An efficient synthesis process for glufosinate-ammonium intermediate

Abstract

The invention discloses an efficient synthesis process of a glufosinate-ammonium intermediate, and belongs to the technical field of synthesis of organophosphorus compound intermediates. The process comprises the following steps: etching foam copper particles with nitric acid to make their surfaces rougher; subjecting the foam copper particles to chemical nickel plating to generate a nickel layer with corrosion resistance; and performing a secondary etching process with urea to grow a tightly contacted nickel hydroxide layer on the surface. The surface of the nickel hydroxide layer has abundant hydroxyl (-OH) functional groups, and in situ generating an organic skeleton with porosity and adsorption capacity on the surface through the hydroxyl groups. The organic skeleton is carbonized on the surface to obtain a nickel-plated foam copper with high strength and a carbon layer wrapped on the surface. The hydroxyl groups remaining on the surface are combined with carboxyl groups of p-hydroxybenzoic acid to generate a metal skeleton with catalytic activity in situ on the surface, thereby improving the catalytic efficiency and service life of the catalyst, improving the productivity of the glufosinate-ammonium intermediate, and improving the utilization rate of phosphorus trichloride.

Description

Technical Field

[0001] The invention belongs to the technical field of synthesis of organophosphorus compound intermediates, and particularly relates to an efficient synthesis process of a glufosinate-ammonium intermediate. Background Art

[0002] Glufosinate is an organophosphorus herbicide developed and produced by Hoechst in the 1980s. It has the characteristics of low toxicity, high efficiency, and non-selectivity (killing properties). Since the domestic sale and use of paraquat aqueous solution was discontinued on July 1, 2016, glufosinate has become a popular alternative for pesticide manufacturers. Methylphosphonic acid dichloride is an important intermediate in the synthesis of organophosphorus compounds and is extremely widely used. It can be used to directly or indirectly synthesize hundreds of organophosphorus compounds.

[0003] There are two traditional routes for synthesizing diethyl methylphosphite: the first is to use diethyl methylphosphinate dichloride and anhydrous ethanol as raw materials. The reaction conditions of this route are harsh and the product yield is low; the second is to use diethyl chlorophosphite and methylmagnesium chloride to synthesize it through the Grignard reaction.

[0004] The prior art uses a batch-type kettle method to synthesize diethyl chlorophosphite, wherein phosphorus trichloride is dropwise added to triethyl phosphite in the presence of a catalyst at a certain temperature. This method has a long reaction time, which results in a relatively high cost of diethyl methylphosphite. Furthermore, the reaction is incomplete, resulting in a large amount of phosphorus trichloride remaining in the product. The excess phosphorus trichloride remains in the reaction system and reacts with the Grignard reagent methylmagnesium chloride in the next step to form trimethylphosphine, which is highly susceptible to flash explosion and combustion. Furthermore, trimethylphosphine has a strong and unpleasant odor, which is easily detrimental to the environment and does not meet the requirements of modern green and environmentally friendly industrial production. Summary of the Invention

[0005] The present invention aims to provide an efficient synthesis process for a glufosinate-ammonium intermediate. The process comprises the following steps: etching a copper foam particle with nitric acid to make its surface rougher; subjecting the copper foam particle to chemical nickel plating treatment to form a nickel layer with corrosion resistance on the surface; and subjecting the copper foam particle to secondary urea etching treatment to grow a tightly contacted nickel hydroxide layer on the surface. The surface of the nickel hydroxide layer has abundant hydroxyl (-OH) functional groups, and in situ generating an organic skeleton with porosity and adsorption capacity on the surface through the hydroxyl groups, which is carbonized on the surface to obtain a nickel-plated copper foam with high strength and a carbon layer on the surface. The remaining hydroxyl groups on the surface combine with the carboxyl groups of p-hydroxybenzoic acid to in situ generate a metal skeleton with catalytic activity on the surface, thereby improving the catalytic efficiency and service life of the catalyst, improving the productivity of the glufosinate-ammonium intermediate, improving the utilization rate of phosphorus trichloride, and avoiding the generation of byproducts such as residual phosphorus trichloride due to incomplete reaction.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] An efficient synthesis process for a glufosinate-ammonium intermediate is prepared by the following steps:

