A preparation method of sodium bisulfite menadione

Abstract

The present application relates to a kind of preparation methods of sodium bisulfite menadione, which is prepared by the reaction of 2-methyl-1,4-naphthoquinone and sodium bisulfite in the presence of K2O-MgO / Al2O3 as an aid in the mixed solution of organic solvent and water.The present application makes the conversion rate of raw materials >99% by introducing K2O-MgO / Al2O3 as an aid, the selectivity is greater than 95%, and can reduce the phenol, quinone impurities (content <800ppm) in the product.The process is simple, the reaction condition is mild, the process is stable, the purity of product is more than 98%, and the total yield is more than 94%.

Description

Technical Field

[0001] This invention belongs to the field of fine chemicals, specifically relating to a method for preparing sodium menadione bisulfite. Background Technology

[0002] 2-Methyl-1,4-naphthoquinone was the earliest form of vitamin K3 used, due to its low price, high activity level, and wide application. However, it suffered from insufficient stability and poor absorption. To overcome these shortcomings, a new, easily absorbed form of vitamin K3, sodium menadione bisulfite, was developed, and its applications have gradually expanded. The main function of vitamin K3 is to promote blood clotting. Animals deficient in vitamin K3 experience significantly longer clotting times, and severe deficiency can lead to death from uncontrollable bleeding.

[0003] Sodium menadione bisulfite, also known as 2-methyl-1,4-naphthoquinone sodium bisulfite, is a white or yellowish-brown crystalline powder. It is odorless or slightly odorless, hygroscopic, readily soluble in water, slightly soluble in ethanol, and unstable and easily decomposes when exposed to light.

[0004] Chinese patent CN101245038A discloses a method for synthesizing sodium menadione bisulfite. The method involves: 1) adding 2-methyl-1,4-naphthoquinone and sodium bisulfite to a solvent, heating and stirring to carry out an addition reaction; 2) after the reaction is complete, cooling the reactants to below 10°C, and centrifuging to obtain crude sodium menadione bisulfite; 3) adding ethanol, activated carbon, and sodium bisulfite to the crude sodium menadione bisulfite, heating to dissolve, filtering while hot, cooling to below 10°C to crystallize, and drying to obtain the sodium menadione bisulfite product. This reaction has poor selectivity and requires a product purification process. The activated carbon decolorization process makes the post-processing complex and consumes a lot of manpower and resources.

[0005] Therefore, it is necessary to develop a new method for preparing sodium menadione bisulfite to improve conversion rate and selectivity. Summary of the Invention

[0006] To overcome the aforementioned shortcomings in the existing technology, this invention provides a method for preparing sodium menadione bisulfite. By introducing K2O-MgO / Al2O3 as an auxiliary agent, the conversion rate and selectivity of the raw materials can be significantly improved, and the content of phenolic and quinone impurities in the product can be reduced to <800 ppm. The method of this invention is simple to operate, has mild reaction conditions, is stable, and the product purity can reach over 98%, with a total yield of over 94%.

[0007] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows:

[0008] This invention provides a method for preparing sodium bisulfite menadione. The method involves reacting 2-methyl-1,4-naphthoquinone with sodium bisulfite in a mixed solution of organic solvent and water, in the presence of the auxiliary agent K2O-MgO / Al2O3, to obtain sodium bisulfite menadione.

[0009] In this invention, the structure of the sodium menadione bisulfite is shown in the following formula:

[0010]

[0011] In this invention, the auxiliary agent K2O-MgO / Al2O3 uses Al2O3 as a carrier and K2O and MgO as metal active components;

[0012] Among them, based on the total mass of the additive K2O-MgO / Al2O3 as 100%, the Al2O3 content is 60-80wt%, such as 60wt%, 62wt%, 65wt%, 68wt%, 70wt%, 72wt%, 75wt%, 78wt%, 80wt%, etc., preferably 65-75wt%; the K2O content is 10-20wt%, such as 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%, etc., preferably 10-15wt%; and the MgO content is 10-20wt%, such as 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%, etc., preferably 15-20wt%.

