Remifentanil acid
3-{4-(Methoxycarbonyl)-4-[phenyl(propanoyl)amino]piperidin-1-yl}propanoic acid
 11518  C19H26N2O5  362.42
 Fentanyl
 InChI=1S/C19H26N2O5/c1-3-16(22)21(15-7-5-4-6-8-15)19(18(25)26-2)10-13-20(14-11-19)12-9-17(23)24/h4-8H,3,9-14H2,1-2H3,(H,23,24)
 GFJKFSFFMHOISI-UHFFFAOYSA-N This stereoisomer Any stereoisomer
 COC(=O)C1(CCN(CC1)CCC(=O)O)N(c1ccccc1)C(=O)CC