[0008] The method comprises the following steps: adding foam copper particles and a nitric acid solution with a concentration of 0.4-0.5 mol / L into a reactor, performing acid etching treatment for 2-3 minutes at 40-45° C. and 400-500 r / min, filtering, washing the treated foam copper particles with deionized water until the final washing liquid is neutral, and obtaining roughened foam copper particles; subjecting the roughened foam copper particles to chemical nickel plating to obtain nickel-plated foam copper powder with a surface nickel film thickness of 5-10 μm; adding the nickel-plated foam copper powder, urea and deionized water into a reactor, heating to 120-130° C. and 400-500 r / min, stirring for 24-26 hours, filtering, washing the filter cake with deionized water until the final washing liquid is neutral, and vacuum drying at 60-80° C. for 1-2 hours, and obtaining roughened nickel-plated foam copper particles.

[0009] Step 2: Add roughened nickel-plated copper foam particles, p-carboxybenzaldehyde and deionized water into the reactor, stir at 20-25 ° C and 500-700 r / min for 40-45 minutes, add 1,3,5-tris (4-aminophenyl) benzene into the reactor, continue stirring for 10-12 minutes, and then add dimethylacetamide, N,N-dimethylformamide, and a concentration of 4-5 mo l / L acetic acid solution was added to the reactor and the stirring was continued for 1-2 hours. Then magnesium chloride hexahydrate was added to the reactor and the stirring reaction was continued for 1-2 hours. The reaction mixture was filtered and the filter cake was washed with deionized water and anhydrous ethanol 2-3 times respectively. The mixture was transferred to a muffle furnace and heated to 550-600 ° C. The mixture was stirred at 400-500 r / min for 48-50 hours. The mixture was naturally cooled. The filter cake was washed with deionized water and anhydrous ethanol 2-3 times respectively. The mixture was vacuum dried at 60-80 ° C for 1-2 hours to obtain porous carbon-wrapped nickel-plated copper foam.

[0010] Step 3: Add porous carbon-wrapped nickel-plated copper foam, p-hydroxybenzoic acid and deionized water into a reactor, add a mixed solution of sodium hexadecyl sulfate and 60-70% ethanol as a surfactant, stir at 50-60°C and 400-500r / min for 1-2h, add magnesium sulfate heptahydrate into the reactor, continue stirring and reacting for 3-4h, filter, wash the filter cake with deionized water 2-3 times, and vacuum dry at 60-80°C for 14-16h to obtain a high-efficiency catalytic material.

[0011] Step 4: Add triethyl phosphite and a high-efficiency catalytic material to a reactor, stir at 20-25°C and 400-500 r / min for 30-40 minutes under nitrogen protection, cool to 0-4°C, add phosphorus trichloride, add iodine element to the reactor, add tetrahydrofuran as a solvent, introduce chloromethane at a rate of 5-6 mL / min for 30-40 minutes, cool to -20°C to -30°C, add diethylene glycol dimethyl ether as a solvent, heat to 20-25°C and keep warm for 1-2 hours, distill at atmospheric pressure to remove tetrahydrofuran, and perform vacuum distillation to obtain a glufosinate-ammonium intermediate.

[0012] Furthermore, in step 1, the pore size of the foam copper particles is 0.5-2 mm, and the particle size is 5-20 mm.

[0013] Furthermore, in step 1, the usage ratio of the foam copper particles to the nitric acid is 40-50 g: 200-300 mL.

[0014] Furthermore, in step 1, the usage ratio of the roughened copper foam particles, glyceryl monostearate, nickel sulfate, citric acid and L-cystine is 20-22 g: 1-2 g: 800-900 mL: 2-4 g: 1-2 g.

[0015] Furthermore, the specific steps of chemical nickel plating in step 1 are as follows:

[0016] Roughened copper foam particles, glyceryl monostearate as a surfactant, nickel sulfate, citric acid as a complexing agent, and L-cystine as a stabilizer are heated to 80-90° C. and stirred at 400-500 r / min for 40-50 minutes, filtered, and the filter cake is washed with deionized water until the last washing liquid is neutral to obtain nickel-plated copper foam powder.

[0017] Furthermore, the usage ratio of nickel-plated copper foam powder, urea and deionized water is 10-15 g: 2-3 g: 400-500 mL.

