diphenpipenol diphenpipenol diphenpipenol is an opioid analgesic drug invented in the 1970s by dainippon pharmaceutical co. it is chemically a 1-substituted-4-(1,2-diphenylethyl)piperazine derivative related to compounds such as mt-45 and ad-1211, but diphenpipenol is the most potent compound in the series, with the more active (s) enantiomer being around 105 times the potency of morphine in animal studies. this makes it a similar strength to fentanyl and its analogues, and consequently diphenpipenol can be expected to pose a significant risk of producing life-threatening respiratory depression, as well as other typical opioid side effects such as sedation, itching, nausea and vomiting. diphenpipenolclinical dataatc codenoneidentifiers iupac name 3--2-phenylethyl]phenol cas number83374-54-3 ypubchem cid13236269chemspider15325002uniizk4vb64wsrchemblchembl1189795chemical and physical dataformulac25h28n2o2molar mass388.511 g·mol−13d model (jsmol)interactive image smiles coc4ccccc4n1ccn(cc1)c(cc2cccc(o)c2)c3ccccc3 inchi inchi=1s/c25h28n2o2/c1-29-25-13-6-5-12-23(25)26-14-16-27(17-15-26)24(21-9-3-2-4-10-21)19-20-8-7-11-22(28)18-20/h2-13,18,24,28h,14-17,19h2,1h3key:ilczmfsacnemgk-uhfffaoysa-n diphenpipenol has been offered for sale online as a designer drug, though analysis of a sample of supposed diphenpipenol found it to instead contain a structural isomer with much weaker opioid activity, and it is unclear if genuine diphenpipenol has actually been sold. alternate isomer sold as diphenpipenol