Several cannabimimetic quinolinyl carboxylates (PB-22, ) and cannabimimetic carboxamide derivatives (ADB-FUBINACA, ) have been identified as designer drugs in illegal products. FDU-PB-22 is a derivative of PB-22 in which the pentyl side chain is replaced by a 4-fluorobenzyl group, a functional group also found in indazole-based synthetic cannabinoids such as ADB-FUBINACA. Additionally, the 8-quinolinol is replaced by a naphthalene group, similar to the structure of AM2201 . The physiological and toxicological properties of this compound are not known. This product is intended for forensic and research applications.