Preparation method of L-glufosinate potassium salt
By using the reaction method of using ethanol and potassium hydroxide aqueous solution in the preparation of L-glufosinate potassium salt, combined with crystallization, filtration and drying steps, the problem of insufficient production yield and content of L-glufosinate potassium salt in the prior art was solved, and an efficient and simple preparation process was achieved, and the quality and industrial value of the product were improved.
Patent Information
- Application Number
- CN202510036383.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-09
- Publication Date
- 2025-05-30
AI Technical Summary
The lack of high yield and high content of L-glufosinate potassium salt preparation methods in the prior art limits its wide application in the agricultural field.
Ethanol is used as the solvent for L-glufosinate, and reacted with aqueous potassium hydroxide solution, and the L-glufosinate potassium salt is prepared by crystallization, filtration and drying steps. The method includes adjusting the mass concentration of the aqueous potassium hydroxide solution, adding the aqueous potassium hydroxide solution in two sessions, controlling the reaction and crystallization temperature, and using activated carbon and potassium citrate as additives to improve the reaction efficiency and product quality.
The high yield and high content preparation of L-glufosinate potassium salt is achieved, the process flow is simplified, and the purity and industrialization value of the product are improved.
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of chemical synthesis, and particularly relates to a method for preparing L-glufosinate potassium salt. Background Art
[0002] As a broad-spectrum herbicide, L-glufosinate has a wide range of applications in the agricultural field and can effectively control a series of gramineous weeds and broad-leaved weeds. L-glufosinate has a relatively low risk to non-target organisms. For this reason, L-glufosinate is becoming increasingly popular, especially in those areas where environmentally friendly agricultural processes must be adopted. With the increasing interest in sustainable agricultural methods, the importance of L-glufosinate as an essential component of global IPM (Integrated Pest Management) has also increased.
[0003] In the prior art, a method for preparing glufosinate potassium salt is disclosed. An aqueous solution of potassium hydroxide or potassium carbonate is added to glufosinate acid or glufosinate hydrochloride, and after reaction, it is purified, concentrated, and dried to obtain glufosinate potassium salt. This method uses water as a reaction medium and has the characteristics of being green and environmentally friendly. However, the post-treatment of the reaction is relatively complex. It is necessary to first filter to remove solid impurities for purification, and then concentrate to remove water to obtain a 30-70% glufosinate potassium salt solution. The value of large-scale production of this method is low.
[0004] The prior art also discloses a method for preparing L-glufosinate monosodium salt. In this method, L-glufosinate and solid sodium hydroxide are reacted in isopropanol with a water content of less than 5000 ppm, and then L-glufosinate monosodium salt is obtained through crystallization and drying. This method has the characteristics of simple post-treatment process, high product content, and high yield. However, it has high requirements for raw materials and poor controllability. There are significant differences in the solubility of L-glufosinate potassium salt and L-glufosinate sodium salt in water and alcohol. Therefore, the preparation method of L-glufosinate sodium salt has little reference significance for L-glufosinate potassium salt.
[0005] However, there are few reports on the synthesis or preparation of L-glufosinate potassium salt in the prior art. L-glufosinate is the active form of glufosinate with herbicidal activity, and there are relatively few products involving L-glufosinate potassium salt on the market.
[0006] Therefore, it is necessary to provide a method for preparing L-glufosinate potassium salt with high yield and high content. Summary of the Invention
[0007] The inventors found during the research process that L-glufosinate potassium salt has the characteristics of not harming crop roots during weeding, having no soil residue during potassium supplementation, improving soil detoxification ability, improving crop stress resistance, and being safe for orchard seedlings. However, there is no preparation method for L-glufosinate potassium salt with high yield and high content in the prior art.
[0008] In view of the above problems, the present invention provides a method for preparing L-glufosinate potassium salt, which comprises the following steps: adding L-glufosinate into ethanol, then adding an aqueous potassium hydroxide solution, reacting, crystallizing, filtering, and drying to obtain the L-glufosinate potassium salt.
