Patent ID: 6414189
Filing Date: 2002-07-02
Classification: C07C

Abstract:
A process for producing crystals of (S,S)-ethylenediamine N,Nâ€²-disuccinic acid, which are columnar having a bulk density of from 0.45 to 1.2 g/cm3, comprising the steps of adjusting an aqueous solution of an (S,S)-ethylenediamine-N,N-disuccinic acid metal salt to a temperature of 40 to 80Â° C. and a pH of from 2.5 to 4.0, partly precipitating or adding crystals of (S,S)-ethylenediamine-N,N-disuccinic acid, and then cooling the resulting solution to a temperature below 40Â° C. over a period of from 0.2 to 10 hours while supplying a mineral acid thereto so as to maintain the pH range to precipitate (S,S)-ethylenediamine-N,N-disuccinic acid in a yield of 90% or more.