A kind of synthetic method of ethyl 3-ethoxypropionate

Abstract

The invention provides a method for synthesizing ethyl 3-ethoxypropionate, and belongs to the technical field of chemical synthesis; the preparation process thereof comprises the following steps: preparation of carbon-encapsulated ferrosoferric oxide; preparation of magnetic hydrotalcite; preparation of a catalyst; and synthesis of ethyl 3-ethoxypropionate. The invention prepares a novel catalyst, which has a significant effect in the reaction of ethyl acrylate and ethanol, can improve the reaction rate and selectivity, shorten the reaction time, and improve the production efficiency; the catalyst has good magnetic properties, excellent stability, can be quickly separated from the reactant under the action of a magnetic field, and can continue to be used after recovery, is conducive to recycling and reuse, and can reduce production costs.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a method for synthesizing ethyl 3-ethoxypropionate. Background Art

[0002] Ethyl 3-ethoxypropionate, as a colorless liquid with a special aroma, has become an indispensable organic solvent and organic synthesis intermediate in the modern chemical industry due to its low toxicity to the human body and excellent solubility. Ethyl 3-ethoxypropionate has shown excellent solubility in coatings, inks, resins and various polymer systems, and can effectively replace traditional alcohol solvents, which not only broadens the application range of coating polymers, but also promotes the development of environmentally friendly materials.

[0003] In recent years, with the increasing global awareness of environmental protection and the demand for sustainable development, the demand for ethyl 3-ethoxypropionate has continued to grow. Its application in many industries such as pharmaceuticals, electronic chemicals, and agricultural chemicals is also becoming increasingly widespread, highlighting its important position as a high-performance solvent.

[0004] At present, the industrial production of ethyl 3-ethoxypropionate mainly adopts the base-catalyzed addition reaction of ethyl acrylate and ethanol. The commonly used catalysts are sodium ethoxide and strong alkaline anion exchange resin. The sodium ethoxide catalysis method is relatively economical, but it is necessary to destroy the sodium ethoxide after the reaction, which produces a lot of salt-containing wastewater; the anion exchange resin has poor high temperature resistance, and the reaction temperature must be controlled below 35°C. Therefore, the development of highly active and easily separable heterogeneous solid base catalysts is of great significance for the efficient and clean production of ethyl 3-ethoxypropionate.

[0005] Therefore, we proposed a method for synthesizing ethyl 3-ethoxypropionate using a highly active and easily separable catalyst. Summary of the invention

[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for synthesizing ethyl 3-ethoxypropionate.

[0007] A method for synthesizing ethyl 3-ethoxypropionate comprises the following steps:

[0008] S1: Preparation of carbon-coated FeO

[0009] Carbon-encapsulated ferroferric oxide was obtained by hydrothermal synthesis using glucose as the carbon source;

[0010] S2: Preparation of magnetic hydrotalcite

[0011] The magnetic hydrotalcite is prepared by adding carbon-coated ferrosoferric oxide to glycerol, water, calcium nitrate tetrahydrate, aluminum nitrate nonahydrate and urea.

[0012] S3: Preparation of catalyst

[0013] Potassium and sodium are loaded on magnetic hydrotalcite to obtain a catalyst;

[0014] S4: Synthesis of ethyl 3-ethoxypropionate

[0015] Ethyl 3-ethoxypropionate was synthesized by the reaction of anhydrous ethanol, catalyst and ethyl acrylate.

[0016] Further, step S1: preparation of carbon-coated ferroferric oxide specifically comprises the following steps:

[0017] S1.1: Add 40-50 parts by weight of ethylene glycol to 1-2 parts by weight of FeCl3·6H2O, stir magnetically for 20-30 minutes, then add 3-5 parts by weight of urea and 0.2-0.5 parts by weight of glucose, stir for 2-3 hours, and obtain a mixed solution;

[0018] S1.2: transferring the mixed solution to a reactor for reaction to obtain a reaction product, and filtering the reaction product to obtain a black solid;

[0019] S1.3: Wash the black solid with deionized water for 2-3 times, and then wash it with anhydrous ethanol for 3-5 times. Put the washed black solid into a 90-100°C oven and dry it for 20-24 hours to obtain carbon-encapsulated ferrosoferric oxide.