[0009] Through the above technical solution, the present application uses ethanol as the solvent for L-glufosinate, reacts with an aqueous potassium hydroxide solution to obtain L-glufosinate potassium salt, with high yield and high content of the prepared L-glufosinate potassium salt.
[0010] Preferably, the mass concentration of the aqueous potassium hydroxide solution is 60-80%.
[0011] Through the above technical solution, by adjusting the mass concentration of the aqueous potassium hydroxide solution within a reasonable range, the reaction system can have a suitable conductivity. The suitable conductivity can improve the migration rate of electrons, thereby improving the reaction efficiency and product yield.
[0012] Preferably, the molar ratio of potassium hydroxide to L-glufosinate is 1.1-1.3:1.
[0013] Preferably, the aqueous potassium hydroxide solution is added in two portions. First, add 1 / 2 of the mass of the aqueous potassium hydroxide solution, and after reacting for 0.5-1 h, add the remaining aqueous potassium hydroxide solution.
[0014] Through the above technical solution, on the one hand, it can avoid too high local concentration, causing non-uniformity and instability of the reaction system. On the other hand, it can better control the reaction rate, reduce the generation of side reactions, and thus improve the yield of the target product.
[0015] Preferably, the reaction temperature is 60-80 °C.
[0016] Through the above technical solution, on the one hand, it can accelerate the target reaction rate and increase the production amount of the product. On the other hand, it can reduce the generation of side reactions and increase the content of L-glufosinate potassium salt.
[0017] Preferably, the crystallization temperature is 5-30 °C.
[0018] Through the above technical solution, using an appropriate crystallization temperature can control the crystal growth rate, ensure that the crystals have enough time to form, and improve the crystal quality and yield.
[0019] Preferably, crystallization is first carried out at 20-30 °C and then at 0-10 °C.
[0020] Through the above technical solution, crystallization is carried out at different temperatures, which can precisely control the crystal growth rate. This helps to reduce the generation of side reactions and the incorporation of impurities, thereby improving the purity of the product.
[0021] Preferably, an additive is added before the reaction. The additive is selected from at least one of activated carbon and potassium citrate, and the mass ratio of the additive to the L-glufosinate is 1:55 - 65.
[0022] Preferably, the additive is composed of activated carbon and potassium citrate, and the mass ratio of the activated carbon to the potassium citrate is 0.66 - 3:1.
[0023] Through the above technical solution, adding activated carbon and potassium citrate is beneficial to the progress of the target reaction, reduces the generation of side reactions and the mixing of impurities. Furthermore, it is beneficial to improve the yield and content of the potassium salt of L-glufosinate.
[0024] Preferably, the drying is vacuum drying. The vacuum degree of the vacuum drying is 0.09 - 0.11 MPa, the temperature is 90 - 110 °C, and the drying time is 2 - 4 hours.
[0025] Preferably, the drying can also be spray drying. The temperature of the spray drying is 130 - 170 °C, and the spray drying time is 1 - 15 seconds.
[0026] In the second aspect of the present invention, the present application provides a potassium salt of L-glufosinate prepared by the above-mentioned preparation method of the potassium salt of L-glufosinate.
[0027] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The present application provides a preparation method of a potassium salt of L-glufosinate, which has a simple process and is easy to industrialize.
[0028] 2. The preparation method of a potassium salt of L-glufosinate provided by the present application has a high yield of the potassium salt of L-glufosinate.
[0029] 3. The potassium salt of L-glufosinate prepared by the preparation method provided by the present application has a high content. Detailed Embodiments
[0030] The following further illustrates the present invention with specific examples. However, the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the following examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. The methods used, unless otherwise specified, are all conventional methods well known in the art. The consumables and reagents used, unless otherwise specified, are all commercially available. Unless otherwise stated, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied to the present invention. The activated carbon used in the examples is coconut shell granular activated carbon purchased from Jiangsu Qisheng Carbon Industry Technology Co., Ltd.
