[jimmysandwiches]

Could someone draw out the mechanism for the reaction between ephedrine, hydroiodic acid and red phosphorus.

I found this on the net, but i cant draw the mechanism for it

In the Nagai method, the β-hydroxyl group on ephedrine or pseudoephedrine is protonated forming a hydronium ion leaving group. A nucleophilic substitution reaction then occurs with an iodide anion. Water is lost to give iodoephedrine, which then undergoes reductive dehalogenation by liberated H2 producing methamphetamine [4]. The mechanism of the “emede method”, a previously popular clandestine procedure, is equivalent; however, in this case it is performed in two separate reactions, isolating the ephedrine halide, usually Bromo- or Chloro-ephedrine, and then reducing it to methamphetamine.

[Dan]

No drug synthesis, read the rules.