| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preparing an aqueous solution comprising an N-acylcarboxylic acid or its salt represented by formula (4) or (5) in high purity comprising synthesizing the N-acylcarboxylic acid or its salt in high yield. SOLUTION: The aqueous solution of the N-acylcarboxylic acid or its salt is obtained as follows. An aliphatic halide represented by formula (1) and an aminocarboxylic acid represented by formula (2) or (3) are subjected to the Schotten-Baumann condensation reaction in a mixed solvent of water/a lower alcohol in the presence of a basic substance. The amount of the lower alcohol in the resultant reaction solution is reduced to 3.0 mass% based on the mass of the N-acylaminocarboxylic acid salt expressed in terms of the corresponding acid in the reaction solution at pH≥7. A mineral acid is then added to regulate the pH to <2. An aqueous phase part containing an inorganic salt is removed to collect an organic phase part containing the objective compound. The basic substance and water are added to the organic phase part. COPYRIGHT: (C)2004,JPO
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