Ok, so Ive been decarboxylating tryptophan using refluxing turpentine and spearmint oil. I've run this reaction about five times and while the solid
tryptophan disappears, the tryptamine that should be present refuses to crystallize out of the turpentine.
Here is the procedure: 75 ml turpentine, 7.14g of tryptophan, and 15 drops of spearmint oil are added to a 250ml flask. The mixture is then brought to
a vigorous boil and refluxed until there is no more visible tryptophan and then reflux is continued for another half hour.
Trouble is, after cooling nothing comes out of the turpentine.
According to the procedure ("Student" on the rhodium archive) there should be crystals forming after some time, around a day, otherwise there should
be a solid, dark oil on the bottom of the flask. The procedure on the archive recommends immersing the flask in boiling water and adding a seed
crystal if trouble is had crystallizing the tryptamine, which I would try if I could get any damn crystals to form. Other things that I have tried
include vinegar extracting which yieled an oily brown crud, gassing the thing with CO2 which yielded a tan brown powder and lots of chunks that seemed
soluble in methyl ethyl ketone, and I'm about to resort to using anhydrous HCl and gassing the tryptamine shit out.
I have yet to try distilling off the turpentine, would that be advisable or are the chances of burning the tryptamine too high?
A thing that I have observed on every run: After all of the tryptophan has disappeared, the solution is an orange-ish honey color, very light, quite
transparent, but upon cooling it darkens to a deep red, almost black yet still transparent (when held up to the light) solution which glows green when
hit with LED lights in the white/blue spectrum. Any ideas about what is causing this color change? I think the green fluorescence is due to a bunch of
nitrogenous molecules because I observed the same thing when I made putrescine (a much less pleasant smelling yet smoother running decarboxylation
lmao) but I'm not entirely sure.
I need to know if I am doing something wrong or if the procedure itself is somehow flawed and I'd really like suggestions as to what I should do next.
All input would be much appreciated!clearly_not_atara - 3-1-2019 at 13:48
Indole is unstable and will always partially decompose when refluxed under air. Those colors are decomposition products.
If your solution is not pure then boiling off the solvent will not give a pure product. It sounds like CO2 gassing worked okay. You might get some
kind of zwitterionic carbamate from that.
Keep in mind that vinegar is not pure acetic acid; it contains various bacterial byproducts as well. You could try an A/B extraction but I do not
recommend vinegar.
I think the most likely reason tryptamine hasn't come out of solution is the solution isn't cold enough. Consider the freezer.
Please refrain from discussing any extension of this reaction to produce an illegal substance.Mothman - 3-1-2019 at 16:18
Thank you for your response, I think I failed to mention that I attempted to freeze out the tryptamine via my freezer in my original post, sorry. That
had no results either, it was the first thing I tried.
Should I just get some dry ice and acetone and get things really cold for the heck of it? I'm always down to work with cryogenic temperatures, maybe I
could chuck a grapefruit in to have fun with in case the crystals still dont form
Also, If the color change is decomposition products is the mere act of taking it off reflux and the still warm solution coming into contact with air
causing the color to change so drastically? Should I cap it as soon as it stops boiling then to prevent loss of product? I guess thats something I
could experiment with, and while its not too amazing just watching something refluxing for three hours I can always find something else to do in my
lab like plotting and scheming...or doing the dishes, glassware doesn't clean itself!
In regards to the zwitterionic carbamate: The solution foamed up and formed a large quantity of nasty brown paste. Washes with MEK yielded a tan
powder with fewer and fewer clumps but I finally wound up with a subgram quantity of whitish powder. Either I had abysmal yields (likely considering
my ignorance to the degree of air sensitivity of tryptamine) or the carbamate dissolved in the MEK. If I were to attempt this again would there be any
solvents that might be better for the washing steps? Also is it possible to react the carbamate with either acid or base to get tryptamine or a salt
thereof or am I stuck with the carbamate after that?
Also I read somewhere that tryptamine was broken down by strong acids, so if I were to A/B this would it be best to mix up an acetic acid solution
using my glacial acetic acid or would super dilute (5%) HCl work too? I guess since Im going to likely run this reaction several more times I can
answer that via experimentation.
Out of curiosity, why is indole so unstable? Is tryptamine more or less stable than plain indole? I know its off topic I'm just curious. If someone
takes the time to explain this to me please spare me no details, Im going to learn from this if nothing else.EilOr - 3-1-2019 at 22:45
I've had to make nearly one mole tryptamine as an intermediate in ~2010 for my training.
Btw. then I've found that "Shellsol T" works sligthly better than the "genuine" turpentuine. So some turpentuine substitutes from hardware store will
also work for sure, as long as they have BP of more than 170°C
But no matter wihich solvent I used (I also tried DMF and DMSO) I always also got an extremly impure product which was hard crystalise and it was
still veryi inpure after second recrystallisation from turpentine or Shellsol T. Precipitation with CO2 as carbamate between room temperature and
-25°C from different solvents (EtOH, EtOAc,...) did never work for me. To be honest I haven't seen any reaction at all so far with CO2 yet. Maybe it
works with dry ice in acetone etc. but it never worked for me so far
But I found two other good ways to get rid of impuritries.
