Patent ID: 6093823
Filing Date: 2000-07-25
Classification: C07D

Abstract:
A process for the production of basic, cyclic and optically active a-amino acids of formula I ##STR10## wherein n, m are integers selected from the group consisting of 0, 1, 2 and 3,Y is CHR.sup.1, NR.sup.1 or OR.sup.1 is H, benzyl, formyl, COR.sup.2 or CO.sub.2 R.sup.2R.sup.2 is (C.sub.1 -C.sub.6) alkyl or benzyl,R.sup.3 is (C.sub.1 -C.sub.6) alkyl or benzyl,* Denotes a carbon atom in R or S configuration,comprising the sequential steps ofa) reacting the racemate of the basic, cyclic 1-amino acid of the formula V ##STR11## wherein Rac indicates that the adjacent carbon atom is racemic, with an optically active auxiliary acid to yield the salt pairs of the formula VI ##STR12## wherein p is an integer from 1 to 6, corresponds to the number of basic centers and is the molar ratio of the chiral acid to the a-amino acid and,b) separating a resultant diastereomeric salt pair of the formula VII from the mother liquor ##STR13## c) combining and racemnizing the mother liquor with the corresponding chiral auxiliary acid used for resolving the racemated) Subsequently combining the thus combined and racemized mother liquor with the racemate of the basic, cyclic amino acid of the formula V ##STR14## to provide the diastereomeric salts pairs of the formula VI, ##STR15## e) Separating a diastereomeric salt pair of the formula VII again from the mother liquor of the previous stepf) Combining this salt pair with the diastereomeric salt pair already obtained in b) andg) Liberating the amino acid therefrom.