[0013] In this invention, the auxiliary agent K2O-MgO / Al2O3 has a specific surface area of ​​100-300 m². 2 ·g -1 For example, 100m 2 ·g -1 120m 2 ·g -1 150m 2 ·g -1 180m 2 ·g -1 200m 2 ·g -1 220m 2 ·g -1 250m 2 ·g -1 280m 2 ·g -1 300m 2 ·g -1 etc., preferably 120-200m 2 ·g -1 The pore volume is 0.2-1.0 ml·g. -1 For example, 0.2 ml·g -10.3 ml·g -1 0.4 ml·g -1 0.5 ml·g -1 0.6 ml·g -1 0.7 ml·g -1 0.8 ml·g -1 0.9 ml·g -1 1.0 ml·g -1 The preferred dosage is 0.5-0.8 ml / g. -1 The average pore size is 6-20nm, such as 6nm, 8nm, 10nm, 12nm, 14nm, 16nm, 18nm, 20nm, etc., preferably 8-15nm.

[0014] In the method for preparing sodium menadione bisulfite provided by this invention, the auxiliary agent used is K2O-MgO supported on Al2O3. The Al2O3 support has a suitable pore structure and a large surface area, making it easy to combine with the active component to form new reactive centers, and possesses strong mechanical strength and thermal conductivity. Simultaneously, Mg is introduced into the auxiliary agent... 2+ With K + The ions coordinate with each other, which can both regulate the alkalinity to reduce product deterioration and promote the forward reaction.

[0015] Based on existing research, the preparation method of sodium menadione bisulfite described in this invention also specifies some particular operating conditions. It should be noted that the methods disclosed below are merely illustrative examples of some preferred solutions adopted to achieve the objectives of this invention. In fact, any method that uses the auxiliary agent K2O-MgO / Al2O3 to react 2-methyl-1,4-naphthoquinone with sodium bisulfite in the aforementioned solution environment to obtain sodium menadione bisulfite should be included within the scope of the technical solution protected by this invention. The preparation method of sodium menadione bisulfite described in this invention should not be limited to the methods exemplified below.

[0016] In some specific examples of the present invention, the molar ratio of 2-methyl-1,4-naphthoquinone to sodium bisulfite is 1:0.9-5.0, for example 1:0.9, 1:1.0, 1:1.5, 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.5, 1:5.0, etc., preferably 1:1.2-2.0.

[0017] In some specific examples of the present invention, the mixed solution of organic solvent and water has a mass fraction of 20-50%, such as 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., preferably 30-40%;

[0018] Preferably, the organic solvent is a protic solvent selected from at least one of alcohols and aromatic hydrocarbons; more preferably, the alcohol is selected from at least one of methanol, ethanol, isopropanol, and hexafluoroisopropanol; the aromatic hydrocarbon is selected from at least one of benzene, toluene, and xylene; and even more preferably, ethanol.

[0019] In some specific examples of the present invention, the amount of the mixed solution of organic solvent and water is 2 to 20 times the mass of 2-methyl-1,4-naphthoquinone, for example, 2 times, 4 times, 6 times, 8 times, 10 times, 12 times, 14 times, 16 times, 18 times, 20 times, etc., preferably 5 to 10 times.

[0020] In some specific examples of the present invention, the amount of the auxiliary agent K2O-MgO / Al2O3 is 5-50% of the mass of 2-methyl-1,4-naphthoquinone, for example 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., preferably 10-20%.

[0021] In some specific examples of the present invention, the reaction is carried out at a temperature of -20 to 100°C, such as -20°C, -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc., preferably 0 to 50°C, and for a time of 1 to 20 hours, such as 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 13 hours, 15 hours, 18 hours, 20 hours, etc., preferably 2 to 10 hours.

[0022] In this invention, the auxiliary agent K2O-MgO / Al2O3 is Al2O3 supported on K2O-MgO, which can be prepared using conventional processes in the field, and there are no special requirements for its source.

[0023] For example, in one specific instance, the auxiliary agent K2O-MgO / Al2O3 is prepared by an impregnation method, specifically including the following steps:

[0024] (1) Add ammonia to the aqueous solution of aluminum salt to carry out a precipitation reaction, then separate the precipitate, dry it, grind it into powder, and obtain hydrated aluminum hydroxide powder.

[0025] (2) The hydrated aluminum hydroxide powder from step (1) is immersed in an aqueous solution of soluble magnesium salt, then dehydrated, dried, and ground to obtain precursor powder.

[0026] (3) The precursor powder from step (2) is immersed in an aqueous solution of soluble potassium salt, then dehydrated, dried, ground, and calcined to obtain the auxiliary agent K2O-MgO / Al2O3.

[0027] The aluminum salt in step (1) is selected from at least one of aluminum oxychloride, aluminum sulfate, aluminum nitrate, and aluminum silicate.

