Thionyl Chloride → Amphetamine

Participants

Reaction Steps

A 100 mL round bottom flask with a magnetic stirrer was charged with thionyl chloride (24.47 g, 15 mL) and norephedrine hydrochloride (5.38 g). The mixture was stirred and heated at reflux temperature for about 1 hour and allowed to cool to ambient temperature. The excess thionyl chloride was removed by evaporation on a rotary evaporator. The residue in the flask was triturated with ether (50 mL) and the solid collected. The crude solid product was recrystallized from methanol-isopropyl ether and the purified solid collected (2.83 g, 48%). The purified 2-amino-1-chloro-1-phenylpropane hydrochloride was then subjected to hydrogenolysis as follows. A solution of 2-amino-1-chloro-1-phenylpropane hydrochloride (2.38 g, 0.0137 mol) in a mixture of 50 mL ethanol/16 mL water was prepared and transferred to a Parr bottle. Under a nitrogen atmosphere, a portion of 10% palladium on carbon catalyst was added to the solution in the Parr bottle. The Parr bottle was then installed on a Parr shaker apparatus and an inert atmosphere produced and maintained in the bottle. The Parr bottle was then pressurized with hydrogen to about 50 psi and was shaken until the hydrogen uptake ceased. The contents of the Parr bottle was filtered to remove the catalyst and the filtrate was evaporated under reduced pressure to remove the ethanol. The remaining aqueous solution was basified with 50% sodium hydroxide solution. The oily top layer with was extracted with ether and the ether layer was separated from the aqueous layer. The ether extract was dried with drying agent and filtered to remove the drying agent. The filtrate was concentrated to obtain crude amphetamine as an oil (1.70 g, 72.3%).

Provenance & Evidence