A method for preparing carbon fiber solid base catalyst for preparing boson

Abstract

The invention discloses a preparation method of a carbon fiber solid base catalyst for preparing bosylamine. The preparation method comprises the following steps: S1, dissolving a magnesium source, an aluminum source, and a titanium source in deionized water; ultrasonically dispersing carbon fibers in the deionized water, and allowing the carbon fibers to adsorb aluminum ions, magnesium ions, and titanium ions on the surface of the carbon fibers; S2, continuously introducing ammonia gas into the deionized water dispersion system obtained in S1 until precipitation is complete, allowing magnesium hydroxide, aluminum hydroxide, and titanium hydroxide to grow on the surface of the carbon fibers, and filtering the precipitate; S3, calcining the precipitate obtained in S2 to obtain carbon fiber-supported MgO-Al2O3-TiO2; and applying the structurally stable solid base catalyst with an adsorption effect prepared by the invention to the preparation of bosylamine, thereby reducing the introduction of cations and cooperating with a double solvent reaction to reduce the chance of boric acid and the dehydration connection of hydroxyl groups of the product, thereby improving the purity and yield of bosylamine.

Description

Technical Field

[0001] The present invention relates to the technical field of solid base catalysts, and in particular to a method for preparing a carbon fiber solid base catalyst for preparing boson. Background Art

[0002] The chemical name of hydroxypropyl tetrahydropyrantriol is hydroxypropyl tetrahydropyrantriol. It is a xylose derivative with anti-aging active ingredients. It can promote the synthesis of collagen, make the skin stronger and more elastic, improve fine lines on the neck, and prevent aging.

[0003] Bosylase is a glycoprotein mixture derived from xylose. However, in the existing technology, the bosylase product contains many impurities, has low purity, and is difficult to separate, resulting in low process yield and unfavorable for controlling production costs.

[0004] L'Oréal's published report on the preparation of bosylcane is a two-step process. The first step involves using D-xylose as the raw material, sodium bicarbonate as the base, and water as the solvent. The reaction is stirred at 90°C for 6 hours. Acetylacetone and xylose undergo condensation, cyclization, and subsequent cleavage, yielding β-acetone xyloside in high yield. In the second step, β-acetone xyloside is reduced using sodium borohydride to produce bosylcane. The selective reduction of β-acetone xyloside is challenging. Using sodium borohydride or lithium borohydride as a reducing agent to reduce the keto carbonyl group in β-acetone xyloside produces a large amount of boric acid as a byproduct. Boric acid readily binds to the polyhydroxylated bosylcane, requiring purification by column chromatography, making it difficult to mass-produce. Using other homogeneous metal catalysts inevitably increases metal residues in the product, making purification difficult. Summary of the Invention

[0005] The first object of the present invention is to provide a method for preparing a carbon fiber solid base catalyst for preparing boson. The present invention produces a structurally stable solid base catalyst with an adsorption effect, in which the magnesium and aluminum used to load hydroxide are effectively fixed, and the catalytic effect is stable during the preparation of boson.

[0006] To solve this technical problem, the technical solution of the present invention is: a method for preparing a carbon fiber solid base catalyst for preparing boson, comprising the following steps:

[0007] S1. Dissolving a magnesium source, an aluminum source, and a titanium source in deionized water; ultrasonically dispersing carbon fibers in the deionized water, and allowing the carbon fibers to adsorb aluminum ions, magnesium ions, and titanium ions on their surfaces;

[0008] S2. Continuously introduce ammonia gas into the deionized water dispersion obtained in S1 until precipitation is complete, magnesium hydroxide, aluminum hydroxide, and titanium hydroxide grow on the surface of the carbon fiber, and filter the precipitate;

[0009] S3. calcining the precipitate obtained in S2 to obtain carbon fiber-supported MgO-Al2O3-TiO2.

[0010] The preferred mass of the carbon fibers is 1% to 3% of the mass of the MgO-Al2O3-TiO2. In the present invention, the carbon fibers are used to support the conjugated precipitate. During the preparation of the solid base catalyst, the magnesium ions, chloride ions, and titanium ions dispersed in deionized water are adsorbed by the carbon fibers, facilitating the adsorption of the MgO-Al2O3-TiO2 and its growth on the carbon fiber surface. Furthermore, during the preparation of bosylamine, the adsorption of xylose increases, enhancing catalytic activity. However, since the carbon fibers themselves are not catalytic, using too much can easily lead to a decrease in the catalytic performance of the solid base.

[0011] The calcination process conditions in S3 are preferably as follows: calcination temperature of 500° C. to 700° C.; calcination time of 1 hour to 3 hours. In the present invention, magnesium, aluminum, and titanium are mixed by calcination to form a conjugated metal oxide.

