Aprepitant: C~23~H~21~F~7~N~4~O~3~. Mw: 534.43. (1) 3H-1,2,4-Triazol-3-one, 5-[[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)-4-morpholinyl]methyl]-1,2-dihydro-; (2) 3-[[(2R,3S)-3-(p-Fluorophenyl)-2-[[(αR)-α-methyl-3,5-bis(trifluoromethyl)benzyl]oxy]morpholino]methyl]-Δ^2^-1,2,4-triazolin-5-one. CAS-170729-80-3 (2000).