阅读说明：本技术 利用MOFs衍生锆基三元氧化物固体酸催化合成丙烯酰胺类化合物的方法 (Method for catalytic synthesis of acrylamide compound by using MOFs derived zirconium-based ternary oxide solid acid ) 是由 吕明 孟春瑜 吕圣佐 李禹羲 尹晓杰 于 2021-08-03 设计创作，主要内容包括：本发明提供了一种以锆基三元氧化物固体酸为催化剂催化合成丙烯酰胺类化合物,低温活性好、选择性强,腐蚀性低可回收套用,合成过程中,酸性小、反应条件温和可控、副产物少,得到丙烯酰胺类化合物后处理过程得到简化,有效提高反应收率,纯度高、品质好,适用于规模化生产的推广应用。(The invention provides a method for catalytically synthesizing acrylamide compounds by taking zirconium-based ternary oxide solid acid as a catalyst, which has the advantages of good low-temperature activity, strong selectivity, low corrosivity, recyclability, small acidity, mild and controllable reaction conditions, few byproducts in the synthesis process, simplified post-treatment process of the obtained acrylamide compounds, effective improvement of reaction yield, high purity and good quality, and is suitable for popularization and application in large-scale production.)

1. A zirconium-based ternary oxide solid acid catalyst is characterized in that a magnetic metal-doped UiO material is used as a precursor, a transition metal element is introduced, and the porous carbon-loaded zirconium-based ternary oxide solid acid is prepared through oxygen-free calcination and acidification modification.

2. The catalyst according to claim 1,

the magnetic metal is selected from iron, cobalt, nickel or manganese,

the magnetic metal doped UiO material is selected from magnetic metal doped UiO-66, magnetic metal doped UiO-67 or magnetic metal doped UiO-68, and preferably is magnetic metal doped UiO-66.

3. A method for synthesizing an acrylamide compound, which is characterized in that the method takes acrylic acid and a secondary amine compound as raw materials and takes the zirconium-based ternary oxide solid acid as claimed in claim 1 or 2 as a catalyst for preparation.

4. The method according to claim 3, characterized in that it comprises in particular the steps of:

step 1, adding acrylic acid and secondary amine into a solvent, and preheating to obtain a solution to be reacted;

step 2, adding zirconium-based ternary oxide solid acid as a catalyst, and carrying out heat preservation reaction to obtain a reaction solution;

and 3, post-treating the reaction liquid to obtain the acrylamide compound.

5. The method according to claim 4, wherein, in step 1,

the molar ratio of the acrylic acid to the secondary amine is (0.5-3.4) 1,

the solvent is selected from one or more of sulfone solvents or aromatic hydrocarbon solvents, and preferably selected from one or more of dimethyl sulfoxide, chlorobenzene, toluene and xylene.

6. The method according to claim 4, wherein the preheating temperature in step 1 is 45-85 ℃.

7. The method according to claim 4, wherein, in step 2,

the mass ratio of the zirconium-based ternary oxide solid acid to the secondary amine is (1-18): 100.

8. The process according to claim 4, wherein in step 2, the reaction time is 3 to 18 hours, preferably 5 to 12 hours.

9. The method according to claim 4, wherein in the step 2, the zirconium-based ternary oxide solid acid is porous carbon-supported zirconium-based ternary oxide solid acid, which is prepared by taking a magnetic metal-doped UiO material as a precursor, introducing a transition metal element, and performing oxygen-free calcination and acidification modification.

10. The method of claim 9, wherein, in step 2,

the magnetic metal doped UiO-66 is prepared by the following method: uniformly mixing organic acid and N, N-dimethylformamide, adding an organic ligand, zirconium tetrachloride and a magnetic metal compound, dispersing, stirring at 90-120 ℃ for 15-30h, naturally cooling to room temperature, washing and drying to obtain a magnetic metal-doped UIO-66, wherein the organic ligand is selected from 2-amino terephthalic acid or terephthalic acid;

replacing an organic ligand with 4, 4-biphenyldicarboxylic acid according to a preparation method of the magnetic metal doped UiO-66 to prepare magnetic metal doped UiO-67;

according to the preparation method of the magnetic metal doped UiO-66, the organic ligand is replaced by dicarboxylic acid terphenyl to prepare the magnetic metal doped UiO-68.

