草铵膦铵盐及其中间体的合成

the Synthesis Process of Glufosinate-ammonium and its Intermediate

[目的]研究不采用剧毒氰化物原料的非Strecker法合成草铵膦铵盐的工艺路线。[方法]以廉价易得的三氯化磷和亚磷酸三乙酯为原料制备氯代亚膦酸二乙酯,经格氏反应得到甲基亚膦酸二乙酯;甲基亚膦酸二乙酯与二溴乙烷在自制催化剂催化下反应得到甲基(2-溴乙基)膦酸乙酯;然后与乙酰氨基丙二酸二乙酯负离子在甲苯中反应,经盐酸酸化,氨水铵化得到草铵膦铵盐。[结果]以三氯化磷计,甲基亚膦酸二乙酯收率为57.6%;以甲基亚膦酸二乙酯计草铵膦铵盐收率为25.8%;制备的草铵膦铵盐各性能指标与文献相符。[结论]以三氯化磷、亚磷酸三乙酯为原料制备氯代亚膦酸二乙酯,经格氏反应得甲基亚膦酸二乙酯是一条原材料成本较低、收率较高、易于工业化的合成路线;甲基亚磷酸二乙酯与二溴乙烷反应制备甲基(2-溴乙基)膦酸乙酯的反应可通过优化催化剂的设计提高过程收率;草铵膦的收率略低于目前以氰化物为原料的Strecker法。

[Aims] The chief aim is to investigate the preparation process of glufosinate-ammonitma by non-Strecker reaction, without using highly toxic cyanide as reactant. [Methods] Diethyl chlorophosphite was prepared from cheap and easily available phosphorous trichloride and triethyl phosphite, and then DEMP was synthesized by Grignard reaction. Ethyl methyl 2-bromide phosphate was produced under the self-made catalyst by the reaction of DEMP and dibromoethane. The obtained bromide was reacted with diethyl acetamidomalonate anion in toluene followed by acidification with hydrochloric acid and ammonification with ammonia to afford glufosinate-ammonium. [Results] The yield of DEMP was 57,6% based on phosphorous trichloride and that of glufosinate-ammonium was 25.8% based on DEMP. The properties of the product are consistent with the literature. [Conclusions] The preparation process in this paper has some advantages of low cost, relatively high yield and easy for industrialization. The process yield of ethyl methyl 2-bromide phosphate may be enhanced by optimizing the catalyst used in the reaction of DEMP with Dibromoethane. The yield of glufosinate-ammonium synthesized by method mentioned in this paper is slightly lower than that by Strecker method using cyanide.