Preparation method of glufosinate-ammonium

Abstract

The invention discloses a preparation method of glufosinate-ammonium. The method comprises the steps that methylphosphonate compound (II) and benzylidene glycine ester compound (III) are reacted, so as to obtain benzylidene phosphonic butyric ester compound (IV); the benzylidene phosphonic butyric ester compound (IV) is further hydrolyzed, so as to obtain hydrochloride (V); finally, the target product glufosinate-ammonium (I) is obtained. The method has the advantages that the utilization of extremely toxic substance cyanide is avoided, the reaction condition is mild, monitoring is easy, and repeated recrystallization is not required for removing inorganic salt. (img file='DDA0000501075940000011.TIF' wi='1408' he=' 672' / ).

Description

technical field [0001] The invention relates to a synthesis technique of herbicide, in particular to a synthesis method of glufosinate-ammonium. Background technique [0002] Glufosinate-ammonium is a high-efficiency, broad-spectrum, low-toxic non-selective herbicide developed by the German Hoechst company. The target enzyme is glutamine synthetase. Glufosinate-ammonium can inhibit all known forms of glutamine synthetase. It leads to the disorder of nitrogen metabolism in plants, the excessive accumulation of ammonia, and the disintegration of chloroplasts, which inhibits photosynthesis and eventually leads to plant death. The commercially available glufosinate-ammonium is a racemic mixture, and only the L- form has herbicidal activity. It is currently an ideal herbicide for transgenic resistant crops and has broad application prospects. Its synthesis methods mainly include chemical synthesis and fermentation. The fermentation method is mainly to produce bialaphos through ...

AI Technical Summary

Problems solved by technology

The relatively mature technology of chemical synthesis method is the strecker method (US6359162, CN1267305A) at present, and this route uses diethyl methyl phosphite as raw material, and after reacting with acrolein, acetal product is obtained, and then reacted with cyanide, ammonium chloride, etc. Obtain α-amino nitrile compounds, then hydrolyze to obtain glufosinate-ammonium, the yield is stable at about 30% (in terms of diethyl methyl phosphite), and the conditions are mild, but highly toxic cyanides will be used, which requires environmental protection. Higher, and the reaction produces a large amount of ammonium chloride, which is difficult to separate from the product glufosinate-ammonium, and the purification process is cumbersome, which affects the product purity and production cost

In addition, the reaction intermediate α-aminonitrile compound is not easy to monitor, which is not conducive to production control

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