[0020] Furthermore, step S2: preparation of magnetic hydrotalcite specifically comprises the following steps:

[0021] S2.1: 30-35 parts by weight of deionized water and 6-10 parts by weight of glycerol are stirred and mixed to dissolve, and then 8-10 parts by weight of calcium nitrate tetrahydrate, 4-7 parts by weight of aluminum nitrate nonahydrate and 20-23 parts by weight of urea are added, and the mixture is stirred and mixed for 2-3 hours to obtain a mixture;

[0022] S2.2: Add 2-3 parts by weight of carbon-coated ferrosoferric oxide to the mixture, stir mechanically for 2-3 hours, put it into a hydrothermal reactor for reaction, and then cool it to room temperature to obtain a reactant;

[0023] S2.3: After extracting the reactants, a precipitate is obtained, and the precipitate is washed with deionized water for 3-5 times, and then washed with anhydrous ethanol for 2-3 times, and dried in an oven at 45-50° C. for 20-24 hours to obtain magnetic hydrotalcite.

[0024] Furthermore, step S3: preparation of the catalyst specifically comprises the following steps:

[0025] S3.1: Dissolve KNO3 in deionized water by ultrasonic to obtain solution I, and dissolve NaOH in deionized water to obtain solution II;

[0026] S3.2: Mix solution I and solution II to obtain a mixed solution, add 1-2 parts by weight of magnetic hydrotalcite to the mixed solution, disperse by ultrasonic for 2-3 hours, and then remove water by rotary evaporation at 70-100°C, and then dry in an oven at 80-100°C for 10-12 hours to obtain a dried solid;

[0027] S3.3: The dried solid is placed in a tubular furnace, nitrogen is introduced, and the catalyst is obtained by reaction.

[0028] Further, step S4: synthesis of ethyl 3-ethoxypropionate specifically comprises the following steps:

[0029] S4.1: 25-30 parts by weight of anhydrous ethanol and 1-2 parts by weight of a catalyst are added to a four-necked flask reactor equipped with a condenser, a thermometer and a mechanical stirrer, the reactor is heated, 10-12 parts by weight of ethyl acrylate is added dropwise at 45-70° C., the reaction is carried out for 3-5 hours, and the reactant is cooled to room temperature to obtain a reactant;

[0030] S4.2: Separate the catalyst from the reactants through an external magnetic field, recover the catalyst, and then distill the remaining reactants to remove excess ethanol and unreacted ethyl acrylate, ultimately obtaining ethyl 3-ethoxypropionate.

[0031] Furthermore, the reaction conditions in step S1.2 are specifically 200-210° C. for 10-12 h.

[0032] Furthermore, the reaction conditions in step S2.2 are specifically as follows: reacting at 120-125° C. for 10-12 hours, and then cooling to 70-75° C. for 4-5 hours.

[0033] Furthermore, in step S3.1, the weight ratio of KNO3 to deionized water is 0.4-0.5:50-60.

[0034] Furthermore, in step S3.1, the weight ratio of NaOH to deionized water is 0.2-0.3:20-30.

[0035] Furthermore, the reaction conditions in step S3.3 are specifically to increase the temperature to 500-600° C. at a rate of 3-4° C. / min and keep the temperature for 3-4 h.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] 1. The novel catalyst prepared by the present invention has a remarkable effect in the reaction of ethyl acrylate and ethanol, can improve the reaction rate and selectivity, shorten the reaction time, and improve the production efficiency. The catalyst has good magnetism and excellent stability, can be quickly separated from the reactants under the action of a magnetic field, and can be used again after recovery, which is conducive to recycling and reuse and can reduce production costs.

[0038] 2. The present invention uses magnetic hydrotalcite material as a carrier, and potassium and sodium can be loaded onto the surface of the hydrotalcite by an impregnation method. The synergistic modification of potassium and sodium increases the base content and base strength of the catalyst surface, and the active sites can be evenly dispersed on the carrier surface, thereby improving the catalytic performance, which can then promote the synthesis of ethyl 3-ethoxypropionate.

