Bischler–Napieralski reaction

The Bischler–Napieralski reaction is an intramolecular electrophilic aromatic substitution reaction that allows for the cyclization of β-arylethylamides or β-arylethylcarbamates. It was first discovered in 1893 by August Bischler and Bernard Napieralski, in affiliation with Basel Chemical Works and the University of Zurich. The reaction is most notably used in the synthesis of dihydroisoquinolines, which can be subsequently oxidized to isoquinolines.