Disclosed is a method for the preparation of salts of N-phosphonomethylglycine which comprises the steps of (a) reacting hydantoin or a 3-substituted hydantoin, a compound of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl having from 1 to 10 carbon atoms, aryl having from 6 to 12 carbon atoms, alkylcarbonyl wherein the alkyl group has from 1 to 10 carbon atoms, and arylcarbonyl wherein the aryl group has from 6 to 12 carbon atoms, with paraformaldehyde in the presence of a low molecular weight carboxylic acid at a temperature and for a sufficient period of time to produce a mixture of intermediate products, including the 1-hydroxymethyl derivative of the starting hydantoin; (b) converting said 1-hydroxymethyl derivative to the 1-phosphonomethyl derivative by thereafter adding to the reaction mixture either (i) a substituted phosphorus compound selected from the group consisting of phosphorus trichloride, and phosphorus tribromide; or (ii) adding to the reaction mixture phosphorous acid and a anhydride selected from the group consisting acetic anhydride, propionic anhydride, butyric anhydride, or mixture thereof, and continuing said reaction at a temperature and for a sufficient period of time to cause completion of the reaction to form the 1-phosphonomethyl derivative; and (c) hydrolyzing the 1-phosphonomethylhydantoin product thus formed with a base selected from the group consisting of alkali metal or alkaline earth hydroxide, to produce a salt of N-phosphonomethylglycine.
本发明公开了一种制备N-
磷酸甲基甘
氨酸盐的方法,包括以下步骤:(a)将恒唑或3-取代恒唑化合物(式中R选自氢、1-10个碳原子的烷基、6-12个碳原子的芳基、烷基羰基,其中烷基含有1-10个碳原子,和芳基羰基,其中芳基含有6-12个碳原子)与低分子量
羧酸在存在下,与多
聚甲醛反应,反应温度和时间足以产生中间产物混合物,包括起始恒唑的1-羟甲基衍
生物;(b)通过向反应混合物中加入以下任一物质将1-羟甲基衍
生物转化为1-
磷酸甲基衍
生物:(i)从
磷酸三
氯化物和
磷酸三
溴化物中选择的取代
磷化合物;或(ii)向反应混合物中加入
磷酸和从
乙酸酐、
丙酸酐、
丁酸酐或其混合物中选择的酸酐,并在温度和时间足以使反应完全进行的条件下继续反应,以形成1-
磷酸甲基衍
生物;(c)用碱
金属或碱土
金属氢氧化物中选择的碱基
水解形成的1-
磷酸甲基恒唑产物,以制备N-
磷酸甲基甘
氨酸盐。