PDM-042 is a potent, selective, and orally active phosphodiesterase 10A (PDE10A) inhibitor. PDM-042 shows potent inhibitory activities for human and rat PDE10A with IC50 values of less than 1 nM and more than 1000-fold selectivity against other phosphodiesterases. PDM-042 can be used for the research of schizophrenia[1].