N-Phenethyl-4-piperidinone

N-Phenethyl-4-piperidinone (NPP) is a derivative of 4-piperidinone with the molecular formula C5H9NO. 4-Piperidone is used as an intermediate in the manufacture of chemicals and pharmaceutical drugs such as fentanyl.

Because of its use in the illicit manufacture of fentanyl, NPP was placed onto the list of controlled chemicals in the USA in 2007, and possession and sales of this compound are now heavily restricted.