CN107552071A - A kind of preparation method for the Raney's nickel that cobalt salt is modified and the method for synthesizing glufosinate-ammonium - Google Patents

Abstract

The invention provides a preparation method of cobalt salt-modified Raney nickel and a method for synthesizing glufosinate-ammonium. The preparation method of cobalt salt-modified Raney nickel comprises the following steps: pulverizing the nickel-aluminum alloy, °C, use 20% to 35% sodium hydroxide solution to stir for 1 to 2 hours, wash with deionized water to obtain Raney nickel, then modify Raney nickel with cobalt salt solution, and finally use deionized water After the washing treatment, the Raney nickel modified by cobalt salt is obtained, and stored in water; the method for synthesizing glufosinate-ammonium: use the Raney nickel catalyst modified by cobalt salt in the present invention as the catalyzer of reductive amination reaction, make the reaction temperature It can be controlled at 30-75°C and the pressure is 2.5-6.5Mpa; the present invention uses cobalt salt-modified Raney nickel as reductive amination catalyst, so that the reductive amination reaction can be carried out under milder conditions, reducing the occurrence of side reactions , improve the selectivity and yield of glufosinate-ammonium, improve production efficiency and reduce production cost.

Description

A kind of preparation method of Raney nickel modified by cobalt salt and the method for synthesizing glufosinate-ammonium

technical field

The invention relates to the field of fine chemicals, in particular to a preparation method of cobalt salt-modified Raney nickel and a method for synthesizing glufosinate-ammonium.

Background technique

Glufosinate-ammonium is a kind of herbicide that kills herbicides. It is an inhibitor of glutamine synthesis. It is a non-selective contact-killing broad-spectrum herbicide with partial systemic effect. In a short period of time after application, the ammonium metabolism in plants is in disorder. Ammonium ions, the cytotoxic agent, accumulate in plants, and at the same time, photosynthesis is severely inhibited to achieve the purpose of weeding. Glufosinate-ammonium is a phosphoric acid herbicide with high activity, low toxicity and good environmental compatibility. The herbicidal performance of glufosinate-ammonium is lower than that of paraquat and higher than that of glyphosate. In 2016, the sale of paraquat aqueous solution was banned in China, and glyphosate was reported to be carcinogenic. Therefore, glufosinate-ammonium has an extremely broad market, and its preparation method has become a research hotspot.

EP0121226A1 reported the method for preparing glufosinate-ammonium by using Raney nickel catalyst for reductive amination reaction, the yield is only 90%, and the purity of the product is not high. Therefore, it is of great practical significance to develop a high-yield, high-purity glufosinate-ammonium synthesis method.

Contents of the invention

The purpose of the present invention is to provide a preparation method of salt-modified Raney nickel and a method for synthesizing glufosinate-ammonium, using cobalt salt-modified Raney nickel as reductive amination catalysis, so that the reductive amination reaction is at a milder temperature. It is carried out under conditions, reduces the occurrence probability of side reactions, improves the selectivity and yield of glufosinate-ammonium, improves production efficiency, and reduces production costs.

To achieve the above object, the present invention is achieved through the following technical solutions:

A method for preparing Raney nickel modified by cobalt salts, comprising the following steps: crushing a nickel-aluminum alloy with a nickel content of 40% to 65% to 60 to 120 meshes, and using 20% to 35% sodium hydroxide solution was stirred for 1 to 2 hours, washed with deionized water to obtain Raney nickel, then modified with cobalt salt solution, and finally washed with deionized water, Raney nickel modified by cobalt salt is obtained and stored in water.

Preferably, the cobalt salt is cobalt carbonate, cobalt sulfate or cobalt nitrate.

Preferably, the specific method for modifying Raney nickel with a cobalt salt solution is: soaking the Raney nickel with a cobalt salt solution with a concentration of 1-10 g/L at 40-60° C. for 24-48 hours.

