The invention relates to N-bis- or N-tris-[(1,2-dicarboxy-ethoxy)-ethyl]-amine derivatives having the formula (I) ##STR1## and R.sub.2 is hydrogen, an alkali metal or an earth-alkali metal. The invention also relates to a method for preparing the same and their use as chelating agents.
本发明涉及具有以下式子(I)的N-双或N-三-[(1,2-二羧基-乙氧基)-乙基]-胺衍
生物:##STR1##其中R.sub.1和R.sub.3分别是氢、C.sub.1-C.sub.6烷基、C.sub.1-C.sub.6烷氧基、C.sub.1-C.sub.6烷基羟基或C.sub.1-C.sub.6烷基羧基,R.sub.2是氢、碱
金属或碱土
金属。本发明还涉及一种制备它们的方法和它们作为
螯合剂的用途。