N-Phenethyl-4-piperidinone (NPP) is a derivative of 4-piperidinone

4-Piperidinone

4-Piperidinone is a derivative of piperidine with the molecular formula C5H9NO. 4-Piperidone is used as an intermediate in the manufacture of chemicals and pharmaceutical drugs .-Piperidones:...

 with the molecular formula C

Carbon

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

₁₃H

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

₁₇N

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

O

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

. 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

DEA list of chemicals

The United States Drug Enforcement Administration maintains lists regarding not only the classification of illicit drugs . It also maintains List I of chemicals and List II of chemicals, which contain chemicals which are used to manufacture the controlled substances/illicit drugs...

 in 2007, and possession and sales of this compound are now heavily restricted.

Preparation

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

Phase transfer catalyst

In chemistry, a phase transfer catalyst or PTC is a catalyst that facilitates the migration of a reactant from one phase into another phase where reaction occurs. Phase transfer catalysis is a special form of heterogeneous catalysis. Ionic reactants are often soluble in an aqueous phase but...

.

Uses

N-Phenethyl-4-piperidinone is useful in the synthesis of pharmaceuticals, primarily fentanyl and its analogs. Paul Janssen

Paul Janssen

Paul Adriaan Jan, Baron Janssen was the founder of Janssen Pharmaceutica, a pharmaceutical company with over 20,000 employees. In 2005 he finished as runner up, after Father Damien, in the poll for The Greatest Belgian organized by the regional Flemish television...

 (founder of Janssen Pharmaceutica

Janssen Pharmaceutica

Janssen Pharmaceutica is pharmaceutical company, established in Belgium in 1953 by Paul Janssen. Its headquarters are located in Beerse, in the Campine region of the province of Antwerp, Belgium. It was created not as a subsidiary of a chemical factory but solely with the aim of conducting...

) 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

Sodium borohydride

Sodium borohydride, also known as sodium tetrahydridoborate, is an inorganic compound with the formula NaBH4. This white solid, usually encountered as a powder, is a versatile reducing agent that finds wide application in chemistry, both in the laboratory and on a technical scale. Large amounts are...

 to 4-anilino-N-phenethylpiperidine(ANPP). This product is reacted with propionyl chloride to form fentanyl.