c-8813 c-8813 c-8813 (thiobromadol) is a potent μ-opioid receptor agonist with a distinctive chemical structure which is not closely related to other established families of opioid drugs. the trans-isomer was found to be around 591 times more potent than morphine in animal studies. the same study assigned a potency of 504 times that of morphine to the related compound bdpc. c-8813identifiers iupac name trans-4-(p-bromophenyl)-4-(dimethylamino)-1-(2-(thiophen-2-yl)ethyl)cyclohexanol cas number616898-54-5 npubchem cid11058633chemspider48059007 nuniid343s4vx5gchemical and physical dataformulac20h26brnosmolar mass408.40 g·mol−13d model (jsmol)interactive image smiles brc1=cc=c(2(cc(cc2)(ccc3=cc=cs3)o)n(c)c)c=c1 inchi inchi=1s/c20h26brnos/c1-22(2)20(16-5-7-17(21)8-6-16)13-11-19(23,12-14-20)10-9-18-4-3-15-24-18/h3-8,15,23h,9-14h2,1-2h3/t19-,20- nkey:xrdniybvnzlpje-mxvihjgjsa-n n ny (what is this?) (verify) c-8813 is claimed to be similarly potent at the δ-opioid receptor, which antagonizes the mu depression of breathing, presumably making the drug safer. c-8813 has never been used in humans.