Organic catalyst as well as preparation method and application thereof

Abstract

The invention provides an organic catalyst as well as a preparation method and application thereof, and belongs to the technical field of organic chemistry. The preparation method comprises the following steps: reacting maleic acid with NiCuAl-LDHs to prepare modified NiCuAl-LDHs, copolymerizing the modified NiCuAl-LDHs with an ionic liquid with double bonds, and further reacting with a Gemini surfactant to prepare the organic catalyst. The organic catalyst prepared by the invention can improve the efficiency of emulsification in which the catalyst participates, so that the efficiency of reaction with sodium sulfite is improved, the occurrence of side reactions can be reduced, the reaction rate is accelerated, the reaction energy barrier is reduced, the reaction conditions are milder, the reaction yield is improved, and the organic catalyst has the effects of saving energy and improving efficiency.

Description

Technical Field

[0001] This invention relates to the field of organic chemistry, specifically to an organic catalyst, its preparation method, and its application. Background Technology

[0002] Sodium 2-chloroethyl sulfonate (CES) is an important pharmaceutical intermediate that can be used to synthesize various alkyl sulfonic acid compounds (including taurine, an important pharmaceutical raw material), as well as alkylated methyl taurate for hard water resistant detergents and sodium vinyl sulfonate for acrylonitrile fiber dyeing modifiers.

[0003] Sodium 2-chloroethylsulfonate is synthesized by reacting 1,2-dichloroethane (DEC) with sodium sulfite, as shown in the following reaction formula:

[0004] ClCH2CH2Cl + NaSO3→ClCH2CH2SO3Na + NaCl

[0005] Based on the different reaction media, there are three methods:

[0006] (1) The method of using water as the reaction medium;

[0007] (2) Using an alcohol-water solution method;

[0008] (3) Using water as the reaction medium and adding a small amount of surfactant.

[0009] In these reactions, the amount of compound produced in a single reaction is small (based on the amount of sodium 2-chloroethylsulfonate produced / total feed including reaction medium: g / kg), the synthesis efficiency is low, and the reaction completion time is long.

[0010] The first method involves 1,2-dichloroethane, which is insoluble in water, resulting in low reaction efficiency.

[0011] The second method uses an alcohol-water solution as the reaction medium. This method increases the solubility of 1,2-dichloroethane in the reaction medium, but significantly reduces the solubility of sodium sulfite, which mostly exists in solid form, requiring a long time to complete the reaction. US Patent 1888794A discloses the reaction of 1,2-dichloroethane and sodium sulfite in an ethanol-water medium in a copper reactor to produce sodium 2-chloroethylsulfonate. The product yield is only about 40%, which is low, and the reaction is very slow, requiring a high proportion of 1,2-dichloroethane and sodium sulfite, making it difficult to carry out industrial-scale production.

[0012] The third method involves adding a small amount of surfactant to the water used as the reaction medium. While 1,2-dichloroethane is not completely soluble in water, the surfactant allows it to emulsify and disperse well in the sodium sulfite aqueous solution, thus increasing its contact area and significantly improving upon the previous two methods. However, repeated experiments revealed the formation of a significant amount of byproducts.

[0013] US Patent US2067873A discloses the reaction of 1-bromo-2-chloroethane with sulfite in the presence of a copper catalyst such as metallic copper or cuprous chloride. Although the reaction yield can reach 78%, the conversion rate of 1-bromo-2-chloroethane is not high, resulting in a relatively high cost for the synthesis of sodium 2-chloroethylsulfonate.

[0014] US Patent 2797239 discloses a method that uses 1-bromo-2-chloroethane instead of 1,2-dichloroethane as a starting material, and finds that the reaction yield can be increased from 42% to 90.7%. However, the method in this patent requires a reaction time of at least 3.5 hours, and generally more than ten hours. Summary of the Invention

[0015] The purpose of this invention is to propose an organic catalyst, its preparation method, and its application, which can improve the emulsification efficiency of the catalyst, thereby increasing the reaction efficiency with sodium sulfite. At the same time, it can also reduce the occurrence of side reactions, accelerate the reaction rate, lower the reaction energy barrier, make the reaction conditions milder, and improve the reaction yield, thus having the effect of energy saving and efficiency improvement.

[0016] The technical solution of this invention is implemented as follows:

[0017] This invention provides a method for preparing an organic catalyst, comprising reacting maleic acid with NiCuAl-LDHs to obtain modified NiCuAl-LDHs, copolymerizing them with an ionic liquid containing double bonds, and further reacting them with a Gemini surfactant to obtain the organic catalyst. The structural formula of the Gemini surfactant is shown in Formula I.

[0018]

[0019] Formula I.