[0018] Furthermore, in step 2, the usage ratio of the roughened nickel-plated copper foam particles, p-carboxybenzaldehyde, deionized water, 1,3,5-tris(4-aminophenyl)benzene, dimethylacetamide, N,N-dimethylformamide, acetic acid and magnesium chloride hexahydrate is 10-12 g: 12-15 g: 300-400 mL: 10-14 g: 3-4 mL: 4-5 mL: 1-2 g: 15-17 g.

[0019] Furthermore, in step three, the usage ratio of porous carbon-wrapped nickel-plated copper foam, p-hydroxybenzoic acid, deionized water, sodium hexadecyl sulfate, ethanol and magnesium sulfate heptahydrate is 8-10 g: 5-7 g: 400-500 mL: 1-2 g: 80-90 mL: 5-6 g.

[0020] Furthermore, in step 4, the usage ratio of triethyl phosphite, high-efficiency catalytic material, phosphorus trichloride, elemental iodine, tetrahydrofuran and diethylene glycol dimethyl ether is 70-80g: 2-4g: 30-40g: 2-3 pellets: 400-500mL: 400-500mL.

[0021] Beneficial effects of the present invention:

[0022] 1. The glufosinate-ammonium intermediate prepared by the present invention has the characteristics of high productivity, high raw material utilization and low by-products by adding a high-efficiency catalytic material in the production process; the high-efficiency catalytic material of the present invention is nitric acid-etched to make the surface of the foam copper particles rougher and increase the porosity, and the surface of the foam copper is nickel-plated to form a nickel layer with corrosion resistance on the surface. The rough surface of the foam copper particles can improve the adhesion to the nickel layer, thereby improving the corrosion resistance of the nickel layer on the foam copper substrate; through secondary urea etching treatment, a nickel hydroxide layer in close contact is grown on the surface, and the surface has rich hydroxyl (-OH) functional groups. The organic skeleton with porosity and adsorption capacity is in situ generated on the surface by the hydroxyl groups and carbonized on the surface to obtain a nickel-plated copper foam with high strength and a surface covered with a carbon layer.

[0023] 2. The porous carbon-wrapped nickel-plated copper foam of the present invention is prepared by etching the copper foam particles with nitric acid to make their surface rougher and increase their porosity, and then nickel-plating the surface of the copper foam. The nickel plating treatment can effectively protect the matrix of the copper foam and prevent it from being damaged during the catalytic reaction. The nickel layer has good chemical stability and mechanical strength and can resist the erosion and physical wear of most chemical substances. In the catalytic reaction, the nickel-plated copper foam has stronger corrosion resistance, thereby extending the service life of the copper foam as a catalyst carrier. The nickel-plated copper foam powder is placed in uric acid for etching, and a layer of closely contacted nickel hydroxide layer grows on the surface. The surface of the nickel foam has rich hydroxyl (-OH) functional groups, which enables it to evenly generate an organic skeleton on the surface to avoid agglomeration of the organic skeleton. The organic skeleton can further improve the adsorption capacity, thereby improving the efficiency of the high-efficiency catalytic material in catalyzing the synthesis of glufosinate-ammonium intermediates and avoiding incomplete reaction. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] Example 1: An efficient synthesis process for a glufosinate-ammonium intermediate, prepared by the following steps:

[0026] S1: 40g of foam copper particles with a pore size of 0.5-2mm and a particle size of 5-20mm and 200mL of a 0.4mol l / L nitric acid solution was added to the reactor, acid-etched for 2 minutes at 40°C and 400r / min, filtered, and the treated foam copper particles were washed with deionized water until the last washing liquid was neutral to obtain roughened foam copper particles; 20g of roughened foam copper particles, 1g of monostearate as a surfactant, 800mL of nickel sulfate, 2g of citric acid as a complexing agent and 1g of L-cystine as a stabilizer were heated to 80°C and stirred at 400r / min for 40min, filtered, and the filter cake was washed with deionized water until the last washing liquid was neutral to obtain nickel-plated foam copper powder with a surface nickel film thickness of 5μm; 10g of nickel-plated foam copper powder, 2g of urea and 400mL of deionized water were added to the reactor, heated to 120°C and stirred at 400r / min for 24h, filtered, and the filter cake was washed with deionized water until the last washing liquid was neutral, and vacuum dried at 60°C for 1h to obtain roughened nickel-plated foam copper particles.