Technical Field

The invention belongs to the technical field of synthesis of acrylamide compounds by using heterogeneous catalysts, and particularly relates to a synthesis method for controllably preparing an acrylamide compound by using zirconium-based ternary oxide solid acid derived from magnetic porous MOFs.

Background

Homogeneous mineral acid catalysts are well soluble in catalytic reactions and are capable of sufficient contact and interaction with reaction substrates, but they also suffer from problems such as: (1) corrosion to reaction equipment, (2) increased industrial cost for waste liquid treatment, and (3) more side reactions and complicated product separation, which are not favorable for recycling.

In order to overcome the above disadvantages, many heterogeneous catalysts have been developed and applied to catalytic reactions. At present, cation exchange resin, ionic liquid, solid acid, solid super acid and the like are mainly available. In recent years, with the introduction of green chemistry, the research on environment-friendly solid acid catalysts has become one of the hot research subjects in the catalytic field in recent years. Especially SO₄ ^2-/ZrO₂The super strong acidity, high catalytic activity, no pollution and other advantages of the solid acid like oxides are of great concern. However SO₄ ^2-/ZrO₂The solid acid catalyst of the oxide-like compound has the disadvantages of poor thermal stability and selectivity, and the effective modification of the solid acid catalyst is a very valuable work.

Due to Sb⁵⁺、Nb⁵⁺、Ta⁵⁺Etc. have a greater ability to accept electrons, and the addition of these materials to the acid catalyst should be more effective in attenuating H in the original acid⁺－O^2-And H⁺－X^-Bonds, making it exhibit greater catalytic activity. In addition, such catalysts still have the problem of small specific surface area of the catalyst in practice, but when the catalyst particle size is reduced, the catalytic activity is better, but the separation and recovery are more difficult.

When the amide derivative with rigidity is introduced into the main chain of the polymer, the high-temperature resistance, salt resistance and shear resistance of the polymer can be obviously improved, and the hydrolysis of the acrylamide polymer is relieved to a certain extent. Song Dynasty, He Yang and the like published a paper that "the synthesis and solution performance of novel piperazine amide polymer oil-displacing agent" synthesized 1-acryloyl-4-methylpiperazine, but the monomer synthesis yield was low and the purity was difficult to exceed 92%. In addition, most of the existing methods for synthesizing amide derivatives are laboratory-conducted trace preparations, and if the methods are used in actual production, the yield is likely to be further reduced due to the increased difficulty in process control in mass production. Meanwhile, when the monomer is used for polymerization, the purity is not high enough, which may cause problems of insufficient polymerization activity, poor polymerization effect or unsuccessful polymerization, etc. The patent name is' a functional monomer for synthesizing polymer oil displacement agent and a preparation method thereof, application numbers: 201910987777.4 "using methylene chloride under the action of NaOH. However, it uses acyl chloride as raw material and free strong base as catalyst, which may cause burden to environment and reaction equipment.

Therefore, there is a need to develop a solid acid heterogeneous catalyst with good catalytic activity, stable performance, and easy separation and recovery.

Disclosure of Invention

In order to solve the problems, the invention provides a method for preparing acrylamide compounds by using zirconium-based ternary oxide solid acid derived from magnetic porous MOFs as a catalyst to catalyze carboxylic acid amidation reaction, particularly acrylic acid amidation. The solid acid takes Metal Organic Framework (MOFs) UO series materials as precursors, transition metal elements are introduced, porous carbon attached with metal oxides is obtained under the condition of high-temperature calcination, the catalyst is high in activity and good in stability, the catalyst can be recycled and applied repeatedly, the reaction conditions are mild in the synthesis process, the corrosion degree of equipment is greatly reduced, and the production process requirement of high-efficiency synthesis can be met.

The invention aims to provide zirconium-based ternary oxide solid acid, which is prepared by taking a magnetic metal doped UiO material as a precursor, introducing a transition metal element, and carrying out anaerobic calcination and acidification modification on the precursor to obtain porous carbon-loaded zirconium-based ternary oxide solid acid.

