Patent ID: 6794515
Filing Date: 2004-09-21
Classification: A61P,C07B,C07C,C07D

Abstract:
A method of preparing an optically active 2-alkylated cysteine represented by Structural Formula (I): or a salt thereof; wherein R1 is a substituted or unsubstituted alkyl group, the method comprising: (a) coupling a compound represented by Structural Formula (II): â€ƒor a salt thereof, with a substituted or unsubstituted aryl nitrile of the formula Arâ€”CN, wherein Ar is a substituted or unsubstituted aryl group; thereby forming a substituted thiazoline carboxylic acid represented by Structural Formula (III): (b) reacting the substituted thiazoline carboxylic acid with an amine represented by Structual Formula (IV): â€ƒwherein R* is a substituted or unsubstituted alkyl group comprising one or more chiral carbon atoms and R2 is a substituted or unsubstituted alkyl or aryl group; thereby forming a substituted thiazoline amide represented by Structural Formula (V): (c) alkylating the substituted thiazoline amide with one or more bases and R1X, wherein X is a leaving group and R1 is as defined above; thereby forming an alkylated substituted thiazoline amide represented by Structural Formula (VI): (d) hydrolyzing the alkylated substituted thiazoline amide, thereby forming an alkylated substituted thiazoline carboxylic acid or a salt thereof, the anion of which is represented by Structural Formula (VII): (e) reacting the alkylated substituted thiazoline carboxylic acid or salt thereof with acid, thereby forming the 2-alkylated cysteine represented by Structural Formula (I).