MOTIVATION

I really hate evaporating solvents as well as lengthy pipetting that never removes all the solvent. On the other hand, I like working with lab glassware. This tek is more suitable for amateur (basement) chemists than kitchen alchemists because of more equipment is needed, but I hope it will be of some interest. Also I just like to share how I do it.

I started using separatory funnel and a distillation apparatus for A/B extraction of DMT. This works great as one is able to remove the solvent layer very precisely, combine the pulls and cleanly distill off the solvent (thus recycling it). The reduced solvent is then poured into a Pyrex dish and left to cool as with traditional freeze-precipitation schemes.

Now one more improvement came to my mind. Why not use DCM as a solvent? First, it forms a bottom layer and thus the pulls can be quickly taken from the separatory funnel while keeping the mother liquor inside the whole time. Second, it has a low boiling point allowing for easy distillation with just a hot water bath.

DCM does not allow freeze precipitation (AFAIK) but we can use small amount of naphtha for this while removing all the DCM.


THE TEK

NOTE: When water is mentioned, it is filtered or distilled.

Grind 250 g MHRB in a cofee grinder, add to a pressure cooker, cover with 1 600 ml of water.
(optional) You can also break down the bark further by covering it with 600 ml water in a Tupperware dish, mix intimately with a fork, then freeze and thaw it 1-3 times. Finally, add everyting to a pressure cooker with additional 1 000 ml water to top it up to the final 1 600 ml.
Pressure cook for 20-30 minutes.
Filter the liquid through a coarse and then fine sieve to separate the solids (bark). Keep extraction liquid in one large enough pot (more will be added) and return the bark to a pressure cooker.
Cover the back with 1 500 ml water, boil (now without a lid) for 20-30 minutes.
Repeat filtering and boiling once more, combine all the water extractions in one pot.
(optional) Transfer the bark to a cheesecloth and squeeze out any remaining liquid.
(optional) The bark in a cheesecloth can be soaked in warm/hot water and squeezed again to remove any trapped actives.
Let the soup sit overnight.
Decant as much clear supernatant liquid as possible to a separate pot, transfer the rest in a cheesecloth and squeeze out any remaining liquid.
(optional) The bark in a cheesecloth can be soaked in warm/hot water and squeezed again to remove any trapped actives.
Reduce the liquid by boiling it down to approx 1 200 - 1 500 ml.
While still hot, add approx. 100-120 g of sodium chloride (non-iodized table salt).
Let the soup cool down a bit.
(optional) De-fatting: Transfer the liquid to a 2 000 ml separatory funnel and extract four times with 50 ml DCM. Discard the DCM.
Transfer the soup to a 2 000 ml beaker.
Add approx. 100 ml of 50% sodium hydroxide solution while stirring.
Heat up the soup to 45 °C.
Transfer the now warm/hot soup to a 2 000 ml separatory funnel.
Extract four times with 50 ml DCM. Combine the DCM pulls. Discard the soup (prefferably neutralize the soup first with acid, boil off any remaining DCM, then let it cool down and only then pour it down the drain).
(optional) You can wash the DCM with slightly basic water or brine in a 250 ml separatory funnel. I use 1% ammonia solution with some salt in it.
To a 500 ml round bottom flask equipped with a stirrer, add the combined DCM pulls, add 40 ml naphtha.
Set up a simple distillation apparatus with hot water bath and an ice bath.
While stirring, heat up the water to 60-80 °C (temperature should be high enough so the DCM will boil off, not too vigorously, but low enough so it's safely below the boiling point of naphtha).
When no further boiling is observed, stop the distillation, remove the boiling flask and pour the naphtha into a Pyrex dish.
Seal the dish and let it stand few hours at room temperature, then few hours in the fridge and finally 12+ hours in the freezer.
Pour off the naphtha, dry the crystals with fan while keeping the dish upside down for 20-30 minutes.
Scrape the crystals.
(optional) Wash the crystals with small amount of 1% ammonia solution.
Crush the crystals (if possible) and further air-dry or vacuum-dry them to remove any trapped naphtha or DCM.


NOTES

I have not determined the best amount of naphtha but that depends on how rich the bark is. Ideally, one can start with small amount (say 20-30 ml) and if the solution is cloudy or shows precipitation, even at 80° C, add small amounts of naphtha until everything is dissolved. The goal is to make a supersaturated solution. This will readily crystallize upon cooling.

The DCM and naphta will end up cross-contaminated to a small extent and may need to be further purified if intended to be used separately.

I am not sure about the solvent washing with basic brine (e.g. 1% ammonia). When doing mescaline extraction, this washing seems to help picking up some discoloration.


EXPERIMENTAL

To be added later.

Have you carried out this procedure yet?

Just a heads up,

I've observed the complete destruction of decent amount of dmt by the use of dcm.
Dcm alkylates dmt to give the alphachloromethyl quaternary ammonium salt. A compound that is likely to be reactive in itself and lead to further degradation products.
This reaction is known in the literature, and has been posted on the nexus before. Happy to dig the reference up for you if you like.

My advice to you would be the following;
Only have dmt in contact with dcm for the shortest amount of time possible.
Do not heat a solution of dmt in dcm, you will speed up this unwanted reaction.

