Use of Triphenyl Phosphite and Bromine as a Mild Reagent for the Bischler-Napieralski Reaction

Cyclisation of phenylethylamides to dihydro-isoquinolines is usually carried out under forcing conditions using POCl₃ or P₂0₅ with heating.  A new milder method using (Ph0)₃P and bromine can achieve the cyclisation at low temperature (Vaccari D et al, Synth Lett, 2008, 2807).