(S)-O-Desmethylraclopride is the key non-radioactive precursor for the synthesis of [¹¹C]raclopride, a selective dopamine D2 receptor antagonist widely used in positron emission tomography (PET) imaging studies. It enables the production of the radioligand to investigate the distribution, density, and occupancy of D2 receptors in the brain. This compound supports research into neurological and psychiatric disorders such as Parkinson's disease, schizophrenia, and addiction by providing insights into dopamine signaling pathways. It facilitates the development of dopamine receptor-targeted therapies through in vivo visualization and quantification of receptor binding. The precursor itself exhibits high specificity and affinity for D2 receptors, making it valuable in neuroscience research.