(4S)-4-[(4-Nitrophenyl)methyl]-2-oxazolidinone-d6 is an intermediate in the synthesis of 3-Des[2-(Dimethylamino)ethyl] Zolmitriptan-d6 3-Acetic Acid (D288969) which is the isotope labelled 3-Des[2-(Dimethylamino)ethyl] Zolmitriptan 3-Acetic Acid (D288965). 3-Des[2-(Dimethylamino)ethyl] Zolmitriptan 3-Acetic Acid is the indole acetic acid metabolite of Zolmitriptan (Z639000) formed by human hepatocytes.