ChEBI: Carboxyfentanyl is the dicarboxylic acid monoamide resulting from the formal condensation of aryl amino group of N-phenyl-1-(2-phenylethyl)piperidin-4-amine with succinic acid. It is a member of piperidines, a monocarboxylic acid and a dicarboxylic acid monoamide. It is functionally related to a succinic acid.