A method for synthesizing glufosinate-ammonium uses the Raney nickel catalyst modified by cobalt salt in the present invention as the catalyst for reductive amination reaction, specifically comprising the following steps:

(1) Put 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid and 25% ammonia water in an autoclave, stir for 2 to 5 hours, then add cobalt-modified Raney nickel catalyst;

(2) Vacuumize the autoclave to 1-3Kpa for 10-30min, then fill the autoclave with hydrogen, control the pressure at 1.2Mpa, and maintain it for 5-10min;

(3) After observing that there is no change in the value of the pressure gauge of the high-pressure reactor, the temperature in the kettle is raised to 30-75°C, the pressure is raised to 2.5-6.5Mpa, and the reaction is 3-8h;

(4) After the pressure in the autoclave remains unchanged, turn off the hydrogen source, lower the temperature of the materials in the autoclave to room temperature, open the vent valve, reduce the pressure in the autoclave to normal pressure, and filter and recover the catalyst to obtain the glufosinate-ammonium solution.

Preferably, in the step (1), the molar amount of ammonia contained in the ammonia water is 3 to 8 times the molar amount of 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid, and the amount of the catalyst is 4-(formyl 1.5% to 6% of the mass of hydroxyphosphoryl)-2-carbonyl-butyric acid.

Preferably, in the step (3), the stirring speed is controlled at 150-300 r/min.

Preferably, in the step (4), the yield of glufosinate-ammonium analyzed by HPLC is 99%, and the purity is 99%.

Preferably, in the step (4), the regeneration method of the recovered catalyst is as follows: after the catalyst is washed in methanol, the hydrogen pressure is 5 MPa, and the reaction is carried out at 60° C. for 5 h.

The beneficial effects of the present invention are:

1) The Raney nickel catalyst modified by cobalt salt does not need high temperature, high pressure and other treatments in the preparation process. It only needs to soak and wash the ordinary Raney nickel catalyst. The operation is simple, safe and low cost.

2), using the cobalt salt modified Raney nickel in the present invention as the reductive amination catalyst, the reaction temperature can be controlled at 30-75°C, the pressure 2.5-6.5Mpa, and the reaction conditions are mild, which is beneficial to reduce the occurrence probability of side reactions , and the purity of glufosinate-ammonium reaches 99%, and the yield reaches 99%, which improves the production efficiency and reduces the production cost.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the present invention Examples, not all examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1:

A preparation method of Raney nickel modified by cobalt salt, comprising the following steps:

Grinding the nickel-aluminum alloy with a nickel content of 55% to 100-120 meshes, stirring and treating with 35% sodium hydroxide solution at 60°C for 1 hour, washing with deionized water to obtain Raney nickel, and then Soak the Raney nickel in an aqueous cobalt carbonate solution with a concentration of 7g/L at 50°C for 32 hours, and finally wash it with deionized water to obtain cobalt salt-modified Raney nickel, which is stored in water.

Example 2:

A preparation method of Raney nickel modified by cobalt salt, comprising the following steps:

The nickel-aluminum alloy with a nickel content of 40% is crushed to 60-80 meshes, stirred and treated with 20% sodium hydroxide solution for 1.5 hours at a temperature of 80°C, and washed with deionized water to obtain Raney nickel. Then soak the Raney nickel in 10g/L cobalt sulfate aqueous solution at 50°C for 24 hours, and finally wash it with deionized water to obtain cobalt salt-modified Raney nickel, which is stored in water.

Example 3:

A preparation method of Raney nickel modified by cobalt salt, comprising the following steps:

The nickel-aluminum alloy with a nickel content of 65% is crushed to 80-100 meshes, stirred and treated with 28% sodium hydroxide solution at 40°C for 2 hours, washed with deionized water to obtain Raney nickel, and then Then soak the Raney nickel in an aqueous cobalt nitrate solution with a concentration of 1g/L at 60°C for 48 hours, and finally wash it with deionized water to obtain cobalt salt-modified Raney nickel, which is stored in water.

