Exploring 3121. To explore a different substance…

Methyl 1-(2-hydroxy-2-phenylethyl)-3-methyl-4-[phenyl(propanoyl)amino]piperidine-4-carboxylate
 3121  C25H32N2O4  424.533
 Fentanyl
 InChI=1S/C25H32N2O4/c1-4-23(29)27(21-13-9-6-10-14-21)25(24(30)31-3)15-16-26(17-19(25)2)18-22(28)20-11-7-5-8-12-20/h5-14,19,22,28H,4,15-18H2,1-3H3
 HVTQDIBOZUDMTH-UHFFFAOYSA-N This stereoisomer Any stereoisomer
 CCC(=O)N(C1(CCN(CC1C)CC(c1ccccc1)O)C(=O)OC)c1ccccc1