[0027] The foam copper particles are etched with nitric acid to make their surface rougher and more porous. The surface of the foam copper is then plated with nickel. The nickel plating treatment can effectively protect the matrix of the foam copper and prevent it from being damaged during the catalytic reaction. The nickel layer has good chemical stability and mechanical strength and can resist the erosion and physical wear of most chemical substances. In the catalytic reaction, the nickel-plated foam copper has stronger corrosion resistance, thereby extending the service life of the foam copper as a catalyst carrier. The nickel-plated foam copper powder is placed in uric acid for etching, and a tightly contacted nickel hydroxide layer grows on the surface, the surface of which has rich hydroxyl (-OH) functional groups.

[0028] S2: 10 g of roughened nickel-plated copper foam particles, 12 g of p-carboxylbenzaldehyde and 300 mL of deionized water were added to the reactor, stirred at 20 ° C and 500 r / min for 40 min, 10 g of 1,3,5-tris (4-aminophenyl) benzene was added to the reactor, and stirring was continued for 10 min. Then 3 mL of dimethylacetamide, 4 mL of N,N-dimethylformamide, and 1 g of acetic acid solution with a concentration of 4 mol / L were added to the reactor, and stirring was continued for 1 h. Then 15 g of magnesium chloride hexahydrate was added to the reactor, and stirring was continued for 1 h. After filtering, the filter cake was washed twice with deionized water and anhydrous ethanol respectively, transferred to a muffle furnace, heated to 550 ° C, and stirred at 400 r / min for 48 h. After natural cooling, the filter cake was washed twice with deionized water and anhydrous ethanol respectively, and dried in vacuo at 60 ° C for 1 h to obtain porous carbon-wrapped nickel-plated copper foam.

[0029] The roughened nickel-plated copper foam particles have abundant hydroxyl (-OH) functional groups on their surface, which are bonded with the carboxyl groups of p-carboxylbenzaldehyde to generate an organic skeleton with porosity and adsorption capacity in situ, which is then carbonized on the surface to obtain a nickel-plated copper foam with high strength and a surface covered with a carbon layer.

[0030] S3: 8 g of porous carbon-wrapped nickel-plated copper foam, 5 g of p-hydroxybenzoic acid and 400 mL of deionized water were added to a reactor, and a mixed solution of 1 g of sodium hexadecyl sulfate as a surfactant and 80 mL of 60% ethanol was added. The mixture was stirred at 50°C and 400 r / min for 1 hour. 5 g of magnesium sulfate heptahydrate was added to the reactor, and the stirring reaction was continued for 3 hours. The mixture was filtered, and the filter cake was washed twice with deionized water. The mixture was vacuum dried at 70°C for 15 hours to obtain a high-efficiency catalytic material.

[0031] The remaining hydroxyl groups on the surface of nickel-plated copper foam are wrapped with porous carbon and combined with the carboxyl groups of p-hydroxybenzoic acid to generate a catalytically active metal skeleton in situ on the surface.

[0032] S4: Add 70g of triethyl phosphite and 2g of high-efficiency catalytic material to a reactor, stir at 20°C and 400r / min for 30min under nitrogen protection, cool to 0°C, add 35g of phosphorus trichloride, add 2 iodine particles to the reactor, add 450mL of tetrahydrofuran as a solvent, introduce chloromethane at a rate of 5mL / min for 30min, cool to -20°C, add 400mL of diethylene glycol dimethyl ether as a solvent, heat to 20°C and keep warm for 1h, distill at atmospheric pressure to remove tetrahydrofuran, and perform vacuum distillation to obtain a glufosinate-ammonium intermediate.

