A pyrimidine hydrazide organic gel factor and preparation and application thereof

Abstract

The present application relates to the technical field of supramolecular chemistry, and particularly relates to a pyrimidine acylhydrazine organic gel factor and preparation and application thereof.The preparation process of the pyrimidine acylhydrazine organic gel factor is simple, and the organic gel prepared by further using the pyrimidine acylhydrazine derivative organic gel factor can effectively adsorb and remove bright green, malachite green, crystal violet, rhodamine B and other organic dyes.Among them, the removal rate of bright green dye can be as high as 99.86%, and the removal efficiency of rhodamine B dye can be as high as 99.89%;it is shown that the organic gel of the present application has excellent removal efficiency on organic dyes.

Description

Technical Field

[0001] This invention relates to the field of supramolecular chemistry, and in particular to a pyrimidinyl hydrazine-based organic gelling agent and its preparation and application. Background Technology

[0002] With the rapid development of modern industry, large amounts of industrial wastewater are discharged into the environment, and the pollution caused to aquatic environments has become a serious problem. The chemical industry produces and uses a large number of various types of dyes. These organic dyes are widely used in textiles, paper, plastics, cosmetics, and paints. While dyes bring people a colorful world and huge economic benefits, the wastewater containing these organic dyes places a heavy burden on water purification. These organic dye molecules, once released into water bodies, are difficult to degrade in the natural environment. The dyes in the wastewater can absorb light, reduce water transparency, consume large amounts of oxygen in the water, causing oxygen deficiency, thus affecting the growth of aquatic organisms, damaging aquatic ecosystems, and greatly threatening terrestrial aquatic systems. Therefore, effectively removing organic dyes from industrial wastewater is a serious and challenging problem facing humanity.

[0003] In recent years, research has found that organic gels can be used to remove organic dyes from wastewater. Small organic molecules form a three-dimensional network structure through weak non-covalent interactions, enabling phase-selective gelation at room temperature and effective adsorption and removal of organic dye molecules from wastewater. They are stable, environmentally friendly, and the dynamic reversibility of the gel-sol phase allows for recycling and reuse, significantly outperforming traditional methods such as biochemical treatment, chemical decomposition, and physical adsorption.

[0004] Zhang et al. synthesized a series of glucose-based phase-selective organic gelling agents. These gelling agents can effectively adsorb organic dyes and can be used to remove crystal violet and rhodamine B from wastewater, with removal rates greater than 97%. Although these gelling agents can effectively remove dyes from wastewater, trace amounts of benzyl alcohol remain in the aqueous solution, which may cause secondary pollution to water bodies.

[0005] Kar et al. reported a group of amphiphilic dipeptide carboxylic acids that can effectively gel organic solvents. The authors found that the hydrogels can be transformed into organic gels through pH response. The pH responsiveness of these amphiphilic dipeptides allows them to adsorb and remove large amounts of crystal violet dye from water within minutes, making them suitable for the adsorption and removal of large amounts of dye in wastewater treatment. However, this pH responsiveness also limits the practical applications of these gels.

[0006] Basu et al. discovered a gelling factor based on low molecular weight peptides. They added organic dye solutions of known concentrations to a hydrogel matrix and monitored the concentration of residual dye in the supernatant using UV-Vis spectrophotometry. The authors found that this type of hydrogel could adsorb cationic or anionic organic dyes in water, including Acid Black, Congo Red, Direct Red 80, Malachite Green, and Rhodamine B, with removal efficiencies of 82%, 98%, 93%, 79%, and 71% respectively within 48 hours. However, the relatively long adsorption time limits its application in practical water pollution control.

[0007] In conclusion, further research is needed on using organic gels to adsorb and remove organic dye molecules from wastewater. Summary of the Invention

[0008] To address the aforementioned problems, the present invention aims to provide a pyrimidinyl hydrazine-based organic gelling factor, its preparation, and its application. This factor can self-assemble into small organic molecule gels with a three-dimensional network structure, exhibiting excellent adsorption and removal effects on organic dyes in wastewater. The preparation process of this invention is simple, and the reaction conditions are mild. The pyrimidinyl hydrazine-based organic gelling factor demonstrates good gelling ability to various organic solvents such as methanol, ethanol, n-propanol, and toluene, and in the gel state, it possesses the characteristic of adsorbing organic dyes (brilliant green, malachite green, crystal violet, and rhodamine B).

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] The first objective of this invention is to provide a pyrimidinyl hydrazine-based organic gelling agent, the structural formula of which is selected from one of the structural formulas shown in formula (I), formula (II), or formula (III).

