Parafluorofentanyl (4-fluorofentanyl, '''para-fluorofentanyl, pFF''') is an opioid analgesic analogue of fentanyl developed by Janssen Pharmaceuticals in the 1960s.
Parafluorofentanyl (4-fluorofentanyl, '''para-fluorofentanyl, pFF') is an opioid analgesic analogue of fentanyl developed by Janssen Pharmaceuticals in the 1960s.
Parafluorofentanyl was sold briefly on the US black market in the early 1980s, before the introduction of the Federal Analog Act which for the first time attempted to control entire families of drugs based on their structural similarity rather than scheduling each drug individually as they appeared. Parafluorofentanyl is made by the same synthetic route as fentanyl, but by substituting para''-fluoroaniline for aniline in the synthesis.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).