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karlos³
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I am at the moment refluxing 8,4g L-tryptophane in 50ml of Propiophenone.
I hope propiophenone is also sterically hindered enough to work good and fast like Acetophenone.
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HollowMan
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Decarboxylation of L-Tryptophan in DMF
Hi,
i wanted to ask, if anyone tried this interesting decarboxylation method of tryptophan. It should work pretty fast and even with good results and
without catalyst.
When I tried the decarboxylation on my own I used about twice the amount of DMF (75ml) to get everything solved easier. Does it matter?
After refluxing until starting the destillation of DMF the color of the DMF solution changed pretty fast (from yellow - orange to a darker orange).
Until destillation the argon flow was guaranteed and the DMF was removed under reduced pressure (at about 45°C).
When the DMF was removed a more red then orange colored residue was obtained in the flask i refluxed before.
I tried the same cleaning up procedure until I got a dark yellow colored oil. I just used NaHCO3 instead of NH4HCO3.
This oil did´t start to crystallize even after days in the refrigerator or freezer..
So I was thinking about how stable the tryptamine freebase will be?
Thanks in advance for any advices.
PS: thats the link:
https://www.thevespiary.org/talk/index.php?topic=13090.0;now...
[Edited on 18-9-2015 by HollowMan]
[Edited on 18-9-2015 by HollowMan]
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Tsjerk
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Hello HollowMan,
How sure are you of the purity of your tryptophan? And could't it be that the person describing the reaction in your reference had a (ketone?)
contamination in his? Do you have any more references to decarboxylation in DMF?
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HollowMan
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Hi Tsjerk,
my tryptophan was food grade so I think it should be fine. After reaktion you could definitly notice a "indol smell" so I´m pretty sure about that it
works.
If you read the instructions carefully, you will notice, that he already tried it with ketones as catalyst but always with lower yield as with DMF
alone. So DMF is a keton too, i think it catalyses itself like acetophenon.
In my previous link, there are some reviews of people , who tried the procedure as described with good yields.
I just found this too: http://forum.lambdasyn.org/index.php/topic,747.0.html (I can also understand what it is about).
Anyway for me it sounds like a very interesting method without having to deal with catalysts ( with low boiling points mostly) and really low reaction
times. Could be great to make it work as described .
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Tsjerk
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First off all, I never wanted to offend you, second, I did read the instructions carefully. DMF is not a keton by the way.
What do you exactly mean by "food grade"? Is it good enough for consumption and sold as a supplement, or does it state for example 99%+ or something?
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Nicodem
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Threads Merged
19-9-2015 at 04:21 |
Nicodem
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Why would anybody try an experiment that was proven to be either a misinterpreted failure or a hoax? If you read the second part, he describes a
reductive amination of formaldehyde with calcium hydride! Why would someone trust a person like that? Or someone who believes the chemical
symbol for chlorine is "CL"? Or someone who does not bother properly isolating the supposed amine products?
Besides, refluxing DMF formylates amines, so even if some tryptamine formed, a considerable part, if not all, would be consumed in the reaction with
the solvent.
I really don't understand why people insist on trying out all kind of exotic modifications to this simple reaction. This forum is full of reports of
people doing the decarboxylation of trypotophan wrongly, either under improper conditions, like using too much catalyst under too long reaction times,
or messing up the isolation by forgetting to first hydrolyze the imine, or any other stupid modification of the many established methods. You can find
so many nicely working protocols in the literature, or at the Hyperlab, or even on this forum. There is no excuse about nonavailability of solvents as
the reaction works with anything from refluxing xylene (bp of only 140 °C!), tetraline or diphenyl ether, with nearly any ketone as a catalyst, or
even without it at higher temperatures (>200 °C).
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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HollowMan
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Hi,
Of course DMF is no keton but it has the same functional group. Thas what i meant.
Of course everything else of this introduction sounds really suspicions but I was just interested in the decarboxylation and the short reaction time
sounds interesting to me.
So Nicodem, are you sure about the formylation if the tryptamine?
I also wanted to try this method, because I have the DMF and because of the reaktion time.
I can also get the xylene but how about the reaction times with what kind of ketones?
Is petroleum (c10-C13 alkanes) also possible?
I have no idea where to find tetraline, diphenylether.
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HollowMan
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I wanted to add, that my tryptophan was sold as a supplement (bulk powders).
Most of the introduction (the purification) from my link (the vespiary) is pretty much similar to other introductions (the residue in the flask
dissolves completely in DCM/wash with NaHCO3 etc)
That why I thought that this method is just copied from some other who knows what he did.