[0012] Preferred MgO-Al2O3-TiO2 Mg :n Al :n Ti The ratio is (1 to 3):3:(1 to 3). In the conjugated product obtained by the present invention, titanium oxide has a porous structure, while the titanium skeleton is stable. MgO and Al2O3 are blended with TiO2 to resist high temperatures. The hydroxide is loaded on magnesium and aluminum, resulting in stable chemical properties and effectively improving the stability of the material.

[0013] The second object of the present invention is to provide an application of the solid base catalyst prepared by the present invention to prepare bosine. The present invention effectively utilizes the solid base catalyst in conjunction with a two-solvent reaction to reduce the chance of boric acid and the hydroxyl group of the product being dehydrated and connected, thereby improving the purity and yield of bosine.

[0014] To solve this technical problem, the technical solution of the present invention is: an application of the solid base catalyst prepared by the present invention to prepare bosonine, and the preparation of bosonine includes the following steps:

[0015] A1. Dissolve xylose in deionized water to obtain a xylose-water solution, and dissolve acetylacetone in methanol to obtain an acetylacetone-methanol solution;

[0016] A2, adding xylose-water solution and acetylacetone-methanol solution into a reactor containing an aqueous dispersion of the solid base catalyst;

[0017] A3. Heat to 120°C to 140°C and react for 10 to 30 minutes;

[0018] A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone;

[0019] A5. Washing the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system;

[0020] A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0021] A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; reduce the system temperature to 0±5°C;

[0022] A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to 0±5°C;

[0023] After the dropwise addition is completed, the mixed system is stirred at a low temperature of 0±5°C for 3 to 4 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

[0024] Preferably, the phase transfer catalyst added to A7 is any one of polyethylene glycol, 18-crown ether-6 and polyethylene glycol diethyl ether;

[0025] The amount of phase transfer catalyst used is 1% to 5% of the mass of xylose. The present invention uses a phase transfer catalyst to ensure that the reduction reaction proceeds fully, and also utilizes a dual solvent to achieve effective separation of boric acid and bosine through organic phase-inorganic phase and liquid phase-solid phase separation.

[0026] Preferably, the amount of sodium borohydride used in A8 is: the mass ratio of sodium borohydride to xylose is (0.05 to 0.08):1.

[0027] Preferably, the mass fraction of xylose in the xylose-water solution is 50% to 80%; the mass fraction of acetylacetone in the acetylacetone-methanol solution is 60% to 80%. The present invention uses different solvents to dissolve xylose and acetylacetone respectively, dissolving the reactants to the greatest extent to obtain small molecule reactants. The more thoroughly the reactants are dissolved, the more dispersed the reactant molecules are, and the greater the probability of intermolecular collisions during the reaction, which is conducive to the thoroughness of the reaction.

[0028] Preferably, the mass ratio of the solid base catalyst to xylose in A2 is (0.01-0.05): 1. In order to effectively ensure the catalytic efficiency of the solid base catalyst, the present invention uses a mass ratio of the solid base catalyst to xylose of (0.01-0.05): 1 to ensure the catalytic effect.

[0029] By adopting the above technical solution, the beneficial effects of the present invention are:

[0030] The invention utilizes xylose and acetylacetone to undergo Knoevenagel condensation under the action of a solid base catalyst to generate 1-C-(β-D-xylopyranosyl)-acetone, and then reduces the ketone carbonyl through the action of sodium borohydride to obtain hydroxypropyl tetrahydropyrantriol, i.e., bosine.

[0031] In the above reaction process, the present invention uses a structurally stable solid base catalyst, namely MgO-Al2O3-TiO2 supported by carbon fibers, wherein the chemical bond of aluminum oxide is a transition type between ionic bonds and covalent bonds, and there are ionic bonds between magnesium oxide and ionic bonds between titanium oxide; ammonia is introduced into deionized water to form a co-precipitate of Mg, Al and Ti; combined with high-temperature calcination, the outermost electrons of the crystal are dislocated at high temperature, the same bonds are close to each other and mixed, and after the temperature is lowered, a precipitate with a conjugated structure is formed; on the premise that the carbon fibers adsorb reactants to promote the generation of 1-C-(β-D-xylopyranosyl)-acetone, the introduction of metal cations in the soluble base is avoided, thereby reducing the content of inorganic salts in the product; further, the MgO-Al2O3-TiO2 supported by carbon fibers has a stable structure, the catalytic effect of the solid base catalyst obtained by the present invention is stable, the catalytic efficiency is higher than that of the existing solid base catalyst, and after application, the yield of 1-C-(β-D-xylopyranosyl)-acetone is high and the purity is high;

[0032] In the process of reducing 1-C-(β-D-xylopyranosyl)-acetone using sodium borohydride, the present invention uses a dual solvent system. According to the properties of the reactants, sodium borohydride is dissolved using deionized water, and 1-C-(β-D-xylopyranosyl)-acetone is dissolved in tetrahydrofuran. The reactants are dissolved to the greatest extent, which is to promote the reaction degree of the reactants and increase the yield.

