Used as a chiral building block in the synthesis of pharmaceuticals, particularly in the development of active pharmaceutical ingredients (APIs) where stereochemistry plays a critical role in biological activity. Its amine functionality allows for coupling reactions to form amides or other nitrogen-containing derivatives. Commonly employed in the production of central nervous system agents, including certain antidepressants and antiviral drugs. The hydrochloride salt enhances stability and solubility, making it suitable for use in reaction intermediates during multi-step syntheses. Also utilized in asymmetric synthesis due to its (S)-configuration, enabling the preparation of enantiomerically pure compounds.