude product, separating and purifying the crude product to obtain an intermediate product; heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone; When the first monomer is glycolic acid or a glycolic acid derivative, the two-step method comprises the following steps: mixing the first monomer, a solvent and an epoxy compound, and carrying out a second reaction without a catalyst or under the action of the first catalyst, concentrating, filtering, washing and distilling the mixture after the reaction to obtain a crude product, separating and purifying the crude product to obtain an intermediate product; heating and distilling the intermediate product under reduced pressure to obtain a six-membered oxygen heterocyclic lactone.

5. The preparation method according to claim 3 or 4, characterized in that: The glycolic acid derivative is one or more of 2-hydroxypropionic acid, 2-hydroxypropionic acid, 2-hydroxybutyric acid, 2-hydroxyvaleric acid, 2-hydroxycaproic acid, sodium glycolate, potassium glycolate, lactic acid, and mandelic acid; The glycolate derivative is one or more of methyl glycolate, ethyl glycolate, tert-butyl glycolate, benzyl glycolate, methyl lactate, ethyl lactate, tert-butyl lactate, and benzyl lactate; and / or The epoxy compound is selected from one or more of the following structures.

6. The preparation method according to claim 4, characterized in that: The molar ratio of the first monomer to the epoxy compound is 30 / 1 to 1 / 10; The molar ratio of the first catalyst to the first monomer is 1 / 100000 to 1 / 2; The temperature of the first reaction is -10 to 200°C; The temperature of the second reaction is -20 to 220°C, preferably 65 to 140°C; and / or The temperature of the heating and reduced pressure distillation is 0-250°C.

7. The preparation method according to claim 4, characterized in that: The first catalyst is selected from one or more of an inorganic acid catalyst, an organic acid catalyst, an inorganic base catalyst, an organic base catalyst, a metal chloride catalyst, a metal oxide catalyst, a metal salt catalyst, and an ionic liquid catalyst; Preferably, the inorganic acid catalyst is selected from one or more of sulfuric acid, hydrochloric acid, hydrobromic acid, tungstic acid, titanic acid, boric acid, acidic zirconium sulfate, and aluminosilicate; The organic acid catalyst is selected from one or more of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, boron trifluoride, tri(pentafluorophenyl)boron, triethylboron, camphorsulfonic acid, benzoic acid, salicylic acid, oxalic acid, malic acid, and ion exchange resin; The inorganic base catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, lithium hydroxide, magnesium hydroxide, zinc hydroxide, copper hydroxide, iron hydroxide, and ammonium hydroxide; The organic base catalyst is selected from one or more of triethylamine, pyridine, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and hexamethyldisilazane; The metal chloride catalyst is selected from one or more of ferric chloride, ferric chloride, zinc chloride, tin chloride, magnesium chloride, titanium chloride, aluminum chloride, indium chloride, and Schiff alkali metal complex catalysts; The metal oxide catalyst is selected from one or more of iron oxide, ferroferric oxide, copper oxide, magnesium oxide, zinc oxide, aluminum oxide, calcium oxide, and titanium oxide; the metal salt catalyst is selected from one or more of copper tetrafluoroborate, bismuth trifluoride, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, cesium carbonate, sodium glycolate, sodium acetate, lithium diisopropylamide, sodium methoxide, sodium tert-butoxide, potassium tert-butoxide, n-butyl lithium, and isobutyl lithium; and / or The ionic liquid catalyst is selected from one or more of imidazole ionic liquids, pyridine ionic liquids, quaternary ammonium salt ionic liquids, and quaternary phosphonium salt ionic liquids.

8. A degradable polyether ester, characterized in that: The degradable polyether ester has the following structure: wherein R' is hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, condensed aromatic, C3-C8 heterocyclic, amide, nitro, cyano, trifluoromethyl or pentafluoroethyl; R 1 , R 2 , R 3 , R 4 R is independently selected from hydrogen, halogen, hydroxyl, optionally substituted straight or branched C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkenyl, C1-C8 alkynyl, optionally substituted aromatic, fused aromatic, C3-C8 heterocyclic, amide, amino, thiol, thioether, acyloxy, peroxy, imino, hydrazone, azo, sulfonic acid, sulfinic acid, sulfone, sulfoxide, phosphino, phosphoryl, silicon, nitro, cyano, aldehyde, keto, carboxyl or azido; 1 , R 2 , R 3 , R 4 Two or more of them may be connected to form a ring, connected to form an aromatic group or a C3-C8 heterocyclic group which may be optionally substituted; The substituted substituent is selected from halogen, C1-10 alkyl, halogenated C1-10 alkyl, C1-10 alkoxy, hydroxyl, cyano, propenyl, ether, and aromatic groups; The heteroatom in the heterocyclic group is selected from oxygen, sulfur, nitrogen, boron and silicon.

9. A method for preparing the degradable polyether ester according to claim 8, characterized in that: The preparation method comprises: The six-membered oxygen heterocyclic lactone is subjected to solvent ring-opening polymerization or bulk ring-opening polymerization and purification treatment to obtain a degradable polyether ester.

10. The preparation method according to claim 9, characterized in that: The solvent ring-opening polymerization is to mix the six-membered oxalolactone with an organic solvent and perform ring-opening polymerization under the action of an initiator and a second catalyst; and / or The solvent ring-opening polymerization is the ring-opening polymerization of the six-membered oxygen heterocyclic lactone under the action of an initiator and a second catalyst.

11. The preparation method according to claim 10, characterized in that: The temperature of the ring-opening polymerization is -60°C to 200°C.

12. The preparation method according to claim 10, characterized in that: The second catalyst is selected from one or more of stannous octoate, diethyl zinc, zinc chloride, dibutyl tin oxide, dioctyl tin oxide, trimethyl aluminum, triethyl aluminum, tetrabutyl titanate, a metal complex containing a Schiff base ligand, diphenyl phosphate, 1,8-diazabicyclo[5.4.0]undec-7-ene, 4-dimethylaminopyridine, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene; The initiator is selected from one or more of methanol, ethanol, isopropanol, n-butanol, tert-butanol, benzyl alcohol, tert-butyl alcohol, ethylene glycol, glycerol, benzyl alcohol, pentaerythritol, preferably benzyl alcohol; and / or The organic solvent is selected from one or more of dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, benzene and toluene.

13. A method for degrading the degradable polyether ester according to claim 8, characterized in that: The degradation method comprises: subjecting the degradable polyether ester to a degradation reaction under the action of a third catalyst, heating and distilling under reduced pressure to obtain a six-membered oxygen heterocyclic lactone.

14. The degradation method according to claim 13, characterized in that: The third catalyst is selected from one or more of stannous octoate, zinc chloride, zinc oxide, sodium glycolate, and stannic chloride; and / or The temperature of the degradation reaction is 0-300°C.

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