Author Topic: Column Purification of DMT  (Read 3588 times)

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heavenadisaster

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Column Purification of DMT
« on: April 03, 2004, 07:19:00 PM »

Lilienthal

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Some general remarks on dialkylated ...
« Reply #1 on: April 04, 2004, 04:17:00 AM »
Some general remarks on dialkylated tryptamines:


The phrase “gradient of ethyl acetate:methanol” I interpret to mean starting with the less polar pure methanol and slowly increasing the ratio of ethyl acetate added, finishing with pure ethyl acetate. Is this correct?


No, gradient must less polar to polar, MeOH is way more polar than ethyl acetate.


looking for a spot with a smaller Rf than that of the starting tryptamine,



No it must be of a higher Rf, tryptamine is way more polar than dialkylated tryptamines


Far less important, does the PDMAB work through forming a highly conjugated imine with the tryptamine?


No, it's an indole-2 (or indole-3 if free) aromatic substitution.


Has anyone ever characterized the formed colored products?


Not as far as I know. But one main degradation product is skatole (3-methyl-indole), it gives tryptamines the characteristic fecal smell. It is of low polarity = high Rf.


kurupira

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detail it!
« Reply #2 on: April 04, 2004, 06:23:00 AM »

heavenadisaster

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very helpful
« Reply #3 on: April 04, 2004, 09:48:00 PM »
Post Rater, What I meant by “I plan to,” is “If one were to.”

Lili, thank you for the corrections—I made the embarrassing mistake of thinking that ethyl acetate was more polar than methanol and that tertiary amine was more polar than primary.  If this impurity redness is on account of the skatole, then it would be expected for the DMT to come out after the skatole(orange/red spot), but before the tryptamine, correct?  How confident of this should one be; would it be a mistake to not start collecting fractions until the colored band clears the column?

Kurupira, I also appreciate how valuable this technique is for extractions of the natural product.  It seems very difficult to obtain crystals from a raw a/b extraction.

The hydrochloride salt will crystallize regardless of impurity.  If one were to botch this chromatography, gassing the oil dissolved in ether would be a good way to store the mixture before next attempt, right?  Is there advantages to other salts(tartarate, oxalate, fumarate) that people speak of?  Do they crystallize easier or are they gentler on the 2-position?

Would a small amount of charcoal be helpful for initial purification?

Does anyone have anything to say about vacuum distillation instead of the column?  Is decomposition an issue?

Lilienthal

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Skatole is colorless.
« Reply #4 on: April 05, 2004, 02:00:00 AM »
Skatole is colorless. As posted earlier: oxalates or fumarates are used for a reason! Vacuum distillation is a good step in purifying lower dialkyltryptamines, but recrystallization seems to be essential to get rid of some impurities (e.g. skatole). As long as you haven't done a specific column chromatography several times you have to take fractions from the front on and test them by TLC. You can the combine the fractions (and free the test tubes) if there is nothing in it.

kurupira

  • Guest
Sure it will improve the process of btaining a
« Reply #5 on: April 05, 2004, 11:02:00 AM »
Sure it will improve the process of obtaining a pure extracted natural product!

also look here:

"N,N-dimethyl tryptamine 2a

1 g of alpha-chloromethyl-gramine HCl is added to a suspension of 2,5 g of NaBH4 in 75 mL of diglyme at 55°C with stirring. The slurry is warmed to 85-90°C and is kept at that temperature for 48h. The yellow coloration has disappeared. After 24h the mixture is cooled and poured on some ice. This is extracted with ethyl acetate and then the solvent is removed. The remaining oil has got a scatole stench and the TLC show two spot with Rf equal respectively to authentic sample of scatole and of DMT. These two products are separated by column chromatography (silice-celite 1/1). The scatole is eluted first with benzene and is identified by its mp and its picrate salt. The DMT is eluted with methanol (270 mg, 37%). After one recrystalisation with hexane, the product melt at 45°C, this mp is inchanged when authentic sample is mixed with it. The DMT is confirmed by its picrate salt, mp 166°C, and by its UV and IR spectra."

it's from:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/dmt.chloromethylgramine.html




heavenadisaster

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skatole picrate?
« Reply #6 on: April 08, 2004, 08:21:00 PM »
"The scatole is eluted first with benzene and is identified by its mp and its picrate salt."

kurupira, how can the skatole form a picrate salt?  Is the indole nitrogen protonated loosing the aromaticity?

Lilienthal

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Picrate 'salts' are not real salts, they just...
« Reply #7 on: April 09, 2004, 01:22:00 AM »
Picrate 'salts' are not real salts, they just form charge-transfer complexes by pi-stacking interactions (as in the DNA).

The suggestion to run a TLC in parallel in an acidic and a basic eluent is only meant as a procedure to identify the product spot which should have varying Rf values between both plates (the ammonium acetate has a much higher polarity (lower Rf) than the free base.

It is usually better to use an open vial with conc. aqueous ammonia in the elution chamber instead of adding triethylamine. TEA gives a front and might result in artifacts. nAdding this base is essential to prevent streakes and smeared spots.