Isomers and tartaric acid

[UWe9o12jkied91d]

here, i made this a while back, the first row describes "my" procedure, i didnt go into detail for D-tartaric acid route because I don't have first hand experience, but using L-tartric in excess as described produces, I think atleast, pretty optically pure product, I don't have a way to prove it yet but the theory checks out, as well as the pharmacology being noticeably better, lower heart rate, no spasm, reduced bruxism.Also the fact that L-tartaric acid(they make the distinction) gets siezed on the regular if you keep up with the literature.It's a case of "trust me bro" but like I said, the theory is solid.

I will put in some work these coming days, working "on the record" with my results and proportions and I might open a thread to show my findings, or post here idk

also excuse the artwork, I am not the best graphic designer

 

[Ihml]

Could a normal paper fillter be used for filltration, or would a borosilicate glass filter need to be used instead? Since amphetamine is a weak base with pH about 11.

 

[Osmosis Vanderwaal]

I know you guys aren't dumping your L- meth when you can do an inversion and make it D- meth. I've seen it done a couple of ways.

 

[G.Patton]

Hi, yes, it can be done via thiols. These compounds extremely bad smell.

 

[Tweaker]

Have either of you performed this?

 

[G.Patton]

No, I've read about this way.

 

[btcboss2022]

Ok I have the results of my tests trying to follow the video method but the similar reagents that I have on hand and that I usually use.
I divided 70gr of racemic freebase(not steam distilled and no acid-base washing made just extracted and dried from the NaBH4 P2P reduction) in 2 equal parts of 35gr each. With the first 35 gr I did video process but with some different reagents and with the other 35gr I did the method that I use to make that is similar to the video process:

- Method 1(Video method)


- 35gr pure freebase
- 42gr L-tartaric
- 205ml Methanol
The amounts are like video ratio but methanol I decided to use a 12% less due ethanol in video is a 88% solution.
I added the acid to the flask later the methanol and finally the freebase.
Once I started stirring immediately happened what usually happened to me in the rest of the processes I have tried for this purpose the solid salts precipitated quickly forming a mass.
I reflux it during one hour, with heating the mass come a thick liquid.
After the refluxing hour I keep it at RT around 4-5 hours until no new solids are visible created in the mixture.
I filtered it and keep in different pots the solid and the liquid part.
-Liquid part
I get cold the liquid part in the freezer with a NaOH solution to avoid excess heat in the alkalinization step.
I added slowly the NaOH solution to the mixture until ph13 and add it to a separation funnel during 30 min.
I take out the aqueous bottom layer and keep it , the thin oil top layer is kept in a pot.
I extract with DCM the aqueous layer and add these DCM extractions to oil layer.
I dried it with anhydrous sodium sulfate and filtered it.
I evaporated the DCM and 10gr of D-meth freebase obtained(don't looks as clean as it should)
- Solid part
I added more or less the same ml of warm water than gr of the solids weight, they has been dissolved it with stirring and let it cool down.
I added slowly the cold NaOH solution until ph13 and add it to a separation funnel during 30 min.
The next steps are exactly the same as the liquid part process.
After DCM is evaporated I got 15gr of L-meth freebase quite "dirty" too

- Method 2(the one I usually do and similar to the video method)


- 35gr pure freebase
- 41,2gr L-tartaric
- 412ml Methanol
Methanol and tartaric are mixed until complete dissolution, freebase is added while stirring and continue stirring vigorously 2-3min.
Let it at RT during 24 hours until the complete solid mass is formed(if in a couple of hours no solids are formed you should stir it again)
It's filtered and now are exactly the same steps as the other method.

- In the liquid part once I had all the DCM extractions I decided to make an acid-base washing, even the DCM color looks cleaner than the other one, to avoid to be "dirty" like the first method happened and I obtained 10gr of D-meth absolutely clean and pure(pic link at the bottom)
- In the solid part 13gr of enough clean L-meth freebase without acid-base washing obtained.
- Cleaning issue could be fixed during the crystallization stage too are many ways.

Obviously is very difficult to check how much D or L are in reality in the stuff only with Chiral analysis not easy accessible.
I also know that it is not the most correct to compare two methods using some different reagents but in reality they do practically the same function in the process.

In short, similar methods and yields the main differences are that in the second one you can avoid the reflux(so could be easier) and the final freebases looks cleaner than the others method.

When I will have free time again like this weekend(unfortunately not usual :-( only will be remaining to test in small scale the"mexican"method for meth isomer separation is quite different and I only did it in big scale although I finally decided to use the method explained for big scale too.
These would be the 3 methods that I did and I can talk about them with experience.

About when and how to make an acid-base washing instead steam distillation...etc etc needs a complete and long post the same for crystallization.

I'm thinking to post all the possible and more profitable options during the route from BMK(5449) to D-Meth HCL but this would be a long work and I don't know when I will have enough time again hahah at least is planned.

Thanks.

 

[Tweaker]

What's the 3rd method? I'm assuming it's much more suited to large scale manufacturing?

 

[btcboss2022]

1 mol tartaric in 200ml of H2O dissolve and add 1 mol of freebase stirring.
Leave it 24H RT.
Filter....

 

[xxxx-8888]

I followed method 2, why doesn't the solid appear?

 

[Acab1312]

I set the methanol/freebase mixture to ph 13, and tried to extract it with toluene, but everything mixed. Because of that, I couldn't separate it. How do you do that, or where is my mistake? Regularly I did it with h2o, quite similar to this method. The only annoying thing is that I have to disconnect 2x to get a high d-isomer and thus get high losses.

 

[Jordan Belfort]

Brother, use hexane.