Example 4:

A method for synthesizing glufosinate-ammonium, comprising the steps of:

(1) 9g 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid, 17.5ml 25% ammonia water are added to the reactor and stirred for 2h, and the Raney nickel catalyst modified by cobalt salt (by Example Prepared by the preparation method in 1) 450 mg wet weight (substrate mass 5%) was added to the reaction kettle;

(2) Vacuum the autoclave to 1-3Kpa, keep it for 30min, then fill it with hydrogen to 1.2Mpa, keep it for 10min;

(3) After observing that there is no change in the value of the pressure gauge on the high-pressure reactor, the temperature in the reactor is raised to 75°C, the pressure is raised to 3.5Mpa, the stirring speed is 300r/min, and the reaction is carried out for 4h;

(4) Turn off the hydrogen source after the pressure in the autoclave remains unchanged, turn off the hydrogen source after the pressure in the autoclave remains unchanged, lower the temperature of the material in the autoclave to room temperature, and open the vent valve to reduce the pressure in the autoclave to normal pressure , The catalyst is recovered by filtration to obtain the glufosinate-ammonium solution, and the HPLC analysis of the glufosinate-ammonium yield reaches 99%, and the purity is 99%.

Example 5:

The catalyst that embodiment 2 reclaims is carried out repeated test, observes the catalytic activity of catalyst, and its result is as shown in table 1:

Table 1:

Reuse times 2 3 4 5 6 7 8…..15 Yield of glufosinate ammonium 99 99 98 98 98 98 97….95 Glufosinate-ammonium purity 99 99 99 99 99 99 98….98

When the number of cycles reached 15 times, the yield of glufosinate-ammonium was reduced to 95%, and the purity was reduced to 98%. At this time, the catalyst should be regenerated.

Catalyst regeneration method: After the catalyst is washed in methanol, the hydrogen pressure is 5MPa, and the reaction is carried out at 60°C for 5h.

By using the regenerated catalyst for reaction, the purity and yield of glufosinate-ammonium are both improved.

Embodiment 6:

(1) 9g 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid, 17.5 25%ml ammoniacal liquor are added to the reactor and stirred for 2h, and the Raney nickel catalyst of the cobalt salt property (by Example Prepared by the preparation method in 1) 225 mg wet weight (substrate mass 2.5%) was added to the reactor;

(2) Vacuum the autoclave to 1-3Kpa, keep it for 20min, then fill it with hydrogen to 1.2Mpa, keep it for 8min;

(3) After observing that there is no change in the value of the pressure gauge on the high-pressure reactor, raise the temperature in the kettle to 30°C, raise the pressure to 6.5Mpa, stir at a speed of 300r/min, and react for 8 hours;

(4) Close the hydrogen source after the pressure in the autoclave does not change, lower the temperature of the material in the still to room temperature, open the vent valve, reduce the pressure in the still to normal pressure, filter and recover the catalyst, and obtain the glufosinate-ammonium solution, HPLC The yield of glufosinate-ammonium analysis is 99%, and the purity is 99%.

Embodiment 7:

(1) 18g 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid, 35ml 25% ammoniacal liquor are added to the reaction kettle and stirred for 2h, and the Raney nickel catalyst of the nature of cobalt salt (by Example 2 Prepared by the preparation method in ) wet weight 900mg (substrate mass 5%) was added to the reactor;

(2) Vacuum the autoclave to 1-3Kpa, keep it for 30min, then fill it with hydrogen to 1.2Mpa, keep it for 10min;

(3) After observing that there is no change in the value of the pressure gauge on the high-pressure reaction kettle, the temperature in the kettle is raised to 50°C, the pressure is raised to 3.5Mpa, the stirring speed is 200r/min, and the reaction is 5h;

(4) Close the hydrogen source after the pressure in the autoclave does not change, lower the temperature of the material in the still to room temperature, open the vent valve, reduce the pressure in the still to normal pressure, filter and recover the catalyst, and obtain the glufosinate-ammonium solution, HPLC The yield of glufosinate-ammonium analysis is 99%, and the purity is 99%.

