SWIA-C has got to be careful , all reports in the past approached from the point of view that it all was the same reaction.
However depending upon the environment I /RP /E /water seem to be able to take a variety of paths , all of them going on at once but with some mechanisms predominating in different enviromnments at different times Phosphorous behaving strangely at different temperatures, Iodine never sure if it wants to be a metal, or a salt or just evaporate into thin air , only to show up somewhere else red again
So, if we consider the steric effect, we could say that a SN2 would be not favoured in the formation of iodomethamphetamine.
hmmm a very good point, SwiW always wondered how the I- could get in so close to the Alpha carbon. SwiA-C answer is , general it won't
Water, HI, hypo or phosphorous acids, polar medium anyway, even if we use RP. For these reasons I think SN1 way is more probable.
hmmm this would lead one to think that the Sn2 mechanism is a hold over from earlier liturature and SwiA-C is right again,
The splitting of I2 into 2I- in the presence of P4 is a farce without a source of easy to get protons, supplied by water or an acid.
But the SN1 reaction is initiated with a simple acids addition of H+ and not a redox reaction.
Obviously in acidic water and low temperature elimination is not favoured and substitution should be the main reaction.
Your logic is outstanding, makes ,much sense,
SwiW called the cold reaction "Cold Lazy Arse method"
SwiW knows that when they used a 1 hour cook, it always would get a bitterness, when vaporized in a glass tube, that requiires re-crystalization to remove, With the Cold Lazy Arse method, under 110F SwiW has not had to recrystaslize , since it was not bitter. The bitterness was present in samples taken before the Cold L A method had finished, Indicating that some chemical has not finished cooking, the obviouis choice would be epherdrine, but E has a distinktive taste anmd it must be that Ephedrine and pseudoephedrine have different taste and reaction rates.. In fact they are seeming to be much less similar than we have been led to believe. It is no wonder extractions are harder, they add things that will block one or both from being extracted , complicating a once simple process. .
Swi-Us may have to extract ephedrine ,then go back and extract pseudo with different conditions.
formation of Ephedrine from pseudo would be apparent in much higher yelds 20-25% improved , but AwiW has not done enough to yet be certain what is going on there. It is possible and it may prove out in the end, somewhere near the 48 hour point.
Unfortunately, precursors are becoming scarce and another approach may need to replace this.
Thanks for your insight, It has cleared up much and has left SwiW with a new set of problems, Always gaining ground, the playing field keeps changing.