MDMA isomers separation - working routes

[Mr Good Cat]

Here I suggest to gather all MDMA isomers separation working method. And first one is I've just finished.

First of all, I don't want to say it is perfect method. I'm also nor sure about final yeld, as I was in a hurry. Probably if I would kept precipitates in the freezer longer, the yeld would be bigger.

So, I had a free day and 77 gr of MDMA HCL, pretty pure, around 92%. It was extracted with NaOH in molar ration 1:1.2 and separated with izohexane cas 107-83-5.

Some isohexane was evaporated briefly but not completely, I intentionally left around 50 gr of izohexane with base. I already did base extraction for this batch, and I knew how much of base I shall get from 77 gr of mdma hcl - I expected 59 gr of base, may be +/-2 gr.
So I evaporated this liquid until total weight was 110 gr.

L-tartaric acid cas 87-69-4 was prepared in molar ratio 1:1 i.e. 54 gr in water 54 ml.

Then I added to base / izohexane liquid 150 ml of acetone and dropped L-tartaric acid.

At this point I got 59 gr of base, 54 gr of water, 54 gr of l-tartaric, 150 ml of acetone in the flask. My idea was:
- izohexane will be mixed with acetone and unreacted base, and got separated as top layer. This is why I left some izohexane with base.
- mdma tartrat will be mixed with acetone and some unreacted base leftovers and some l-tartaric leftovers, and got separated as bottom layer.

I kept it stirring for a while, and soon I got two layers in the flask.

I separated them and evaporated top layer completely just to see what base amount I will get there. I was pretty surprised there was ZERO of base in top layer! Nothing, all evaporated.

Now I had something as mdma tartrate, unreacted base, 54 gr of water, some unreacted l-tartaric, and 120 ml of acetone in the flask. I left lower layer stirred for more time, but nothing precipitated. I left it in the freezer for one hour, but nothing happened. It was strange as I had all objective evidences of insolubles in water acetone compound presence. So the riddle was how to get it precipitated.

Luckily, I thought of adding more acetone to this mixture, in amount 150 ml. As I did it I put it in the freezer, and solids precipitated immediately. As I was in a hurry, I kept it in the freezer for 2 hours only, and this might be my mistake, but not sure.

I filtered it on bunzen, and got huge volume of dense porridge in buchner. The volume, that reffers to something as 120-150 gr of mdma chloride. That was also strange. I also noticed this porridge was barely permeable to air while filtered.

So I washed this porridge with frozen acetone right in buchner and slowly dissolved part of porridge. I repeated this washing again and again till constant volume in buchner. It took for me 750 ml of frozen acetone.

Here is an important remark: the liquid containing water, acetone, unreacted base and tartaric leftovers separated right in bunzen in two layers.


As solids were dried, the yeld of mdma tartrate was 38 gr. I guess, some mdma tartrate was washed out with acetone or didn't precipitated.


I dissolved mdma tartrate in water. But it took 160 ml of water to dissolve it completely. So mdma tartrate is much less soluble in water if compare with mdma hcl.

I extracted them with NaOH in molar ratio 1:1.4, but was surprised with PH=11 only. So I added some more NaOH, probably in final molar ration 1:2. And got base but not on the top - in bottom layer. I separated base easily, evaporated solvent and got 20 gr of S-izomer base.


Other liquid layer from bunzen was also evaporated, and here I got 38 gr of R-izomer base, slightly pinkish.


The question is where I lost 10 gr of base, but this lost is OK for first attempt.

Briefly, I can conclude, this method of isomers separation works well, but not necessary to leave izohexane with base, and acetone shall be much more. At least 270 ml per 60 gr of base.

I have strong feeling: for some reason mdma tartrate, tartaric leftovers and unreacted base are bonded in a kind of compound (similar with emulsion), that doesn't allow solids to precipitate. I also think this is the only reason I got a fault here: http://bbzzzsvqcrqtki6umym6itiixfhn...via-tartaric-acid.81/page-12#xfmg-comment-689

 

[Mr Good Cat]

Sorry, not 38 gr, but 28 gr of R-isomer base.

 

[Mr Good Cat]

Also a note. As I dried powder completely, I found several (luckily just a few) lumps smalll size 2-3 mm in the powder that were not crumbly like powder, but rather rubbery, like lumps of powder glued together with some kind of glue.

 

[Mr Good Cat]

Obvious problems of this method!!!​

I acidify S-freebase with 36% HCl till PH=2, in frozen acetone on the ice bath. Normally, I keep it in the freezer for 72 hours, and get around 90-95% yeld of expected. Then, if I keep leftovers in the freezer more, I get more crystals as well.

But, in this case I kept solution in the freezer for 96 hours, and got yeld less than 75%!!!
I.e., base weight 20 gr, expected S-MDMA HCL weight - 24 gr. Yeld S-MDMA HCL - 16.5 gr only.

Rest of leftovers were thrown in crystallizer and kept on the hotplate with surface T=56c for a while till constant weight 7 gr. Crystallizer was taken out from hotplate and kept at RT. And these leftovers aren't similar with regular MDMA HCL leftover. They are rather a kind of rubber or resin, very sticky. It took around 5-6 hours to keep them in the crystallizer regularly pushing and pressing them at RT till I got a kind of powder that is possible to crush in mortar.

Weight was checked at this point - 6 gr. It means 1.5 gr of expected weight was lost. It is possible for such small amount in ilter, bunzen and buchner, so OK.

But more important: it took 5-6 hours to get this compound of 6 gr of S-MDMA HCL and 1 gr of water/acetone leftovers more or less dry. It points on the explanation: MDMA isomers are bonded together with water/acetone in some compound with viscosity of stickness different if compare with racemic mixture. This viscosity looks very similar with those I saw as was washing S-MDMA tartrate.

I also think, this sticky compound is based on water - not acetone, as acetone washes S-MDMA HCL pretty well, but you need a lot of acetone, much more than usually.

So, this method is not perfect, but it may point a right direction.

 

[Jordan Belfort]

The reason why you don't have 50/50 yield of s isomer is becuase minor racimisation already occurs in the reaction when making the base

 

[Mr Good Cat]

No, I'm not about 50/50 isomers. I mean: I got 20 gr of "S" base and 28 gr of "R" base against 58-60 gr of racemic base. 10 gr of base lost.

 

[Mr Good Cat]

I guess, considering this experience, isomers separation must be done completely without water. It is possible to do in puure acetone. MDMA FB is well soluble in acetone. At the same time, L-tartaric also soluble in acetone in proportions 14.6 gr of acetone per 1.0 gr of L-tartaric at RT. And little more, around 12 gr of acetone per 1.0 gr of L-tartaric at T-12c.

Will try and report on occasion.

 

[Mr Good Cat]

I did try to recrystallize isomers from both S and R leftovers in water as oversaturated solutions to get "big" crystals - hahaha.. Fucking jewellery work considering small amounts of samples.
Here you can see a crystal of S isomer after crystallization for example.


Same after washing in acetone. I washed it in a beaker. Crystals aren't strong and easily broken completely different from those, I get from racemic.


It's fucking funny but expectable: as I drained acetone out and took crystals out, on the the bottom of beaker I got the same colloid sticky substance. This is how it looks as as scratched it out with spatula.


The same issue, but little less about opposite "R".