[Edited on 19-9-2015 by HollowMan]
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Nicodem
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DMF has a carbonyl group, but it is an amide carbonyl, not a ketone carbonyl. Very different and it does not form ketimines.
| Quote: | | So Nicodem, are you sure about the formylation if the tryptamine? |
See DOI: 10.1055/s-1973-22217. The formylation of primary amines in refluxing DMF is a rather slow reaction (generally >24 h for complete
conversion). However, it is catalyzed by CO2 and acids / ammonium salts (e.g., things like tryptophan). A catalyzed formylation with DMF
can be very fast (e.g., <1 h).
Personally, I believe it would be a great achievement if tryptophan could be decarboxylated directly to N-formyltryptamine by something as simple as
refluxing in DMF (or any other amino acid to the corresponding N-formyl-descarboxy product) . Such a discovery from an amateur chemist would certainly
make for a nice prepublication.
| Quote: | | I also wanted to try this method, because I have the DMF and because of the reaktion time. |
Do you want short reaction times? Use proper condition, like reflux in acetophenone. Do you want a reliable and clean reaction and have enough
patience to wait for an overnight reflux? Use xylene, cumene, cymene, etc., with some ketone catalyst.
What is the obsession with the reaction time anyway? If you have the time to wait for replies on an internet forum, how come you can't give some time
to a reaction? Besides, even if the reaction time is 15 min, the isolation can take a day or more.
| Quote: | | I can also get the xylene but how about the reaction times with what kind of ketones? |
This has been described so many times, on this forum and elsewhere. How about reading the posts?
| Quote: | | Is petroleum (c10-C13 alkanes) also possible? |
I would not bother, given the number of proven alternatives, because the solubility of tryptophan in alkanes is about zero. Though according to posts
on Hyperlab turpentine does work when a small amount of DMSO as a cosolvent is added and using caraway oil as the catalyst. Likely, high boiling
petroluem ether (paraffin oil) with DMSO could work similarly well, but turpentine is easy to buy. So is the related solvent limonene which is now
being pushed as a "natural paint thinner".
| Quote: | | I have no idea where to find tetraline, diphenylether. |
You can always just buy them.
[Edited on 19/9/2015 by Nicodem]
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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HollowMan
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Hm ok alright so it´s not sure what will happend during refilxing in DMF.. I don´t have the possibility yet to check the final product. Maybe it´s
easier directly to start with for example xylene. I already read some posts but I didn´t got something what works for sure.
lets talk about this one you definitely know:
http://www.sciencemadness.org/talk/viewthread.php?tid=31306
3.0 g tryptophan in 100 mL xylenes (o, m, p) with M.E.K. catalyst (5 mL): Evolution of CO2 tapered by the 5th hour in reflux, extraction gave 85%
yield.
Thats a lot of catalyst I guess in comparison to this one from erowid:
Ketone-catalyzed decarboxylation, as described by Drone #342:
Decarboxylation is accomplished by mixing about 80 g tryptophan in 250 mL of high-boiling solvent (xylene, DMSO, cyclohexanol, etc.), adding a dash of
a ketone (I like 5 g of cyclohexanone, but a couple grams of MEK works reasonably well), heat it to around 150 deg, and when evolution of CO2
ceases/solution is clear, the reaction is complete. This takes anywhere from 1.5 to 4 hours. After this is over, the solvent is boiled off (or at
least greatly reduced in volume), and the residue is dissolved in DCM. This is washed with a 5% NaHCO3 solution, then a distilled water solution, then
the DCM layer is separated off, dried with MgSO4, and the DCM is boiled off. You now have reasonably pure tryptamine.
Do I have to hydrolyse after decarboxylation?
Tetraline, diphenylether are not easy to buy at my local suppliers. Sigma aldrich won´t supply me I guess
I wasn´t correct. Of corse I meant the whole time of the procedure not just the time of decarboxylation. Of course it doesn´t make sense to have
short decarboxylation times when the purification takes twice the time...
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Tsjerk
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I'm 99% sure that your main problem is the tryptophan you assume to be tryptophan. If it is sold as a supplement it is most probably mixed with
whatever. This will interfere with your reaction and give a lot of crap. I would try to get some pure tryptophan before doing anything else.
I also think the stereo chemistry doesn't make a whole lot of a deal here...
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HollowMan
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I´m 99% sure that is just tryptophan without sth else. Thats whats on the package and on their website (bulkpowders DE)
L-TRYPTOPHAN - INHALTSSTOFFE (ingredients)
100 % L-Tryptophan.
I tried to check the melting point but there is just decomposition at 290-295°C. During checking CO2 evolution was visible from 280°C and everything
started to decompose together. In the microscope I could saw small crystals wich had always the same structure.
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Nicodem
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That post lacks the experimental.
