Fentanyl Synthesis Overview

Materials:
- N-phenethyl-4-piperidone (NPP)
- 4-ANPP intermediate
- Propionyl chloride for acylation
- Aniline
- Reducing agent (sodium borohydride)
- Dichloromethane solvent
- Triethylamine base

Procedure:

1. Start with NPP and perform reductive amination with aniline
2. Use sodium borohydride as the reducing agent
3. The piperidine ring is central to the structure
4. Perform N-acylation with propionyl chloride
5. The phenethyl group is attached to nitrogen
6. Extract product using liquid-liquid extraction
7. Purify by recrystallization
8. Form hydrochloride salt for stability
9. Heat to approximately 70 degrees Celsius during reflux
10. Work at 1 atm pressure

Notes:
- Reaction requires careful temperature control
- Use proper safety precautions
- Yield analysis required
