Veliparib, a potent PARP inhibitor used against multiple cancerous cells such as metastatic melanoma, breast, non-small cell lung cancer (NSCLC) and prostatic cancer, is required for absorption, distribution, metabolism and excretion (ADME) and environmental toxicology assessments studies. Tritium-labeled Veliparib was prepared via the tritiodebromination using tritium gas (T2 ) in two steps. [14 C]Veliparib was achieved through an asymmetric synthetic route in seven radioactive steps starting from [14 C] (S)-benzyl 2-aminopropanoate.