The invention also aims to provide a method for synthesizing acrylamide compounds by using the zirconium-based ternary oxide solid acid as a catalyst, wherein the method takes acrylic acid and secondary amine compounds as raw materials for preparation. The method specifically comprises the following steps:

step 1, adding acrylic acid and secondary amine into a solvent, and preheating to obtain a solution to be reacted;

step 2, adding zirconium-based ternary oxide solid acid as a catalyst, and carrying out heat preservation reaction to obtain a reaction solution;

and 3, post-treating the reaction liquid to obtain the acrylamide compound.

The synthesis method for catalytically synthesizing the acrylamide compound by utilizing the MOFs-derived zirconium-based ternary oxide solid acid has the following beneficial effects:

(1) according to the invention, magnetic porous carbon-loaded zirconium-based ternary oxide solid acid is used as a catalyst to catalyze the reaction of acrylamide and secondary amine, so that the reaction condition is milder, the acidity of a reaction solution is greatly reduced, and the corrosion of equipment is reduced.

(2) The catalyst is a heterogeneous magnetic catalyst, is easy to separate, recycle and reuse in practical application, is particularly suitable for continuous production, is beneficial to reducing the cost of the catalyst, and reduces the residue of the catalyst in a product.

(3) The synthesis method has the advantages of good low-temperature activity of the catalyst, strong selectivity, less side reaction, high product yield, high purity, simple catalyst recovery treatment, easy separation of the obtained target product and good quality.

Drawings

FIG. 1 shows the preparation of 4-methyl-1-acryloylpiperazine which is the product of example 3 of the present invention¹H NMR chart;

FIG. 2 shows the preparation of 4-methyl-1-acryloylpiperazine which is the product of example 3 of the present invention¹C NMR chart;

FIG. 3 shows the preparation of 1, 4-diacryloylpiperazine, a product of example 4 of the present invention¹H NMR chart;

FIG. 4 shows the preparation of 1, 4-diacryloylpiperazine, a product of example 4 of the present invention¹C NMR chart;

FIG. 5 shows the preparation of N, N' -diethylacrylamide, a product of example 6 according to the invention¹H NMR chart;

FIG. 6 shows the preparation of N, N' -diethylacrylamide, a product of example 6 of the present invention¹C NMR chart;

FIG. 7a shows an SEM photograph of a magnetic iron-doped UIO-66 prepared in example 1 of the present invention;

FIG. 7b shows an SEM photograph of a magnetic iron-doped UIO-66 prepared in example 1 of the present invention;

FIG. 7c shows a zirconium based ternary oxide solid acid (ZrO) before calcination, prepared in example 1 of the present invention₂-Fe₃O₄-Nb₂O₅) SEM photograph of (a);

FIG. 7d shows a zirconium based ternary oxide solid acid (ZrO) before calcination prepared in example 1 of the present invention₂-Fe₃O₄-Nb₂O₅) SEM photograph of (a).

Detailed Description

The present invention will now be described in detail by way of specific embodiments, and features and advantages of the present invention will become more apparent and apparent from the following description.

The invention provides a zirconium-based ternary oxide solid acid catalyst, which is prepared by taking a magnetic metal-doped UO material as a precursor, introducing a transition metal element, and carrying out anaerobic calcination and acidification modification on the precursor to obtain porous carbon-loaded zirconium-based ternary oxide solid acid.

The magnetic metal is selected from iron, cobalt, nickel or manganese, preferably iron or cobalt, more preferably iron. The magnetic metal doped UiO material is selected from magnetic metal doped UiO-66, magnetic metal doped UiO-67 or magnetic metal doped UiO-68, and preferably is magnetic metal doped UiO-66. In one aspect, the introduction of an oxidized form of a magnetic metal, such as Fe, results in magnetic nano-Fe₃O₄Particles are convenient for magnetic field auxiliary separation in the using process of the catalyst. More importantly, Fe₃O₄The interface of the material and zirconium oxide and niobium is subjected to effective electron transfer, so that the electron obtaining capability of an acid center is improved, and the Lewis acid strength of the material is improved.