Easiest and fastest is high vacuum destillation. You will get already an >95% pure slightly amber colored produkt within minutes in I suspect an
almost quanitative yield, good enough for most further synthesis. From this state it can be very easily recristallised using a mixture of EtOAc and PE
to obtain purely white flakes of tryptamine freebase (trying the solvent system on less pure tryptamine this only yields into a goo)
I've even achieved to destillate it with a good water jet pump, 10bar water pressure and perfectly sealed equipment
Though it's easier to get rid of all solvents moisture in a water jet vacuum and then use an good rotary vane pump and a heat gun to do the rest
Another maybe even "purer" way I found in parallel is to crystallise it as fumerate (0.5eq fumaricd acid to >1mol tryptamine, USE A TEST TUBE TO
FIND PERFECT RATIOS BEFORE YOU DO IT IN LARGE SCALE!) from an alcohol of you choice. I've made it from hot EtOH with great success one time. But it
won't work if the tryptamine is extremly dirty. If it doesn't work, make an A/B extration with the raw tryptamine before it, then it will work for
sure.
And keep in mind fumaric acid has very low soloublity in water, a quite low in EtOH (but usable), and biggest in IPA and MeOH and the base needs to be
in a very slight excess as Tryptaminehydrogenfumerate doesn't crystallise as easily as the Ditryptaminefumerate-salt.
Tryptamine-fumerate once made can be then be easily recrystallised from EtOH/Water in high yield. Product is nice shiny and completly SNOW WHITE
crystals which can be dissolved in dest. water and when mixed with 2eq NaOH to yield very pure white Tryptamine freebase will precipitate out of the
aqueus solution immediatly.
As far as I know tartaric acid can be used instead of fumaric acid aswell, but no guarentee for that
[Edited on 4-1-2019 by EilOr]Mothman - 5-1-2019 at 03:39
First of all, thank you for your response, I really appreciate the assistance!
Secondly, tartaric acid is much more readily available to me, I think I'm going to be looking into that route, and only because I happen to be a
hundred miles away from my rotary vane vacuum pump right now :'(
I'm going to go make some tartaric acid from cream of tartar and give this a shot. Would adding the appropriate quantity of the alcoholic solution of
tartaric acid straight to the turpentine be a good idea or should I distill off as much turpentine as I am able?
EDIT: Forgot to add that I didnt dry the CO2 beforehand, carbonic acid has to form somehow right? I didnt get anything too great from the gassing
though so the procedure probably needs improvement.
[Edited on 5-1-2019 by Mothman]AvBaeyer - 5-1-2019 at 13:30
I just stumbled across this paper while searching my files. It provides information regarding salts of 5-methoxytryptamine. The information might well
be useful for the isolation of tryptamine itself.
...Tryptamine-fumerate once made can be then be easily recrystallised from EtOH/Water in high yield...
Thats
good to know.
I would expect tryptamine fumarate to be quite soluble in water. Do you remember just how much water was in your recrystallization solvent?Mothman - 6-1-2019 at 16:50
Ok so I ran a decarboxylation again. This time I immediately stoppered the flask after heating was removed and boiling had slowed to a crawl. I let
the flask cool then added some tartaric acid dissolved in acetone/water to the mixture. There was immediately noticed a dark black oily chunk coming
out of solution, and about 50 ml of water and an arbitrary amount of tartaric acid were added and the flask shaken until it looked as if most of the
oily gunk had dissolved again. The turpentine was a light orange and the water layer was a dark yellow/brown color. The solution was filtered then the
layers were separated, leaving me with what I presume to be a solution very crude tryptamine tartrate. I plan to adjust the pH to around 8 and wash
the mixture with a bit of chloroform tomorrow and then Ill be adding some ammonia to precipitate the tryptamine freebase. If I have any further
questions I'll post them here but until then thank you all for your assistance in this endeavor.
For now, back to lurking. Muwahahaha...Mothman - 8-1-2019 at 10:59
Success!
I added a small scoop of sodium carbonate to the mixture to re-basify and then washed the solution with chloroform and then added about 100 ml of 10%
aqueous ammonia resulting in a pale yellow precipitate. I threw it in the fridge and now there is a chunk of orange viscous oil in the bottom of the
flask! I plan to weigh it to calculate final yield and I'm running another decarboxylation to see if I can improve the process! Thank you all for your
assistance!Elrik - 8-1-2019 at 13:51
You must enjoy decarboxylations, I would have taken the first run to completion before doing it six more times.
If you do any purification by recrystallization of the tartrate please do let us know how it goes. I imagine the ~pH 7-8 tartrate would crystallize
best from fairly low water content ethanol or isopropanol, with the ~pH 4 bitartrate crystallizing from warm water with some added alcohol, but I
havent tried it yet.
I assume you added acetone as a co-solvent to speed tryptamine-tartaric acid reaction. This seems unwise to me [not to mention amusing, since you used
spearmint oil as decarboxylation catalyst]. Tartaric acid may not be strong enough to cause acetone condensation without reflux, but tryptamine easily
could be not to mention that ammonia+acetone can produce some diacetoneamine which would contaminate your product, and under acidic conditions
tryptamine will react with acetone to produce 1,1-dimethyl-ß-carboline [I wonder if that would glow in blacklight at pH≤7].
Your making me want to make some tryptamine
Solubility parameters of the base and the various salts seem poorly defined, I could help fill in those gaps.
Remember, dont react aldehydes or ketones with your product unless you want 1-substituted ß-carbolines
