Methyl (alphaS)-alpha-amino-2-chlorobenzeneacetate is the methyl ester of a specific enantiomer, meaning it is a chiral intermediate. It is derived from 2-(2-chlorophenyl)glycine through a process that involves esterification and enantiomeric resolution. In the synthesis of clopidogrel, the racemic 2-(2-chlorophenyl)glycine is often prepared first. Then, through processes like esterification and resolution, the desired (S)-enantiomer of the methyl ester, Methyl (alphaS)-alpha-amino-2-chlorobenzeneacetate is obtained, which is then used in subsequent steps to form the final drug product. Methyl (alphaS)-alpha-amino-2-chlorobenzeneacetate is the methyl ester of a specific enantiomer, meaning it is a chiral intermediate. 2-(2-Chlorophenyl)glycine (CAS 141196-64-7) and Methyl (alphaS)-alpha-amino-2-chlorobenzeneacetate (CAS 141109-14-0), can function as intermediates in the synthesis of pharmaceuticals, particularly clopidogrel. However, their roles are distinct stages in the overall process.