[0033] In view of the technical problem in the prior art that sodium borohydride generates boric acid after the reaction, and the boric acid is easily dehydrated and connected with the hydroxyl group of the product and is difficult to remove, the present invention uses a water-tetrahydrofuran dual solvent system, and in the process of reducing the ketone carbonyl to obtain hydroxypropyl tetrahydropyrantriol with sodium borohydride, a two-liquid phase system is formed by dissolving sodium borohydride in an aqueous phase and dissolving 1-C-(β-D-xylopyranosyl)-acetone in tetrahydrofuran, and passivating 1-C-(β-D-xylopyranosyl)-acetone under the action of a phase transfer catalyst. Ketone groups increase the solubility of sodium borohydride and 1-C-(β-D-xylopyranosyl)-acetone in their respective phases. 1-C-(β-D-xylopyranosyl)-acetone and sodium borohydride are dissolved in different phases and then reacted, ensuring that the reducing agent sodium borohydride in the aqueous phase participates in the reaction. The generated boric acid is insoluble in the organic phase and returns to the aqueous phase, while bosine forms a precipitate in the tetrahydrofuran phase. Through the coordination of the above two solvents, the chance of boric acid dehydrating and connecting with the hydroxyl group of the product is reduced, thereby improving the purity and yield of bosine.

[0034] The present invention utilizes a phase transfer catalyst to coordinate water and tetrahydrofuran to achieve mutual dissolution, thereby preventing sodium borohydride from being affected by tetrahydrofuran and precipitating when dissolved in deionized water; similarly, 1-C-(β-D-xylopyranosyl)-acetone is also prevented from precipitating from tetrahydrofuran due to the presence of deionized water, thereby ensuring that 1-C-(β-D-xylopyranosyl)-acetone and sodium borohydride fully contact and react. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a nuclear magnetic resonance spectrum analysis (NMR) diagram of the product obtained in Example 4 of the present invention;

[0036] Figure 2 This is the SEM of Example 4 using a solid base catalyst;

[0037] Figure 3 This is the thermogravimetric test of Example 4 using a solid base catalyst. DETAILED DESCRIPTION

[0038] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0039] Example 1

[0040] This embodiment discloses a method for preparing a carbon fiber solid base catalyst for preparing boson, comprising the following steps:

[0041] S1, magnesium source, aluminum source, titanium source according to n Mg :n Al :n Ti The carbon fiber is dissolved in deionized water at a ratio of 1:3:1; the carbon fiber is ultrasonically dispersed in the deionized water, and the carbon fiber adsorbs aluminum ions, magnesium ions and titanium ions on the surface of the carbon fiber;

[0042] The mass of carbon fiber is 1% of the mass of MgO-Al2O3-TiO2.

[0043] S2. Continuously introduce ammonia gas into the deionized water dispersion obtained in S1 for 5 hours until precipitation is complete, and magnesium hydroxide, aluminum hydroxide, and titanium hydroxide grow on the surface of the carbon fiber, and filter the precipitate;

[0044] S3. Calcinate the precipitate obtained in S2 to obtain a conjugated product MgO-Al2O3-TiO2 supported by carbon fibers, in which the outermost electrons are free and mutually mixed.

[0045] In S3, the calcination temperature is 500° C. and the calcination time is 3 h.

[0046] This embodiment also discloses the use of the prepared carbon fiber-supported MgO-Al2O3-TiO2 to prepare bosonine, comprising the following steps:

[0047] A1. Use deionized water to dissolve xylose to obtain a xylose-water solution, and use methanol to dissolve acetylacetone to obtain an acetylacetone-methanol solution; dissolve 50 g of xylose in 100 mL of aqueous solution to obtain a xylose-water solution, and dissolve 30 g of acetylacetone in 50 mL of methanol to obtain an acetylacetone-methanol solution.

[0048] A2. Simultaneously adding a xylose-water solution and an acetylacetone-methanol solution to a reactor containing an aqueous dispersion of the solid base catalyst; the mass of the solid base catalyst in A2 is 0.01 times the mass of the xylose. The mass ratio of the solid base catalyst to deionized water in the aqueous dispersion of the solid base catalyst is 20:80.

[0049] A3, heat to 120℃ and react for 30 minutes;

[0050] A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone;

[0051] A5. Wash the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system; the organic solvent is acetic acid;

[0052] A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0053] A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in three volumes of tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; lower the system temperature to 0°C;

[0054] The phase transfer catalyst added to A7 is polyethylene glycol; its mass is 2.32 g, and the amount of phase transfer catalyst used is about 5% of the mass of xylose.

