Exploring 1623. To explore a different substance…

Methyl 4-[phenyl(propanoyl)amino]-1-[2-(thiophen-3-yl)ethyl]piperidine-4-carboxylate
 1623  C22H28N2O3S  400.534
 Fentanyl
 InChI=1S/C22H28N2O3S/c1-3-20(25)24(19-7-5-4-6-8-19)22(21(26)27-2)11-14-23(15-12-22)13-9-18-10-16-28-17-18/h4-8,10,16-17H,3,9,11-15H2,1-2H3
 JPFRMUAREHIGHU-UHFFFAOYSA-N This stereoisomer Any stereoisomer
 COC(=O)C1(CCN(CC1)CCc1cscc1)N(c1ccccc1)C(=O)CC