Embodiment 8:

(1) 18g 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid, 45ml 25% ammoniacal liquor are added to the reaction kettle and stirred for 2h, and the Raney nickel catalyst of the nature of cobalt salt (by Example 3 Prepared by the preparation method in ) wet weight 1080mg (substrate mass 6%) was added to the reactor;

(2) Vacuum the autoclave to 1-3Kpa, keep it for 30min, then fill it with hydrogen to 1.2Mpa, keep it for 5min;

(3) After observing that there is no change in the value of the pressure gauge on the high-pressure reaction kettle, the temperature in the kettle is raised to 70°C, the pressure is 2.5Mpa, the stirring speed is 150r/min, and the reaction is 3h;

(4) Close the hydrogen source after the pressure in the autoclave does not change, lower the temperature of the material in the still to room temperature, open the vent valve, reduce the pressure in the still to normal pressure, filter and recover the catalyst, and obtain the glufosinate-ammonium solution, HPLC The yield of glufosinate-ammonium analysis is 99%, and the purity is 99%.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be described in the foregoing embodiments Modifications are made to the recorded technical solutions, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. A preparation method of Raney nickel modified by cobalt salts, characterized in that, comprising the following steps: pulverizing nickel-aluminum alloys with a nickel content of 40% to 65%, pulverizing to 60 to 120 orders, At 80°C, use 20% to 35% sodium hydroxide solution to stir for 1 to 2 hours, wash with deionized water to obtain Raney nickel, then use cobalt salt solution to modify Raney nickel, and finally use After washing with ion water, Raney nickel modified by cobalt salt is obtained and stored in water. 2. the preparation method of the Raney nickel catalyst of cobalt salt modification according to claim 1, is characterized in that, described cobalt salt is cobalt carbonate, cobalt sulfate or cobalt nitrate. 3. the preparation method of the Raney nickel catalyst of cobalt salt modification according to claim 1 is characterized in that, the concrete method that Raney nickel is modified with cobalt salt solution is: be 1～10g/L with concentration Soak the Raney nickel in an aqueous cobalt salt solution at 40-60°C for 24-48 hours. 4. a method for synthesizing glufosinate-ammonium, is characterized in that, uses the Raney nickel catalyst of the cobalt salt modification as described in any one of claim 1-3 as the catalyzer of reductive amination reaction. 5. the method for synthetic glufosinate-ammonium as claimed in claim 4, is characterized in that, comprises the following steps: (1) Put 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid and 25% ammonia water in an autoclave, stir for 2 to 5 hours, then add cobalt-modified Raney nickel catalyst; (2) Vacuumize the autoclave to 1-3Kpa for 10-30min, then fill the autoclave with hydrogen, control the pressure at 1.2Mpa, and maintain it for 5-10min; (3) After observing that there is no change in the value of the pressure gauge of the high-pressure reactor, the temperature in the kettle is raised to 30-75°C, the pressure is raised to 2.5-6.5Mpa, and the reaction is 3-8h; (4) After the pressure in the autoclave remains unchanged, turn off the hydrogen source, lower the temperature of the materials in the autoclave to room temperature, open the vent valve, reduce the pressure in the autoclave to normal pressure, and filter and recover the catalyst to obtain the glufosinate-ammonium solution. 6. the method for synthesizing glufosinate-ammonium according to claim 5, is characterized in that, in described step (1), the molar weight that ammoniacal liquor contains ammonia is 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid The molar amount is 3-8 times, and the dosage of the catalyst is 1.5%-6% of the mass of 4-(methylhydroxyphosphoryl)-2-carbonyl-butyric acid. 7. The method for synthesizing glufosinate-ammonium according to claim 5, characterized in that, in the step (3), the stirring speed is controlled at 150-300r/min. 8. the method for synthesizing glufosinate-ammonium according to claim 5, is characterized in that, in described step (4), HPLC analysis glufosinate-ammonium yield is 99%, and purity is 99%. 9. the method for synthesizing glufosinate-ammonium according to claim 5 is characterized in that, in the described step (4), the regeneration method of the recovered catalyst is: after the catalyst is washed in methanol, hydrogen pressure 5MPa, 60 DEG C Under the condition of reaction 5h.