The transition metal element is selected from the group consisting of lanthanide metals, tungsten, molybdenum, tantalum or niobium, preferably from tungsten, molybdenum, tantalum or niobium, more preferably niobium. After the transition metal element is introduced into the magnetic metal doped UiO material, the stability of the catalyst can be improved, and the service life of the catalyst can be prolonged. In particular, after niobium is introduced, the acidity of the oxide decreases after water absorption, and niobium oxide has a strong acidity after water absorption. In addition, due to the strong interaction between Nb-O bonds, the stability and the service life of the catalyst can be obviously improved by adding a small amount of niobium oxide. The invention also provides a method for synthesizing acrylamide compounds by using the zirconium-based ternary oxide solid acid as a catalyst, which takes acrylic acid and secondary amine compounds as raw materials for preparation, and specifically comprises the following steps:

step 1, adding acrylic acid and secondary amine into a solvent, and preheating to obtain a solution to be reacted.

The molar ratio of acrylic acid to secondary amine is (0.5-3.4):1, preferably (0.8-2.8):1, more preferably (1.1-2.2): 1.

The solvent is selected from one or more of sulfone solvents or aromatic hydrocarbon solvents, preferably selected from one or more of dimethyl sulfoxide, chlorobenzene, toluene and xylene, and more preferably is toluene.

The molar volume ratio of acrylic acid to solvent is 1 (1-20), preferably 1 (3-10), more preferably 1 (4-6), for example 1: 5.

The preheating temperature is 45-85 ℃, preferably 55-75 ℃.

And 2, adding zirconium-based ternary oxide solid acid as a catalyst, and carrying out heat preservation reaction to obtain a reaction solution.

The mass ratio of the zirconium-based ternary oxide solid acid to the secondary amine is (1-18):100, preferably (3-15):100, and more preferably (5-12): 100.

The reaction time is 3 to 18 hours, preferably 5 to 12 hours.

The zirconium-based ternary oxide solid acid is porous carbon-loaded zirconium-based ternary oxide solid acid, and is prepared by taking a magnetic metal-doped UiO material as a precursor, introducing a transition metal element, and performing anaerobic calcination, acidification and modification.

The magnetic metal is selected from iron, cobalt, nickel or manganese, preferably iron or cobalt, more preferably iron. The magnetic metal doped UiO material is selected from magnetic metal doped UiO-66, magnetic metal doped UiO-67 or magnetic metal doped UiO-68, and preferably is magnetic metal doped UiO-66.

The transition metal element is selected from the group consisting of lanthanide metals, tungsten, molybdenum, tantalum or niobium, preferably from tungsten, molybdenum, tantalum or niobium, more preferably niobium. After the transition metal element is introduced, the bonding of the catalyst can be increased from the molecular structure, so that the stability of the catalyst is improved, and the service life of the catalyst is prolonged. In particular, niobium is introduced to form niobium oxide, which has strong acidity after water absorption without reducing acidity, and a small amount of niobium oxide is added to significantly improve the stability and service life of the catalyst due to the strong interaction between Nb and O bonds.

The magnetic metal doped UiO-66 is prepared by the following method: mixing organic acid and N, N-Dimethylformamide (DMF) uniformly, adding organic ligand, zirconium tetrachloride and magnetic metal compound, dispersing, stirring at 90-120 deg.C for 15-30h, such as 24h, naturally cooling to room temperature, washing and drying to obtain magnetic metal doped UIO-66.

The organic acid is selected from monobasic organic acids, such as benzoic acid, phenylacetic acid, formic acid, acetic acid, preferably from formic acid and/or acetic acid, more preferably acetic acid.

The organic ligand is selected from 2-amino terephthalic acid or terephthalic acid.

The molar ratio of the zirconium tetrachloride, the organic ligand and the N, N-dimethylformamide is 1 (0.5-1.5): 1000-1800), preferably 1 (0.7-1.2): 1200-1600.

The molar ratio of the organic acid to the zirconium tetrachloride is (80-150):1, preferably (100-.