[0055] A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to 5°C;

[0056] The mass of sodium borohydride added to A8 is 2.5 g, and the mass ratio of xylose to sodium borohydride is 1:0.05.

[0057] After the addition is completed, the mixed system is stirred at a low temperature of 5°C for 3 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

[0058] Example 2

[0059] This embodiment discloses a method for preparing a carbon fiber solid base catalyst for preparing boson, comprising the following steps:

[0060] S1, magnesium source, aluminum source, titanium source according to n Mg :n Al :n Ti The carbon fibers are dissolved in deionized water at a ratio of 2:3:1; the carbon fibers are ultrasonically dispersed in the deionized water, and the carbon fibers adsorb aluminum ions, magnesium ions, and titanium ions on the surface of the carbon fibers;

[0061] The mass of carbon fiber is 1% of the mass of MgO-Al2O3-TiO2.

[0062] S2. Continuously introduce ammonia gas into the deionized water dispersion obtained in S1 for 6 hours until precipitation is complete, and magnesium hydroxide, aluminum hydroxide, and titanium hydroxide grow on the surface of the carbon fiber, and filter the precipitate;

[0063] S3. Calcinate the precipitate obtained in S2 to obtain a conjugated product MgO-Al2O3-TiO2 supported by carbon fibers, in which the outermost electrons are free and mutually mixed.

[0064] In S3, the calcination temperature is 600°C and the calcination time is 2h.

[0065] This embodiment also discloses the use of the prepared carbon fiber-supported MgO-Al2O3-TiO2 to prepare bosonine, comprising the following steps:

[0066] A1. Use deionized water to dissolve xylose to obtain a xylose-water solution, and use methanol to dissolve acetylacetone to obtain an acetylacetone-methanol solution; dissolve 50 g of xylose in 84 mL of aqueous solution to obtain a xylose-water solution, and dissolve 35 g of acetylacetone in 50 mL of methanol to obtain an acetylacetone-methanol solution.

[0067] A2: Simultaneously adding a xylose-water solution and an acetylacetone-methanol solution to a reactor containing an aqueous dispersion of the solid base catalyst; the mass of the solid base catalyst in A2 is 0.02 times the mass of the xylose; and the mass ratio of the solid base catalyst to deionized water in the aqueous dispersion of the solid base catalyst is 20:80.

[0068] A3. Heat to 120°C and react for 10 to 30 minutes;

[0069] A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone;

[0070] A5. Wash the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system; the organic solvent is acetic acid;

[0071] A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0072] A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in three times the volume of tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; lower the system temperature to 0°C;

[0073] The phase transfer catalyst added to A7 is 18-crown ether-6, with a mass of 1.76 g. The amount of phase transfer catalyst used is 3.5% of the mass of xylose.

[0074] A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to 4°C;

[0075] 3 g of sodium borohydride was added to A8, and the mass ratio of xylose to sodium borohydride was 1:0.06.

[0076] After the addition is completed, the mixed system is stirred at a low temperature of 4°C for 3.5 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

[0077] Example 3

[0078] This embodiment discloses a method for preparing a carbon fiber solid base catalyst for preparing boson, comprising the following steps:

[0079] S1, magnesium source, aluminum source, titanium source according to n Mg :n Al :n Ti The carbon fibers are dissolved in deionized water at a ratio of 2:3:2; the carbon fibers are ultrasonically dispersed in the deionized water, and the carbon fibers adsorb aluminum ions, magnesium ions, and titanium ions on the surface of the carbon fibers;

[0080] The mass of carbon fiber is 2% of the mass of MgO-Al2O3-TiO2.

[0081] S2. Continuously introduce ammonia gas into the deionized water dispersion obtained in S1 for 7 hours until precipitation is complete, and magnesium hydroxide, aluminum hydroxide, and titanium hydroxide grow on the surface of the carbon fiber, and filter the precipitate;

[0082] S3. Calcinate the precipitate obtained in S2 to obtain a conjugated product MgO-Al2O3-TiO2 supported by carbon fibers, in which the outermost electrons are free and mutually mixed.

[0083] In S3, the calcination temperature is 700°C and the calcination time is 1 hour.

[0084] This embodiment also discloses the use of the prepared carbon fiber-supported MgO-Al2O3-TiO2 to prepare bosonine, comprising the following steps:

[0085] A1. Use deionized water to dissolve xylose to obtain a xylose-water solution, and use methanol to dissolve acetylacetone to obtain an acetylacetone-methanol solution; dissolve 50 g of xylose in 72 mL of the aqueous solution to obtain a xylose-water solution, and dissolve 40 g of acetylacetone in 50 mL of methanol to obtain an acetylacetone-methanol solution.

