| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing N-carbobenzoxy-S-phenyl-L-cysteine in high yield with high purity by an industrially realistic method in the method for producing the N-carbobenzoxy-S-phenyl-L-cysteine. SOLUTION: This method for producing an N-protected amino acid is characterized in that the N-protected amino acid obtained by introducing a protective group to the amino group of an amino acid in an alkaline water-based medium, is dissolved or extracted into an organic solvent, the resultant liquid is added into water regulated in the condition of 10-85 deg.C and 40-1 kPa reduced pressure to distil off the organic solvent, and the resultant liquid is mixed with a poor solvent to precipitate the crystal.</p> |
