AP-238 is an opioiddesigner drug related to drugs such as azaprocin and bucinnazine, with around the same potency as morphine.[2] It was first discovered in Italy in the 1960s but was never marketed,[3] subsequently appearing on the illicit market around 2020 and being detected in both Slovenia and the USA.[4][5]
^Cignarella G, Testa E (May 1968). "2,6-Dialkylpiperazines. IV. 1-Propionyl-4-substituted cis-2,6-dimethylpiperazines structurally related to the analgetic 8-acyl-3,8-diazabicyclo[3.2.1]octanes". Journal of Medicinal Chemistry. 11 (3): 592–594. doi:10.1021/jm00309a039. PMID5656502.