been looking into this potential and economically viable conversion of voacangine to ibogaine.
V.africana rootbark goes for about 140E/kg, containing up to 10% voacangine.
simple acetic acid or methanol extraction yield the total alkaloid.
voacangine is easily converted to ibogaine.
the tricky part is separating the voacangine from the rest of the similar alks in the mixture.
"Voacangine has a molecule which is the same as ibogaine except there is a
group, -CO2CH3, hanging off, where ibogaine has only a -H atom. If this
group is removed, then voacangine becomes ibogaine. Boiling voacangine in
alcohol which contains lye causes the CH3 to fall off and be replaced by an
Na, so now there is a -CO2Na dangling from the ibogaine molecule. If acid
is added, the Na is replaced by H to give a -CO2H group. When warmed
gently, this group releases carbon dioxide, CO2, so that only the -H is
left, and ibogaine is obtained.
The patent also says that, given this easy conversion of voacangine into
ibogaine, it is better to make ibogaine from voacangine than to extract it
directly from Tabernanthe iboga. The reasons for this are that the Voacanga
africana tree whose bark contains lots of voacangine is much more
widespread than T. iboga, and the bark can be harvested more easily than
root can, and the bark can be harvested in a manner which allows the tree
to live."
The most promising alternative source of ibogaine was its semisynthesis from voacangine, obtained from the bark of the Voacanga africana tree. A
patent (10) by Janot and Goutarel claims that while T. iboga root bark contains only 0.3% ibogaine, the more abundant and accessible trunk bark of V.
africana contains 0.5% voacangine, which can be easily converted into ibogaine. Extraction of V. africana trunk bark using vinegar (see the
experimental section) was highly successful in isolating crude alkaloids. However, extensive attempts to isolate or even identify voacangine in this
mixture, or to convert the mixture into ibogaine according to the patent, were completely unsuccessful. A later publication (13) found only 0.14%
voacangine in the bark, and suggests that the concentration of voacangine varies.
i have looked into direct suppliers of pure voacangine, but alas, to no avail. they mostly sell the TA, and the few that do list voacangine in their
products list all say they're out of it.
any ideas as to how to go about this?
ScienceSquirrel - 6-4-2011 at 06:13
Might be barking up wrong tree here GreenD - 6-4-2011 at 06:27
I doubt there are much suppliers of it - and if there are they are smart and have sky rocketed the price.
Since the only place I know of ibogaine use is in africa, I'm assuming that the only widespread population of the specific tree you're looking for is
in africa, and thusly probably not in a capitalistic center - and thusly not avalable in large quantities.
Ibogaine is one of the rarer of the strong psychoactives. It looks incredibly interesting though -
it has the methoxy group, and also has a semi-rigged structure for the tertiary amine. They don't know exactly why some indole-amines are active while
others aren't (look up Chris Douglas in biochemistry papers).
I am also not completely certain how easy it would to give up that carbon dioxide. It may be given up easy due to it's clutter environement, but I
don't see a great reason why "gentle" heating would take it off - maybesomeone else could help me out on that.
And yes you may be barking up the wrong tree - I don't know the standards here...Nicodem - 6-4-2011 at 09:20
Copypasting without providing the reference is considered not just rude and irresponsible, but is also an excellent way of annoying the moderators
here!
Besides, open referenceless threads only in the Beginnings section.
i usually do provide refs, was just too lazy to do so the other night.
sorry if anyone got annoyed.
as i understand it, ibogaine is an illegal substance in the states, but not in most of the EU, where i reside.
if that is an issue.
said that, i have tried ibogaine on 2 occasions. i daresay it's what saved my life and got me off the opiates. though it has a lot of potential going
beyond that.
what i am interested in is isolating the voacangine from the voacanga total alkaloid.
little can i find in regards to that. and from the looks of the listed alks in the TA, might not be so easy.
anyway.
nevermind. Nicodem - 7-4-2011 at 06:35
Voacangine is the major alkaloid in Voacanga africana, so it seems obvious that a separation by recrystallization is the method of choice for those
who want to avoid chromatography. The choice of salt form and solvent is a matter of empirical trials, but checking the literature first is always the
best start.Nicodem - 7-4-2011 at 11:19
I can't make much sense about the procedure described in the patent. I can't see how refluxing voacangine with KOCH3 in methanol can cause the
decarbomethoxylation. Superficially it looks like the Krapcho decarbomethoxylation, but in methanol reflux? Unlikely. In any case, this is not what
the copypasta in the original post talks about. There is no hydrolysis of the methyl ester mentioned in the patent (if it was a hydrolysis, it would
not use KOCH3).
But the patent is not all the story! Surprisingly though, the decarbomethoxylation of (iso)voacangine is actually described in the literature, by
quite eminent authors (Helv. Chim. Acta, 42, 1572, attached). Coincidently, the article is just after Hofmann's, Heim's et al. article reporting the
discovery of psilocybin. Anyway, the reaction uses hydrazine or ethanolamine in a mechanistically pretty peculiar reaction. It is more alike to a
retro-acylation, than actual decarboxylation, and as such is actually in support of the patent claiming direct decarbomethoxylation by methoxide. Even
more, tabernanthine is made from isovoakangine by hydrolysis followed by decarboxylation, so I stand corrected about disbelieving about the ease of
such a synthesis.
Thats a good find and seems pretty reasonable. I was also thinking, that if in the first example, if HBr was replaced by HCl (or another strong acid
which forms a poorly nucleophilic conjugate base) I wonder if cleavage of the ether could be avoided.GreenD - 8-4-2011 at 14:10
What HCl are you talking about?
The reference that nico put down uses hydrazine in methanol... (pretty neat reaction though... would not have seen that).
But what HCl?Vogelzang - 8-4-2011 at 15:36
Some interesting patents.
US 2813873
US 2823204 Alkaloids of voacanga
US 2866784 Process for obtaining voacanga alkaloids
US 2945851 Process for obtaining an active substance with action on the heart from plants of the voacanga genus
US 3049546 Process for the decarbalkoxylation of alkyl esters of unsaturated, nitrogen containing carboxylic acids
US 3481937 POLYCYCLIC INDOLE DERIVATIVES
US 3758478 PROCESS OF OBTAINING TABERSONINE
US 3799933 METHOD OF PREPARING NEW INDOLIC DERIVATIVES USABLE FOR SYNTHESIZING
DEXTRO-ROTARY VINCAMINE
US 3681362 PROCESS FOR THE PREPARATION OF ISOQUINUCLIDINE ALKALOIDS
[Edited on 8-4-2011 by Vogelzang]
[Edited on 8-4-2011 by Vogelzang]smuv - 8-4-2011 at 17:27
In that part of the post, I was referring to the patent I posted where they made desmethyl ibogaine by refluxing voacangine in HBr/AcOH, speculating
conditions where ether cleavage could be avoided.