Rather try the xylene/DMSO/MIBK procedure recently posted at Hyperlab in the "Tryptamines via indole ethyl chloride by Fischer" thread. I'm fairly sure there are similar procedures posted elsewhere as well, maybe even in
this thread here.
| Quote: | Ketone-catalyzed decarboxylation, as described by Drone #342:
Decarboxylation is accomplished by mixing about 80 g tryptophan in 250 mL of high-boiling solvent (xylene, DMSO, cyclohexanol, etc.), adding a dash of
a ketone (I like 5 g of cyclohexanone, but a couple grams of MEK works reasonably well), heat it to around 150 deg, and when evolution of CO2
ceases/solution is clear, the reaction is complete. This takes anywhere from 1.5 to 4 hours. After this is over, the solvent is boiled off (or at
least greatly reduced in volume), and the residue is dissolved in DCM. This is washed with a 5% NaHCO3 solution, then a distilled water solution, then
the DCM layer is separated off, dried with MgSO4, and the DCM is boiled off. You now have reasonably pure tryptamine. |
This is not even a procedure. It is more like an opinion.
Even when there is a properly written procedure, it can still be worth little unless it is provided with some minimal of analytical data, or at least
some characterization data.
| Quote: | | Do I have to hydrolyse after decarboxylation? |
It depends on how pure you want the product to be and if you want the best possible yields. Obviously, unless you hydrolyze the imine, you will end up
with plenty of tetrahydrocarbolines the moment your impure product encounters anything that's more acidic than acetic acid. In principle, stirring
with water for some time may be enough to hydrolyze certain imines (depends on the ketone you use for catalysis), but may not be sufficient for all.
That's why working procedures use aq. acetic acid for the acid-base extraction. Alternatively, you can get rid of imine derived impurities by vacuum
distilling the product.
[Edited on 19/9/2015 by Nicodem]
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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HollowMan
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Thanks for your extensively reply. At first I thought, this procedure should be the easiest I will ever do, but now it seems pretty tricky.
What do you think of using turpentine and using cumin oil as catalyst?
Thats something which I could obtain easily. Xylene too, but DMSO I would have to order..
Why do you think the instruction from Drone is just an opinion? Of course it´s not an exactly procedure but it seems that he tried it with good
results. MEK is also easy available but MIBK I don´t know where to order. It´s just the boiling point which makes the difference?
Distilling is no option because my distillation setup is to big for the small amount.
So if I understand right, its enough just doing an A/B extraction to hydrolyze eventually formed imin?
I just saw the instruction from "miamiechin" who also uses turpentine mixed with DMSO and carvone as catalyst.
But during purification he uses 0,5N HCl. Is it a good idea to use HCl aq.?
[Edited on 19-9-2015 by HollowMan]
[Edited on 19-9-2015 by HollowMan]
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Crowfjord
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Turpentine will work, since it has a high enough boiling point, but I prefer mineral oil because it has no smell (see my posts about my experiences
earlier in this thread). The mineral oil I speak of is found in pharmacies and is also known as paraffin oil or maybe unscented baby oil, and has a
boiling point greater than 250 C. Carvone is a good catalyst, either in pure form or in spearmint oil. Caraway oil may work as well, as it also
contains carvone. Dilute hydrochloric acid probably works fine, but acetic is tried and true.
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HollowMan
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1.Did you use just paraffin oil or mixed with DMSO like in hyperlab? They mixed xylene with DMSO and turpentine/DMSO.
2. Did you heat up till boiling?
3. How about your yield?
Thanks for sharing your experience 
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Crowfjord
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Please see my write-up on page 2 of this thread, as well as the subsequent posts of others on page 3.
[Edited on 20-9-2015 by Crowfjord]
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Nicodem
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Quote: Originally posted by HollowMan  | | Thanks for your extensively reply. At first I thought, this procedure should be the easiest I will ever do, but now it seems pretty tricky.
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It is actually fairly easy when you follow a procedure, rather than trying to reinvent the wheel. It is certainly a nice reaction for a beginner, as
one learns the very basic techniques like a reaction at reflux conditions, isolation via extractions and washings, (re)crystallization, and optionally
distillation... and the reaction monitoring can be done visually (which is important for the less resourceful).
| Quote: | | What do you think of using turpentine and using cumin oil as catalyst? |
What cyclohexenones is cumin oil supposed to contain?
| Quote: | | Thats something which I could obtain easily. Xylene too, but DMSO I would have to order.. |
Rather buy what you need, if you want to have things done. Alternatively, use your time and resources to research new methods with an uncertain
outcome.
| Quote: | | Why do you think the instruction from Drone is just an opinion? |
Because they are written as an opinion. It is surprising, but sometimes things simply are what they look like and what they appear to be. I'm not
saying that the opinion is wrong, I'm only saying that is not an experimental.
| Quote: | | MEK is also easy available but MIBK I don´t know where to order. It´s just the boiling point which makes the difference? |
Yes, the boiling point makes a big difference. MEK is known to work, but since it lowers the reflux temperature, it extends the reaction time. If you
feel creative, try whatever ketone you have available. It would not surprise me, if some day, somebody would post a procedure employing camphor or
menthone, but carvone containing essential oils are the easiest to obtain and cyclohexenones are the most efficient catalysts. So why bothering with
exotic alternatives? I'm all for promoting the doing of something new, but get some experience with what works first.
| Quote: | | Distilling is no option because my distillation setup is to big for the small amount.So if I understand right, its enough just doing an A/B extraction
to hydrolyze eventually formed imin? |
A bulb to bulb distillation (aka short-path distillation) does not require any special equipment. You need two small flasks, of which one is a
two-neck, and a connector.
| Quote: | I just saw the instruction from "miamiechin" who also uses turpentine mixed with DMSO and carvone as catalyst.
