(S)-3-Phenylpiperazin-2-one is primarily utilized in the field of medicinal chemistry as a key intermediate in the synthesis of various pharmaceutical compounds. Its structure is particularly valuable in the development of drugs targeting the central nervous system, including potential treatments for neurological disorders such as anxiety, depression, and schizophrenia. The compound's chiral center allows for the creation of enantiomerically pure substances, which can enhance the efficacy and reduce the side effects of the resulting drugs. Additionally, it is explored in the design of bioactive molecules that interact with serotonin and dopamine receptors, making it a significant building block in the research and development of psychotropic medications.