n-methylnorcarfentanil n-methylnorcarfentanil n-methylnorcarfentanil (r-32395) is an opioid analgesic drug related to the highly potent animal tranquilizer carfentanil, but several thousand times weaker, being only slightly stronger than morphine. it was first synthesised by a team of chemists at janssen pharmaceutica led by paul janssen, who were investigating the structure-activity relationships of the fentanyl family of drugs. they found that replacing the phenethyl group attached to the piperidine nitrogen of fentanyl with a smaller methyl group, made it so much weaker that it was inactive as an analgesic in animals. however the same change made to the more potent analogue carfentanil retained reasonable opioid receptor activity, reflecting the higher binding affinity produced by the 4-carbomethoxy group. n-methylnorcarfentanillegal statuslegal status ca: schedule i uk: class a identifiers iupac name methyl 1-methyl-4-(n-phenylpropanamido)piperidine-4-carboxylate cas number59708-50-8pubchem cid12298013chemspider26231037 yunii85wel251jzchemical and physical dataformulac17h24n2o3molar mass304.390 g·mol−13d model (jsmol)interactive image smiles o=c(oc)c1(n(c2=cc=cc=c2)c(cc)=o)ccn(c)cc1 inchi inchi=1s/c17h24n2o3/c1-4-15(20)19(14-8-6-5-7-9-14)17(16(21)22-3)10-12-18(2)13-11-17/h5-9h,4,10-13h2,1-3h3 ykey:kkevielpqlxprr-uhfffaoysa-n y (verify) side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. fentanyl analogs have killed hundreds of people throughout europe and the former soviet republics since the most recent resurgence in use began in estonia in the early 2000s, and novel derivatives continue to appear.