The incorporation of the 4-phenylpiperidine pharmacophore found in morphine into 4- anilidopiperidines related to fentanyl (1) led to a novel class of potent opioid analgesic and anesthetic agents with a favorable pharmacological profile. The synthesis, analgesic activity, and anesthetic properties of a series of 4-phenyl-4-anilidopiperidines (13-29) are discussed. Isosteric replacement of the phenyl by various heteroaryl substituents extended the series ...
![4-phenyl-4-[N-(2-fluorophenyl)propionamido]piperidine Structure](https://image.chemsrc.com/caspic/475/122823-22-7.png)