[0033] Example 2: An efficient synthesis process for a glufosinate-ammonium intermediate, prepared by the following steps:

[0034] S1: 45 g of copper foam particles with a pore size of 0.5-2 mm and a particle size of 5-20 mm and 250 mL of a 0.45 mol / L nitric acid solution were added to a reactor, and acid-etched for 2.5 min at 43° C. and 450 r / min, filtered, and the treated copper foam particles were washed with deionized water until the final washing solution was neutral to obtain roughened copper foam particles; 21 g of the roughened copper foam particles, 1.2 g of glycerol monostearate as a surfactant, 850 mL of nickel sulfate, 2.4 g of citric acid as a complexing agent, and 1.2 g of L-cystine as a stabilizer were heated to 85° C. and 450 r / min. min, stirred for 45 minutes, filtered, and washed the filter cake with deionized water until the last washing liquid was neutral to obtain nickel-plated copper foam powder with a surface nickel film thickness of 7 μm; 13 g of nickel-plated copper foam powder, 2.3 g of urea and 450 mL of deionized water were added to a reactor, heated to 125° C. and stirred at 450 r / min for 25 hours, filtered, and washed the filter cake with deionized water until the last washing liquid was neutral, and vacuum dried at 70° C. for 1.2 hours to obtain roughened nickel-plated copper foam particles.

[0035] S2: 11 g of roughened nickel-plated copper foam particles, 13 g of p-carboxylbenzaldehyde and 350 mL of deionized water were added to the reactor, stirred at 23 ° C and 600 r / min for 43 min, 13 g of 1,3,5-tris (4-aminophenyl) benzene was added to the reactor, and stirring was continued for 11 min. Then, 3.5 mL of dimethylacetamide, 4.5 mL of N,N-dimethylformamide, and 1.5 g of acetic acid solution with a concentration of 4.5 mol / L were added to the reactor and stirring was continued for 1.2 h. Then, 16 g of magnesium chloride hexahydrate was added to the reactor and the reaction was continued with stirring for 1.2 h. After filtering, the filter cake was washed twice with deionized water and anhydrous ethanol respectively, transferred to a muffle furnace, heated to 580 ° C, and stirred at 450 r / min for 49 h. After natural cooling, the filter cake was washed three times with deionized water and anhydrous ethanol respectively, and dried in vacuo at 80 ° C for 2 h to obtain porous carbon-wrapped nickel-plated copper foam.

[0036] S3: 9 g of porous carbon-wrapped nickel-plated copper foam, 5.5 g of p-hydroxybenzoic acid and 450 mL of deionized water were added to a reactor, and a mixed solution of 1.2 g of sodium hexadecyl sulfate as a surfactant and 85 mL of 65% ethanol was added. The mixture was stirred at 55°C and 450 r / min for 1.2 h. 5.5 g of magnesium sulfate heptahydrate was added to the reactor, and the stirring reaction was continued for 3.5 h. The mixture was filtered, and the filter cake was washed twice with deionized water. The mixture was vacuum dried at 70°C for 15 h to obtain a high-efficiency catalytic material.

[0037] S4: Add 75g of triethyl phosphite and 2.4g of high-efficiency catalytic material to a reactor, stir at 23°C and 450r / min for 35min under nitrogen protection, cool to 3°C, add 35g of phosphorus trichloride, add 3 iodine particles to the reactor, add 450mL of tetrahydrofuran as a solvent, introduce chloromethane at a rate of 5.5mL / min for 35min, cool to -25°C, add 450mL of diethylene glycol dimethyl ether as a solvent, heat to 23°C and keep warm for 1.2h, distill at atmospheric pressure to remove tetrahydrofuran, and perform vacuum distillation to obtain a glufosinate-ammonium intermediate.

[0038] Example 3: An efficient synthesis process for a glufosinate-ammonium intermediate, prepared by the following steps:

[0039] S1: 50g of foam copper particles with a pore size of 0.5-2mm and a particle size of 5-20mm and 300mL of a 0.5mol l / L nitric acid solution was added to the reactor, acid-treated for 3 minutes at 45°C and 500r / min, filtered, and the treated foam copper particles were washed with deionized water until the last washing liquid was neutral to obtain roughened foam copper particles; 22g of roughened foam copper particles, 2g of monostearate as a surfactant, 900mL of nickel sulfate, 4g of citric acid as a complexing agent and 2g of L-cystine as a stabilizer were heated to 90°C and stirred at 500r / min for 50min, filtered, and the filter cake was washed with deionized water until the last washing liquid was neutral to obtain nickel-plated foam copper powder with a surface nickel film thickness of 10μm; 15g of nickel-plated foam copper powder, 3g of urea and 500mL of deionized water were added to the reactor, heated to 130°C and stirred at 500r / min for 26h, filtered, and the filter cake was washed with deionized water until the last washing liquid was neutral, and vacuum dried at 80°C for 2h to obtain roughened nickel-plated foam copper particles.

