Imine is the name of the functional group. The compound is named xxxx-xxxx-imine. Same principle like with the amines.
If Adams catalyst, platinium oxide or a similar Pt/C catalyst in acidic conditions is used, then the imine comes first followed by the hydroxy group on the alpha carbon and next to come would be the aromatic ring itself.
The reduction of the imine and the hydroxy group "overlapp", the ringreduction needs more rigid conditions. To avoid ringreduction the amount of hydrogen taken up can be measured and the reaction terminated in time. Or it can be done CTH style.
But this requires quite sophisticated equipment and catalysts and very clean starting compounds.
If Al/Hg or Zn/Hg or Zn/HCl is used ringreduction wont be a problem AFAIK, but I doubt that the OH-group will be reduced like the imine, say you will have a mixture of meth and ephedrine.
As in a plain reductive alkylation with Al/Hg and methylamine the raw extract from the biosynth can be used with very good yields it is IMHO better to do this in two steps. First l-PAC to ephedrine (or by using rougher conditions to a mixture of meth and ephedrine) followed by one of the wellknown reactions to convert this to meth exclusivly. d-meth of course.
It should be not forgotten that the recrystallized product of the alkylation is un-gakked ephedrine which is not to compare to the pfed extracts from pills. Whoever remembers the old days will back this up.
Somebody who masters the biosynth and red. alkylation for sure will be able to produce HI without phosphorus and to recover the iodine after the reaction for reuse.
If one is able to produce l-PAC but finally lost his nerves on this (pseudo)ephedrine reduction thingie, like I did, he might take a look into Bandils most famous writeups and realize that l-PAC can be converted to norephedrine the same as it is converted to ephedrine.
But first: LEARN TO MAKE BENZALDEHYDE FROM OTC COMPOUNDS BEFORE TALKING ABOUT SHORTCUTS FOR l-PAC TO METH!
got this?