Hexane layers with methanol and water.
Toluene layers with water but NOT with methanol

https://www.sigmaaldrich.com/MK/en/technical-documents/technical-article/analytical-chemistry/purification/solvent-miscibility-table

 

[Acab1312]

Thank you

 

[Mr Good Cat]

Could someone describe some basic principles of tartaric acid for the newbies, please? Or, might be, there is some popular article about it?

I read some "leaflet" about tartaric acid, and got the impression it reacts separately with one isomer only (LorD) leaving another one intact. Is it wrong?

Of course, I can repeat the steps as described in the "manual" without understanding, but my state of mind always demands to fully understand the topic.

 

[Never to sleep]

Very simple.

To a solution containing your racemic mixture of choice is added L-tartaric acid until no more precipitate forms. The precipitate is the levo isomer.

If that's what you wanted you filter it, the filter cake is your product (a tartrate salt).

If you want the dextro isomer it remains dissolved in the filtrate instead of the filter cake. Then you convert it to the desired salt like for instance a hydrochloride by pumping HCl gas through the solution. There are usually mane stable salts which you can precipitate from the filtrate afterwards. Depends on which one you want.

To note though you can also buy D-tartaric acid but it is more expensive and generally not worth it.

The general idea is that since the acid is either (L-) or (D-) it will always react only with the specific isomer of the two enantiomers.

 

[Mr Good Cat]

We did talk about this R-S confusion here: http://bbzzzsvqcrqtki6umym6itiixfhn...-via-tartaric-acid.81/page-7#xfmg-comment-460
But, probably some precipitated R might be used as well to make a cocktail 2:1

 

[UWe9o12jkied91d]

I don't see why it would be different but okay, would be interesting to know empirically with an EC test.
Its not at all exothermic, esp. in petroleum ether medium.It is not very soluble in pether, best solubility other than water or something impractical is alcohols.

 

[btcboss2022]

No again no please! hahahahahah THE "STRONG" ISOMER(R-D) IN METH WITH L-TARTARIC SOLUTION IS IN THE LIQUID PART NOT SOLID PART! AND FOR MDMA YOU WANT THE SOLID PART INSTEAD THE LIQUID ONE(S-L).
;-)

 

[Jordan Belfort]

If that is the case, you would be able to extract it with hexane or toluene. But you can't

 

[Never to sleep]

Did you even actually try to perform this yourself? You know that there is no way D-methamphetamine tartrate precipitates when you add L-tartaric acid right? The acid which is the L- isomer only reacts with the same isomer of an opposite base. Meaning it is exactly like I said. Your desired D-methamphetamine (the better isomer of the two you would wanna keep) stays dissolved in the freebase which is the liquid filtrate which you can then directly pump with dry HCl gas to obtain the sweet D-methamphetamine hydrochloride salt. Trust me man. This is how it goes... Thank me later once you try out the result.

This truly does seem to confuse the shit out people.

 

[Mr Good Cat]

thanks for correction. I'm not confused with R-S, but still confused with solid and liquid: so a lot of debates about it)) haha

 

[Mr Good Cat]

First time MDMA isomers separation. Full report.

Step 1.
40 gr of FB washed with p.ether obtained.
The color slightly yellowish but good.


Step 2.
20.65 gr of L-tartaric CAS 87-69-4 prepared in 40 ml of water. Molar proportions FB:tartaric 1:08.
FB and tartaric colled in the freezer till 0C.

Step 3.
Tartaric added till PH=2 in 10 minutes with some stirring (100 RPM) and left for the overnight.
Important! Reaction is pretty exotermic!!!
The color got cloudy brown.
Used weight of tartaric = 22 gr, that allows to calculate the weight of reacted FB as 28.34 gr. and point on pretty high percentage of S-iso in original racemic.

Step 4.
As upper FB layer emulgated with lower layer, p.ether was used to separate them in 3 steps 15+10+10 ml. Total volume of FB in upper layer (R-isomer) after evaporation is 9 gr.

Step 5.
FB from lower water layer (S-iso) was extracted with NaOH. FB with cloudy brown color was separated pretty easy. Weight after drying with magnesium, is 40 gr.
Ether washing wasn't applied to this part of FB.


Step 6.
HCl 36% added in volume 14 ml till PH=2, that allows to estimate the weight of reacted FB as 27-29 gr.

Step 7.
MDMA HCl was heated up to 130C and washed in 200 ml of frozen acetone.


Job done!

Interesting fact is the weight of FB separated with step 5 - 40 gr. It is equal with the weight of FB at the beginning (Step 1). At the same time, the volume of HCl used with step 6 сorresponds to weight of reacted FB in 27-29 gr.
Apparently some leftovers and side products of tartaric were mixed with FB during base extraction.

 

[Mr Good Cat]

Small correction on Step 2: Prepared L-tartaric - 24.85 gr.
Used 22 gr.

 

[Mr Good Cat]

S-iso was taken after 24 hours in the freezer.
Final yeld is 29 gr of pinkish powder.
PH = 5


It was dissolved in water 1 gr : 1 ml, and heated up to 108C for re-crystallization.
Second photo at point 106C.


Color is weird. Probably around-2-4% of impurities. Next time I will wash it with ether for better result.

Also remark about PH control in two layers. The sample is taken from lower layer with Pasteur. Then as it taken out, it washed in acetone and dropped on litmus. Nothing difficult.

 

[Never to sleep]

Congrats man!

 

[Mr Good Cat]

28.2 gr yeld after re-crystallization.
PH=8.

 

[Mr Good Cat]

Please disregard this my post.

The result is not correct. It MUST BE reconsidered in accordance the new experience!!!

I will come back with new MDMA isomers separation method in a couple of days.​