High specific activity (+)-amphetamine and (+)-methamphetamine

High specific activity (+)-amphetamine and (+)-methamphetamine were prepared by reductive dechlorination of (S)-(3',5'-dichlorophenyl)-2-propylazide and (S)-2'6'-dichloromethamphetamine, respectively. While the latter was readily obtained by resolution of racemic 2'6'-dichloromethamphetamine using (+)-dibenzoyltartaric acid, the analogous amphetamine resisted all efforts to resolve it. Hence, the required chiral precursor was prepared by stereospecific total synthesis following methodology that had been previously developed in our Laboratories. The tritium labeled compounds had specific activity 30.1 Ci/mmol and 38.3 Ci/mmol, respectively.