[0031] In the first aspect of the present invention, the present invention provides a method for preparing L-glufosinate potassium salt, comprising the following steps: adding L-glufosinate to ethanol, then adding an aqueous potassium hydroxide solution, reacting, crystallizing, filtering, and drying to obtain the L-glufosinate potassium salt.
[0032] Preferably, the mass concentration of the aqueous potassium hydroxide solution is 60-80%.
[0033] Preferably, the molar ratio of potassium hydroxide to L-glufosinate is 1.1-1.3:1.
[0034] Preferably, the aqueous potassium hydroxide solution is added in two portions. First, 1 / 2 of the mass of the aqueous potassium hydroxide solution is added, and after reacting for 0.5-1 h, the remaining aqueous potassium hydroxide solution is added.
[0035] Preferably, the reaction temperature is 60-80 °C.
[0036] Preferably, the crystallization temperature is 5-30 °C.
[0037] Preferably, crystallization is carried out first at 20-30 °C and then at 0-10 °C.
[0038] Preferably, at least one of activated carbon and potassium citrate is added before the reaction.
[0039] Preferably, activated carbon and potassium citrate are added before the reaction, and the mass ratio of the activated carbon to the potassium citrate is 0.66-3:1.
[0040] Preferably, drying is vacuum drying, the vacuum degree of the vacuum drying is 0.09-0.11 MPa, the temperature is 90-110 °C, and the drying time is 2-4 hours.
[0041] Preferably, drying can also be spray drying, the temperature of the spray drying is 130-170 °C, and the spray drying time is 1-15 seconds.
[0042] In the second aspect of the present invention, the present application provides an L-glufosinate potassium salt prepared by the above method for preparing L-glufosinate potassium salt.
[0043] Example 1 A method for preparing L-glufosinate potassium salt, comprising the following steps: adding 30 g of L-glufosinate to 100 g of ethanol, stirring, and adding 16 g of an aqueous KOH solution with a mass concentration of 70% at one time while stirring. After adding, reacting at 70 °C for 3.5 h, cooling to 5 °C, crystallizing, and filtering to obtain a crude product of L-glufosinate potassium salt, and drying the crude product to obtain L-glufosinate potassium salt. The drying treatment is vacuum drying, the vacuum degree of the vacuum drying is 0.1 MPa, the temperature is 100 °C, and the drying time is 3 hours.
[0044] Example 2 The difference between Example 2 and Example 1 is that 14 g of KOH aqueous solution with a mass concentration of 80% is added at one time.
[0045] Example 3 The difference between Example 3 and Example 1 is that 18.7 g of a KOH aqueous solution with a mass concentration of 60% is added at one time.
[0046] Example 4 The preparation method of L-glufosinate ammonium potassium salt comprises the following steps: adding 30g of L-glufosinate ammonium to 100g of ethanol, stirring, adding 8g of a KOH aqueous solution with a mass concentration of 70%, stirring while adding, heating to 70°C, reacting for 1h, then adding 8g of a KOH aqueous solution with a mass concentration of 70%, and after adding, continuing to react at 70°C for 2.5h, cooling to 5°C, crystallizing, filtering, obtaining a crude L-glufosinate ammonium potassium salt, and drying the crude product to obtain L-glufosinate ammonium potassium salt. The drying treatment is vacuum drying, the vacuum degree of the vacuum drying is 0.1MPa, the temperature is 100°C, and the drying time is 3 hours.
[0047] Example 5 The difference between Example 5 and Example 4 is that 0.5 g of activated carbon is added before heating, and the activated carbon is filtered out before cooling.
[0048] Example 6 The difference between Example 6 and Example 4 is that 0.5 g of potassium citrate is added before heating.
[0049] Example 7 The difference between Example 7 and Example 4 is that before heating, 0.25 g of activated carbon and 0.25 g of potassium citrate are added, and before cooling, the activated carbon is filtered out.
[0050] Example 8 The difference between Example 8 and Example 7 is that 0.375 g of activated carbon and 0.125 g of potassium citrate were added before heating.