[0086] A2. Simultaneously adding a xylose-water solution and an acetylacetone-methanol solution to a reactor containing an aqueous dispersion of the solid base catalyst; the mass of the solid base catalyst in A2 is 0.01 times the mass of the xylose. The mass ratio of the solid base catalyst to deionized water in the aqueous dispersion of the solid base catalyst is 20:80.

[0087] A3, heat to 140℃, react for 10 minutes;

[0088] A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone;

[0089] A5. Wash the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system; the organic solvent is acetic acid;

[0090] A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0091] A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in three times the volume of tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; lower the system temperature to 0°C;

[0092] The phase transfer catalyst added to A7 is polyethylene glycol diethyl ether, the added mass is 1.62g, and the amount of phase transfer catalyst used is 3.2% of the mass of xylose.

[0093] A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to 3°C;

[0094] 3.5 g of sodium borohydride was added to A8, and the mass ratio of xylose to sodium borohydride was 1:0.07.

[0095] After the addition is completed, the mixed system is stirred at a low temperature of 3°C for 4 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

[0096] Example 4

[0097] This embodiment discloses a method for preparing a carbon fiber solid base catalyst for preparing boson, comprising the following steps:

[0098] S1, magnesium source, aluminum source, titanium source according to n Mg :n Al :n Ti The carbon fibers are dissolved in deionized water at a ratio of 3:3:2; the carbon fibers are ultrasonically dispersed in the deionized water, and the carbon fibers adsorb aluminum ions, magnesium ions, and titanium ions on the surface of the carbon fibers;

[0099] The mass of carbon fiber is 3% of the mass of MgO-Al2O3-TiO2.

[0100] S2. Continuously introduce ammonia gas into the deionized water dispersion obtained in S1 for 8 hours until precipitation is complete, magnesium hydroxide, aluminum hydroxide, and titanium hydroxide grow on the surface of the carbon fiber, and filter the precipitate;

[0101] S3. Calcinate the precipitate obtained in S2 to obtain a conjugated product MgO-Al2O3-TiO2 supported by carbon fibers, in which the outermost electrons are free and mutually mixed.

[0102] In S3, the calcination temperature is 700°C and the calcination time is 1 hour.

[0103] This embodiment also discloses the use of the prepared carbon fiber-supported MgO-Al2O3-TiO2 to prepare bosonine, comprising the following steps:

[0104] A1. Use deionized water to dissolve xylose to obtain a xylose-water solution, and use methanol to dissolve acetylacetone to obtain an acetylacetone-methanol solution; dissolve 50 g of xylose in 63 mL of aqueous solution to obtain a xylose-water solution, and dissolve 50 g of acetylacetone in 63 mL of methanol to obtain an acetylacetone-methanol solution.

[0105] A2: Simultaneously adding a xylose-water solution and an acetylacetone-methanol solution to a reactor containing an aqueous dispersion of the solid base catalyst; the mass of the solid base catalyst in A2 is 0.04 times the mass of the xylose; and the mass ratio of the solid base catalyst to deionized water in the aqueous dispersion of the solid base catalyst is 20:80.

[0106] A3, heat to 120℃ and react for 30 minutes;

[0107] A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone;

[0108] A5. Wash the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system; the organic solvent is acetic acid;

[0109] A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0110] A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in three times the volume of tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; lower the system temperature to 0°C;

[0111] The phase transfer catalyst added to A7 is polyethylene glycol, the added mass is 2.50 g, and the amount of phase transfer catalyst used is 5% of the mass of xylose.

[0112] A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to 2°C;

[0113] 4 g of sodium borohydride was added to A8, and the mass ratio of xylose to sodium borohydride was 1:0.08.

[0114] After the addition is completed, the mixed system is stirred at a low temperature of 2°C for 4 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

[0115] Example 5

[0116] This embodiment discloses a method for preparing a carbon fiber solid base catalyst for preparing boson, comprising the following steps:

[0117] S1, magnesium source, aluminum source, titanium source according to n Mg :n Al :n Ti The carbon fibers are dissolved in deionized water at a ratio of 3:3:3; the carbon fibers are ultrasonically dispersed in the deionized water, and the carbon fibers adsorb aluminum ions, magnesium ions, and titanium ions on the surface of the carbon fibers;

[0118] The mass of carbon fiber is 3% of the mass of MgO-Al2O3-TiO2.

[0119] S2. Continuously introduce ammonia gas into the deionized water dispersion obtained in S1 for 8 hours until precipitation is complete, magnesium hydroxide, aluminum hydroxide, and titanium hydroxide grow on the surface of the carbon fiber, and filter the precipitate;

[0120] S3. Calcinate the precipitate obtained in S2 to obtain a conjugated product MgO-Al2O3-TiO2 supported by carbon fibers, in which the outermost electrons are free and mutually mixed.

