(1S,2S)-1-Methylamino-1-phenyl-2-chloropropane: Route specific marker impurity of methamphetamine synthesized from ephedrine via chloroephedrine

Identification of route specific marker impurities of (S)-(+)-methamphetamine can provide us with very useful information for (S)-(+)-methamphetamine abuse criminal investigation. (1S,2S)-(+)-Chloropseudoephedrine and (1R,2S)-(-)-chloroephedrine are well known impurities of (S)-(+)-methamphetamine synthesized by metal catalyzed hydrogenation of (1R,2S)-(-)-ephedrine or (1S,2S)-(+)-pseudoephedrine. In this report (1S,2S)-1-methylamino-1-phenyl-2-chloropropane is identified as a route specific marker impurity from metal catalyzed hydrogenation method for the synthesis of (1R,2S)-(-)-ephedrine or (1S,2S)-(+)-pseudoephedrine via its chloro-derivative. (1S,2S)-1-Methylamino-1-phenyl-2-chloropropane is a ring-opening compound of cis-1,2-dimethyl-3-phenylaziridine by reacting with HCl in high temperature condition of GC inlet.