[0020] As a further improvement of the present invention, the method for preparing the Gemini surfactant includes the following steps:

[0021] S1. Aliphatic amines and glycidol were reacted to prepare product 1, with the following structure: ;

[0022] S2. Product 1 is reacted with a bromoalkane to obtain product 2, with the following structure: ;

[0023] S3. Product 2 was reacted with sodium hydroxide to obtain product 3, with the following structure:

[0024] ;

[0025] S4. Product 3 was reacted with sodium 2-bromoethylsulfonate to obtain product 4, with the following structure:

[0026] ;

[0027] S5. The product 4 was reacted with 1,3-dichloro-2-propanol to prepare a Gemini-type surfactant.

[0028] As a further improvement of the present invention, the molar ratio of the fatty amine and glycidol in step S1 is 1:1-1.1, and the fatty amine is selected from at least one of n-octylamine, n-nonylamine, dodecylamine, n-hexadecylamine, and n-octadecylamine; the molar ratio of product 1 and bromoalkane in step S2 is 1-1.1:1, and the bromoalkane is selected from at least one of 1-bromononane, 1-bromodecane, 1-bromododecane, 1-bromotetradecane, 1-bromohexadecane, and 1-bromooctadecane; the molar ratio of product 2 and sodium hydroxide in step S3 is 1:1.3-1.7; the molar ratio of product 3 and sodium 2-bromoethylsulfonate in step S4 is 1:2-2.2; and the molar ratio of product 4 and 1,3-dichloro-2-propanol in step S5 is 2-2.05:1.

[0029] As a further improvement to the present invention, the following steps are included:

[0030] (1) Preparation of NiCuAl-LDHs: Aluminum nitrate, copper oxide and nickel oxide were added to nitric acid solution to obtain solution A; NaOH and concentrated nitric acid were dissolved in water to obtain solution B; inert gas was introduced into solution A, solution B was added dropwise, the reaction was heated and stirred, microwaved, filtered, washed and dried to obtain NiCuAl-LDHs;

[0031] (2) Modification: NiCuAl-LDHs were added to ethanol, silane coupling agent KH570 was added, the mixture was heated and stirred to react, filtered, washed and dried to obtain modified NiCuAl-LDHs;

[0032] (3) Copolymerization: Modified NiCuAl-LDHs, acrylic acid, and 1-allyl-3-methylimidazolium chloride were added to ethanol. Under inert gas protection, an initiator was added, and the mixture was heated and stirred to react. After centrifugation, washing, and drying, copolymerized NiCuAl-LDHs were obtained.

[0033] (4) Reaction: Add the copolymerized NiCuAl-LDHs, Gemini-type surfactant and p-toluenesulfonic acid to toluene, heat and reflux and stir to react, filter, wash and dry to obtain the organic catalyst.

[0034] As a further improvement of the present invention, in step (1), the molar ratio of aluminum nitrate, copper oxide and nickel oxide is 1:1-2:1-2, the concentration of the nitric acid solution is 5-10wt%, the mass ratio of NaOH and concentrated nitric acid is 7-9:1-2, the concentration of the concentrated nitric acid is 68wt%, the power of the microwave reaction is 300-500W, and the time is 0.5-1.5h; in step (2), the mass ratio of NiCuAl-LDHs and silane coupling agent KH570 is 10:2-3, the temperature of the heating and stirring reaction is 40-50℃, and the time is 3-5h.

[0035] As a further improvement of the present invention, in step (3), the mass ratio of modified NiCuAl-LDHs, acrylic acid, 1-allyl-3-methylimidazolium chloride and initiator is 10:2-3:2-4:0.05-0.1, the temperature of the heating and stirring reaction is 50-60℃, and the time is 3-5h; in step (4), the mass ratio of copolymerized NiCuAl-LDHs, Gemini type surfactant and p-toluenesulfonic acid is 12-15:3-5:0.5-1, and the time of the heating and reflux stirring reaction is 6-8h.

[0036] The present invention further protects an organic catalyst prepared by the above-described preparation method.

[0037] The present invention further protects the use of the above-mentioned organic catalyst in catalyzing the reaction of 1,2-dichloroethane with sodium sulfite to produce sodium 2-chloroethylsulfonate.

[0038] This invention further protects a method for the catalytic synthesis of sodium 2-chloroethylsulfonate using the above-mentioned organic catalyst, comprising the following steps:

[0039] 1,2-Dichloroethane and sodium sulfite were added to an aqueous methanol solution, along with an organic catalyst. The mixture was heated and stirred in a high-pressure reactor. After the reaction was stopped, the high-pressure reactor was opened, and methanol and unreacted 1,2-dichloroethane were removed under reduced pressure. The mixture was filtered, and the filtrate was dried to obtain a mixture. This mixture was then added to methanol, filtered, and the methanol was removed under reduced pressure from the filtrate to obtain sodium 2-chloroethylsulfonate.