[0011]

[0012]

[0013] A second objective of this invention is to provide a method for preparing a pyrimidinyl hydrazine-based organic gelling factor, comprising the following steps:

[0014] (1) Methyl p-hydroxybenzoate, K2CO3 and bromododecane are mixed in a first organic solvent, and after substitution reaction and post-treatment, methyl p-dodecyloxybenzoate is obtained.

[0015] (2) Methyl p-dodecyloxybenzoate and NH2NH2·H2O prepared in step (1) are mixed in a second organic solvent, and after a first condensation reaction, the mixture is post-treated (recrystallized with ethanol after filtration) to obtain p-dodecyloxybenzoylhydrazine; then 2-carboxylic acid pyrimidine is mixed with a condensing agent in tetrahydrofuran, and after a second condensation reaction with p-dodecyloxybenzoylhydrazine, the mixture is post-treated (separated and purified) to obtain a pyrimidinylhydrazine organic gel factor with the structural formula shown in formula (I).

[0016] Alternatively, NaOH, H2O and the methyl p-dodecyloxybenzoate prepared in step (1) are mixed in a second organic solvent, and after hydrolysis reaction, post-treatment is performed (cooling after reaction and adjusting pH to 1-2, then pouring into cold water, collecting flocculent precipitate and drying) to obtain p-dodecyloxybenzoic acid; then p-dodecyloxybenzoic acid and condensing agent are mixed in tetrahydrofuran, and after condensation reaction with pyrazine-2-formylhydrazine, post-treatment (separation and purification) is performed to obtain pyrimidinylhydrazine organic gelling factor with the structural formula shown in formula (II);

[0017] Alternatively, the methyl p-dodecyloxybenzoate prepared in step (1) and NH2NH2·H2O are mixed in a second organic solvent, and after a first condensation reaction, the mixture is post-treated (recrystallized with ethanol after filtration) to obtain p-dodecyloxybenzoylhydrazine; then 4-pyrimidinecarboxylic acid and a condensing agent are mixed in tetrahydrofuran, and after a second condensation reaction with p-dodecyloxybenzoylhydrazine, the mixture is post-treated (separated and purified) to obtain a pyrimidine hydrazine-based organic gelling factor with the structural formula shown in formula (III).

[0018] In one embodiment of the present invention, in step (1), the molar ratio of methylparaben, K2CO3 and bromododecane is 1:0.8-1.2:0.8-1.2;

[0019] During the substitution reaction, the temperature is 70℃~90℃ and the time is 7h~10h.

[0020] In one embodiment of the present invention, in step (1), the first organic solvent is N,N-dimethylformamide.

[0021] In one embodiment of the present invention, in step (1), the post-processing is filtration, extraction, and column chromatography separation.

[0022] In one embodiment of the present invention, in step (2), the condensing agent is a mixture of EDCl and HOBt.

[0023] In one embodiment of the present invention, in step (2), the second organic solvent is a mixture of dichloromethane and ethanol with a volume ratio of 1:0.8 to 1.2.

[0024] In one embodiment of the present invention, in step (2), when preparing the pyrimidinyl hydrazine organic gelling factor with the structural formula shown in formula (I), the molar ratio of methyl dodecyloxybenzoate to NH2NH2·H2O is 1:65-70; during the one-time condensation reaction, the temperature is 18℃-35℃ and the time is 24h-36h.

[0025] The molar ratio of 2-carboxylic acid pyrimidine, EDCl, HOBt and p-dodecyloxybenzoylhydrazine is 2–8:3–7:3–7:5; the temperature during the secondary condensation reaction is 18℃–35℃ and the time is 24h–36h.

[0026] In one embodiment of the present invention, in step (2), when preparing the pyrimidinyl hydrazine organic gel factor with the structural formula shown in formula (II), the ratio of NaOH, H2O to methyl p-dodecyloxybenzoate is 0.3-0.5g: 2-3mL: 1g; during the hydrolysis reaction, the temperature is 60℃-70℃ and the time is 5h-8h.

[0027] The molar ratio of p-dodecyloxybenzoic acid, EDCl, HOBt and pyrazine-2-carboxylhydrazide is 2–8:3–7:3–7:5; the condensation reaction is carried out at a temperature of 18℃–35℃ for 24–36 hours.

[0028] In one embodiment of the present invention, in step (2), when preparing the pyrimidinyl hydrazine organic gelling factor with the structural formula shown in formula (III), the molar ratio of methyl dodecyloxybenzoate to NH2NH2·H2O is 1:65-70; during the one-time condensation reaction, the temperature is 18℃-35℃ and the time is 24h-36h.

[0029] The molar ratio of 4-pyrimidinecarboxylic acid, EDCl, HOBt and p-dodecyloxybenzoylhydrazine is 2–8:3–7:3–7:5; the temperature during the secondary condensation reaction is 18℃–35℃ and the time is 24h–36h.