After my observations, I decided that I would never use dcm with dmt, despite, as you point out, it being a convenient solvent.

Hope that helps.

This is true, avoid longterm exposure of DMT and DCM and avoid applying heat.

I still use it for extraction, the reaction takes at least a day for the alkylated product to show up in mass spec. So the reaction is very slow.

Either way, it can potentially contaminate your product as well.

What you can do instead is instead of freeze precipitating, salt out the fumarate salt with FASA instead. You can dilute the DCM with naphtha and acetone to help precipitate, but you should concentrate it down first, since pure DCM can dissolve salts pretty easily.

Then I always recrystallize the fumarate salt with boiling IPA, which would remove any traces of that. I've never witnessed any of the chloromethyl product in even the crude by proton NMR, which is good to about 99.9%

If you don't have the ability to quickly strip DCM by use of rotovap, just use toluene. Its a great solvent for DMT extraction, and you can FASA out of it directly, and then reuse it dozens of times no problem. DCM will evaporate too quickly, so in my opinion, for the home extraction its not the ideal solvent nor is it environmentally sustainable.

Thanks for all the advice. I didn't know about the DCM reacting with DMT.

As for the distillation, I can also apply farily strong vacuum (-690 mmHg). This might lower the b.p. of naphtha enough so that distilling it off won't hurt DMT.

Stripping off DCM under vacuum is possible but I don't have a rotavap, only the distillation apparatus. I at first thought about removing all DCM from the boiling flask, then adding naphtha, but I was afraid the intermediate product will be a sticky paste (trapping some DCM in it) that refuses to dissolve in naphtha.

Another option is to use hexane instead of naphtha as it has lower boiling point at atmospheric pressure and not being so volatile as DCM (?).

Yes toluene is also an option. I never tried FASA with that. I only did FASA on already extracted DMT. I am afraid FASA will lower the yield plus adding more steps to the procedure (freebasing). But it seems to shorten the time of the whole procedure too.

So here are the possible alternate procedures as far as I understand:

PROCEDURE 1: extract with toluene, FASA, filter, dry, convert to freebase

PROCEDURE 2: extract with hexane/heptane/naphtha, distill off the solvent under vacuum until cloudy, heat up (to redissolve the product), freeze-precipitate

PROCEDURE 3: extract with DCM, distill off all the solvent (possibly under vacuum), redissolve product in a small amount of naphtha, freeze-precipitate

PROCEDURE 4: extract with DCM, distill off all the solvent (possibly under vacuum), redissolve product in a small amount of acetone/toluene, FASA, filter, dry, convert to freebase

So now the no. 2 seems most viable to me. I like no. 3 too but only as long as there won't be traces of DCM in the product.

Note that I always vacuum dry the powdered product in a dessicator, so the solvent should not be there in the end anyway.

I plan to get a rotavap as I love plant extractions in general as well as simple organic syntheses that involve extractions. But it's an expensive item and I am saving for it... hopefully some day...

removing DCM by vacuum over simple distillation is problematic, vapor pressure of dcm is high so pulling a strong vacuum on it without fast rotation (magnetic stirring is not enough) will cause it to violently bump and pull all of the DMT solution into the condenser and receiver flask.

It's also not good for the pump to pull that much solvent vapor through, since under vacuum, the DCM won't condense at all in the condenser. If you have a good vacuum regulator, you could do it, but a simple T valve is not good enough.

Yes bumping is a big concern here although I can equip the flask with an anti-bumping adapter (still some product could end there and make it messy). The pump has a smooth pressure regulator (it is the PTFE-coated lab diaphragm pump for exactly these uses).

But I will stick with other solvents as there are already too many issues with DCM. The only advantage is the bottom-layer forming (quicker pulling, less risk of spillage from pouring aqueous layer back to funnel, less smell).

Just putting the following up for completeness sake. From brandt's 2008 paper;

"Synthesis of N-chloromethyl-DMT chloride 2
DMT (1.1 mmol) was dissolved in DCM at 10 mg/ml. This solution was left sealed and stored at ambient temperatures for 4 days until precipitation of the product was complete. The crys- talline white needles were filtered, washed with the solvent and dried under vacuum over P2 O5 . Data for N-chloromethyl-DMT chloride 2 (189 mg, 0.69 mmol, 63%)"

My personal observation involved heat, prolonged exposure and no rotavap. The result: 2.5g transformed into tar. Very sad.

So I tried hexane but it failed. My yield was about 0.5% of dirty crystals while with naphtha it's about 0.9-1.1% of white fluffy crystals.

After distilling off most of the hexane, I poured it to the Pyrex dish and the crysals crashed out immediately. Next day I poured off hexane and to my suprise, there was very little of it (it was several times more when poured):



The crystals are very tiny and brown:



Final yield of 0.5%



One hypothesis is that hexane is bad solvent for DMT. Another is that is volatilizes DMT and distills it off like in steam distillation.

Yet another is that my solvent washing step (washing with 1% ammonia with salt) removes lots of product in case of hexane is used.

So in the end I will probably stick with naphtha or heptane and distill it off under vacuum. Hexane seems to be too volatile.