[0040] As a further improvement of the present invention, the mass ratio of 1,2-dichloroethane, sodium sulfite, and organic catalyst is 105-115:50-60:1-3, the concentration of the methanol aqueous solution is 30-35wt%, the heating and stirring reaction temperature is 100-120℃, the time is 0.5-1h, and the pressure is 0.2-0.4Mpa.

[0041] The present invention has the following beneficial effects:

[0042] This invention prepares an organic catalyst by modifying the surface of NiCuAl-LDHs with a silane coupling agent KH570, resulting in double bonds on the surface. This allows the catalyst to copolymerize with acrylic acid and an imidazole-based ionic liquid containing double bonds, thereby immobilizing the polyacrylic acid and the ionic liquid on the NiCuAl-LDHs surface. The ionic liquid acts as a "microreactor," providing an optimized reaction microenvironment for the substrate and Lewis acid sites of NiCuAl-LDHs by controlling parameters such as polarity, acidity / basicity, and hydrophilicity / hydrophobicity. This improves the reaction rate and the selectivity of the target product. The ionic liquid can also act as a dispersant and stabilizer for the active centers of metals such as Ni and Cu, inhibiting metal particle aggregation and deactivation, and extending the catalyst lifetime. Simultaneously, anchoring the ionic liquid on the LDHs surface constructs a solid-liquid interface catalytic system, achieving the dual advantages of homogeneous catalytic efficiency and easy separation of heterogeneous catalysts.

[0043] Furthermore, this invention prepares a Gemini-type multi-site zwitterionic surfactant with excellent surface activity. Its emulsifying effect is significantly superior to commercially available surfactants. By immobilizing it on the surface of the copolymer NiCuAl-LDHs through an esterification reaction with acrylate, it serves two main purposes: firstly, as a surfactant, it helps improve the solubility of 1,2-dichloroethane in water, enhancing the emulsification efficiency with catalyst participation, thereby increasing the reaction efficiency with sodium sulfite, while also reducing side reactions. Secondly, it promotes the participation of metal catalysts in the reaction, accelerating the reaction rate, lowering the reaction energy barrier, and increasing the reaction yield.

[0044] The organic catalyst prepared by this invention can improve the emulsification efficiency of catalyst participation, thereby improving the reaction efficiency with sodium sulfite. At the same time, it can also reduce the occurrence of side reactions, accelerate the reaction rate, lower the reaction energy barrier, make the reaction conditions milder, and improve the reaction yield, thus having the effect of energy saving and efficiency improvement. Detailed Implementation

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Preparation Example 1: Gemini Surfactant

[0047] The synthesis route is as follows:

[0048]

[0049] The preparation method includes the following steps:

[0050] S1. Dissolve 300 mmol n-octylamine and 300 mmol glycidyl in 100 mL of ethanol, stir at room temperature for 4 h, remove ethanol by rotary evaporation under reduced pressure to obtain product 1; ESI-MS calculated value: C 11 H 26 NO2(M+H) + 204.19, measured value: 204.2, yield: 85%.

[0051] MRI results: 1 H NMR (300MHz, CDCl3) δ3.75-3.82 (m, 3H), 2.57-2.74 (m, 4H), 2.0-2.2 (br, 3H), 1.43 (m, 2H), 1.28-1.33 (m, 10H), 0.92 (t, 3H).

[0052] S2. 200 mmol of product 1 and 200 mmol of 1-bromononane were added to 100 mL of dichloromethane, and the mixture was heated under reflux with stirring for 4 h. The solvent was removed under reduced pressure, and the mixture was filtered with water, washed, and dried to obtain product 2. ESI-MS calculated value: C 20 H 44 NO2(M+H) + 330.33, measured value: 330.3, yield: 81%.

[0053] MRI results: 1 H NMR (300MHz, CDCl3) δ3.54-3.73 (m, 3H), 2.57-2.61 (m, 2H), 2.37 (m, 4H), 2.0 (br, 2H), 1.25-1.39 (m, 26H), 0.93-0.97 (m, 6H).

[0054] S3. Add 100 mmol of product 2 and 130 mmol of sodium hydroxide to 150 mL of cyclohexane, heat to 80 °C, stir for 6 h, wash with water, collect the organic layer, remove the solvent under reduced pressure to obtain product 3.