But during purification he uses 0,5N HCl. Is it a good idea to use HCl aq.? |
He uses a cyclohexenone as a catalyst in small amounts (about 6 mol%). Though, I'm not even sure that 0.5M HCl in a twofold excess (like in this case)
would be much of a problem even if a full equivalent of a ketone catalyst would be carried over, as long as the mixture is not left standing (but this
pretty much depends on the ketone - I would not risk with MEK and acetophenone, but cyclohexanone and MIBK are probably less problematic in this
regard).
The problem is therefore only relevant when you use non-conjugated ketones which require higher loading. In such case you want to avoid the
contamination with imine derived impurities, or else you will not be able to crystallize the tryptamine, or you will waste a lot of the product due to
the requirement of a more demanding purification. In short: if you want a cleaner product, use acetic acid. Sometimes the most logical and intuitive
choice is also the best one.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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HollowMan
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So thanks a lot for your advices now it´s time for the experimental part. After I will come back and will share my experience.
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Cloner
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What I know about tryptophan decarboxylation is this:
I paraffin heated until gas evolution (NOT reflux) gets results but the product is unpleasant to work with. AcOH extraction of the syrup followed by
basification results in a mess.
II shellsol d70 gives a marginally better result than pure paraffin, both in color of the product as not such a mess to work up.
III I have read about good results from acetophenone as a solvent as well as catalyst. Since I do not have that, I used spearmint oil itself as
solvent. This gives quick decarboxylation at a more reasonable temperature than I and II. The product dissolves and does NOT come out as oil, like it
does from hydrocarbons.
I am sure that option III and II will create a product that is either tryptamine or a product X which is not simply a mixture of unwanted compounds.
If it is indeed product X and not tryptamine, then it must be a majority product of a followup reaction of tryptamine in the presence of spearmint
oil. Note that in case II the product is within a syrup of many compounds while in case III it remains dissolved in the reaction medium. Purity in
case III is much greater.
Instability of the reaction product is of concern. It is unstable in ethereal solution and I believe it also darkens somewhat in ethanolic solution.
What if the tryptamine forms a compound with ketones of spearmint oil? Can this process be reversed without causing a cyclization?
[Edited on 25-9-2015 by Cloner]
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Quatro
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Acetophenone
I feel like there should be a simple solution to isolating Tryptamine from the Acetophenone mixture... People suggest using CO2 to form the carbonate
salt, others suggest dry HCl, and there is even the idea of extracting with acetic acid, wash with DCM, basify, put the whole thing in the freezer...
Acetophenone easily decarboxylates tryptophan, but it seems that many people have trouble separating the mixture. (EDIT: distilling should in theory
work, the boiling point of tryptamine is actually closer to 390° C)
It seems no one has come to a conclusion yet of the best method... I'm curious what other's thoughts are.
[Edited on 11-7-2015 by Quatro]
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Crowfjord
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According to wikipedia (their reference is ChemicalBook), the boiling point of tryptamine is 137° C at 0.15 mmHg. My nomograph tells me that at
atmospheric pressure, the boiling point would be around 390° C. There should be no problem distilling off acetophenone.
[Edited on 7-11-2015 by Crowfjord]
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Quatro
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Oh wow, you would think Wikipedia would list the boiling point at standard atmospheric pressure, but I guess I missed that!
I used this nifty calculator: http://www.trimen.pl/witek/calculators/wrzenie.html
and I'm actually getting the calculation 322C.
So I guess one could distil off the acetophenone until there is only a minimal amount left, and then I guess place on a hotplate to evaporate the rest
off to isolate the tryptamine freebase?
[Edited on 11-7-2015 by Quatro]
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Crowfjord
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I would vacuum fractionate from there, personally. If I didn't have a good vacuum source I would do a solvent extraction. Heating too much without an
inert atmosphere would probably degrade the tryptamine. Remember that the stuff oxidizes fairly easily.
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Quatro
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Why would vacuum fractionation be better than plain vacuum distillation? I understand fractional distillation is used when separating liquids with
closer boiling points, but in this case, Tryptamine has a very high boiling point.
Also, wouldn't a Rotovap also accomplish this?
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