[0121] In S3, the calcination temperature is 700°C and the calcination time is 1 hour.

[0122] This embodiment also discloses the use of the prepared carbon fiber-supported MgO-Al2O3-TiO2 to prepare bosonine, comprising the following steps:

[0123] A1. Use deionized water to dissolve xylose to obtain a xylose-water solution, and use methanol to dissolve acetylacetone to obtain an acetylacetone-methanol solution; dissolve 50 g of xylose in 100 mL of aqueous solution to obtain a xylose-water solution, and dissolve 30 g of acetylacetone in 50 mL of methanol to obtain an acetylacetone-methanol solution.

[0124] A2. Simultaneously adding a xylose-water solution and an acetylacetone-methanol solution to a reactor containing an aqueous dispersion of the solid base catalyst; the mass of the solid base catalyst in A2 is 0.05 times the mass of the xylose; and the mass ratio of the solid base catalyst to deionized water in the aqueous dispersion of the solid base catalyst is 20:80.

[0125] A3, heat to 120℃ and react for 30 minutes;

[0126] A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone;

[0127] A5. Wash the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system; the organic solvent is acetic acid;

[0128] A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0129] A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in three times the volume of tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; lower the system temperature to 0°C;

[0130] The phase transfer catalyst added to A7 is polyethylene glycol diethyl ether, with an added mass of 2.7 g. The amount of phase transfer catalyst used is about 5% of the mass of xylose.

[0131] A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to be 0°C;

[0132] 2.5 g of sodium borohydride was added to A8, and the mass ratio of xylose to sodium borohydride was 1:0.05.

[0133] After the addition is completed, the mixed system is stirred at a low temperature of 0°C for 4 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

[0134] Comparative Example 1

[0135] This comparative example discloses a method for preparing boson using liquid alkali as a catalyst, comprising the following steps:

[0136] Add 50 g of xylose, 20 g of sodium hydroxide, 50 g of acetylacetone and 500 mL of water to the reaction flask, react at 50 ° C for 2 h, and after the reaction is complete, extract with 100 mL of ethyl acetate, remove excess acetylacetone, collect the aqueous phase, and spin dry to obtain a viscous residue. Add 500 mL of methanol without treatment to dissolve it, then add 2.5 g of sodium borohydride at -10 to 0 ° C. During the addition process, control the reaction temperature not to exceed 0 ° C. After the addition is completed, keep the reaction warm for 5 h. After the reaction is completed, add saturated ethyl acetate to quench the reaction, spin dry, dissolve in water, add sodium hydroxide to adjust the pH, and then spin dry, dissolve in ethanol, remove insoluble matter, and then spin dry to obtain bosine.

[0137] Comparative Example 2

[0138] This comparative example discloses a method for preparing bosine using solid base AOP-KF (commercially available) as a catalyst, comprising the following steps:

[0139] A1. Dissolve 50 g of xylose in 100 mL of aqueous solution to obtain a xylose-water solution, and dissolve 30 g of acetylacetone in 50 mL of methanol to obtain an acetylacetone-methanol solution. The xylose-water solution and the acetylacetone-methanol solution are simultaneously introduced into a reactor to react;

[0140] A2, the reactor contains 100 mL of solid base AOP-KF (commercially available) aqueous solution, where the mass ratio of solid base to xylose is 0.01:1;

[0141] A3, reactor reaction temperature is 120 ℃; reaction time is 30min;

[0142] A4, Filtration: Filter the solution through A3 to obtain a solid product, and wash the solid with acetic acid, an organic solvent, to obtain an acetic acid solution containing 1-C-(β-D-xylopyranosyl)-acetone;

[0143] A5. Distill the acetic acid solution of 1-C-(β-D-xylopyranosyl)-acetone obtained in A4 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0144] A6. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone in 200 mL of tetrahydrofuran and add 2.32 g of polyethylene glycol as a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran solution. Lower the system temperature to 0°C.

[0145] A7. Add sodium borohydride aqueous solution dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran solution, controlling the system temperature to 5°C during the addition process; in this comparative example, 2.5g of the reducing agent sodium borohydride was dissolved in water to prepare a 50% sodium borohydride aqueous solution;

[0146] A8. After the dropwise addition is completed, the mixed solution is stirred at 5°C for 3 h, and ethyl acetate as a quencher is added to stop the reaction. The mixture is filtered to obtain a solid product, which is bosen.