[0055] S4. 100 mmol of product 3 and 200 mol of sodium 2-bromoethylsulfonate were added to 150 mL of toluene, heated to 80 °C, and stirred for 6 h. The solvent was removed under reduced pressure, and the inorganic salt was removed by adding dichloromethane. The mixture was filtered, and the solvent was removed from the filtrate under reduced pressure to obtain product 4. ESI-MS calculated value: C 24 H 50 NNa2O6S2(M+H) + 558.28, measured value: 558.3, yield: 84%.

[0056] MRI results: 1 H NMR (300MHz, CDCl3) δ3.93 (m, 4H), 3.58-3.64 (m, 6H), 3.4 (m, 1H), 2.37-2.62 (m, 6H), 1.29-1.37 (m, 26H), 0.93-0.99 (m, 6H).

[0057] S5. 80 mmol of product 4, 40 mmol of 1,3-dichloro-2-propanol, and 100 mmol of triethylamine were added to 100 mL of ethyl acetate. The mixture was heated to 80 °C and stirred for 12 h. The solvent was removed under reduced pressure, and the mixture was recrystallized in acetone. The solution was filtered, washed, and dried to obtain the Gemini surfactant. Infrared analysis results are as follows: at a wavenumber of 1042 cm⁻¹... -1 The weaker characteristic peaks at these locations are attributed to the stretching vibrations of CN in the tertiary amine bond; the peaks at wavenumbers of 1102 and 1114 cm⁻¹ are also attributed to these vibrations. -1 The presence of sharp characteristic peaks at 2929 and 2849 cm⁻¹ indicates the presence of -COC- ether bonds; -1 With 2912, 2850cm -1 The characteristic peak of -(CH2)n- is located at 1035 and 1061 cm⁻¹. -1 The presence of a characteristic peak corresponding to the sulfonic acid group indicates that the sulfonic acid group was successfully attached to the product, and the target product was synthesized.

[0058] Preparation Example 2: Gemini Surfactant

[0059] The preparation method includes the following steps:

[0060] S1. Dissolve 300 mmol dodecylamine and 330 mmol glycidyl in 100 mL ethanol, stir at room temperature for 4 h, remove ethanol by rotary evaporation under reduced pressure to obtain product 1;

[0061] S2. Add 220 mmol of product 1 and 200 mmol of 1-bromotetradecane to 100 mL of dichloromethane, heat under reflux and stir for 4 h, remove the solvent under reduced pressure, filter with water, wash, and dry to obtain product 2.

[0062] S3. Add 100 mmol of product 2 and 170 mmol of sodium hydroxide to 150 mL of cyclohexane, heat to 80 °C, stir for 6 h, wash with water, collect the organic layer, remove the solvent under reduced pressure to obtain product 3.

[0063] S4. Add 100 mmol of product 3 and 220 mol of sodium 2-bromoethylsulfonate to 150 mL of toluene, heat to 80 °C, stir for 6 h, remove the solvent under reduced pressure, add dichloromethane to remove inorganic salts, filter, remove the solvent from the filtrate under reduced pressure to obtain product 4.

[0064] S5. 82 mmol of product 4, 40 mmol of 1,3-dichloro-2-propanol, and 100 mmol of triethylamine were added to 100 mL of ethyl acetate, heated to 80 °C, stirred for 12 h, the solvent was removed under reduced pressure, and the product was recrystallized in acetone, filtered, washed, and dried to obtain the Gemini surfactant.

[0065] Preparation Example 3: Gemini Surfactant

[0066] The preparation method includes the following steps:

[0067] S1. Dissolve 300 mmol n-hexadecylamine and 315 mmol glycidyl in 100 mL ethanol, stir at room temperature for 4 h, remove ethanol by rotary evaporation under reduced pressure to obtain product 1;

[0068] S2. Add 210 mmol of product 1 and 200 mmol of 1-bromododecane to 100 mL of dichloromethane, heat under reflux and stir for 4 h, remove the solvent under reduced pressure, filter with water, wash, and dry to obtain product 2.

[0069] S3. Add 100 mmol of product 2 and 150 mmol of sodium hydroxide to 150 mL of cyclohexane, heat to 80 °C, stir for 6 h, wash with water, collect the organic layer, remove the solvent under reduced pressure to obtain product 3.

[0070] S4. Add 100 mmol of product 3 and 210 mol of sodium 2-bromoethylsulfonate to 150 mL of toluene, heat to 80 °C, stir for 6 h, remove the solvent under reduced pressure, add dichloromethane to remove inorganic salts, filter, remove the solvent from the filtrate under reduced pressure to obtain product 4.

[0071] S5. 81 mmol of product 4, 40 mmol of 1,3-dichloro-2-propanol, and 100 mmol of triethylamine were added to 100 mL of ethyl acetate, heated to 80 °C, stirred for 12 h, the solvent was removed under reduced pressure, and the product was recrystallized in acetone, filtered, washed, and dried to obtain the Gemini surfactant.

