[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][C][=Branch1][C][=O][N][Branch1][=Branch2][C][C][C][N][C][C][Ring1][=Branch1][C][=C][C][=C][C][=C][Ring1][=Branch1]"}, {"from": "gpt", "value": "The molecule is a monocarboxylic acid amide resulting from the formal condensation of the aryl amino group of 4-(N'-phenyl)piperidin-4-amine with propanoic acid. A major metabolite of fentanyl. It has a role as an opioid analgesic and a drug metabolite. It is an anilide, a member of piperidines and a monocarboxylic acid amide."}]