Process for the preparation of a mixture of chelating agents

摘要

The present invention relates to a process for the preparation of a mixture of aspartic acid diethoxy succinate and an amino acid derivative of the general formula (I) wherein n is 1-10, m is 0 or 1, and R is hydrogen or an alkali metal or alkaline earth metal ion, comprising reacting maleate with diethanol amine under alkaline conditions in the presence of a lanthanoid catalyst to form aspartic acid diethoxy succinate followed by adding aspartic acid which reacts with unreacted maleate to form imino disuccinic acid, i.e. an amino acid derivative of formula (I) wherein m is 0, or by adding a diamine derivative of the general formula (II) NH2(CH2)nNH2 wherein n is as defined above, which reacts with unreacted maleate to form an amino acid derivative of formula (I) wherein m is 1 and n is as defined above.;

主权项

1. A process for the preparation of a mixture of aspartic acid diethoxy succinate and an amino acid derivative of the general formulawherein n is 1-10, m is 0 or 1, and R is hydrogen or an alkali metal or alkaline earth metal ion, comprising reacting maleate with diethanol amine under alkaline conditions wherein the amount of the diethanol amine is substoichiometric in relationship to the amount of the maleate, in the presence of a lanthanoid catalyst to form aspartic acid diethoxy succinate followed by adding aspartic acid which reacts with unreacted maleate to form imino disuccinic acid, wherein the amino disuccinic acid is an amino acid derivative of formula I wherein m is 0, or by adding a diamine derivative of the general formula
NH2(CH2)nNH2   IIwherein n is as defined above, which reacts with unreacted maleate to form an amino acid derivative of formula I wherein m is 1 and n is as defined above.