[0030] A third objective of this invention is to provide a method for preparing an organic gel for adsorbing and removing dyes, comprising the following steps:

[0031] The above-mentioned pyrimidinyl hydrazine-based organic gelling factor was mixed with an organic solvent and then self-assembled by a heating-cooling method to obtain an organic gel for adsorbing and removing dyes.

[0032] In one embodiment of the present invention, the heating-cooling method involves heating to the phase transition temperature of the pyrimidinyl hydrazine organic gelling factor to completely dissolve the pyrimidinyl hydrazine organic gelling factor, and then cooling to room temperature;

[0033] During the heating process, the temperature is above 80℃.

[0034] In one embodiment of the present invention, the organic solvent is selected from methanol, ethanol, n-propanol or toluene;

[0035] The ratio of pyrimidinyl hydrazine organic gelling agent to organic solvent is 18 mg to 22 mg: 0.2 mL to 0.5 mL.

[0036] In one embodiment of the present invention, the organic dye is selected from one of Brilliant Green, Malachite Green, Crystal Violet, or Rhodamine B.

[0037] A fourth objective of this invention is to provide an organic gel prepared by the above method for adsorbing and removing dyes.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) This invention designs and synthesizes a pyrimidinyl hydrazine derivative organic gel factor, which can self-assemble into a stable organic gel in a variety of organic solvents such as methanol, ethanol, n-propanol and toluene through non-covalent weak interactions such as hydrogen bonds between amide groups, π-π interactions between benzene rings and hydrophobic interactions between long alkyl chains; and the three-dimensional network structure of the organic gel can effectively adsorb organic dyes.

[0040] (2) The preparation process of this invention is simple. The organic gel prepared using pyrimidinyl hydrazine derivative organic gelling factors can effectively adsorb and remove organic dyes such as brilliant green, malachite green, crystal violet, and rhodamine B. Among them, the removal rate of brilliant green dye can reach up to 99.86%, and the removal efficiency of rhodamine B dye can reach up to 99.89%; indicating that the organic gel of this invention has excellent removal efficiency for organic dyes. Attached Figure Description

[0041] Figure 1 These are images showing the effect of organic gel adsorption and dye removal in Examples 3-6;

[0042] Figure 2 The UV-Vis absorption spectra of the organic gel before and after adsorption of bright green dye in Example 3 are shown.

[0043] Figure 3 The image shows the UV-Vis absorption spectra of the organic gel before and after the adsorption of malachite green dye in Example 4.

[0044] Figure 4 The image shows the UV-Vis absorption spectra of the organic gel before and after the adsorption of crystal violet dye in Example 5.

[0045] Figure 5 The image shows the UV-Vis absorption spectra of the organic gel before and after adsorption of Rhodamine B dye in Example 6. Detailed Implementation

[0046] This invention provides a pyrimidinyl hydrazine-based organic gelling factor, the structural formula of which is selected from one of the structural formulas shown in formula (I), formula (II), or formula (III).

[0047]

[0048] This invention provides a method for preparing a pyrimidinyl hydrazine-based organic gelling factor, comprising the following steps:

[0049] (1) Methyl p-hydroxybenzoate, K2CO3 and bromododecane are mixed in a first organic solvent, and after substitution reaction and post-treatment, methyl p-dodecyloxybenzoate is obtained.

[0050] (2) Methyl p-dodecyloxybenzoate and NH2NH2·H2O prepared in step (1) are mixed in a second organic solvent, and after a first condensation reaction, the mixture is post-treated (recrystallized with ethanol after filtration) to obtain p-dodecyloxybenzoylhydrazine; then 2-carboxylic acid pyrimidine is mixed with a condensing agent in tetrahydrofuran, and after a second condensation reaction with p-dodecyloxybenzoylhydrazine, the mixture is post-treated (separated and purified) to obtain a pyrimidinylhydrazine organic gel factor with the structural formula shown in formula (I).

[0051] Alternatively, NaOH, H2O and the methyl p-dodecyloxybenzoate prepared in step (1) are mixed in a second organic solvent, and after hydrolysis reaction, post-treatment is performed (cooling after reaction and adjusting pH to 1-2, then pouring into cold water, collecting flocculent precipitate and drying) to obtain p-dodecyloxybenzoic acid; then p-dodecyloxybenzoic acid and condensing agent are mixed in tetrahydrofuran, and after condensation reaction with pyrazine-2-formylhydrazine, post-treatment (separation and purification) is performed to obtain pyrimidinylhydrazine organic gelling factor with the structural formula shown in formula (II);

[0052] Alternatively, the methyl p-dodecyloxybenzoate prepared in step (1) and NH2NH2·H2O are mixed in a second organic solvent, and after a first condensation reaction, the mixture is post-treated (recrystallized with ethanol after filtration) to obtain p-dodecyloxybenzoylhydrazine; then 4-pyrimidinecarboxylic acid and a condensing agent are mixed in tetrahydrofuran, and after a second condensation reaction with p-dodecyloxybenzoylhydrazine, the mixture is post-treated (separated and purified) to obtain a pyrimidine hydrazine-based organic gelling factor with the structural formula shown in formula (III).