[0028] In step (1), the aluminum salt aqueous solution has a mass fraction of 1-30%, such as 1%, 3%, 5%, 8%, 10%, 13%, 15%, 18%, 20%, 23%, 25%, 28%, 30%, etc., preferably 5-20%, more preferably 10-15%.

[0029] In step (1), the mass ratio of aluminum salt to ammonia is 0.1-1, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc., preferably 0.2-0.5;

[0030] Preferably, the ammonia concentration is 10-50%, such as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., and more preferably 20-30%.

[0031] In step (1), the precipitation reaction does not require a specific temperature; room temperature is sufficient. The ammonia water is added slowly, preferably dropwise, into the system during the reaction. Preferably, the ammonia water is added over a period of 1-5 hours, such as 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours, until the precipitate is completely formed.

[0032] Preferably, the pH at the reaction endpoint is controlled to be 10.5-12.5, such as 10.5, 11, 11.5, 12, 12.5, etc.

[0033] In step (1), the separation, precipitation, drying, and grinding are all conventional operations in the field. Preferably, the drying is carried out in a drying oven at a temperature of 10-200℃, such as 10℃, 30℃, 50℃, 80℃, 100℃, 130℃, 150℃, 180℃, 200℃, etc., preferably 20-150℃, more preferably 50-100℃; the drying time is 1-20h, such as 1h, 3h. The grinding time is 5h, 8h, 10h, 13h, 15h, 18h, 20h, etc., preferably 5-10h; the grinding is carried out by ball milling until the powder particle size is 10-500μm, such as 10μm, 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, etc., preferably 50-100μm.

[0034] The soluble magnesium salt in step (2) is selected from at least one of magnesium nitrate, magnesium chloride, magnesium sulfate, etc.

[0035] In step (2), the soluble magnesium salt aqueous solution contains 10-30% by mass, such as 10%, 13%, 15%, 18%, 20%, 23%, 25%, 28%, 30%, etc., preferably 15-20%.

[0036] In step (2), the mass ratio of hydrated aluminum hydroxide powder to the aqueous solution of soluble magnesium salt is 1:5-20, for example, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, 1:20, etc., preferably 1:5-10.

[0037] In step (2), there is no temperature requirement for the immersion, room temperature is sufficient, and the immersion time is 5-30h, such as 5h, 8h, 10h, 13h, 15h, 18h, 20h, 23h, 25h, 28h, 30h, etc., preferably 10-20h.

[0038] In step (2), the dehydration, drying, and grinding are conventional operations in the field. Preferably, the dehydration and drying process involves first evaporating moisture using a water bath, followed by drying. The water bath temperature is 50-100℃, such as 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, etc., preferably 70-90℃; the drying temperature is 100-150℃, such as 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc., preferably 110℃. The drying temperature is 0-130℃; the drying time is 5-20h, such as 5h, 8h, 10h, 13h, 15h, 18h, 20h, etc., preferably 10-15h; the grinding is carried out by ball milling until the powder particle size is 50-500μm, such as 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, etc., preferably 50-150μm.

[0039] The soluble potassium salt in step (3) is selected from at least one of potassium chloride, potassium nitrate, and potassium sulfate.

[0040] In this invention, the mass fraction of potassium salt in the aqueous solution of the soluble potassium salt in step (3) is 1-20%, for example, 1%, 3%, 5%, 8%, 10%, 13%, 15%, 18%, 20%, etc., preferably 5-10%.

[0041] In step (3), the mass ratio of the precursor powder to the aqueous solution of the soluble potassium salt is 1:10-50, for example, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, etc., preferably 1:20-30.

[0042] In step (3), there is no temperature requirement for the immersion, room temperature is sufficient, and the immersion time is 5-30h, such as 5h, 8h, 10h, 13h, 15h, 18h, 20h, 23h, 25h, 28h, 30h, etc., preferably 10-20h.

[0043] In step (3), the dehydration, drying, grinding, and calcination are all conventional operations in the field. Preferably, the dehydration involves first evaporating moisture using a water bath, followed by drying. The water bath temperature is 30-80℃, such as 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, etc., preferably 50-80℃; the drying temperature is 90-150℃, such as 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc., preferably 100-120℃; and the drying time is 10-30h, such as 10h, 13h, 15h, 18h, 20h, 23h, 25h. The grinding time is 28h, 30h, etc., preferably 15-20h; the grinding is carried out by ball milling until the powder particle size is 50-300μm, such as 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, etc., preferably 50-200μm; the calcination temperature is 400-1000℃, such as 400℃, 500℃, 600℃, 700℃, 800℃, 900℃, 1000℃, etc., preferably 500-700℃, and the calcination time is 5-20h, such as 5h, 8h, 10h, 13h, 15h, 18h, 20h, etc., preferably 10-15h.

