Preparation method for l-glufosinate-ammonium powder

Patent metadata

Field	Value
Publication number	US-2023225314-A1
Application number	US-202017927867-A
Country	US
Kind code	A1
Filing date	Dec 26, 2020
Priority date	Aug 26, 2020
Publication date	Jul 20, 2023
Grant date	—

Abstract

The present invention discloses a method for preparing L-glufosinate ammonium powder. The method includes the following steps: (1) obtaining a transformation solution for performing biocatalytic transformation to prepare L-glufosinate ammonium, and filtering out bacteria to obtain a filtrate; (2) detecting the amount of ammonium sulfate in the filtrate obtained in step (1), adding calcium hydroxide or calcium oxide to react with the ammonium sulfate to produce calcium sulfate precipitates, and filtering out the calcium sulfate precipitates to obtain a filtrate; (3) detecting the amount of glufosinate ammonium in the filtrate obtained in step (2), adding zinc salt, adjusting pH to 5.5-6.8 to produce glufosinate ammonium zinc salt precipitates, and filtering and collecting the glufosinate ammonium zinc salt precipitates; (4) adding a solvent to dissolve the glufosinate ammonium zinc salt precipitates collected in step (3), and adjusting pH of a solution to 2-2.5 to produce L-glufosinate ammonium precipitates; and (5) recrystallizing the L-glufosinate ammonium precipitates obtained in step (4) to obtain purified L-glufosinate ammonium powder. The method provided by the present invention is simple to operate and low in cost, and has a better industrialization prospect.

First claim

1 . A method for preparing L-glufosinate ammonium powder, comprising the following steps:
(1) obtaining a transformation solution for performing biocatalytic transformation to prepare L-glufosinate ammonium, and filtering out bacteria to obtain a filtrate; (2) detecting the amount of ammonium sulfate in the filtrate obtained in step (1), adding calcium hydroxide or calcium oxide to react with the ammonium sulfate to produce calcium sulfate precipitates, and filtering out the calcium sulfate precipitates to obtain a filtrate; (3) detecting the amount of glufosinate ammonium in the filtrate obtained in step (2), adding zinc salt, adjusting pH to 5.5-6.8 to produce glufosinate ammonium zinc salt precipitates, and filtering and collecting the glufosinate ammonium zinc salt precipitates, wherein the zinc salt is zinc nitrate or zinc chloride; (4) adding a solvent to dissolve the glufosinate ammonium zinc salt precipitates collected in step (3), and adjusting pH of a solution to 2-2.5 to produce L-glufosinate ammonium precipitates; and (5) recrystallizing the L-glufosinate ammonium precipitates obtained in step (4) to obtain purified L-glufosinate ammonium powder.

2 . The method for preparing L-glufosinate ammonium powder according to claim 1 , wherein in step (1), the concentration of the L-glufosinate ammonium in the transformation solution is 70-80 g/L, the concentration of the ammonium sulfate is 20-30 g/L, and the concentration of gluconic acid is 35-45 g/L.

3 . The method for preparing L-glufosinate ammonium powder according to claim 1 , wherein the filtrate obtained in step (1) is concentrated under reduced pressure at 65° C. to 31-33% of the volume before concentration.

4 . The method for preparing L-glufosinate ammonium powder according to claim 1 , wherein in step (2), the addition amount of the calcium hydroxide or the calcium oxide is at least equimolar with the amount of the ammonium sulfate; and in step (3), the addition amount of the zinc salt is 1.0-1.5 times the amount of the glufosinate ammonium in molar mass.

5 . The method for preparing L-glufosinate ammonium powder according to claim 1 , wherein ammonia water is used for pH adjustment in step (3), and phosphoric acid, hydrochloric acid or sulfuric acid is used for pH adjustment in step (4).

6 . The method for preparing L-glufosinate ammonium powder according to claim 1 , wherein the solvent used in step (4) is an aqueous ethanol solution with a volume concentration of 50%; and the concentration of dissolved glufosinate ammonium zinc salt is 200-400 g/L.

7 . The method for preparing L-glufosinate ammonium powder according to claim 1 , wherein during the recrystallization in step (5), the L-glufosinate ammonium precipitates are dissolved in the aqueous ethanol solution or an aqueous acetone solution, concentrated under reduced pressure and recrystallized.

8 . The method for preparing L-glufosinate ammonium powder according to claim 7 , wherein a volume concentration of the aqueous ethanol solution or the aqueous acetone solution during the recrystallization in step (5) is 90%, and the mass of the aqueous ethanol solution or the aqueous acetone solution added is 5-7 times the mass of the L-glufosinate ammonium precipitates; and precipitates obtained by recrystallization in step (5) are dried in vacuum to obtain the purified L-glufosinate ammonium powder.

9 . The method for preparing L-glufosinate ammonium powder according to claim 7 , wherein supernates containing zinc ions in step (3) and step (4) are combined, then pH is adjusted to be more than 7 to produce zinc hydroxide precipitates, the zinc hydroxide precipitates are separated, and nitric acid or hydrochloric acid is added to dissolve the zinc hydroxide precipitates to obtain zinc nitrate or zinc chloride for reuse.

Assignees

• Univ Zhejiang Technology

Inventors

• Xue Yaping
• Mao Jie
• Cheng Feng
• Zou Shuping
• Xu Jianmiao
• Zheng Yuguo

Classifications

• A01N25/12 Primary

  Powders or granules (A01N25/26 takes precedence) · CPC title

• A01N57/20 Primary

  containing acyclic or cycloaliphatic radicals · CPC title

• C07F9/301 Primary

  Acyclic saturated acids which can have further substituents on alkyl · CPC title

• C07B2200/07

  Optical isomers · CPC title