[0053] In one embodiment of the present invention, in step (1), the molar ratio of methylparaben, K2CO3 and bromododecane is 1:0.8-1.2:0.8-1.2;

[0054] During the substitution reaction, the temperature is 70℃~90℃ and the time is 7h~10h.

[0055] In one embodiment of the present invention, in step (1), the first organic solvent is N,N-dimethylformamide.

[0056] In one embodiment of the present invention, in step (1), the post-processing is filtration, extraction, and column chromatography separation.

[0057] In one embodiment of the present invention, in step (2), the condensing agent is a mixture of EDCl and HOBt.

[0058] In one embodiment of the present invention, in step (2), the second organic solvent is a mixture of dichloromethane and ethanol with a volume ratio of 1:0.8 to 1.2.

[0059] In one embodiment of the present invention, in step (2), when preparing the pyrimidinyl hydrazine organic gelling factor with the structural formula shown in formula (I), the molar ratio of methyl dodecyloxybenzoate to NH2NH2·H2O is 1:65-70; during the one-time condensation reaction, the temperature is 18℃-35℃ and the time is 24h-36h.

[0060] The molar ratio of 2-carboxylic acid pyrimidine, EDCl, HOBt and p-dodecyloxybenzoylhydrazine is 2–8:3–7:3–7:5; the temperature during the secondary condensation reaction is 18℃–35℃ and the time is 24h–36h.

[0061] In one embodiment of the present invention, in step (2), when preparing the pyrimidinyl hydrazine organic gel factor with the structural formula shown in formula (II), the ratio of NaOH, H2O to methyl p-dodecyloxybenzoate is 0.3-0.5g: 2-3mL: 1g; during the hydrolysis reaction, the temperature is 60℃-70℃ and the time is 5h-8h.

[0062] The molar ratio of p-dodecyloxybenzoic acid, EDCl, HOBt and pyrazine-2-carboxylhydrazide is 2–8:3–7:3–7:5; the condensation reaction is carried out at a temperature of 18℃–35℃ for 24–36 hours.

[0063] In one embodiment of the present invention, in step (2), when preparing the pyrimidinyl hydrazine organic gelling factor with the structural formula shown in formula (III), the molar ratio of methyl dodecyloxybenzoate to NH2NH2·H2O is 1:65-70; during the one-time condensation reaction, the temperature is 18℃-35℃ and the time is 24h-36h.

[0064] The molar ratio of 4-pyrimidinecarboxylic acid, EDCl, HOBt and p-dodecyloxybenzoylhydrazine is 2–8:3–7:3–7:5; the temperature during the secondary condensation reaction is 18℃–35℃ and the time is 24h–36h.

[0065] This invention provides a method for preparing an organic gel for adsorbing and removing dyes, comprising the following steps:

[0066] The above-mentioned pyrimidinyl hydrazine-based organic gelling factor was mixed with an organic solvent and then self-assembled by a heating-cooling method to obtain an organic gel for adsorbing and removing dyes.

[0067] In one embodiment of the present invention, the heating-cooling method involves heating to the phase transition temperature of the pyrimidinyl hydrazine organic gelling factor to completely dissolve the pyrimidinyl hydrazine organic gelling factor, and then cooling to room temperature;

[0068] During the heating process, the temperature is above 80℃.

[0069] In one embodiment of the present invention, the organic solvent is selected from methanol, ethanol, n-propanol or toluene;

[0070] The ratio of pyrimidinyl hydrazine organic gelling agent to organic solvent is 18 mg to 22 mg: 0.2 mL to 0.5 mL.

[0071] In one embodiment of the present invention, the organic dye is selected from one of Brilliant Green, Malachite Green, Crystal Violet, or Rhodamine B.

[0072] This invention provides an organic gel prepared by the above method for adsorbing and removing dyes.

[0073] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0074] Unless otherwise specified, all reagents used in the following embodiments are commercially available reagents, and all detection methods and techniques used are conventional detection methods and techniques in the art.

[0075] Example 1

[0076] This embodiment provides a pyrimidinyl hydrazine-based organic gelling agent and its preparation method.

[0077] The preparation process of the pyrimidinyl hydrazine-based organic gelling factor in this embodiment is as follows:

[0078] (1) Methyl p-hydroxybenzoate, K2CO3 and bromododecane were dissolved in N,N-dimethylformamide in a molar ratio of 1:1:1 and mixed well. The mixture was reacted at 80°C for 8 hours. After filtration, extraction and column chromatography separation, methyl p-dodecyloxybenzoate was obtained.