[0040] S2: 12 g of roughened nickel-plated copper foam particles, 15 g of p-carboxylbenzaldehyde and 400 mL of deionized water were added to the reactor, stirred at 25 ° C and 700 r / min for 45 min, 14 g of 1,3,5-tris (4-aminophenyl) benzene was added to the reactor, and stirring was continued for 12 min. Then, 4 mL of dimethylacetamide, 5 mL of N,N-dimethylformamide, and 2 g of acetic acid solution with a concentration of 5 mol / L were added to the reactor, and stirring was continued for 2 h. Then, 17 g of magnesium chloride hexahydrate was added to the reactor, and stirring was continued for 2 h. After filtering, the filter cake was washed with deionized water and anhydrous ethanol three times respectively, transferred to a muffle furnace, heated to 600 ° C, and stirred at 500 r / min for 50 h. After natural cooling, the filter cake was washed with deionized water and anhydrous ethanol three times respectively, and dried in vacuo at 80 ° C for 2 h to obtain porous carbon-wrapped nickel-plated copper foam.

[0041] S3: 10g of porous carbon-wrapped nickel-plated copper foam, 7g of p-hydroxybenzoic acid and 500mL of deionized water were added to the reactor, and 2g of sodium hexadecyl sulfate as a surfactant and 90mL of a mixed solution of 70% ethanol were added. The mixture was stirred at 60°C and 500r / min for 2h. 6g of magnesium sulfate heptahydrate was added to the reactor, and the stirring reaction was continued for 4h. The mixture was filtered, and the filter cake was washed with deionized water 3 times. The mixture was vacuum dried at 80°C for 16h to obtain a high-efficiency catalytic material.

[0042] S4: Add 80g of triethyl phosphite and 4g of high-efficiency catalytic material to a reactor, stir at 25°C and 500r / min for 40min under nitrogen protection, cool to 4°C, add 40g of phosphorus trichloride, add 3 iodine particles to the reactor, add 500mL of tetrahydrofuran as a solvent, introduce chloromethane at a rate of 6mL / min for 40min, cool to -30°C, add 500mL of diethylene glycol dimethyl ether as a solvent, heat to 25°C and react for 2h, distill at atmospheric pressure to remove tetrahydrofuran, and perform vacuum distillation to obtain a glufosinate-ammonium intermediate.

[0043] Comparative Example 1: Based on Example S3, the roughened copper foam particles in step S1 were replaced with the copper foam particles in step S2, and the other steps remained unchanged to prepare a glufosinate-ammonium intermediate.

[0044] Comparative Example 2: Based on Example S3, the roughened nickel-plated copper foam particles in step S2 were replaced with nickel-plated copper foam powder in step S1, and the remaining steps remained unchanged to prepare a glufosinate-ammonium intermediate.

[0045] Comparative Example 3: Based on Example S3, the porous carbon-wrapped nickel-plated copper foam in step S3 is replaced by the roughened nickel-plated copper foam particles in step S1, and the other steps remain unchanged to prepare a glufosinate-ammonium intermediate.

[0046] The performance of the high-efficiency catalytic materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 in catalyzing the synthesis of glufosinate-ammonium intermediates was tested, and the performance of the catalytic synthesis of glufosinate-ammonium intermediates was tested again after charcoal regeneration at 400° C. and recycled 100 times. The results are shown in Table 1:

[0047] The calculation method of phosphorus trichloride conversion rate and glufosinate ammonium intermediate selectivity is as follows: phosphorus trichloride conversion rate = (phosphorus trichloride content in raw material - phosphorus trichloride content in product) / phosphorus trichloride content in raw material × 100wt%,

[0048] Selectivity of glufosinate intermediate = (content of glufosinate intermediate in product - content of glufosinate intermediate in raw material) / (content of glufosinate intermediate in raw material - content of glufosinate intermediate in product) × 100 wt %; the results are shown in Table 1:

