mirfentanil mirfentanil mirfentanil is a fentanyl derivative with strong selectivity for the μ opioid receptor. at lower doses, it antagonizes the analgesic effects of alfentanil and substitutes for naloxone in morphine-treated monkeys; however, it also reverses naloxone-precipitated withdrawal in pigeons trained to discriminate morphine from naloxone. mirfentanil names preferred iupac name n--n-pyrazinylfuran-2-carboxamide other names ms-32, nih-10647 identifiers cas number 117523-47-4 y 3d model (jsmol) interactive image chemspider 54703 n mesh c069209 pubchem cid 60698 unii q2u943h24p y comptox dashboard (epa) dtxsid10151799 inchi inchi=1s/c22h24n4o2/c27-22(20-7-4-16-28-20)26(21-17-23-11-12-24-21)19-9-14-25(15-10-19)13-8-18-5-2-1-3-6-18/h1-7,11-12,16-17,19h,8-10,13-15h2 nkey: bjzzdolvvlwfhn-uhfffaoysa-n ninchi=1/c22h24n4o2/c27-22(20-7-4-16-28-20)26(21-17-23-11-12-24-21)19-9-14-25(15-10-19)13-8-18-5-2-1-3-6-18/h1-7,11-12,16-17,19h,8-10,13-15h2key: bjzzdolvvlwfhn-uhfffaoyan smiles c1cn(ccc1n(c2=nc=cn=c2)c(=o)c3=cc=co3)ccc4=cc=cc=c4 properties chemical formula c22h24n4o2 molar mass 376.460 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references at high doses, it exhibits analgesic activity which is not fully reversed by opioid antagonists, suggesting that the drug has both opioid and non-opioid mechanisms of action. 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. synthesis mirfentanil was synthesized via acylation of the product of the reaction of 2-chloropyrazine and 1-(2-phenylethyl)-4-piperidinone oxime with 2-furoyl chloride.