[0044] Compared with the prior art, the positive effects of the present invention are as follows:

[0045] 1) This invention introduces K2O-MgO / Al2O3 as an auxiliary agent, which has the advantages of high activity and high selectivity. There is no problem of product over-reaction, which reduces the purification difficulty in the post-processing. The raw material conversion rate is over 99%, the selectivity is over 95%, and it can effectively reduce phenolic and quinone impurities in the product (content <800ppm).

[0046] 2) The reaction conditions of the method of the present invention are mild, the selected auxiliary agents have high thermal stability, avoiding deactivation at high temperature, and have high mechanical strength, and can maintain high reaction efficiency even after multiple (≥10 times) applications.

[0047] 3) The process is simple to operate, the product conversion rate is high, and the generation of waste is reduced, which lowers the production cost and is conducive to industrial production. The product purity is above 98% and the total yield is above 94%. Detailed Implementation

[0048] The following embodiments will further illustrate the method provided by the present invention, but the present invention is not limited to the listed embodiments, and should also include any other known modifications within the scope of the claims of the present invention.

[0049] Gas chromatography analysis conditions: Online analysis was performed using an Agilent HP-5 polysiloxane column with a two-stage temperature program: initial temperature 50°C, held for 1 minute, then increased to 100°C at a rate of 10°C / min; subsequently increased to 250°C at a rate of 15°C / min. High-purity N2 was used as the carrier gas with a split ratio of 150:1. The injection temperature was 250°C, and the detector was an FID with a detector temperature of 260°C. The injection volume was 0.5 μL.

[0050] The source information of the main raw materials in the embodiments and comparative examples of this invention is shown in the table below. Unless otherwise specified, other raw materials and reagents were obtained through commercially available channels.

[0051] Reagent Name Reagent Specifications Manufacturer 2-Methyl-1,4-naphthoquinone 98%, AR Inokai Ethanol, methanol, toluene 99%, AR Annegi <![CDATA[Ammonia water, AlOCl2·8H2O]]> 98%, AR Sinopharm

[0052]

[0053] Example 1

[0054] Preparation of the auxiliary agent K2O-MgO / Al2O3:

[0055] 100g of AlOCl2·8H2O was dissolved in 1.0L of water, and 200g of 50wt% ammonia solution was slowly added dropwise to carry out a precipitation reaction. The ammonia solution was added dropwise over 2.5h, and the precipitation reaction was controlled to end at pH=11.8. The solid and liquid phases were then separated in a vacuum filter funnel. The resulting filter cake was dried in a drying oven at 150℃ for 6.0h, and then ground in a ball mill to obtain hydrated aluminum hydroxide powder with a particle size of about 65μm.

[0056] 10g of hydrated aluminum hydroxide powder was added to 100g of 30wt% magnesium nitrate aqueous solution and soaked for 20h. Then, the water was evaporated in a water bath at 90℃ and dried in an oven at 150℃ for 6.0h. The resulting solid powder was thoroughly ground in a ball mill to obtain precursor powder with a particle size of 120μm.

[0057] 5g of precursor powder was added to 100g of 10wt% potassium nitrate aqueous solution and soaked for 10.0h. Then, the water was evaporated in a water bath at 70℃ and dried in an oven at 120℃ for 15h. The resulting solid was ground in a ball mill for 1.0h and then calcined in a muffle furnace at 600℃ for 12.0h. After cooling, solid additive #1 K2O-MgO / Al2O3 was obtained.

[0058] XRD analysis revealed that the average particle size of solid additive #1 was 155 μm, and the specific surface area was 155 m². 2 ·g -1 The pore volume is 0.52 ml·g -1The average pore size is 8 nm. Based on the total mass of the additives K2O-MgO / Al2O3 being 100%, the Al2O3 content is 65.5 wt%, the K2O content is 14.8 wt%, and the MgO content is 19.7 wt%.

[0059] Preparation of sodium menadione bisulfite:

[0060] Using a 1.0L three-necked flask as the reaction vessel, a mixed solution of 40g ethanol and 60g water, 0.1mol (17.2g) 2-methyl-1,4-naphthoquinone, 0.15mol sodium bisulfite, and 2.3g of solid additive K2O-MgO / Al2O3 were added sequentially. The reaction system was placed in an oil bath at 50℃ and stirred to start the reaction. After 6.0h, the reaction was stopped, and samples were taken for liquid chromatography analysis. The reaction conversion rate was 99.3%, the selectivity was 96.2%, the reaction yield was 95.5%, the product purity was 98.3%, the phenolic impurity content was 550ppm, and the quinone impurity content was 102ppm.