[0072] Test Example 1

[0073] The Gemini-type surfactants prepared in Examples 1-3 were formulated into solutions of different concentrations. The surface tension of the aqueous solutions was measured at room temperature. The obtained data were plotted as γ-lgC curves. The inflection point of the curve is the critical micelle concentration (cmc) of the Gemini-type surfactant. The surface tension at the critical micelle concentration was also measured. The results are shown in Table 1.

[0074] Table 1

[0075] Group Surface tension (mN / m) cmc (mol / L) Preparation Example 1 23.2 <![CDATA[1.2×10 -5 ]]> Preparation Example 2 22.9 <![CDATA[1.1×10 -5 ]]> Preparation Example 3 21.0 <![CDATA[0.9×10 -5 ]]>

[0076] As can be seen from the table above, the Gemini-type surfactants prepared in Examples 1-3 of this invention have low critical micelle concentration (cmc) and surface tension.

[0077] Example 1

[0078] This embodiment provides a method for preparing an organic catalyst, including the following steps:

[0079] (1) Preparation of NiCuAl-LDHs: 0.1 mol aluminum nitrate, 0.1 mol copper oxide and 0.1 mol nickel oxide were added to 200 mL of 5 wt% nitric acid solution to obtain solution A; 7 g NaOH and 1 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, microwaved at 300 W for 0.5 h, filtered, washed and dried to obtain NiCuAl-LDHs;

[0080] (2) Modification: 10g NiCuAl-LDHs were added to 200mL of ethanol, 2g of silane coupling agent KH570 were added, the mixture was heated to 40℃, stirred for 3h, filtered, washed and dried to obtain modified NiCuAl-LDHs.

[0081] (3) Copolymerization: 10g of modified NiCuAl-LDHs, 2g of acrylic acid and 2g of 1-allyl-3-methylimidazolium chloride were added to 200mL of ethanol. Under nitrogen protection, 0.05g of ammonium persulfate was added, heated to 50℃, stirred and reacted for 3h, centrifuged, washed and dried to obtain copolymerized NiCuAl-LDHs;

[0082] (4) Reaction: 12g of copolymerized NiCuAl-LDHs, 3g of Gemini-type surfactant prepared in Example 1 and 0.5g of p-toluenesulfonic acid were added to 300mL of toluene, heated and stirred under reflux for 6h, filtered, washed and dried to obtain the organic catalyst.

[0083] Example 2

[0084] This embodiment provides a method for preparing an organic catalyst, including the following steps:

[0085] (1) Preparation of NiCuAl-LDHs: 0.1 mol aluminum nitrate, 0.2 mol copper oxide and 0.2 mol nickel oxide were added to 200 mL of 10 wt% nitric acid solution to obtain solution A; 9 g NaOH and 2 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, microwaved at 500 W for 1.5 h, filtered, washed and dried to obtain NiCuAl-LDHs;

[0086] (2) Modification: 10g NiCuAl-LDHs were added to 200mL of ethanol, 3g of silane coupling agent KH570 were added, the mixture was heated to 50℃, stirred for 5h, filtered, washed and dried to obtain modified NiCuAl-LDHs;

[0087] (3) Copolymerization: 10g of modified NiCuAl-LDHs, 3g of acrylic acid and 4g of 1-allyl-3-methylimidazolium chloride were added to 200mL of ethanol. Under nitrogen protection, 0.1g of ammonium persulfate was added, heated to 60℃, stirred and reacted for 5h, centrifuged, washed and dried to obtain copolymerized NiCuAl-LDHs;

[0088] (4) Reaction: 15g of copolymerized NiCuAl-LDHs, 5g of Gemini-type surfactant prepared in Example 2 and 1g of p-toluenesulfonic acid were added to 300mL of toluene, heated and stirred under reflux for 8h, filtered, washed and dried to obtain the organic catalyst.

[0089] Example 3

[0090] This embodiment provides a method for preparing an organic catalyst, including the following steps:

[0091] (1) Preparation of NiCuAl-LDHs: 0.1 mol aluminum nitrate, 0.15 mol copper oxide and 0.15 mol nickel oxide were added to 200 mL of 7 wt% nitric acid solution to obtain solution A; 8 g NaOH and 1.5 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, microwaved at 400 W for 1 h, filtered, washed and dried to obtain NiCuAl-LDHs;

[0092] (2) Modification: 10g NiCuAl-LDHs were added to 200mL of ethanol, 2.5g of silane coupling agent KH570 were added, the mixture was heated to 45℃, stirred for 4h, filtered, washed and dried to obtain modified NiCuAl-LDHs;

[0093] (3) Copolymerization: 10g of modified NiCuAl-LDHs, 2.5g of acrylic acid and 3g of 1-allyl-3-methylimidazolium chloride were added to 200mL of ethanol. Under nitrogen protection, 0.07g of ammonium persulfate was added, heated to 55℃, stirred and reacted for 4h, centrifuged, washed and dried to obtain copolymerized NiCuAl-LDHs;

[0094] (4) Reaction: 13g of copolymerized NiCuAl-LDHs, 4g of Gemini-type surfactant prepared in Example 3 and 0.7g of p-toluenesulfonic acid were added to 300mL of toluene, heated and stirred under reflux for 7h, filtered, washed and dried to obtain the organic catalyst.

