mister, Acid4Blood and bogman - thanks for the comments!
I should have qualified what I said in one respect. Whilst the glycidate situation does appear to be the issue, one other possibility is that new catalysts are being utilised in the reductive amination phase of the production which are stereoselective or favour the production of one isomer over the other. Perhaps the use of these catalysts was coincidental to the rise of the glycidate (with catalysts being far more likely to be used by very large laboratories of the kind which seem to be using the new precursor) and the glycidate isn't the problem.
I think the above is less likely but still feasible. Which is why I referred to using "standard" (i.e. the well publicised ones) reductive amination techniques in the post above. Regardless, the use of a new stereoselective catalyst is once again a business decision driven largely by commercial considerations. It still is something which the manufacturers could change if they wanted to.
Frankly, I don't think they are treating the glycidate precursor as the precious commodity that it is, likely due to there being limited restrictions on its availability currently. We know this because they are prepared to pump 200-250mg of MDMA into the pills, which would require twice as much glycidate as a 100-125mg pill containing racemic MDMA powder. See, whilst the glycidate remains readily available and likely quite cheap, it is likely more profitable to use twice as much of this precursor than it is to spend time extracting and purifying the MD-P2P easily made from the glycidate; if this situation changed and suddenly the cost parameters of these two variables were essentially reversed, then perhaps we would see a rapid return to MDMA that seems to be of better quality and where mega dosed pills are few and far between.
Brenner:
That purple in the marquis reaction is unmistakeable. It is certainly how I remembered it to be from most of the pills I tested from 1999 to 2005. The question is what causes this colour change and does it definitely relate to the actual MDMA contained in the pills and not due to some other factor which may have nothing to do with the MDMA at all (e.g. a particular binder which was used in the old days; or the purity of MDMA commonly found in older pills etc).
I have tested sassafras oil with marquis reagent a long, long time ago and it went the characteristic purple colour, albeit very dark, but never becoming black. The link below is to a PDF of a rather dated but still entirely valid manual produced by the UN.
https://www.unodc.org/pdf/publications/st-nar-13-rev1.pdf.
This document confirms that:
(i) MD-P2P turns marquis orange/brown (see page 80), so it cannot account for the purple;
(ii) MDMA turns marquis black (page 45), although this doesn't mean that it wasn't dark purple at first before becoming black; and
(iii) safrole/isosafrole turns marquis deep purple (p89/p78 ), the colour never progressing to black at all.
The question is whether the purple colour is from the marquis reacting to left over safrole/isosafrole or whether (for whatever reason) racemic MDMA goes dark purple first but MDMA that is mainly the R isomer, goes straight to black:
- if it is the former then the "dark purple first" marquis reaction is actually only useful as evidence
supporting but not proving that safrole/isosafrole has been used as a precursor; which as I stated in the earlier post is not a pre-condition for the MDMA to be racemic (although in the present climate this may well be the case).
- if it is the latter then marquis reagent may well be able to distinguish between racemic MDMA and R-MDMA, regardless of the way in which it was manufactured.
Unfortunately, I do not know the answer to this one and I am not sure that anyone necessarily does - unless Shulgin (or someone similar) recorded the results of a marquis test on the various racemic and isometrically pure samples of MDMA that we know he produced a long time ago.