[0039] 3. The present invention can obtain carbon-coated ferroferric oxide after hydrothermal synthesis by adding glucose. After adding glucose, carbon coating can be achieved on the surface of ferroferric oxide, and the carbon layer has more pore structures, thereby increasing the specific surface area of ​​carbon-coated ferroferric oxide. After loading active components, the active components can be combined with functional groups on the carbon layer to cover the surface of the magnetic core. At the same time, the larger pore volume of the catalyst is conducive to the entry of reaction substrates, so that the mass transfer process can be better carried out. Therefore, carbon coating can not only protect the crystal structure of Fe3O4, avoid oxidation of magnetic particles Fe3O4 at high temperatures, and improve the high magnetism of the magnetic core, but also increase its specific surface area. The increase in specific surface area is conducive to the magnetic core loading more active components, which is conducive to improving the activity of the catalyst, thereby facilitating the synthesis of 3-ethoxypropionic acid ethyl ester. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0041] Figure 1 The present invention is a flow chart of the synthesis method of ethyl 3-ethoxypropionate used in the embodiments of the present invention. DETAILED DESCRIPTION

[0042] The following is a detailed description of a method for synthesizing ethyl 3-ethoxypropionate provided by the present invention in conjunction with the accompanying drawings and specific embodiments. It is also noted that, in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0043] Example 1

[0044] A synthetic method of 3-ethoxyethyl propionate, such as Figure 1 As shown, the following steps are included:

[0045] S1: Preparation of carbon-coated FeO

[0046] S1.1: Add 40 parts by weight of ethylene glycol to 1 part by weight of FeCl3·6H2O, stir magnetically for 20 minutes, then add 3 parts by weight of urea and 0.2 parts by weight of glucose, stir for 2 hours, and obtain a mixed solution;

[0047] S1.2: The mixed solution was transferred to a reaction kettle and reacted at 200°C for 10 hours to obtain a reaction product, and the reaction product was filtered to obtain a black solid;

[0048] S1.3: Wash the black solid twice with deionized water and then three times with anhydrous ethanol. Dry the washed black solid in an oven at 90°C for 20 hours to obtain carbon-encapsulated ferrosoferric oxide.

[0049] S2: Preparation of magnetic hydrotalcite

[0050] S2.1: 30 parts by weight of deionized water and 6 parts by weight of glycerol are stirred and mixed to dissolve, and then 8 parts by weight of calcium nitrate tetrahydrate, 4 parts by weight of aluminum nitrate nonahydrate and 20 parts by weight of urea are added, and the mixture is stirred and mixed for 2 hours to obtain a mixture;

[0051] S2.2: Add 2 parts by weight of carbon-coated ferrosoferric oxide to the mixture, stir mechanically for 2 hours, put it into a hydrothermal reactor, react at 120° C. for 10 hours, then cool to 70° C. for 4 hours, and cool to room temperature to obtain a reactant;

[0052] S2.3: The reactants are extracted to obtain a precipitate, which is washed three times with deionized water, then washed twice with anhydrous ethanol, and dried in an oven at 45° C. for 20 h to obtain magnetic hydrotalcite.

[0053] S3: Preparation of catalyst

[0054] S3.1: 0.4 parts by weight of KNO3 was ultrasonically dissolved in 50 parts by weight of deionized water to obtain solution I, and 0.2 parts by weight of NaOH was dissolved in 20 parts by weight of deionized water to obtain solution II;

[0055] S3.2: Solution I and solution II are mixed to obtain a mixed solution, 1 part by weight of magnetic hydrotalcite is added to the mixed solution, and after ultrasonic dispersion for 2 hours, water is removed by rotary evaporation at 70°C, and then dried in an oven at 80°C for 10 hours to obtain a dried solid;

[0056] S3.3: Place the dried solid into a tubular furnace, introduce nitrogen, raise the temperature to 500°C at a rate of 3°C / min and keep the temperature for 3 h to obtain a catalyst.

