| 摘要 |
PROBLEM TO BE SOLVED: To industrially, practically and efficiently produce an (S,S)- alkylenediamine-N,N'-disuccinic acid at a low cost without deteriorating the quality of a product in a method for producing the (S,S)-alkylenediamine-N,N'- disuccinic acid. SOLUTION: Ammonium L-aspartate is brought into contact with an alkali metal hydroxide compound and the deammoniating distillation is then carried out. The resultant product is subsequently reacted with a dihaloalkane to produce an (S,S)-alkylenediamine-N,N'-disuccinic acid. In this case, the residual ammonia concentration in an aqueous medium after carrying out the deammoniating distillation is <=4.0 wt.% based on the amount of the aspartic salt in the aqueous medium expressed in terms of the aspartic acid.
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