PROCESS FOR THE PREPARATION OF A SALT OF OPTICALLY ACTIVE LYSINE

摘要

1,250,730. Purification of lysine sulphanilate. STAMICARBON N.V. 30 Sept., 1969 [2 Oct., 1968], No. 57063/70. Divided out of 1,250,557. Heading C2C. The optical purity of a lysine sulphanilate consisting of unequal amounts of the D- and L-antipodes is increased by separating DL- lysine sulphanilates from the said salt by treating the salt with a solvent to obtain a saturated or substantially saturated liquid phase containing lysine sulphanilate of lower optical purity and a solid phase mainly comprising the antipode present in larger amount in the original salt and having a higher optical purity than the original salt, and then separating the phases. The solvent may be water or mixtures of water with methanol, ethanol, propanol, acetone or butanone. The purified sulphanilate can be split into lysine and sulphanilic acid, e.g. by use of a weakly basic ion exchanger, or a strong acid ion exchanger in the form of NH 4 +, eluting the lysine with dilute NH 4 OH.