NaOH wash milky pink/purple

I was trying to isomerze CBD to d9 with DCM and AlCl3.

Proproptions use were 1:3 CBD: DCM and 5 percent w/w AlCl3

The procedure was going as expected, after the reaction I washed the product with saturated brine water, citric acid and NaOH. When I added the last reagent I noticed that the DCM solution turned a milky pink/purple color with a soapy/fatty layer between the organic and aqueous phase.

I suspect i have turned some leftovers cbd into cbdq
I’m wondering if i will be able to remove it during distillation

If this is not cause what could it be? And how can one fix this if ifs even fixable?
Thank you

I’ve never done that reaction, and so it’s entirely probable I’m wrong, but is it possible you had some lipids in your cbd?

That part of the wash was expected (lipid payer), the initial was >99,5% pure

Not very familiar with this rxn so dont take this as specific advise or my word as gospel, but it strikes me as odd to have the workup start with brine and end with NaOH. Usually the rationale of a workup is
i) deactivate the reagent (presumably the purpose of the NaOH??)
ii) extract/remove the reagent (presumably the intention of using aqueous washes)
iii) remove anything left from steps (i) and (ii), usually water/salt/acids/bases (in most cases, finishing with a DI water/Brine combination wash…maybe some HCl+Bicarb to remove NaOH, etc)

Sometimes steps (i) and (ii) are a single step, like adding aqueous base (bicarb, sodium hydroxide, etc) to an organic reaction with an acid catalyst (pTSA, HCl) - the base deactivates the acid by turning it into a salt, and the water extracts the salt all in a single step. And then from there you try and remove leftover base/salt/water (step iii) with HCL/Bicarb/Brine. This is a very general example, there’s a lot of nuance I’m glossing over.

Sometimes steps (i) and (ii) are separate because the method of extraction is incompatible (hazardous) with the active form of the reagent. Like if you’re using a reagent that reacts violently with water, but extracts well into water - you might hit it with alcohol/DCM to kill reactivity, and then extract into water in two separate steps. Again, just a general example.

I think you should assess what each step in your workup is supposed to be doing and whether or not its actually achieving its intention, and whether the order of operations makes sense in that context. In your workup, I don’t know if citric acid is even doing anything - and even if it is, I suspect that there are better options.

If your last wash is a strong base, you PROBABLY want some washes after that which remove the strong base. Cannabinoids go purple around bases, sometimes irreversibly. Theres a chance that if you adjusted your final pH back to like 5-7 you’d see that purple go away. But also yes, if you left unreacted CBD in there then you probably have done some damage by hitting it with base - monitor your rxns with HPLC, GC or TLC before quenching.

If I was using NaOH to quench something, I’d follow it with some acid/water to pull out the NaOH, and maybe follow that with bicarb depending on what acid I used, and then follow that with water/brine to get rid of any lingering bicarb/water/salts. DCM is a bitch for aq workups, you may need to swap for the workup.

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Why would one expect there to be “lipids” if your input is >99.5%?!?

That are no lipids.Its an emulsion of cbd / thcd9 and aluminium hydroxide and aluminium oxide.
You wont be able to separate that easy…
Your quench is wrong!

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@Zzzeko23 is right you have quenched the reaction with no option for the aluminium to go to it s now become aluminium hydroxide a very fine poeder gel wich is a bitch to clean up
It will Settle over time so i would recomend set it aside

Either way distilling this oil is gona have it isomerize all to D8 so your goal will not be archieved

I think that between @Zzzeko23 and me

100 kg where trashed before we figured it out
Still have a sour taste of this period

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Ahhh I think you accidentally turned it all into purple heroin.

Better luck next time

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@GreenCalm , I am really not sure you should be doing conversion chemistry.
If you don’t understand purple, you shouldn’t be doing the chemistry. @roguelab , @Zzzeko23 and @eyeworm are trying to be polite.
I’m concerned that you may end up with


Aluminum “phenolate” salts that would test as D9 …you might poison your self and others. (Of course it would be the cannabinol- phenolate).

Dont worry the whole run was disposed of

Schecked my notes doubt it s citrans for they would have showen in Tails more prevalant

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For better or worse this info is fairly common now but the reaction I found to work best after a ton of trials was Anhydrous DCM and powdered dry AlCl3 under nitrogen. 4:1 DCM to CBD, and a tiny AlCl3 of .05% molar equiv of CBD amount. Keep -40C with nitrogen, 15mins to 45mins depending on TLC. Quench with DI water (chromium in tap did strange things) and the more the better, brine, carbonate and pH if needed, Rotovap and distill. NaOH is probably the last thing you want unless you can do the balance calculations precisely (titration curves). Also as a note AlCl3 is pyrophoric so I please handle safely. Aluminum triflate is not air reactive and gets similar purities but not as good as AlCl3.

At -40 you are nowhere near completion of cbd
At -40C it will be near impossible to keep 1 kg dissolved in dcm

You are right that. You made thc but I bet without further steps you cannot keep the 9 and all will turn to 8 upon distilling

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If you have d8 conversion from distilling there is a contaminant as I observed no isomerization due to just heat. We even did -60c to no change but still to completion and no CBD. The key is anhydrous and nitrogen as even the smallest amount of water quenches the catalyst. I had no issues keeping the cannabinoids dissolved even to 2:1.

10000% sure you can not distill keeping the 9

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Does that mean natural extracted and distilled THCD9 is different than the converted? They don’t have isomerization so how are they different? Trace Iso-THCs and Exo aside I had no increase in d8.

I don t want to be rude or Mr know it all

But it s said before this is insufficient cleanup to keep it All in thc-D9

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Can confirm. I wasted so much time and $$ playing with AlCl3. Ran GC throughout process, and had high D9 all the way up to distillation, but after distillation it had all converted to D8. Rogue and I had many conversations about it back in the day. Very frustrating work.

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