The molar ratio of the zirconium tetrachloride to the magnetic metal compound is 9 (0.2-3), preferably 9 (0.5-2), and more preferably 9 (0.8-1.2). When the content of the magnetic metal is too low, magnetic particles satisfying the use requirements cannot be formed, for example, when the content of Fe is too low, a certain amount of Fe cannot be formed₃O₄Nanoparticles, which have an insufficient number of interfaces for electron transfer; when the content of the magnetic metal is too high, the formed oxide is liable to aggregate and accumulate on the catalyst surface, resulting in a decrease in the interfacial area, for example, whenWhen the Fe content is too high, Fe₃O₄The aggregate is large particles, the interface area of the aggregate is reduced, and the aggregate is accumulated on the surface of the catalyst to influence the acidification process.

According to the preparation method of the magnetic metal-doped UiO-66, the organic ligand is replaced by 4, 4-biphenyldicarboxylic acid (BPDC), and the magnetic metal-doped UiO-67 is prepared.

According to the preparation method of the magnetic metal doped UiO-66, the organic ligand is replaced by dicarboxylic acid Terphenyl (TPDC) to prepare the magnetic metal doped UiO-68.

In the invention, a magnetic metal doped UiO material is added into a transition metal compound solution to be impregnated for 12-48h, and after filtration and drying, the mixture is calcined for 4-10h at the temperature of 700-. When the calcining temperature is too low, the three metal elements are easy to phase separate and cannot form a structure with uniform components; the calcination temperature is too high, so that the three metal elements form solid solution oxide, and magnetic oxide nanoparticles (such as Fe) cannot be formed₃O₄Nanoparticles) no longer have magnetic and interfacial electron transfer properties.

And (3) carrying out acid modification on the intermediate product, adding the intermediate product into an acid solution, soaking for 9-15h, such as 12h, filtering, drying, calcining at the temperature of 500-700 ℃, such as 3h, and naturally cooling to obtain the zirconium-based ternary oxide solid acid. Acidification may be effected by reacting B acid groups (-SO)₄ ^2-) Effectively introduced to the surface of the oxide and improves the acidity of the catalyst. As the calcination temperature is increased, the number of strong acid sites increases, the number of weak acid sites decreases, and the strength of the solid acid gradually increases. However, above 700 c, the acid strength rapidly decreases, since too high a calcination temperature decomposes and desorbs the impregnated surface sulfonic acid groups.

And 3, post-treating the reaction liquid to obtain the acrylamide compound.

And the post-treatment is to filter the reaction solution, separate the zirconium-based ternary oxide solid acid catalyst and recycle the catalyst. Preferably, the reaction solvent is washed and recycled.

And (3) separating the catalyst, washing the reaction solution with alkali liquor, for example, washing with a sodium hydroxide solution with the pH value of 10 for 3-7 times, neutralizing, removing the solvent by rotary evaporation, and drying to obtain the acrylamide compound.

Compared with the existing synthesis method (such as the synthesis method in the comparative example), in the method for synthesizing the acrylamide compound by using the zirconium-based ternary oxide solid acid catalyst, the method provided by the invention does not need to use an acyl chloride compound (such as acryloyl chloride) from the aspect of raw materials, and is convenient for storing and using the raw materials in actual production; in the aspect of synthesis conditions, feeding and reaction are not needed at low temperature, the reaction conditions are mild and are easy to control, and the method is favorable for popularization and application of industrial production; in the aspect of reaction time, the catalyst applied in the invention has good reaction activity, can be recycled and reused, can accelerate the reaction process, shorten the synthesis time and realize high-efficiency synthesis under mild conditions; in the aspect of product quality, the synthesis method provided by the invention has the advantages that the yield is effectively improved on the premise of ensuring the product purity, the obtained product has good quality and few byproducts.

According to the invention, the acrylamide compound is synthesized by catalysis of the zirconium-based ternary oxide solid acid serving as the catalyst, the yield is high and can reach 99% at most, the product purity is high, the catalyst has no corrosion to equipment, the activity at low temperature is good, the synthesis reaction can be carried out at low temperature, the selectivity is strong, the byproducts are few, and the catalyst can be recycled and reused, and is particularly suitable for continuous devices. The acrylamide compound product is easy to separate and is beneficial to large-scale production.