[0057] S4: Synthesis of ethyl 3-ethoxypropionate

[0058] S4.1: 25 parts by weight of anhydrous ethanol and 1 part by weight of a catalyst are added to a four-necked flask reactor equipped with a condenser, a thermometer and a mechanical stirrer. The reactor is heated, 10 parts by weight of ethyl acrylate is added dropwise at 45° C., and the mixture is reacted for 3 hours, and then cooled to room temperature to obtain a reactant;

[0059] S4.2: Separate the catalyst from the reactants through an external magnetic field, recover the catalyst, and then distill the remaining reactants to remove excess ethanol and unreacted ethyl acrylate, ultimately obtaining ethyl 3-ethoxypropionate.

[0060] Example 2

[0061] A synthetic method of 3-ethoxyethyl propionate, such as Figure 1 As shown, the following steps are included:

[0062] S1: Preparation of carbon-coated FeO

[0063] S1.1: Add 50 parts by weight of ethylene glycol to 2 parts by weight of FeCl3·6H2O, stir magnetically for 20 minutes, then add 5 parts by weight of urea and 0.5 parts by weight of glucose, stir for 2 hours, and obtain a mixed solution;

[0064] S1.2: The mixed solution was transferred to a reaction kettle and reacted at 200°C for 10 hours to obtain a reaction product, and the reaction product was filtered to obtain a black solid;

[0065] S1.3: Wash the black solid twice with deionized water and then three times with anhydrous ethanol. Dry the washed black solid in an oven at 90°C for 20 hours to obtain carbon-encapsulated ferrosoferric oxide.

[0066] S2: Preparation of magnetic hydrotalcite

[0067] S2.1: 35 parts by weight of deionized water and 10 parts by weight of glycerol are stirred and mixed to dissolve, and then 10 parts by weight of calcium nitrate tetrahydrate, 7 parts by weight of aluminum nitrate nonahydrate and 23 parts by weight of urea are added, and the mixture is stirred and mixed for 2 hours to obtain a mixture;

[0068] S2.2: Add 3 parts by weight of carbon-coated ferrosoferric oxide to the mixture, stir mechanically for 2 hours, put it into a hydrothermal reactor, react at 120° C. for 10 hours, then cool to 70° C. for 4 hours, and cool to room temperature to obtain a reactant;

[0069] S2.3: The reactants are extracted to obtain a precipitate, which is washed three times with deionized water, then washed twice with anhydrous ethanol, and dried in an oven at 45° C. for 20 h to obtain magnetic hydrotalcite.

[0070] S3: Preparation of catalyst

[0071] S3.1: 0.5 parts by weight of KNO3 was ultrasonically dissolved in 60 parts by weight of deionized water to obtain solution I, and 0.3 parts by weight of NaOH was dissolved in 30 parts by weight of deionized water to obtain solution II;

[0072] S3.2: Solution I and solution II are mixed to obtain a mixed solution, 2 parts by weight of magnetic hydrotalcite is added to the mixed solution, and after ultrasonic dispersion for 2 hours, the water is removed by rotary evaporation at 70°C, and then the solution is dried in an oven at 80°C for 10 hours to obtain a dried solid;

[0073] S3.3: Place the dried solid into a tubular furnace, introduce nitrogen, raise the temperature to 500°C at a rate of 3°C / min and keep the temperature for 3 h to obtain a catalyst.

[0074] S4: Synthesis of ethyl 3-ethoxypropionate

[0075] S4.1: 30 parts by weight of anhydrous ethanol and 2 parts by weight of a catalyst are added to a four-necked flask reactor equipped with a condenser, a thermometer and a mechanical stirrer, the reactor is heated, 12 parts by weight of ethyl acrylate is added dropwise at 45° C., the mixture is reacted for 3 hours, and the mixture is cooled to room temperature to obtain a reactant;

[0076] S4.2: Separate the catalyst from the reactants through an external magnetic field, recover the catalyst, and then distill the remaining reactants to remove excess ethanol and unreacted ethyl acrylate, ultimately obtaining ethyl 3-ethoxypropionate.