[0049] Table 1 Catalytic synthesis results of glufosinate-ammonium intermediates

[0050] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Conversion rate wt% 60.2 65.6 70.9 42.8 43.3 42.5 Conversion rate after 100 times wt% 59.8 63.5 68.5 38.2 39.1 38.1 Selectivity wt% 97.2 97.4 97.7 85.3 86.7 85.2 Selectivity wt% after 100 times 95.5 95.8 96.1 80.2 81.5 80.3

[0051] As can be seen from Table 1, Examples 1 to 3 of the present invention prepare glufosinate-ammonium intermediates with high selectivity and high conversion rate to phosphorus trichloride. After regeneration, the values in Examples 1 to 3 decrease slightly, with no significant difference. However, the decrease in the values in the comparative examples is greater than that in the examples, indicating that the catalyst prepared by the present invention can efficiently and stably catalyze the synthesis of glufosinate-ammonium intermediates.

[0052] In Comparative Example 1, roughened copper foam particles are used to replace copper foam particles, and the copper foam is acid-etched to remove part of the material on the surface of the copper foam through a chemical reaction, thereby increasing the roughness of its surface. The rough surface helps to enhance the bonding strength between the copper foam and the nickel layer and improve the adhesion of the nickel layer. Without acid etching of the copper foam, the overall performance of the copper foam as a catalyst matrix is reduced, which in turn leads to a reduction in the catalytic effect, affecting the catalytic effect and reducing the purity and quality of the product. After 100 cycles of use, the adhesion of the nickel layer is significantly reduced, resulting in a performance test performance decline greater than that of the embodiment.

[0053] In Comparative Example 2, the roughened nickel-plated copper foam particles are replaced with nickel-plated copper foam powder. After secondary etching with urea, a tightly contacted nickel hydroxide layer grows on the surface. The surface has rich hydroxyl (-OH) functional groups, which enable it to be tightly combined with the organic skeleton to avoid uneven dispersion and agglomeration of the organic skeleton. Without secondary etching treatment, the organic skeleton loaded on the surface will be unevenly distributed, and carbonization will form an uneven carbon layer on the surface, which will affect the surface structure and porosity of the catalyst, affect the catalytic efficiency, and reduce the purity and quality of the product. After 100 cycles of use, the uneven carbon layer formed on the surface will fall off, thereby changing the porosity of the catalyst surface, resulting in a performance test performance decline greater than that in the embodiment.

[0054] In Comparative Example 3, the porous carbon-wrapped nickel-plated copper foam is replaced with roughened nickel-plated copper foam particles. The hydroxyl groups on the surface combine with p-carboxylbenzaldehyde to form a uniform organic skeleton on the surface, further increasing the specific surface area of the catalyst. A high specific surface area means more active sites. The carbon layer formed after carbonization has certain mechanical strength and chemical stability, which can protect the roughened nickel-plated copper foam particle matrix from corrosion or wear, thereby extending the service life of the catalyst.