[0079] (2) Methyl p-dodecyloxybenzoate obtained in step (1), NaOH, and H2O were dissolved in a mixed solution of dichloromethane and ethanol (volume ratio of dichloromethane to ethanol was 1:1) at a feed ratio of 1 g: 0.4 g: 2.5 mL and reacted at 65 °C for 7 h. After cooling, the pH was adjusted to 2 and then poured into cold water. The flocculent precipitate was collected and dried to obtain p-dodecyloxybenzoic acid.

[0080] (3) Dissolve the p-dodecyloxybenzoic acid and condensing agent (EDCl and HOBt) obtained in step (2) in tetrahydrofuran, then add pyrazine-2-carboxylhydrazine and carry out a condensation reaction at 25°C for 30 h. After extraction and column chromatography separation, a white powdery pyrimidinylhydrazine organic gel factor (structural formula as shown in formula (II)) is obtained.

[0081]

[0082] The molar ratio of p-dodecyloxybenzoic acid, EDCl, HOBt, and pyrazine-2-formylhydrazide is 1:1:1:1.

[0083] Example 2

[0084] This embodiment provides an organic gel for adsorbing and removing dyes and a method for preparing the same.

[0085] 20 mg of the pyrimidinyl hydrazine organic gel factor prepared in Example 1 was placed in a glass vial with a screw cap (sample vial), 0.3 mL of toluene was added, and the mixture was heated to 87 °C. After it was completely dissolved, it was cooled to room temperature. When no flow was observed after the sample vial was inverted, an organic gel for adsorbing and removing dyes (hereinafter referred to as "organic gel") was prepared.

[0086] Among them, pyrimidinyl hydrazine organic gelling agents can form stable white organic gels in solvents such as methanol, ethanol and toluene.

[0087] Example 3

[0088] This embodiment tests the adsorption and removal capacity of the organic gel prepared in Example 2 for bright green dye.

[0089] The organic gel prepared in Example 2 (containing 20 mg of pyrimidinyl hydrazine organic gelling factor) was placed in 3 mL of brilliant green solution (3 × 10⁻⁶). -5 In M), after 24 hours, the bright green dye ( Figure 1 (1) The color of the aqueous solution gradually changed from dark blue to colorless, indicating that the dye was effectively adsorbed by the organic gel.

[0090] After collecting the water layer, dilute it three times and mix it with 1×10 -5 The UV-Vis absorption spectrum of the bright green solution of M is shown below. Figure 2As shown in the figure, the effect of organogel adsorption on the removal of brilliant green dye was studied using a UV-Vis spectrophotometer. The purification efficiency E was calculated using E = (A0 - A) / A0, where A0 and A represent the absorption peak intensities of the brilliant green solution at 624 nm before and after purification, respectively. The calculation using the provided equation showed that the organogel achieved an adsorption removal rate of 99.86% for brilliant green dye.

[0091] Example 4

[0092] This embodiment tests the adsorption and removal capacity of the organic gel prepared in Example 2 for malachite green dye.

[0093] The organic gel prepared in Example 2 (containing 20 mg of pyrimidinyl hydrazine organic gelling factor) was placed in 3 mL of malachite green solution (3 × 10⁻⁶). -5 In M), malachite green dye (M) was applied 24 hours later. Figure 1 (2) The color of the aqueous solution changed from blue to colorless, indicating that the dye was effectively adsorbed by the organic gel.

[0094] After collecting the water layer, dilute it three times and mix it with 1×10 -5 The UV-Vis absorption spectrum of malachite green solution M is shown below. Figure 3 As shown in the figure, the effect of organic gel adsorption on the removal of malachite green dye was studied using a UV-Vis spectrophotometer. The purification efficiency E was calculated using E = (A0 - A) / A0, where A0 and A represent the absorption peak intensities of the malachite green solution at 616 nm before and after purification, respectively. The calculation using the provided equation showed that the adsorption removal rate of malachite green dye by the organic gel reached 90.39%.

[0095] Example 5

[0096] This embodiment tests the adsorption and removal capacity of the organic gel prepared in Example 2 for crystal violet dye.

[0097] The organic gel prepared in Example 2 (containing 20 mg of pyrimidinyl hydrazine organic gelling factor) was placed in 3 mL of crystal violet solution (3 × 10⁻⁶). -5 In M), crystal violet dye (M) was applied after 24 hours. Figure 1 (3) The color of the aqueous solution gradually changed from dark purple to light purple, indicating that the dye was effectively adsorbed by the organic gel.

