Bischler-Napieralski reaction

The Bischler-Napieralski reaction is a chemical reaction that dehydrates an N-acyl β-arylethyl amines into the corresponding heterocycle.



With less nucleophilic aryl groups, more harsh conditions are required. Indoles react readily upon warming in benzene. Benzene rings require higher temperatures.

Phosphorus oxychloride is the most often used dehydrating agent. Phosphorus pentachloride, polyphosphoric acid, and zinc chloride have also proven successful.