[0095] Comparative Example 1

[0096] The difference compared to Example 3 is that no copper oxide was added.

[0097] Specifically as follows:

[0098] Preparation of NiAl-LDHs: 0.1 mol aluminum nitrate and 0.3 mol nickel oxide were added to 200 mL of 7 wt% nitric acid solution to obtain solution A; 8 g NaOH and 1.5 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, and microwaved at 400 W for 1 h. The mixture was then filtered, washed, and dried to obtain NiAl-LDHs.

[0099] Comparative Example 2

[0100] The difference compared to Example 3 is that nickel oxide was not added.

[0101] Specifically as follows:

[0102] Preparation of CuAl-LDHs: 0.1 mol aluminum nitrate and 0.3 mol copper oxide were added to 200 mL of 7 wt% nitric acid solution to obtain solution A; 8 g NaOH and 1.5 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, and microwaved at 400 W for 1 h. The mixture was then filtered, washed, and dried to obtain CuAl-LDHs.

[0103] Comparative Example 3

[0104] The difference from Example 3 is that 1-allyl-3-methylimidazolium chloride was not added in step (3).

[0105] Specifically as follows:

[0106] (1) Preparation of NiCuAl-LDHs: 0.1 mol aluminum nitrate, 0.15 mol copper oxide and 0.15 mol nickel oxide were added to 200 mL of 7 wt% nitric acid solution to obtain solution A; 8 g NaOH and 1.5 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, microwaved at 400 W for 1 h, filtered, washed and dried to obtain NiCuAl-LDHs;

[0107] (2) Modification: 10g NiCuAl-LDHs were added to 200mL of ethanol, 2.5g of silane coupling agent KH570 were added, the mixture was heated to 45℃, stirred for 4h, filtered, washed and dried to obtain modified NiCuAl-LDHs;

[0108] (3) Copolymerization: 10g of modified NiCuAl-LDHs and 2.5g of acrylic acid were added to 200mL of ethanol. Under nitrogen protection, 0.07g of ammonium persulfate was added, heated to 55℃, stirred and reacted for 4h, centrifuged, washed and dried to obtain copolymerized NiCuAl-LDHs;

[0109] (4) Reaction: 13g of copolymerized NiCuAl-LDHs, 4g of Gemini-type surfactant prepared in Example 3 and 0.7g of p-toluenesulfonic acid were added to 300mL of toluene, heated and stirred under reflux for 7h, filtered, washed and dried to obtain the organic catalyst.

[0110] Comparative Example 4

[0111] The difference from Example 3 is that step (4) was not performed.

[0112] (1) Preparation of NiCuAl-LDHs: 0.1 mol aluminum nitrate, 0.15 mol copper oxide and 0.15 mol nickel oxide were added to 200 mL of 7 wt% nitric acid solution to obtain solution A; 8 g NaOH and 1.5 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was introduced into solution A, solution B was added dropwise, the mixture was heated to 40 °C, microwaved at 400 W for 1 h, filtered, washed and dried to obtain NiCuAl-LDHs;

[0113] (2) Modification: 10g NiCuAl-LDHs were added to 200mL of ethanol, 2.5g of silane coupling agent KH570 were added, the mixture was heated to 45℃, stirred for 4h, filtered, washed and dried to obtain modified NiCuAl-LDHs;

[0114] (3) Copolymerization: 10g of modified NiCuAl-LDHs, 2.5g of acrylic acid and 3g of 1-allyl-3-methylimidazolium chloride were added to 200mL of ethanol. Under nitrogen protection, 0.07g of ammonium persulfate was added, heated to 55℃, stirred and reacted for 4h, centrifuged, washed and dried to obtain copolymerized NiCuAl-LDHs, which is an organic catalyst.

[0115] Comparative Example 5

[0116] Compared with Example 3, the difference is that steps (2) to (4) were not performed.

