Method for synthesizing glufosinate

Abstract

The invention relates to a synthesizing method for pesticide glufosinate, i.e., ((D,L)-2-amino-4-(hydroxyl(methyl)phosphinyl)butyrate) and a salt of an acid or an alkali thereof. In the synthesizing method, the pesticide glufosinate is prepared by undergoing a strecker reaction, and an intermediate compound, i.e., (3-nitrile-3-hydroxy)propyl methyl phosphonic acid directly reacts with carbon dioxide and ammonia gas in an aqueous solution to synthesize the pesticide glufosinate and a salt of an acid or an alkali thereof. The method comprises the following specific steps of: adding the intermediate compound, i.e., (3-nitrile-3-hydroxy) propyl methyl phosphonic acid into a high-pressure kettle; adding carbon dioxide, ammonia gas and water, wherein ammonium bicarbonate or ammonium carbonate and the like can be used for replacing carbon dioxide carbon and ammonium, the molar ratio of the intermediate to the carbon dioxide is between 1 and 12, and the ratio of the ammonia gas to the carbon dioxide is between 0.5 and 5; adding 15-75 times of water; heating to 120-180 DEG C; reacting for about 4-20 hours; and after the reaction, cooling, taking the reaction liquid out, and concentrating to directly obtain an ammonium salt of glufosinate. The yield is over 80 percent.

Description

technical field [0001] The present invention relates to a kind of synthetic method of pesticide glufosinate-ammonium referring to formula (I) and its salt with acid or alkali, it is a kind of synthetic method for preparing pesticide glufosinate-ammonium by Strecker (strecker) reaction, formula ( II) The intermediate compound (3-cyano-3-hydroxyl) propylmethylphosphonic acid reacts directly with carbon dioxide and ammonia in aqueous solution to synthesize the pesticide glufosinate-ammonium and its salt with acid or base. [0002] (Ⅰ) [0003] (Ⅱ) Background technique [0004] Glufosinate-ammonium (see formula (I)) is the common name of the active compound (D, L)-2-amino-4-(hydroxy(methyl)phosphinyl)butyric acid, and the commercially available product is in the form of monoammonium salt , and can be used as a herbicide sprayed on the leaves (see DE-A-2717440, US-A-4168963). Glufosinate-ammonium is a systemic herbicide with broad-spectrum herbicidal activity and is widel...

AI Technical Summary

Problems solved by technology

[0006] In the production process of the chemically synthesized pesticide glufosinate-ammonium, among the currently known synthetic literatures, the most representative one is to hydrolyze the aminonitrile compound with hydrochloric acid or sodium hydroxide to produce glufosinate-ammonium. This method has an obvious The disadvantage is that a large amount of salt will be produced, mainly sodium chloride, which leads to the separation step of sodium chloride and product in industrial production, and the solubility of glufosinate-ammonium and sodium chloride is somewhat similar For example, they are all dissolved in water, which makes this physical process not easy. At present, methanol is used to isolate sodium chloride in the product. Such an operation will take up a lot of equipment, and it is added to the synthesis process. The original raw material methanol, and bring higher operating costs