[0061] Example 2

[0062] Preparation of the auxiliary agent K2O-MgO / Al2O3:

[0063] 100g of AlOCl2·8H2O was dissolved in 1.0L of water, and 250g of 35wt% ammonia solution was slowly added dropwise to carry out a precipitation reaction. The ammonia solution was added dropwise over 2.5h, and the precipitation reaction was controlled to end at pH=11.1. The solid and liquid phases were then separated in a vacuum filter funnel. The resulting filter cake was dried in a drying oven at 120℃ for 6.0h, and then ground in a ball mill to obtain hydrated aluminum hydroxide powder with a particle size of about 69μm.

[0064] 10g of hydrated aluminum hydroxide powder was added to 100g of 25wt% magnesium nitrate aqueous solution and soaked for 18h. Then, the water was evaporated in a water bath at 80℃ and then dried in an oven at 135℃ for 8.0h. The resulting solid powder was thoroughly ground in a ball mill to obtain precursor powder with a particle size of 162μm.

[0065] 5g of precursor powder was added to 200g of 15wt% potassium sulfate aqueous solution and soaked for 15.0h. Then, the water was evaporated in a water bath at 60℃ and dried in an oven at 125℃ for 25h. The resulting solid was ground in a ball mill for 1.0h and then calcined in a muffle furnace at 700℃ for 10.0h. After cooling, solid additive #2 K2O-MgO / Al2O3 was obtained.

[0066] XRD analysis revealed that the average particle size of solid additive #2 was 115.6 μm and the specific surface area was 165 m². 2 ·g -1 The pore volume is 0.69 ml·g-1 The average pore size is 12 nm. Based on the total mass of the additives K2O-MgO / Al2O3 being 100%, the Al2O3 content is 70.3 wt%, the K2O content is 14.2 wt%, and the MgO content is 15.5 wt%.

[0067] Preparation of sodium menadione bisulfite:

[0068] Using a 1.0L three-necked flask as the reaction vessel, a mixed solution of 35g ethanol and 65g water, 0.1mol (17.2g) 2-methyl-1,4-naphthoquinone, 0.18mol sodium bisulfite, and 4.6g of solid additive K2O-MgO / Al2O3 were added sequentially. The reaction system was placed in an oil bath at 40℃ and stirred to start the reaction. After 6.0h, the reaction was stopped, and samples were taken for liquid chromatography analysis. The reaction conversion rate was 99.2%, the selectivity was 95.9%, the reaction yield was 95.1%, the product purity was 98.3%, the phenolic impurity content was 352ppm, and the quinone impurity content was 118ppm.

[0069] Recycling and reuse of solid additive #2 K2O-MgO / Al2O3:

[0070] Solid additive #2, K2O-MgO / Al2O3, was recovered by filtration. The above operation was repeated to prepare sodium menadione bisulfite. Samples were taken for liquid chromatography analysis. The results of 10 applications are shown in the table below:

[0071]

[0072] Example 3

[0073] Preparation of the auxiliary agent K2O-MgO / Al2O3:

[0074] 100g of AlOCl2·8H2O was dissolved in 1.0L of water, and 200g of 45wt% ammonia solution was slowly added dropwise to carry out a precipitation reaction. The ammonia solution was added dropwise over 3.0h, and the precipitation reaction was controlled to end at pH=12.0. The solid and liquid phases were then separated in a vacuum filter funnel. The resulting filter cake was dried in a drying oven at 140℃ for 8.0h, and then ground in a ball mill to obtain hydrated aluminum hydroxide powder with a particle size of about 75μm.

[0075] 10g of hydrated aluminum hydroxide powder was added to 100g of 20wt% magnesium nitrate aqueous solution and soaked for 15h. Then, the water was evaporated in a water bath at 90℃ and dried in an oven at 120℃ for 10.0h. The resulting solid powder was thoroughly ground in a ball mill to obtain a precursor powder with a particle size of 90μm.