[0077] Example 3

[0078] A synthetic method of 3-ethoxyethyl propionate, such as Figure 1 As shown, the following steps are included:

[0079] S1: Preparation of carbon-coated FeO

[0080] S1.1: Add 40 parts by weight of ethylene glycol to 1 part by weight of FeCl3·6H2O, stir magnetically for 30 minutes, then add 3 parts by weight of urea and 0.2 parts by weight of glucose, stir for 3 hours, and obtain a mixed solution;

[0081] S1.2: The mixed solution was transferred to a reactor and reacted at 210°C for 12 hours to obtain a reaction product, and the reaction product was filtered to obtain a black solid;

[0082] S1.3: Wash the black solid with deionized water for 3 times, and then wash it with anhydrous ethanol for 5 times. Put the washed black solid into an oven at 100°C and dry it for 24 hours to obtain carbon-encapsulated ferrosoferric oxide.

[0083] S2: Preparation of magnetic hydrotalcite

[0084] S2.1: 30 parts by weight of deionized water and 6 parts by weight of glycerol are stirred and mixed to dissolve, and then 8 parts by weight of calcium nitrate tetrahydrate, 4 parts by weight of aluminum nitrate nonahydrate and 20 parts by weight of urea are added, and the mixture is stirred and mixed for 3 hours to obtain a mixture;

[0085] S2.2: Add 2 parts by weight of carbon-coated ferrosoferric oxide to the mixture, stir mechanically for 3 hours, put it into a hydrothermal reactor, react at 125°C for 12 hours, then cool to 75°C for 5 hours, and cool to room temperature to obtain a reactant;

[0086] S2.3: The reactants were extracted to obtain a precipitate, which was washed with deionized water for 5 times, and then washed with anhydrous ethanol for 3 times, and dried in an oven at 50° C. for 24 h to obtain magnetic hydrotalcite.

[0087] S3: Preparation of catalyst

[0088] S3.1: 0.4 parts by weight of KNO3 was ultrasonically dissolved in 50 parts by weight of deionized water to obtain solution I, and 0.2 parts by weight of NaOH was dissolved in 20 parts by weight of deionized water to obtain solution II;

[0089] S3.2: Solution I and solution II are mixed to obtain a mixed solution, 1 part by weight of magnetic hydrotalcite is added to the mixed solution, and after ultrasonic dispersion for 3 hours, water is removed by rotary evaporation at 100°C, and then dried in an oven at 100°C for 12 hours to obtain a dried solid;

[0090] S3.3: Place the dried solid into a tubular furnace, introduce nitrogen, raise the temperature to 600°C at a rate of 4°C / min and keep the temperature for 4 hours to obtain a catalyst.

[0091] S4: Synthesis of ethyl 3-ethoxypropionate

[0092] S4.1: 25 parts by weight of anhydrous ethanol and 1 part by weight of a catalyst are added to a four-necked flask reactor equipped with a condenser, a thermometer and a mechanical stirrer, the reactor is heated, 10 parts by weight of ethyl acrylate is added dropwise at 70° C., the reaction is carried out for 5 hours, and the reactant is cooled to room temperature to obtain a reactant;

[0093] S4.2: Separate the catalyst from the reactants through an external magnetic field, recover the catalyst, and then distill the remaining reactants to remove excess ethanol and unreacted ethyl acrylate, ultimately obtaining ethyl 3-ethoxypropionate.

[0094] Comparative Example 1

[0095] Compared with Example 1, the difference of Comparative Example 1 is that Comparative Example 1 removes step S1, replaces the carbon-coated ferrosoferric oxide in step S2.2 with an equal mass of ferrosoferric oxide, and the remaining steps remain unchanged to synthesize 3-ethoxyethyl propionate, which is recorded as Comparative Example 1.

[0096] Comparative Example 2

[0097] Compared with Example 1, the difference of Comparative Example 2 is that Comparative Example 2 removes the "ultrasonic dissolution of 0.4-0.5 weight parts of KNO3 in 50-60 weight parts of deionized water to obtain solution I" in step S3.1 and the "mixing solution I with solution II to obtain a mixed solution" in step S3.2, and replaces the mixed solution in step S3.2 with an equal mass of solution II, and the remaining steps remain unchanged to synthesize 3-ethoxyethyl propionate, which is recorded as Comparative Example 2.

