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.

Preperation

N-Phenethyl-4-piperidinone can be prepared via a simple S_N2 substitution by reacting phenethyl bromide with 4-piperidinone in the presence of a phase transfer catalyst.

Uses

N-Phenethyl-4-piperidinone is useful in the synthesis of pharmaceuticals, primarily fentanyl and its analogs. Paul Janssen (founder of Janssen Pharmaceutica) first synthesized fentanyl in 1960 from NPP. Janssen's synthesis involved reacting N-Phenethyl-4-piperidinone with aniline, and then reducing the imine product with sodium borohydride to 4-anilino-N-phenethylpiperidine(ANPP). This product is reacted with propionyl chloride to form fentanyl.

References

http://pubs.acs.org/cen/coverstory/83/8325/8325fentanyl.html