On Diazotization and WizardX's site
(Rated as: excellent)
Formation of Amphetamine precursors by diazotization of 3-phenylpropylamine
In a 200ml round-bottom flask equipped with magnetic stirring there is placed 13.8g of NaNO2 in 75ml of distilled H2O, chilled to 0*C. To this there is added 13.5g (100mmol, 14.26ml) of 3-phenylpropylamine. Stir the mixture to emulsion and begin adding a chilled solution of H2SO4 (5.4ml of concentrated acid was added to 10ml of water, 100mmol, C = 10M ) dropwise over 10-20 minutes. Let the mixture stir for an additional 30 minutes. Then slowly allow the temperature to rise to RT. Once at RT, if no more gas evolution is apparent, extract the organics 2x50ml DCM. The combined extracts are washed with water, bicarbonate, water and then dried with magnesium sulfate or sodium sulfate. The organics are then fractionally distilled to give:
3-phenypropyl chloride (5%)
allylbenzene and propenylbenzene (combined yield 37%)
(Credit is given to WizardX, as the yields are from his page)
Hopefully, the procedural details given will inspire somebody to try this route for fun.