[0098] After collecting the water layer, dilute it three times and mix it with 1×10 -5 The UV-Vis absorption spectrum of the crystal violet solution of M is shown below. Figure 4As shown in the figure, the effect of organic gel adsorption on the removal of crystal violet dye was studied using a UV-Vis spectrophotometer. The purification efficiency E was calculated using E = (A0 - A) / A0, where A0 and A represent the absorption peak intensities of the crystal violet solution at 591 nm before and after purification, respectively. The calculation using the provided equation showed that the adsorption removal rate of crystal violet dye by the organic gel reached 93.67%.

[0099] Example 6

[0100] This embodiment tests the adsorption and removal capacity of the organic gel prepared in Example 2, which is capable of adsorbing and removing organic dyes, for Rhodamine B dye.

[0101] The organic gel prepared in Example 2 (containing 20 mg of pyrimidinyl hydrazine organic gelling factor) was placed in 3 mL of Rhodamine B solution (3 × 10⁻⁶). -5 In M), after 24 hours, Rhodamine B dye ( Figure 1 (4) The color of the aqueous solution changed from pink to colorless, indicating that the dye was effectively adsorbed by the organic gel.

[0102] After collecting the water layer, dilute it three times and mix it with 1×10 -5 The UV-Vis absorption spectrum of Rhodamine B solution M is shown below. Figure 5 As shown in the figure, the effect of organic gel adsorption on the removal of Rhodamine B dye was studied using a UV-Vis spectrophotometer. The purification efficiency E was calculated using E = (A0 - A) / A0, where A0 and A represent the absorption peak intensities of the Rhodamine B solution at 554 nm before and after purification, respectively. The calculation using the provided equation showed that the adsorption removal rate of Rhodamine B dye by the organic gel reached 99.89%.

[0103] Example 7

[0104] This embodiment provides a pyrimidinyl hydrazine-based organic gelling agent and its preparation method.

[0105] The preparation process of the pyrimidinyl hydrazine-based organic gelling factor in this embodiment is as follows:

[0106] (1) Methyl p-hydroxybenzoate, K2CO3 and bromododecane were dissolved in N,N-dimethylformamide in a molar ratio of 1:1:1 and mixed well. The mixture was reacted at 80°C for 8 hours. After filtration, extraction and column chromatography separation, methyl p-dodecyloxybenzoate was obtained.

[0107] (2) Methyl p-dodecyloxybenzoate and NH2NH2·H2O were mixed in ethanol at a molar ratio of 1:68. The mixture was stirred under reflux and condensed for 24 h. The mixture was then poured into water and the suspension was filtered. The suspension was washed with 50 mL of water and the product was recrystallized from ethanol to obtain p-dodecyloxybenzoylhydrazine.

[0108] (3) Dissolve 2-carboxylic acid pyrimidine and condensing agent (EDCl and HOBt) in tetrahydrofuran, then add p-dodecyloxybenzoyl hydrazine obtained in step (2) and carry out condensation reaction at 25°C for 30 h. After extraction and column chromatography separation, a white powdery pyrimidine hydrazine organic gel factor (structural formula as shown in formula (I)) is obtained.

[0109]

[0110] The molar ratio of 2-carboxylic acid pyrimidine, EDCl, HOBt, and p-dodecyloxybenzoyl hydrazine is 1:1:1:1.

[0111] Example 8

[0112] This embodiment provides an organic gel for adsorbing and removing dyes and a method for preparing the same.

[0113] 20 mg of the pyrimidinyl hydrazine-based organic gel factor prepared in Example 7 was placed in a glass vial (sample vial) with a screw cap, 0.3 mL of toluene was added, and the mixture was heated to 87 °C. After complete dissolution, the mixture was cooled to room temperature. When no flow was observed after the sample vial was inverted, an organic gel for adsorbing and removing dyes was prepared.

[0114] Example 9

[0115] This embodiment provides a pyrimidinyl hydrazine-based organic gelling agent and its preparation method.

[0116] The preparation process of the pyrimidinyl hydrazine-based organic gelling factor in this embodiment is as follows:

[0117] (1) Methyl p-hydroxybenzoate, K2CO3 and bromododecane were dissolved in N,N-dimethylformamide in a molar ratio of 1:1:1 and mixed well. The mixture was reacted at 80°C for 8 hours. After filtration, extraction and column chromatography separation, methyl p-dodecyloxybenzoate was obtained.

[0118] (2) Methyl p-dodecyloxybenzoate and NH2NH2·H2O were mixed in ethanol at a molar ratio of 1:70. The mixture was stirred under reflux and condensed for 24 h. The mixture was then poured into water and the suspension was filtered. The suspension was washed with 50 mL of water and the product was recrystallized from ethanol to obtain p-dodecyloxybenzoylhydrazine.