[0117] Specifically as follows:

[0118] Preparation of NiCuAl-LDHs: 0.1 mol aluminum nitrate, 0.15 mol copper oxide, and 0.15 mol nickel oxide were added to 200 mL of 7 wt% nitric acid solution to obtain solution A; 8 g NaOH and 1.5 g 68 wt% concentrated nitric acid were dissolved in 100 mL of water to obtain solution B; nitrogen gas was bubbled into solution A, solution B was added dropwise, the mixture was heated to 40 °C, and microwaved at 400 W for 1 h. After filtration, washing, and drying, NiCuAl-LDHs were obtained, which is an organic catalyst.

[0119] Test Example 2

[0120] The specific surface area of ​​the organic catalysts prepared in Examples 1-3 and Comparative Examples 1-5 was determined using a multi-station high-throughput gas adsorption analyzer. The results are shown in Table 2.

[0121] Table 2

[0122] Group <![CDATA[Specific surface area (m 2 / g)]]> Example 1 556.2 Example 2 559.4 Example 3 560.7 Comparative Example 1 522.1 Comparative Example 2 504.8 Comparative Example 3 543.2 Comparative Example 4 538.9 Comparative Example 5 533.7

[0123] As can be seen from the table above, the organic catalysts prepared in Examples 1-3 of this invention have a large specific surface area.

[0124] Example 4

[0125] This embodiment provides a method for synthesizing sodium 2-chloroethylsulfonate, including the following steps:

[0126] 105g of 1,2-dichloroethane and 50g of sodium sulfite were added to 500mL of 30wt% methanol aqueous solution, along with 1g of the organic catalyst prepared in Example 1. The mixture was heated and stirred in a high-pressure reactor at 100℃ for 0.5h and 0.2MPa. After the reaction was stopped, the high-pressure reactor was opened, and methanol and unreacted 1,2-dichloroethane were removed under reduced pressure. The mixture was filtered, dried, and a mixture was added to 200mL of methanol. The mixture was filtered, methanol was removed under reduced pressure, washed, and dried to obtain sodium 2-chloroethylsulfonate.

[0127] Example 5

[0128] This embodiment provides a method for synthesizing sodium 2-chloroethylsulfonate, including the following steps:

[0129] 115g of 1,2-dichloroethane and 60g of sodium sulfite were added to 500mL of 35wt% methanol aqueous solution, along with 3g of the organic catalyst prepared in Example 2. The mixture was heated and stirred in a high-pressure reactor at 120℃ for 1h and 0.4MPa. After the reaction was stopped, the high-pressure reactor was opened, and methanol and unreacted 1,2-dichloroethane were removed under reduced pressure. The mixture was filtered, dried, and a mixture was added to 200mL of methanol. The mixture was filtered, and methanol was removed under reduced pressure. The mixture was washed and dried to obtain sodium 2-chloroethylsulfonate.

[0130] Example 6

[0131] This embodiment provides a method for synthesizing sodium 2-chloroethylsulfonate, including the following steps:

[0132] 110g of 1,2-dichloroethane and 55g of sodium sulfite were added to 500mL of 32wt% methanol aqueous solution, along with 2g of the organic catalyst prepared in Example 3. The mixture was heated and stirred in a high-pressure reactor at 110℃ for 0.5h and 0.3MPa. After the reaction was stopped, the high-pressure reactor was opened, and methanol and unreacted 1,2-dichloroethane were removed under reduced pressure. The mixture was filtered, dried, and a mixture was added to 200mL of methanol. The mixture was filtered, methanol was removed under reduced pressure, washed, and dried to obtain sodium 2-chloroethylsulfonate.

[0133] Comparative Examples 6-10

[0134] The difference from Example 6 is that the organic catalysts were prepared from Comparative Examples 1-5, respectively.

[0135] Test Example 3

[0136] The methods in Examples 4-6 and Comparative Examples 6-10 were evaluated, and the results are shown in Table 3.

[0137] Table 3

[0138]

[0139] As can be seen from the table above, the sodium 2-chloroethylsulfonate prepared by the methods in Examples 4-6 of this invention has a high yield and purity.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an organic catalyst, characterized in that, Modified NiCuAl-LDHs were prepared by reacting maleic acid with NiCuAl-LDHs. After copolymerization with an ionic liquid containing double bonds, the modified NiCuAl-LDHs were further reacted with a Gemini surfactant to prepare an organic catalyst. The structural formula of the Gemini surfactant is shown in Formula I. Formula I.

2. The preparation method according to claim 1, characterized in that, The preparation method of the Gemini surfactant includes the following steps: S1. Aliphatic amines and glycidol were reacted to prepare product 1, with the following structure: ; S2. Product 1 is reacted with a bromoalkane to obtain product 2, with the following structure: ; S3. Product 2 was reacted with sodium hydroxide to obtain product 3, with the following structure: ； S4. Product 3 was reacted with sodium 2-bromoethylsulfonate to obtain product 4, with the following structure: ； S5. The product 4 was reacted with 1,3-dichloro-2-propanol to prepare a Gemini-type surfactant.