[0098] Comparative Example 3

[0099] Compared with Example 1, the difference of Comparative Example 3 is that Comparative Example 3 removes the steps of "additionally dissolving 0.2-0.3 parts by weight of NaOH in 20-30 parts by weight of deionized water to obtain solution II" in step S3.1 and "mixing solution I with solution II to obtain a mixed solution" in step S3.2, and replaces the mixed solution in step S3.2 with an equal mass of solution I, and the remaining steps remain unchanged to synthesize ethyl 3-ethoxypropionate, which is recorded as Comparative Example 3.

[0100] The catalyst performance of Examples 1-3 and Comparative Examples 1-3 was evaluated, and the catalyst performance evaluation results are shown in Table 1.

[0101] Table 1. Catalyst performance evaluation results of Examples 1-3 and Comparative Examples 1-3

[0102] Conversion rate of ethyl acrylate (%) Selectivity of ethyl 3-ethoxypropionate (%) Example 1 93.34 97.38 Example 2 92.83 96.39 Example 3 92.92 96.28 Comparative Example 1 73.72 85.82 Comparative Example 2 76.97 87.38 Comparative Example 3 78.37 88.67

[0103] As can be seen from Table 1, the conversion rate of ethyl acrylate and the selectivity of ethyl 3-ethoxypropionate in Comparative Example 1 are lower than those in Example 1, indicating that the activity of the catalyst prepared by carbon-coating ferrosoferric oxide is better than that of the catalyst prepared without carbon-coating, and is therefore more conducive to the synthesis of ethyl 3-ethoxypropionate.

[0104] The conversion rate of ethyl acrylate and the selectivity of ethyl 3-ethoxypropionate in Comparative Examples 2 and 3 are lower than those in Example 1, indicating that compared with the loading of a single component, after potassium and sodium are loaded onto the surface of hydrotalcite by impregnation, the catalyst can be improved by the synergistic modification of potassium and sodium, and then the synthesis of ethyl 3-ethoxypropionate can be further promoted.

[0105] Catalyst reusability performance test:

[0106] The catalyst prepared in Example 1 was separated from the reaction system by an external magnetic field, washed with methanol three times and then dried in an oven. The dried catalyst was put back into the reaction system and reused five times. The performance of the catalyst was measured again. The measurement results are shown in Table 2.

[0107] Table 2. Performance test results of the catalyst after repeated use for 5 times in Example 1

[0108] Conversion rate of ethyl acrylate (%) Selectivity of ethyl 3-ethoxypropionate (%) Example 1 89.49 95.96

[0109] It can be seen from Table 2 that after repeated use for 5 times, the conversion rate of ethyl acrylate is 89.49%, and the selectivity of ethyl 3-ethoxypropionate is 95.96%. It can be seen that the active components of the catalyst are lost slowly, and the long-term operation effect is good. The catalyst can be separated from the reactants under the action of the magnetic field and then recycled and reused, which can reduce the production cost.

[0110] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for synthesizing ethyl 3-ethoxypropionate, characterized in that: The steps include: S1: Preparation of carbon-coated FeO Carbon-encapsulated ferroferric oxide was obtained by hydrothermal synthesis using glucose as the carbon source; S2: Preparation of magnetic hydrotalcite The magnetic hydrotalcite is prepared by adding carbon-coated ferroferric oxide to glycerol, water, calcium nitrate tetrahydrate, aluminum nitrate nonahydrate and urea. S3: Preparation of catalyst Potassium and sodium are loaded on magnetic hydrotalcite to obtain a catalyst; S4: Synthesis of ethyl 3-ethoxypropionate Ethyl 3-ethoxypropionate was synthesized by reacting anhydrous ethanol, a catalyst and ethyl acrylate; Step S1: Preparation of carbon-coated ferroferric oxide, specifically comprising the following steps: S1.1: Add 40-50 parts by weight of ethylene glycol to 1-2 parts by weight of FeCl3·6H2O, stir magnetically for 20-30 minutes, then add 3-5 parts by weight of urea and 0.2-0.5 parts by weight of glucose, stir for 2-3 hours, and obtain a mixed solution; S1.2: transferring the mixed solution to a reactor for reaction to obtain a reaction product, and filtering the reaction product to obtain a black solid; S1.3: Wash the black solid with deionized water for 2-3 times, and then wash it with anhydrous ethanol for 3-5 times. Put the washed black solid into a 90-100°C oven and dry it for 20-24 hours to obtain carbon-encapsulated ferrosoferric oxide.