[0119] (3) Dissolve 4-pyrimidinecarboxylic acid and condensing agents (EDCl and HOBt) in tetrahydrofuran, then add p-dodecyloxybenzoylhydrazine obtained in step (2) and carry out a condensation reaction at 25°C for 30 h. After extraction and column chromatography separation, a white powdery pyrimidine hydrazine organic gel factor (structural formula as shown in formula (III)) is obtained.

[0120]

[0121] The molar ratio of 4-pyrimidinecarboxylic acid, EDCl, HOBt, and p-dodecyloxybenzoylhydrazine is 1:1:1:1.

[0122] Example 10

[0123] This embodiment provides an organic gel for adsorbing and removing dyes and a method for preparing the same.

[0124] 20 mg of the pyrimidinyl hydrazine-based organic gel factor prepared in Example 9 was placed in a glass vial (sample vial) with a screw cap, 0.3 mL of toluene was added, and the mixture was heated to 87 °C. After complete dissolution, the mixture was cooled to room temperature. When no flow was observed after the sample vial was inverted, an organic gel for adsorbing and removing dyes was prepared.

[0125] Example 11

[0126] This embodiment provides a pyrimidinyl hydrazine-based organic gelling agent and its preparation method.

[0127] The preparation process of the pyrimidinyl hydrazine-based organic gelling factor in this embodiment is as follows:

[0128] (1) Methyl p-hydroxybenzoate, K2CO3, and bromododecane were dissolved in N,N-dimethylformamide in a molar ratio of 1:0.8:0.8 and mixed well. The mixture was reacted at 70°C for 10 h. After filtration, extraction, and column chromatography separation, methyl p-dodecyloxybenzoate was obtained.

[0129] (2) Methyl p-dodecyloxybenzoate obtained in step (1), NaOH, and H2O were dissolved in a mixed solution of dichloromethane and ethanol (volume ratio of dichloromethane to ethanol was 1:0.8) at a feed ratio of 1g:0.3g:2mL and reacted at 60℃ for 8h. After cooling, the pH was adjusted to 1 and then poured into cold water. The flocculent precipitate was collected and dried to obtain p-dodecyloxybenzoic acid.

[0130] (3) Dissolve the p-dodecyloxybenzoic acid and condensing agent (EDCl and HOBt) obtained in step (2) in tetrahydrofuran, then add pyrazine-2-carboxylhydrazine and carry out a condensation reaction at 18°C ​​for 36 h. After extraction and column chromatography separation, a white powdery pyrimidinylhydrazine organic gel factor (structural formula as shown in formula (II)) is obtained.

[0131] The molar ratio of p-dodecyloxybenzoic acid, EDCl, HOBt, and pyrazine-2-formylhydrazide is 2:3:3:5.

[0132] Example 12

[0133] This embodiment provides a pyrimidinyl hydrazine-based organic gelling agent and its preparation method.

[0134] The preparation process of the pyrimidinyl hydrazine-based organic gelling factor in this embodiment is as follows:

[0135] (1) Methyl p-hydroxybenzoate, K2CO3, and bromododecane were dissolved in N,N-dimethylformamide in a molar ratio of 1:1.2:1.2 and mixed well. The mixture was reacted at 90°C for 7 h. After filtration, extraction, and column chromatography, methyl p-dodecyloxybenzoate was obtained.

[0136] (2) Methyl p-dodecyloxybenzoate obtained in step (1), NaOH, and H2O were dissolved in a mixed solution of dichloromethane and ethanol (volume ratio of dichloromethane to ethanol was 1:1.2) at a feed ratio of 1g:0.5g:3mL and reacted at 70℃ for 5h. After cooling, the pH was adjusted to 1, and then poured into cold water. The flocculent precipitate was collected and dried to obtain p-dodecyloxybenzoic acid.

[0137] (3) Dissolve the p-dodecyloxybenzoic acid and condensing agent (EDCl and HOBt) obtained in step (2) in tetrahydrofuran, then add pyrazine-2-carbamoylhydrazine and carry out a condensation reaction at 35°C for 24 h. After extraction and column chromatography separation, a white powdery pyrimidinylhydrazine organic gel factor (structural formula as shown in formula (II)) is obtained.

[0138] The molar ratio of p-dodecyloxybenzoic acid, EDCl, HOBt, and pyrazine-2-formylhydrazide is 8:7:7:5.

