Process for the preparation of aqueous solutions of methylglycine-N,N-diacetic acid trialkali metal salts
    66.
    发明授权
    Process for the preparation of aqueous solutions of methylglycine-N,N-diacetic acid trialkali metal salts 有权
    制备甲基甘氨酸-N,N-二乙酸三烷基金属盐水溶液的方法

    公开(公告)号:US08802894B2

    公开(公告)日:2014-08-12

    申请号:US13431381

    申请日:2012-03-27

    IPC分类号: C07C227/18

    摘要: A process for preparing an aqueous solution of a methylglycine-N,N-diacetic acid trialkali metal salt at a high yield and purity by Strecker synthesis, the process including: reacting an aqueous solution containing α-alanine with formaldehyde and hydrocyanic acid, to obtain α-alanine-N,N-diacetonitrile in one reaction unit; and saponification of the α-alanine-N,N-diacetonitrile with a base, to obtain the methylglycine-N,N-diacetic acid trialkali metal salt, wherein the α-alanine is partially neutralized and the addition of formaldehyde and hydrocyanic acid are controlled such that a concentration of free hydrocyanic acid in the liquid reaction mixture at any time is limited such that secondary reactions that produce formaldehyde cyanohydrin, consecutive reactions of formaldehyde cyanohydrin, and the polymerization of hydrocyanic acid, only occur insofar as the specification requirements, such as nitrilotriacetic acid content and color, for methylglycine-N,N-diacetic acid trialkali metal salts are observed.

    摘要翻译: 一种通过Strecker合成以高产率和纯度制备甲基甘氨酸-N,N-二乙酸三烷基金属盐的水溶液的方法,该方法包括:使含有α-丙氨酸的水溶液与甲醛和氢氰酸反应,得到 α-丙氨酸-N,N-二乙腈在一个反应​​单元中; 并用碱对α-丙氨酸-N,N-二乙腈进行皂化,得到甲基甘氨酸-N,N-二乙酸三碱金属盐,其中α-丙氨酸被部分中和,加入甲醛和氢氰酸被控制 使得在任何时候液体反应混合物中的游离氢氰酸的浓度受到限制,使得产生甲醛氰醇的二次反应,甲醛氰醇的连续反应和氢氰酸的聚合仅发生在规范要求的范围内,例如 观察到甲基甘氨酸-N,N-二乙酸三烷基金属盐的次氮基三乙酸含量和颜色。