Examples

Example 1

10mL of acetic acid and 50mL of N, N-Dimethylformamide (DMF) were mixed uniformly, 2mol of 2-aminoterephthalic acid, 2.7mol of zirconium chloride and 0.3mol of ferric chloride were added thereto, and after ultrasonic dispersion, the resulting solution was transferred to a round-bottomed flask equipped with a reflux apparatus, stirred at 120 ℃ for 24 hours, cooled naturally to room temperature, washed 3 times with DMF and 3 times with methanol, and then the resulting powder was dried under vacuum at 60 ℃ for 12 hours to obtain 1.6g of magnetic iron-doped UIO-66, whose SEM photographs are shown in FIG. 7a and FIG. 7 b.

1.0g of magnetic iron-doped UIO-66 was added to 0.2mL of a saturated niobium oxalate solution to impregnate for 24 hours, followed by vacuum drying at 60 ℃ for 12 hours to obtain a solid powder.

And (3) placing the solid powder in a tubular furnace, calcining for 6h at 900 ℃ in a nitrogen atmosphere, raising the temperature at the rate of 5 ℃/min, and naturally cooling to room temperature to obtain an intermediate product.

The intermediate product was added to 10mL of 1mol/L sulfuric acid solution, immersed for 12h, filtered, and after drying the sample in a vacuum oven at 60 ℃ for 12h, SEM photographs thereof were tested, as shown in FIG. 7c and FIG. 7 d. Calcining at 600 ℃ for 3h, and naturally cooling to obtain the zirconium-based ternary oxide solid acid (ZrO)₂-Fe₃O₄-Nb₂O₅)。

Example 2

A50 mL Schlenk flask was charged, after baking and argon exchange, with acrylic acid (0.72g, ca. 12mmol) and morpholine (0.87g, ca. 10mmol) dissolved in 20mL of toluene, followed by addition of the zirconium-based ternary oxide solid acid (ZrO) prepared in example 1₂-Fe₃O₄-Nb₂O₅) The catalyst (8.7mg) was heated to 60 ℃ and stirred for 6 hours, then the catalyst was filtered and washed with toluene 2 times and recovered for reuse. Washing the filtrate for 3 times by using NaOH aqueous solution with the pH value of 10, separating the solution after the saline solution is washed to be neutral, carrying out rotary evaporation on an organic phase to remove the solvent, and carrying out vacuum drying to obtain the 4-acryloyl morpholine with the yield of 95 and the purity of 99%.

Example 3

A50 mL Schlenk flask was charged, after baking and argon gas exchange, with acrylic acid (0.72g, about 12mmol) and methylpiperazine (1.00g, about 10mmol) dissolved in 20mL of toluene, and the zirconium-based ternary oxide solid acid (ZrO) prepared in example 1 was added₂-Fe₃O₄-Nb₂O₅) The catalyst (10mg) was heated to 60 ℃ and stirred for 6h, then the catalyst was filtered and washed with toluene 2 times and recycled. Washing the filtrate for 3 times by using NaOH aqueous solution with the pH value of 10, separating the solution after washing the filtrate to be neutral by using brine, rotatably evaporating an organic phase to remove the solvent, and drying the organic phase in vacuum to obtain the 4-methyl 1-acryloyl piperazine with the yield of 98 percent and the purity of 99.1 percent. The structure is as follows:

the products were subjected to nuclear magnetic hydrogen spectroscopy and nuclear magnetic carbon spectroscopy, and the results are shown in fig. 1 and 2.

Example 4

A50 mL Schlenk flask was charged, after baking and argon exchange, with acrylic acid (1.44g, about 24mmol) and piperazine (0.86g, about 10mmol) dissolved in 20mL of toluene, followed by addition of the zirconium-based ternary oxide solid acid (ZrO) prepared in example 1₂-Fe₃O₄-Nb₂O₅) (8.6mg), heating to 60 ℃, stirring for reaction for 6 hours, filtering the catalyst, washing the catalyst with toluene for 2 times, and recycling and reusing. Washing the filtrate for 3 times by using NaOH aqueous solution with the pH value of 10, separating the solution after the filtrate is washed to be neutral by using brine, rotatably evaporating an organic phase to remove the solvent, and drying the organic phase in vacuum to obtain the 1, 4-diacryloylpiperazine with the yield of 95 percent. The structure is as follows:

the products were subjected to nuclear magnetic hydrogen spectroscopy and nuclear magnetic carbon spectroscopy, and the results are shown in fig. 3 and 4.