[0147] Comparative Example 3

[0148] This comparative example discloses a method for preparing a carbon fiber-supported MgO-Al2O3 solid base catalyst, comprising the following steps:

[0149] S1, ultrasonically dispersing carbon fibers in aqueous solution;

[0150] Add magnesium chloride and aluminum chloride and disperse evenly;

[0151] The molar ratio of aluminum to magnesium is 3:1;

[0152] The amount of carbon fiber used is 1% of the mass of MgO-Al2O3.

[0153] S2. Continue to introduce ammonia gas into the above liquid for 5 hours, and monitor with equipment until the oxide precipitation stops increasing, i.e., the precipitation is complete;

[0154] S3. Filter the above solution to obtain carbon-supported hydroxide, and calcine at 500° C. for 3 h to obtain carbon fiber-supported MgO-Al 2 O 3 solid base catalyst.

[0155] This comparative example discloses a method for preparing boson using the solid base catalyst obtained in this comparative example, comprising the following steps:

[0156] A1. Dissolve 50 g of xylose in 100 mL of aqueous solution to obtain a xylose-water solution, and dissolve 30 g of acetylacetone in 50 mL of methanol to obtain an acetylacetone-methanol solution. The xylose-water solution and the acetylacetone-methanol solution are simultaneously introduced into a reactor to react;

[0157] A2, the reactor contains 100 mL of the carbon fiber-supported MgO-Al2O3 solid base catalyst aqueous solution prepared in this comparative example, wherein the mass ratio of the solid base to xylose is 0.01:1;

[0158] A3, reactor reaction temperature is 120 ℃; reaction time is 30min;

[0159] A4, filtering the solution obtained in A3 to obtain a solid product, washing the product with acetic acid, an organic solvent, to obtain an acetic acid solution containing 1-C-(β-D-xylopyranosyl)-acetone;

[0160] A5, distilling the acetic acid solution containing 1-C-(β-D-xylopyranosyl)-acetone obtained in A4 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone;

[0161] A6. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone in 200 mL of tetrahydrofuran and add 2.32 g of polyethylene glycol as a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran solution. Lower the system temperature to 0°C.

[0162] A7. Add the reducing agent sodium borohydride-water solution dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran solution. Control the system temperature at 5°C during the addition process.

[0163] The concentration of sodium borohydride-water solution is: dissolve 2.5g of reducing agent sodium borohydride in water, and the mass fraction of sodium borohydride is 50%;

[0164] A8. After the dropwise addition is completed, the mixed solution is stirred at 5°C for 3 hours. The quencher ethyl acetate is added to stop the reaction to obtain a precipitate. The precipitate is filtered to obtain bosine.

[0165] The performance of the catalysts corresponding to Comparative Examples 1 to 3 and Examples 1 to 5 and the prepared bosons were tested respectively, specifically including the following:

[0166] 1. Test the base strength of the catalyst;

[0167] Toluidine titration method: weigh 0.2g solid base and mix it with 2mL benzene, and titrate it with benzoic acid-benzene solution titration method. The titration amount of benzoic acid is the number of base centers;

[0168] 2. Yield;

[0169] Yield = actual solid mass obtained / theoretical solid mass of product obtained * 100%;

[0170] 3. Purity;

[0171] The product purity was tested by liquid chromatography: chromatographic column: ChromCoreHILIC-Amide (5 μm, 4.6×250 mm); mobile phase: acetonitrile:methanol:water = 80:15:5; flow rate: 1 mL / min; column temperature: 30°C; injection volume: 20 μL;

[0172] The specific test data are shown in Table 1.

[0173] Table 1 Comparison of the number of catalyst base centers and the yield and purity of boson in Examples 1 to 5 and Comparative Examples 1 to 3

[0174] Group Number of base centers (mmol / g) Yield / % purity / % Comparative Example 1 -- 78.9 79 Comparative Example 2 9.11 83.1 84 Comparative Example 3 10.23 88.2 86 Example 1 13.45 90.3 95 Example 2 13.71 91.7 96 Example 3 14.01 95.2 98 Example 4 13.89 94.3 99 Example 5 13.76 93.9 96

[0175] As can be seen from Table 1, the solid base proposed in the present invention has a significantly higher number of base centers than commercially available solid bases, and the solid base catalyst prepared by the present invention can load more hydroxide groups. It can also be seen from Table 1 that the use of a solid base to replace an inorganic base proposed in the present invention, combined with a water-tetrahydrofuran two-liquid system reaction, effectively improves the purity of the product. The purity of Comparative Example 1 is only 79%, while the purity of the preparation scheme proposed in the present invention exceeds 95%, among which the purity of Example 4 is as high as 99%. The solid base catalyst prepared by the present invention and the non-solid base catalyst in Comparative Example 1 have obvious differences in the yield and purity of the target product. The solid base catalyst proposed in the present invention can be recovered by filtration separation and does not introduce cations. The scheme proposed in the present invention effectively reduces impurities in bosphorus.