[0076] 5g of precursor powder was added to 150g of 10wt% potassium nitrate aqueous solution and soaked for 20.0h. Then, the water was evaporated in a water bath at 70℃ and dried in an oven at 140℃ for 20h. The resulting solid was ground in a ball mill for 1.0h and then calcined in a muffle furnace at 550℃ for 15.0h. After cooling, solid additive K2O-MgO / Al2O3 was obtained.

[0077] XRD analysis revealed that the average particle size of solid additive #3 was 90.6 μm, and its specific surface area was 132.2 m². 2 ·g -1 The pore volume is 0.58 ml·g -1 The average pore size is 9 nm. Based on the total mass of the additives K2O-MgO / Al2O3 being 100%, the Al2O3 content is 68.3 wt%, the K2O content is 11.8 wt%, and the MgO content is 19.9 wt%.

[0078] Preparation of sodium menadione bisulfite:

[0079] A 1.0L three-necked flask was used as the reaction vessel. A mixed solution of 40g toluene and 60g water, 0.1mol (17.2g) 2-methyl-1,4-naphthoquinone, 0.12mol sodium bisulfite, and 2.5g of solid additive K₂O-MgO / Al₂O₃ were added sequentially. The reaction system was placed in an oil bath at 45℃ and stirred to initiate the reaction. After 6.0h, the reaction was stopped, and samples were taken for liquid chromatography analysis. The conversion rate was 99.6%, the selectivity was 97.2%, the yield was 96.8%, the product purity was 98.9%, and the content of phenolic impurities was 465ppm and the content of quinone impurities was 147ppm.

[0080] Example 4

[0081] Preparation of the auxiliary agent K2O-MgO / Al2O3:

[0082] 100g of AlOCl2·8H2O was dissolved in 1.0L of water, and 230g of 40wt% ammonia solution was slowly added dropwise to carry out a precipitation reaction. The ammonia solution was added dropwise over 2.5h, and the precipitation reaction was controlled to end at pH=11.7. The solid and liquid phases were then separated in a vacuum filter funnel. The resulting filter cake was dried in a drying oven at 100℃ for 10.0h, and then ground in a ball mill to obtain hydrated aluminum hydroxide powder with a particle size of about 68μm.

[0083] 10g of hydrated aluminum hydroxide powder was added to 100g of 30wt% magnesium nitrate aqueous solution and soaked for 20h. Then, the water was evaporated in a water bath at 85℃ and then dried in an oven at 115℃ for 20.0h. The resulting solid powder was thoroughly ground in a ball mill to obtain precursor powder with a particle size of 125μm.

[0084] 5g of precursor powder was added to 200g of 5wt% potassium chloride aqueous solution and soaked for 16.0h. Then, the water was evaporated in a water bath at 80℃ and dried in an oven at 120℃ for 18h. The resulting solid was ground in a ball mill for 1.0h and then calcined in a muffle furnace at 600℃ for 8.0h. After cooling, solid additive #4 K2O-MgO / Al2O3 was obtained.

[0085] XRD analysis revealed that the average particle size of solid additive #4 was 120.2 μm, the specific surface area was 152 m²·g⁻¹, the pore volume was 0.62 ml·g⁻¹, and the average pore size was 15 nm. Based on a total mass of 100% K₂O-MgO / Al₂O₃, the Al₂O₃ content was 73.2 wt%, the K₂O content was 14.5 wt%, and the MgO content was 12.3 wt%.

[0086] Preparation of sodium menadione bisulfite:

[0087] A 1.0L three-necked flask was used as the reaction vessel. A mixed solution of 40g xylene and 60g water, 0.1mol (17.2g) 2-methyl-1,4-naphthoquinone, 0.15mol sodium bisulfite, and 2.3g of solid additive K2O-MgO / Al2O3 (No. 4) were added sequentially. The reaction system was placed in an oil bath at 50℃ and stirred to initiate the reaction. After 5.0h, the reaction was stopped, and samples were taken for liquid chromatography analysis. The conversion rate was 99.5%, the selectivity was 95.6%, the yield was 95.1%, the product purity was 98.3%, and the content of phenolic impurities was 560ppm and the content of quinone impurities was 119ppm.

[0088] Example 5

[0089] Preparation of the auxiliary agent K2O-MgO / Al2O3:

[0090] 100g of AlOCl2·8H2O was dissolved in 1.0L of water, and 200g of 50wt% ammonia solution was slowly added dropwise to carry out a precipitation reaction. The ammonia solution was added dropwise over 3.5h, and the precipitation reaction was controlled to end at pH=11.8. The solid and liquid phases were then separated in a vacuum filter funnel. The resulting filter cake was dried in a drying oven at 150℃ for 5.0h, and then ground in a ball mill to obtain hydrated aluminum hydroxide powder with a particle size of about 76μm.