Example 5

A50 mL Schlenk flask was charged, after baking and argon gas exchange, with acrylic acid (0.72g, about 12mmol) and imidazole (0.68g, about 10mmol) dissolved in 20mL of toluene, and then the zirconium-based ternary oxide solid acid (ZrO) prepared in example 1 was added₂-Fe₃O₄-Nb₂O₅) (6.8mg), heating to 60 ℃, stirring for reaction for 6 hours, filtering the catalyst, washing the catalyst with toluene for 2 times, and recycling and reusing. And washing the filtrate for 3 times by using NaOH aqueous solution with the pH value of 10, separating the solution after the filtrate is washed to be neutral by using brine, rotatably evaporating an organic phase to remove the solvent, and drying the organic phase in vacuum to obtain the 1-acryloyl imidazole, wherein the yield is 90%.

Example 6

A50 mL Schlenk flask was charged, after baking and argon exchange, with acrylic acid (0.72g, ca. 12mmol) and diethylamine (0.73g, ca. 10mmol) dissolved in 20mL of toluene, and then the zirconium-based ternary oxide solid acid (ZrO) prepared in example 1 was added₂-Fe₃O₄-Nb₂O₅) (7.3mg), heating to 60 ℃, stirring to react for 6h, filtering the catalyst, washing the catalyst with toluene for 2 times, and recycling and reusing. And washing the filtrate for 3 times by using NaOH aqueous solution with the pH value of 10, washing the filtrate by using brine until the filtrate is neutral, separating the liquid, rotatably evaporating an organic phase to remove the solvent, and drying the organic phase in vacuum to obtain the N, N' -diethylacrylamide with the yield of 95 percent. The structure is as follows:

the products were subjected to nuclear magnetic hydrogen spectroscopy and nuclear magnetic carbon spectroscopy, and the results are shown in fig. 5 and 6.

Example 7

A50 mL Schlenk flask was charged, after baking and argon exchange, with acrylic acid (0.72g, about 12mmol) and diphenylamine (1.69g, about 10mmol) dissolved in 20mL of toluene, followed by addition of the zirconium-based ternary oxide solid acid (ZrO) prepared in example 1₂-Fe₃O₄-Nb₂O₅) (84.5mg), heating to 60 ℃, stirring to react for 6h, filtering the catalyst, washing the catalyst with toluene for 2 times, and recycling and reusing. And washing the filtrate for 3 times by using NaOH aqueous solution with the pH value of 10, washing the filtrate by using brine until the filtrate is neutral, separating the liquid, rotatably evaporating an organic phase to remove the solvent, and drying the organic phase in vacuum to obtain the N, N' -diphenyl acrylamide with the yield of 85 percent.

Comparative example

4-methyl 1-acryloyl piperazine (1- (4-methylpiperazin-1-yl) prop-2-en-1-one) was prepared according to the method in chinese patent CN 110746379A:

3L of methylene chloride and 0.66kg of acryloyl chloride (7.2mol) were added to the reaction kettle in this order. 0.6kg of N-methylpiperazine (6mol) was added slowly at 5 ℃ using a constant pressure dropping funnel. After the dropwise addition is finished, slowly heating to room temperature, and continuously reacting for 10 hours; during the dropwise addition, yellow flocculent insolubles were gradually generated.

After the reaction was complete, 0.6L of deionized water was added followed by addition of saturated NaOH solution and vigorous stirring until the pH of the reaction solution reached 12. Then adding dichloromethane with 3 times of volume of the reaction liquid for extractionSeparating with separating funnel and collecting dichloromethane-containing organic phase, and adding large amount of anhydrous Na₂SO₄Drying for 14 h.

Filtering with sand core funnel, separating solid in organic phase, collecting organic phase containing dichloromethane, and removing dichloromethane with rotary evaporator at 40 deg.C to obtain yellow oily crude product with purity of 91%. The crude product was dried using a freeze dryer with a final product yield of 93%.

The invention has been described in detail with reference to specific embodiments and/or illustrative examples and the accompanying drawings, which, however, should not be construed as limiting the invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention. The scope of the invention is defined by the appended claims.