3. The preparation method according to claim 2, characterized in that, In step S1, the molar ratio of the fatty amine to glycidol is 1:1-1.1, and the fatty amine is selected from at least one of n-octylamine, n-nonylamine, dodecylamine, n-hexadecylamine, and n-octadecylamine; in step S2, the molar ratio of product 1 to bromoalkane is 1-1.1:1, and the bromoalkane is selected from at least one of 1-bromononane, 1-bromodecane, 1-bromododecane, 1-bromotetradecane, 1-bromohexadecane, and 1-bromooctadecane; in step S3, the molar ratio of product 2 to sodium hydroxide is 1:1.3-1.7; in step S4, the molar ratio of product 3 to sodium 2-bromoethylsulfonate is 1:2-2.2; and in step S5, the molar ratio of product 4 to 1,3-dichloro-2-propanol is 2-2.05:

1.

4. The preparation method according to claim 1, characterized in that, Includes the following steps: (1) Preparation of NiCuAl-LDHs: Aluminum nitrate, copper oxide and nickel oxide were added to nitric acid solution to obtain solution A; NaOH and concentrated nitric acid were dissolved in water to obtain solution B; inert gas was introduced into solution A, solution B was added dropwise, the reaction was heated and stirred, microwaved, filtered, washed and dried to obtain NiCuAl-LDHs; (2) Modification: NiCuAl-LDHs were added to ethanol, silane coupling agent KH570 was added, the mixture was heated and stirred to react, filtered, washed and dried to obtain modified NiCuAl-LDHs; (3) Copolymerization: Modified NiCuAl-LDHs, acrylic acid, and 1-allyl-3-methylimidazolium chloride were added to ethanol. Under inert gas protection, an initiator was added, and the mixture was heated and stirred to react. After centrifugation, washing, and drying, copolymerized NiCuAl-LDHs were obtained. (4) Reaction: Add the copolymerized NiCuAl-LDHs, Gemini-type surfactant and p-toluenesulfonic acid to toluene, heat and reflux and stir to react, filter, wash and dry to obtain the organic catalyst.

5. The preparation method according to claim 4, characterized in that, In step (1), the molar ratio of aluminum nitrate, copper oxide, and nickel oxide is 1:1-2:1-2, the concentration of the nitric acid solution is 5-10 wt%, the mass ratio of NaOH to concentrated nitric acid is 7-9:1-2, the concentration of the concentrated nitric acid is 68 wt%, the power of the microwave reaction is 300-500 W, and the time is 0.5-1.5 h; in step (2), the mass ratio of NiCuAl-LDHs and silane coupling agent KH570 is 10:2-3, the temperature of the heating and stirring reaction is 40-50℃, and the time is 3-5 h.

6. The preparation method according to claim 4, characterized in that, In step (3), the mass ratio of modified NiCuAl-LDHs, acrylic acid, 1-allyl-3-methylimidazolium chloride and initiator is 10:2-3:2-4:0.05-0.1, and the heating and stirring reaction temperature is 50-60℃ for 3-5h; in step (4), the mass ratio of copolymerized NiCuAl-LDHs, Gemini surfactant and p-toluenesulfonic acid is 12-15:3-5:0.5-1, and the heating and reflux stirring reaction time is 6-8h.

7. An organic catalyst prepared by the method according to any one of claims 1-6.

8. The use of the organic catalyst as described in claim 7 in the catalytic reaction of 1,2-dichloroethane with sodium sulfite to produce sodium 2-chloroethylsulfonate.

9. A method for catalytic synthesis of sodium 2-chloroethylsulfonate using the organic catalyst of claim 7, characterized in that, Includes the following steps: 1,2-Dichloroethane and sodium sulfite were added to an aqueous methanol solution, along with an organic catalyst. The mixture was heated and stirred in a high-pressure reactor. After the reaction was stopped, the high-pressure reactor was opened, and methanol and unreacted 1,2-dichloroethane were removed under reduced pressure. The mixture was filtered, and the filtrate was dried to obtain a mixture. This mixture was then added to methanol, filtered, and the methanol was removed under reduced pressure from the filtrate to obtain sodium 2-chloroethylsulfonate.

10. The method according to claim 9, characterized in that, The mass ratio of 1,2-dichloroethane, sodium sulfite, and organic catalyst is 105-115:50-60:1-3, the concentration of the methanol aqueous solution is 30-35 wt%, the heating and stirring reaction temperature is 100-120℃, the time is 0.5-1 h, and the pressure is 0.2-0.4 MPa.

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