[0139] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A pyrimidine hydrazide-based organogelator, characterized by, is selected from one of structural formulae (I), (II) or (III), 2. A process for the preparation of a pyrimidine hydrazide-based organogelator as claimed in claim 1, characterized in that, The method comprises the following steps: (1) mixing methyl p-hydroxybenzoate, K2CO3 and bromododecane in a first organic solvent, and carrying out substitution reaction to obtain methyl p-dodecyloxybenzoate, and then carrying out post-treatment; (2) mixing methyl p-dodecyloxybenzoate obtained in step (1) and NH2NH2·H2O in a second organic solvent, and carrying out one-step condensation reaction to obtain p-dodecyloxybenzohydrazide, and then mixing 2-carboxypyrimidine and a condensing agent in tetrahydrofuran, and carrying out two-step condensation reaction with p-dodecyloxybenzohydrazide to obtain a pyrimidine hydrazide organic gel factor with a structural formula as shown in formula (I); or, mixing NaOH, H2O and methyl p-dodecyloxybenzoate obtained in step (1) in a second organic solvent, and carrying out hydrolysis reaction to obtain p-dodecyloxybenzoic acid, and then mixing p-dodecyloxybenzoic acid and a condensing agent in tetrahydrofuran, and carrying out condensation reaction with pyrazine-2-carboxyhydrazide to obtain a pyrimidine hydrazide organic gel factor with a structural formula as shown in formula (II); or, mixing methyl p-dodecyloxybenzoate obtained in step (1) and NH2NH2·H2O in a second organic solvent, and carrying out one-step condensation reaction to obtain p-dodecyloxybenzohydrazide, and then mixing 4-pyrimidine carboxylic acid and a condensing agent in tetrahydrofuran, and carrying out two-step condensation reaction with p-dodecyloxybenzohydrazide to obtain a pyrimidine hydrazide organic gel factor with a structural formula as shown in formula (III).

3. The method for preparing a pyrimidinyl hydrazine-based organic gelling factor according to claim 2, characterized in that, In step (1), the molar ratio of methyl p-hydroxybenzoate, K2CO3 and bromododecane is 1:0.8-1.2:0.8-1.

2. In the substitution reaction process, the temperature is 70-90°C, and the time is 7-10 hours.

4. The method for preparing a pyrimidinyl hydrazine-based organic gelling factor according to claim 2, characterized in that, In step (2), the condensing agent is a mixture of EDCl and HOBt.

5. The method for preparing a pyrimidinyl hydrazine-based organogel agent according to claim 4, characterized in that, In step (2), when the pyrimidine hydrazide organic gel factor with a structural formula as shown in formula (I) is prepared, the molar ratio of methyl p-dodecyloxybenzoate and NH2NH2·H2O is 1:65-70; in the one-step condensation reaction process, the temperature is 18-35°C, and the time is 24-36 hours. The molar ratio of 2-carboxypyrimidine, EDCl, HOBt and p-dodecyloxybenzohydrazide is 2-8:3-7:3-7:5; in the two-step condensation reaction process, the temperature is 18-35°C, and the time is 24-36 hours.

6. The method for preparing a pyrimidinyl hydrazine-based organogel agent according to claim 4, characterized in that, In step (2), when the pyrimidine hydrazide organic gel factor with a structural formula as shown in formula (II) is prepared, the dosage ratio of NaOH, H2O and methyl p-dodecyloxybenzoate is 0.3-0.5 g:2-3 mL:1 g; in the hydrolysis reaction process, the temperature is 60-70°C, and the time is 5-8 hours. The molar ratio of p-dodecyloxybenzoic acid, EDCl, HOBt and pyrazine-2-carboxyhydrazide is 2-8:3-7:3-7:5; in the condensation reaction process, the temperature is 18-35°C, and the time is 24-36 hours.

7. The method of claim 4, wherein the organic gelator is prepared by the reaction of 2,4,6-trichloropyrimidine and hydrazine hydrate in the presence of a solvent. In step (2), the molar ratio of methyl dodecylbenzenesulfonate and NH2NH2·H2O is 1:65-70 in the preparation of the pyrimidine hydrazide organic gelator of formula (III); the temperature is 18-35°C and the time is 24-36 hours in the first condensation reaction; The molar ratio of 4-pyrimidine carboxylic acid, EDCl, HOBt and p-dodecylbenzoyl hydrazine is 2-8:3-7:3-7:5 in the second condensation reaction; the temperature is 18-35°C and the time is 24-36 hours.

8. A process for the preparation of an organic gel for the adsorptive removal of dyes, characterized in that The method comprises the following steps: The pyrimidine hydrazide organic gelator of claim 1 is mixed with an organic solvent to obtain an organic gel for adsorbing and removing dyes by a heating-cooling method; The organic solvent is selected from one of methanol, ethanol, n-butanol or toluene.

9. A process for the preparation of an organic gel for the adsorptive removal of dyes as claimed in claim 8, wherein, The heating-cooling method is heating to the phase transition temperature of the pyrimidine hydrazide organic gelator to dissolve the pyrimidine hydrazide organic gelator, and then cooling to room temperature.

10. An organic gel for adsorbing and removing dyes prepared by the method of any one of claims 8-9.

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