[0051] Example 9 The difference between Example 9 and Example 7 is that 0.2 g of activated carbon and 0.3 g of potassium citrate were added before heating.
[0052] Example 10 The difference between Example 10 and Example 7 is that the temperature is lowered to 30° C. until the number of crystals stops increasing, and then the temperature is lowered to 5° C.
[0053] Embodiment 11 The difference between Example 11 and Example 7 is that the temperature is lowered to 20° C. until the number of crystals stops increasing, and then the temperature is lowered to 5° C.
[0054] Comparative Example 1 The difference between Example 3 and Example 1 is that ethanol is replaced by isopropanol.
[0055] The yields of L-glufosinate potassium salt and the contents of L-glufosinate potassium salt in Examples 1-9 and Comparative Example 1 are shown in Table 1.
[0056] Table 1 Yield (%) Content (%) Example 1 90.4 93.1 Example 2 87.1 90.5 Example 3 88.9 91.2 Example 4 92.1 94.6 Example 5 92.9 95.3 Example 6 93.6 94.7 Example 7 95.6 97.8 Example 8 94.1 95.9 Example 9 94.2 95.7 Example 10 97.5 99.2 Example 11 96.2 98.9 Comparative Example 1 80.4 82.3 Comparing Comparative Example 1 with Example 1 in combination with Table 1, it can be seen that when the reaction medium changes from ethanol to isopropanol, the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt both decrease.
[0057] Comparing Examples 2 and 3 with Example 1 in combination with Table 1, it can be seen that the mass concentration of KOH in the KOH aqueous solution affects the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt.
[0058] Comparing Example 4 with Example 1 in combination with Table 1, it can be seen that when the KOH aqueous solution is added in two portions, the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt are both improved.
[0059] Comparing Examples 5 and 6 with Example 4 in combination with Table 1, it can be seen that adding activated carbon or potassium citrate both improves the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt to a certain extent.
[0060] Comparing Examples 7-9 with Example 4 in combination with Table 1, it can be seen that adding a mixture of activated carbon and potassium citrate in a certain proportion can increase the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt. When the mass ratio of activated carbon to potassium citrate is 0.66-3:1, the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt are optimal.
[0061] Comparing Examples 10 and 11 with Example 7 in combination with Table 1, it can be seen that when crystallizing, adopting gradient cooling crystallization is beneficial to increasing the yield of L-glufosinate potassium salt and the content of L-glufosinate potassium salt.
[0062] The above are all preferred embodiments of this application. The protection scope of this application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.
Claims
1. A method for preparing L-glufosinate-ammonium potassium salt, characterized in that: The method comprises the following steps: adding L-glufosinate ammonium into ethanol, then adding potassium hydroxide aqueous solution, reacting, crystallizing, filtering and drying to obtain the L-glufosinate ammonium potassium salt.
2. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: The mass concentration of the potassium hydroxide aqueous solution is 60-80%.
3. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: The molar ratio of potassium hydroxide to L-phosphinothion is 1.1-1.3:
1.
4. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: The potassium hydroxide aqueous solution is added in two portions. First, 1 / 2 of the mass of the potassium hydroxide aqueous solution is added, and after reacting for 0.5-1h, the remaining potassium hydroxide aqueous solution is added.
5. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: The reaction temperature is 60-80 degrees Celsius.
6. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: The crystallization temperature is 5-30 degrees Celsius.
7. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: The crystallization is first performed at 20-30°C and then at 0-10°C.
8. The method for preparing L-glufosinate-ammonium potassium salt according to claim 1, characterized in that: An additive is added before the reaction, wherein the additive is selected from at least one of activated carbon and potassium citrate, and the mass ratio of the additive to the L-phosphinothricin is 1:55-65.
9. The method for preparing L-glufosinate-ammonium potassium salt according to claim 8, characterized in that: The additive consists of activated carbon and potassium citrate, and the mass ratio of the activated carbon to potassium citrate is 0.66-3:
1.
10. L-glufosinate potassium salt prepared by the method for preparing L-glufosinate potassium salt according to any one of claims 1 to 9.