2. A method for synthesizing ethyl 3-ethoxypropionate according to claim 1, characterized in that, Step S2: Preparation of magnetic hydrotalcite, specifically comprising the following steps: S2.1: 30-35 parts by weight of deionized water and 6-10 parts by weight of glycerol are stirred and mixed to dissolve, and then 8-10 parts by weight of calcium nitrate tetrahydrate, 4-7 parts by weight of aluminum nitrate nonahydrate and 20-23 parts by weight of urea are added, and the mixture is stirred and mixed for 2-3 hours to obtain a mixture; S2.2: Add 2-3 parts by weight of carbon-coated ferrosoferric oxide to the mixture, stir mechanically for 2-3 hours, put it into a hydrothermal reactor for reaction, and then cool it to room temperature to obtain a reactant; S2.3: After extracting the reactants, a precipitate is obtained, and the precipitate is washed with deionized water for 3-5 times, and then washed with anhydrous ethanol for 2-3 times, and dried in an oven at 45-50° C. for 20-24 hours to obtain magnetic hydrotalcite.

3. A method for synthesizing ethyl 3-ethoxypropionate according to claim 2, characterized in that, Step S3: Preparation of catalyst, specifically comprising the following steps: S3.1: Dissolve KNO3 in deionized water by ultrasonic to obtain solution I, and dissolve NaOH in deionized water to obtain solution II; S3.2: Mix solution I and solution II to obtain a mixed solution, add 1-2 parts by weight of magnetic hydrotalcite to the mixed solution, disperse by ultrasonic for 2-3 hours, and then remove water by rotary evaporation at 70-100°C, and then dry in an oven at 80-100°C for 10-12 hours to obtain a dried solid; S3.3: The dried solid is placed in a tubular furnace, nitrogen is introduced, and the catalyst is obtained by reaction.

4. A method for synthesizing ethyl 3-ethoxypropionate according to claim 3, characterized in that, Step S4: Synthesis of ethyl 3-ethoxypropionate, specifically comprising the following steps: S4.1: 25-30 parts by weight of anhydrous ethanol and 1-2 parts by weight of a catalyst are added to a four-necked flask reactor equipped with a condenser, a thermometer and a mechanical stirrer, the reactor is heated, 10-12 parts by weight of ethyl acrylate is added dropwise at 45-70° C., the reaction is carried out for 3-5 hours, and the reactant is cooled to room temperature to obtain a reactant; S4.2: Separate the catalyst from the reactants through an external magnetic field, recover the catalyst, and then distill the remaining reactants to remove excess ethanol and unreacted ethyl acrylate, ultimately obtaining ethyl 3-ethoxypropionate.

5. A method for synthesizing ethyl 3-ethoxypropionate according to claim 1, characterized in that, The specific reaction conditions in step S1.2 are 200-210° C. for 10-12 h.

6. A method for synthesizing ethyl 3-ethoxypropionate according to claim 2, characterized in that, The reaction conditions in step S2.2 are specifically 120-125° C. for 10-12 h, then cooling to 70-75° C. for 4-5 h.

7. A method for synthesizing ethyl 3-ethoxypropionate according to claim 3, characterized in that, In step S3.1, the weight ratio of KNO3 to deionized water is 0.4-0.5:50-60.

8. A method for synthesizing ethyl 3-ethoxypropionate according to claim 3, characterized in that: In step S3.1, the weight ratio of NaOH to deionized water is 0.2-0.3:20-30.

9. A method for synthesizing ethyl 3-ethoxypropionate according to claim 3, characterized in that: The reaction conditions in step S3.3 are specifically to increase the temperature to 500-600°C at 3-4°C / min and keep the temperature for 3-4h.

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