Question LPAC to P2P?

[Blammo]

Is there any facile ways to do this? I may be able to access LPAC somewhat easily, but not any of the traditional methods for ephedrine. So I'm seeing if it can be converted into P2P

 

[G.Patton]

I think this way is better. By the way, I haven't seen L-PAC => P2P.

https://bbgate.com/threads/l-ephedrine-synthesis-from-l-phenylacetylcarbinol-l-pac.1342/

 

[handle]

Reductive Amination of L-PAC to form ephedrine/pseudoephedrine.
L-PAC + methylamine (CH₃NH₂) in the presence of a reducing agent (e.g., NaBH₄, H₂/Pd, or catalytic hydrogenation)
=Racemix of ephedrine/pseudoephedrine, Therefore no need for P2P.

 

[Blammo]

As I stated in the prompt, getting things for ephedrine I harder for me than getting the things for p2p reduction. So that's why i'm asking, as one way is more accessible to me.

 

[handle]

The P2P route is mainly used when ephedrine is unavailable, but if you already have ephedrine, the direct reduction method is faster and simpler.

 

[Blammo]

I can get access to lpac, not ephedrine, and the reagents for the reduction of ephedrine are harder to get for me than the ones for p2p

 

[handle]

I think 2 ROUNDS of Al/Hg Amalgam + Methylamine might work.
L-PAC + CH₃NH₂ + [H] → Ephedrine
Ephedrine + CH₃NH₂ + [H]→ Methamphetamine
bit slower and Mercury can be abit toxic at times.
better to try get some Sodium cyanoborohydride as this does not attack the alchol group (-OH) on the LPAC.
Use NaBH₃CN or Al/Hg + methylamine instead.