[0055] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0056] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An efficient synthesis process for a glufosinate-ammonium intermediate, characterized in that: Prepared by the following steps: Step 1: adding porous carbon-wrapped nickel-plated copper foam, p-hydroxybenzoic acid and deionized water into a reactor, adding a mixed solution of sodium hexadecyl sulfate and 60-70% ethanol as a surfactant, stirring at 50-60°C and 400-500 r / min for 1-2 hours, adding magnesium sulfate heptahydrate into the reactor, continuing to stir and react for 3-4 hours, filtering, washing the filter cake with deionized water 2-3 times, and vacuum drying at 60-80°C for 14-16 hours to obtain a high-efficiency catalytic material; Step 2: Add triethyl phosphite and a high-efficiency catalytic material to a reactor, stir at 20-25°C and 400-500 r / min for 30-40 minutes under nitrogen protection conditions, cool to 0-4°C, add phosphorus trichloride, add iodine element to the reactor, add tetrahydrofuran, introduce chloromethane at a rate of 5-6 mL / min for 30-40 minutes, cool to -20°C to -30°C, add diethylene glycol dimethyl ether, heat to 20-25°C, keep warm for 1-2 hours, distill at atmospheric pressure to remove tetrahydrofuran, and perform vacuum distillation to obtain a glufosinate-ammonium intermediate; The porous carbon-wrapped nickel-plated copper foam described in step 1 is prepared by the following steps: Roughened nickel-plated copper foam particles, p-carboxylbenzaldehyde, and deionized water were added to a reactor, stirred at 20-25° C. and 500-700 r / min for 40-45 min, 1,3,5-tris(4-aminophenyl)benzene was added to the reactor, and stirring was continued for 10-12 min. Dimethylacetamide, N,N-dimethylformamide, and acetic acid solution with a concentration of 4-5 mol / L were added to the reactor, and stirring was continued for 1-2 h. Magnesium chloride hexahydrate was then added to the reactor, and stirring was continued for 1-2 h. The reaction mixture was filtered, and the filter cake was washed with deionized water and anhydrous ethanol for 2-3 times, respectively. The mixture was transferred to a muffle furnace, heated to 550-600° C., stirred at 400-500 r / min for 48-50 h, and cooled naturally. The filter cake was washed with deionized water and anhydrous ethanol for 2-3 times, respectively, and vacuum dried to obtain porous carbon-wrapped nickel-plated copper foam; The roughened nickel-plated copper foam particles are prepared by the following steps: The roughened copper foam particles are subjected to chemical nickel plating to obtain nickel-plated copper foam powder having a surface nickel film thickness of 5-10 μm; the nickel-plated copper foam powder, urea, and deionized water are added to a reaction kettle, heated to 120-130° C. and stirred at 400-500 rpm for 24-26 hours, filtered, and the filter cake is washed with deionized water until the last washing solution is neutral, and vacuum dried to obtain roughened nickel-plated copper foam particles; The roughened copper foam particles are prepared by the following steps: The foamed copper particles and a nitric acid solution with a concentration of 0.4-0.5 mol / L are added to a reactor, and acid etching is performed at 40-45° C. and 400-500 r / min for 2-3 minutes. The treated foamed copper particles are filtered, and the treated foamed copper particles are washed with deionized water until the last washing solution is neutral to obtain roughened foamed copper particles.

2. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 1, characterized in that: The usage ratio of the porous carbon-wrapped nickel-plated copper foam, p-hydroxybenzoic acid, deionized water, sodium hexadecyl sulfate, ethanol and magnesium sulfate heptahydrate in step 1 is 8-10 g: 5-7 g: 400-500 mL: 1-2 g: 80-90 mL: 5-6 g.

3. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 1, characterized in that: The usage ratio of triethyl phosphite, high-efficiency catalytic material, phosphorus trichloride, elemental iodine, tetrahydrofuran and diethylene glycol dimethyl ether in step 2 is 70-80g: 2-4g: 30-40g: 2-3 pellets: 400-500mL: 400-500mL.

4. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 1, characterized in that: The roughened nickel-plated copper foam particles, p-carboxylbenzaldehyde, deionized water, 1,3,5-tris(4-aminophenyl)benzene, dimethylacetamide, N,N-dimethylformamide, acetic acid and magnesium chloride hexahydrate are used in a ratio of 10-12 g: 12-15 g: 300-400 mL: 10-14 g: 3-4 mL: 4-5 mL: 1-2 g: 15-17 g.

5. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 1, characterized in that: The usage ratio of the nickel-plated copper foam powder, urea and deionized water is 10-15 g: 2-3 g: 400-500 mL.

6. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 1, characterized in that: The specific steps of the chemical nickel plating are as follows: Roughened copper foam particles, glycerol monostearate, nickel sulfate, citric acid and L-cystine are heated to 80-90° C. and stirred at 400-500 r / min for 40-50 minutes, filtered, and the filter cake is washed with deionized water until the last washing liquid is neutral to obtain nickel-plated copper foam powder with a surface nickel film thickness of 5-10 μm.

7. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 6, characterized in that: The usage ratio of the roughened copper foam particles, glyceryl monostearate, nickel sulfate, citric acid and L-cystine is 20-22 g: 1-2 g: 800-900 mL: 2-4 g: 1-2 g.

8. The efficient synthesis process of a glufosinate-ammonium intermediate according to claim 1, characterized in that: The usage ratio of the foam copper particles and nitric acid is 40-50 g: 200-300 mL; the pore diameter of the foam copper particles is 0.5-2 mm, and the particle diameter is 5-20 mm.