[0091] 10g of hydrated aluminum hydroxide powder was added to 100g of 30wt% magnesium nitrate aqueous solution and soaked for 15h. Then, the water was evaporated in a water bath at 75℃ and then dried in an oven at 130℃ for 15.0h. The resulting solid powder was thoroughly ground in a ball mill to obtain precursor powder with a particle size of 136μm.

[0092] 5g of precursor powder was added to 100g of 10wt% potassium nitrate aqueous solution and soaked for 18.0h. Then, the water was evaporated in a water bath at 65℃ and dried in an oven at 110℃ for 20h. The resulting solid was ground in a ball mill for 1.0h and then calcined in a muffle furnace at 600℃ for 10.0h. After cooling, solid additive #5 K2O-MgO / Al2O3 was obtained.

[0093] XRD analysis revealed that the average particle size of solid additive #5 was 135.6 μm and the specific surface area was 198 m². 2 ·g -1 The pore volume is 0.77 ml·g -1 The average pore size is 11 nm. Based on the total mass of the additives K2O-MgO / Al2O3 being 100%, the Al2O3 content is 71.5 wt%, the K2O content is 17.6 wt%, and the MgO content is 10.9 wt%.

[0094] Preparation of sodium menadione bisulfite:

[0095] Using a 1.0L three-necked flask as the reaction vessel, a mixed solution of 30g ethanol and 70g water, 0.1mol (17.2g) 2-methyl-1,4-naphthoquinone, 0.15mol sodium bisulfite, and 2.5g of solid additive K2O-MgO / Al2O3 were added sequentially. The reaction system was placed in an oil bath at 45℃ and stirred to initiate the reaction. After 4.0h, the reaction was stopped, and samples were taken for liquid chromatography analysis. The reaction conversion rate was 99.7%, the selectivity was 95.8%, the reaction yield was 95.5%, the product purity was 98.1%, the phenolic impurity content was 483ppm, and the quinone impurity content was 105ppm.

[0096] Comparative Example 1

[0097] The method for preparing sodium menadione using sodium bisulfite was described in Example 1, except that solid additive K2O-MgO / Al2O3 (No. 1) was not added. All other operations and conditions remained unchanged. The reaction conversion rate was 99.1%, the selectivity was 93.4%, the reaction yield was 92.6%, the product purity was 96.5%, and the content of phenolic impurities was 1520 ppm and the content of quinone impurities was 296 ppm.

[0098] Comparative Example 2

[0099] The preparation method of sodium bisulfite menadione in Example 1 was followed, except that solid additive K2O-MgO / Al2O3 was replaced with tetrabutylammonium chloride. All other operations and conditions remained unchanged. The reaction conversion rate was 98.9%, the selectivity was 91.8%, the reaction yield was 90.8%, the product purity was 97.2%, the phenolic impurity content was 1056 ppm, and the quinone impurity content was 281 ppm.

[0100] Comparative Example 3

[0101] The preparation method of sodium bisulfite menadione in Example 1 was followed, except that solid additive K2O-MgO / Al2O3 was replaced with 18-crown ether. All other operations and conditions remained unchanged. The reaction conversion rate was 98.5%, the selectivity was 93.6%, the reaction yield was 92.2%, the product purity was 96.4%, the phenolic impurity content was 945 ppm, and the quinone impurity content was 237 ppm.

[0102] Comparative Example 4

[0103] The preparation method of sodium bisulfite menadione in Example 1 was followed, except that solid additive K2O-MgO / Al2O3 was replaced with MgO / Al2O3. All other operations and conditions remained unchanged. The reaction conversion rate was 93.7%, the selectivity was 88.6%, the reaction yield was 83.0%, the product purity was 95.6%, and the content of phenolic impurities was 2587 ppm and the content of quinone impurities was 549 ppm.

[0104] The preparation method of MgO / Al2O3 is the same as that of solid additive K2O-MgO / Al2O3, except that the potassium nitrate aqueous solution impregnation step is omitted.

[0105] Comparative Example 5

[0106] The preparation method of sodium menadione in Example 1 was followed, except that solid additive #1 K2O-MgO / Al2O3 was replaced with K2O / Al2O3. All other operations and conditions remained unchanged. The reaction conversion rate was 92.4%, the selectivity was 96.4%, the reaction yield was 89.1%, the product purity was 95.1%, the phenolic impurity content was 1569 ppm, and the quinone impurity content was 192 ppm.