[0176] Comparative Example 2 is a commercially available solid base. Compared with Example 1, its yield and purity are not as good as those of Example 1.

[0177] In Comparative Example 3, the solid base catalyst without titanium addition has a catalytic efficiency of 88.2%, but its purity is not high, only 86%. This shows that the skeleton of the magnesium-aluminum catalyst is unstable and will form impurities that affect the purity of the product.

[0178] The present invention adopts a dual-liquid system to facilitate the full dispersion of the reactants. With the help of a phase transfer catalyst, small particle molecules react, which can effectively increase the probability of collision between molecules and increase the yield. Therefore, the yield of Comparative Example 1 is only 78.9%. The yield of the solution proposed in the present invention is greater than 90%, among which the yield in Example 3 is as high as 95.2%. It can be seen that the solution proposed in the present invention effectively improves the production yield and meets the needs of industrialization.

[0179] The Bose prepared in Example 4 was used as a representative, and nuclear magnetic spectrum test was performed on it. Figure 1 As shown. Figure 1 It can be seen from the spectrum: 1H-NMR (400MHZ, D2O) 1.39 -1.57 (m, 1H), 2.92~3.14 (m, 3H), 3.20~3.25 (m, 1H), 3.28~3.39 (m, 1H), 3.41~3.59 (m, 1H), 3.80~3.88 (m, 1H), 3.9~4.00 (m, 1H); from the above data, it can be seen that the present invention successfully prepared boson.

[0180] The SEM of the solid base catalyst obtained in Example 4 is as follows: Figure 2 As shown, from Figure 2 It is clear that granular oxides are deposited on the surface of the carbon fibers in the solid base catalyst obtained in Example 4. The solid base obtained in Example 4 is subjected to a thermogravimetric test. Figure 3As shown, the solid base obtained in Example 4 has a small weight loss at about 500°C and is not completely decomposed until 1000°C. This shows that the solid base catalyst proposed in the present invention has good heat resistance and a stable skeleton, and is more suitable for loading hydroxide.

Claims

1. An application of a solid base catalyst in preparing boson, characterized in that: The preparation of boson includes the following steps: A1. Dissolve xylose in deionized water to obtain a xylose-water solution, and dissolve acetylacetone in methanol to obtain an acetylacetone-methanol solution; A2, adding xylose-water solution and acetylacetone-methanol solution into a reactor containing an aqueous dispersion of the solid base catalyst; The solid base catalyst is MgO-Al2O3-TiO2 supported by carbon fiber, and n Mg :n Al :n Ti is (1 to 3):3: (1 to 3); A3. Heat to 120°C to 140°C and react for 10 to 30 minutes; A4. Filter the solution to obtain a solid product, which contains a solid base catalyst and 1-C-(β-D-xylopyranosyl)-acetone; A5. Washing the solid product obtained in A4 with an organic solvent, wherein 1-C-(β-D-xylopyranosyl)-acetone is dissolved in the organic solvent to separate the solid base catalyst, thereby obtaining a 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion system; A6, distilling the 1-C-(β-D-xylopyranosyl)-acetone-organic solvent dispersion obtained in A5 to obtain the intermediate product 1-C-(β-D-xylopyranosyl)-acetone; A7. Dissolve the intermediate product 1-C-(β-D-xylopyranosyl)-acetone obtained in A6 in tetrahydrofuran, add a phase transfer catalyst to obtain a 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture; reduce the system temperature to 0±5°C; The phase transfer catalyst added in A7 is any one of polyethylene glycol, 18-crown ether-6 and polyethylene glycol diethyl ether; A8, adding a reducing agent, sodium borohydride aqueous solution, dropwise to the 1-C-(β-D-xylopyranosyl)-acetone-tetrahydrofuran mixture obtained in A7, while controlling the temperature of the mixture to 0±5°C; After the dropwise addition is completed, the mixed system is stirred at a low temperature of 0±5°C for 3 to 4 hours, and the quencher ethyl acetate is added to stop the reaction. The precipitate is filtered to obtain the product bosylamine.

2. The method for preparing boson according to claim 1, wherein: The amount of phase transfer catalyst used is 1% to 5% of the mass of xylose.

3. The use of preparing boson according to claim 1, characterized in that: The amount of sodium borohydride used in A8 is: the mass ratio of sodium borohydride to xylose is (0.05 to 0.08):

1.

4. The use of preparing boson according to claim 1, characterized in that: The mass fraction of xylose in the xylose-water solution is 50% to 80%; the mass fraction of acetylacetone in the acetylacetone-methanol solution is 60% to 80%.

5. The use of preparing boson according to claim 1, characterized in that: The mass ratio of solid base catalyst to xylose in A2 is (0.01-0.05):1.

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