PRODUCTION OF HIGH-PURITY ASPARTIC ACID DIBENZYL ESTER- SULFONATE AND HIGH-PURITY ASPARTIC ACID DIBENZYL ESTER- SOLFONATE

摘要

PROBLEM TO BE SOLVED: To obtain an aspartic acid dibenzyl ester-sulfonate having high purity with simple procedure by purifying a crude aspartic acid dibenzyl ester-sulfonate in an organic solvent containing a specific amount of water. ;SOLUTION: The objective compound is produced by purifying (A) a crude aspartic acid dibenzyl ester-sulfonate of formula (R1 and R2 are each H, a 1-4C lower alkyl, a 1-4C lower alkoxy or a halogen; R3 is H or a 1-3C lower alkyl and the substitution position may be ortho, meta or para; (n) is 0-2) is (B) an organic solvent containing ≥2 times mol of water based on the component A. The purification procedure of the component A depends upon the content of water-soluble impurities. For example, when the component A contains only a small amount of water-soluble impurities, the procedure is carried out by suspending the component in an organic solvent, adding ≥2 times mol of water based on the component A while stirring the suspension at a prescribed temperature, cooling the product, separating the precipitated crystal by filtration and drying the crystal.;COPYRIGHT: (C)2000,JPO