[0107] The preparation method of K2O / Al2O3 is the same as that of solid additive K2O-MgO / Al2O3, except that the step of impregnating with magnesium nitrate aqueous solution is omitted.

[0108] Comparative Example 6

[0109] The preparation method of sodium menadione bisulfite in Example 1 was followed, except that solid additive #1 K2O-MgO / Al2O3 was replaced with K2O-MgO / coconut shell activated carbon. All other operations and conditions remained unchanged. The reaction conversion rate was 91.5%, the selectivity was 88.6%, the reaction yield was 81.1%, the product purity was 94.6%, and the content of phenolic impurities was 3697 ppm and the content of quinone impurities was 1258 ppm.

[0110] The preparation method of K2O-MgO / coconut shell activated carbon is the same as that of solid additive K2O-MgO / Al2O3, except that the preparation step of hydrated aluminum hydroxide is omitted and replaced with coconut shell activated carbon.

Claims

1. A method for preparing sodium menadione bisulfite, characterized in that, The method involves reacting 2-methyl-1,4-naphthoquinone with sodium bisulfite in a mixed solution of organic solvent and water, in the presence of the auxiliary K2O-MgO / Al2O3, to prepare sodium bisulfite methylnaphthoquinone. The additive K2O-MgO / Al2O3 uses Al2O3 as a carrier and K2O and MgO as metal active components; wherein, based on the total mass of the additive K2O-MgO / Al2O3 being 100%, the Al2O3 content is 60-80wt%, the K2O content is 10-20wt%, and the MgO content is 10-20wt%.

2. The preparation method according to claim 1, characterized in that, The additive K2O-MgO / Al2O3, based on a total mass of 100% K2O-MgO / Al2O3, has an Al2O3 content of 65-75 wt%, a K2O content of 10-15 wt%, and a MgO content of 15-20 wt%.

3. The preparation method according to claim 1, characterized in that, The additive K2O-MgO / Al2O3 has a specific surface area of ​​100-300 m². 2 •g -1 The pore volume is 0.2-1.0 ml•g -1 The average pore size is 6-20 nm.

4. The preparation method according to claim 3, characterized in that, The specific surface area is 120-200 m² 2 •g -1 .

5. The preparation method according to claim 3, characterized in that, The pore volume is 0.5-0.8 ml•g -1 .

6. The preparation method according to claim 3, characterized in that, The average pore size is 8-15 nm.

7. The preparation method according to claim 1, characterized in that, The molar ratio of 2-methyl-1,4-naphthoquinone to sodium bisulfite is 1:0.9-5.

0.

8. The preparation method according to claim 7, characterized in that, The molar ratio of 2-methyl-1,4-naphthoquinone to sodium bisulfite is 1:1.2-2.

0.

9. The preparation method according to claim 1, characterized in that, The mixture of organic solvent and water, wherein the mass fraction of organic solvent is 20-50%.

10. The preparation method according to claim 9, characterized in that, The organic solvent has a mass fraction of 30-40%.

11. The preparation method according to claim 1, characterized in that, The organic solvent is selected from at least one of alcohols and aromatic hydrocarbons.

12. The preparation method according to claim 11, characterized in that, The alcohol is selected from at least one of methanol, ethanol, isopropanol, and hexafluoroisopropanol.

13. The preparation method according to claim 11, characterized in that, The aromatic hydrocarbon is selected from at least one of benzene, toluene, and xylene.

14. The preparation method according to claim 1, characterized in that, The amount of the mixed solution of organic solvent and water is 2 to 20 times the mass of 2-methyl-1,4-naphthoquinone.

15. The preparation method according to claim 14, characterized in that, The amount of the mixture of organic solvent and water used is 5-10 times the mass of 2-methyl-1,4-naphthoquinone.

16. The preparation method according to claim 1, characterized in that, The amount of the auxiliary agent K2O-MgO / Al2O3 is 5-50% of the mass of 2-methyl-1,4-naphthoquinone.

17. The preparation method according to claim 16, characterized in that, The amount of the auxiliary agent K2O-MgO / Al2O3 is 10-20% of the mass of 2-methyl-1,4-naphthoquinone.

18. The preparation method according to claim 1, characterized in that, The reaction is carried out at a temperature of -20 to 100°C for a time of 1 to 20 hours.

19. The preparation method according to claim 18, characterized in that, The reaction is carried out at a temperature of 0-50℃ for 2-10 hours.

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