1-​(Benzyloxycarbonyl)​pyrrolidine-​3-​carboxylic Acid is a reagent used in the synthesis of cyclin-dependent kinase 4-inhibitors (CDK4) for cancer treatments. Also used towards the discovery of a potent inhibitor of poly(ADP-ribose) polymerase (PARP) for the treatment of cancer pased upon benzimidazole carboxamide moieties.