This any help?
Author
Topic: What did he not-do this time?
KrZ
Member
posted 11-16-1999 06:03 PM
Well, I came up with a good use for all that leftover NaCNBH3 you might have laying around.
"Tryptophan (454g) was suspended in tetralin (1150 ml) containing acetone (12.9 g) and the mixture was heated
to reflux for 12 hours with vigorous stirring until no more carbon dioxide was evolved and the reaction mixture
became clear. The solvent was removed under vacuum, and the residue was distilled under reduced pressure to
give a yellow crystalline solid. (from rhodium). Next 30g of formaldehyde and 120g Tryptophan were disolved in
1800ml of MeOH, to this was slowly added dropwise 50g of NaCNBH3 disolved in 550ml MeOH. Then 14g Glacial
Acetic Acid was added dropwise with stirring. The mixture was then stirred for 60 hours. The majority of the
MeOH was distilled off (2L collected) to the distillation flask was added 1L of 5% Aq. Ammonia which was
extracted with 3x 250ml of DCM. The DCM was washed with a salt solution (not saturated but still pretty strong)
then the DCM seperated and dried with a large portion of MgSO4 made by dehydrating epsom salts overnight in
the oven at 450C (the rock-solid mass had to be pounded into a powder with a hammer and the small remaining
clumps ground in a pestal, quickly so as not to allow H2O uptake from the atmosphere). The DCM was distilled off
at atmospheric and then the distillation was continued (~1 torr now) until the dimethyltryptamine was collected.
Which was recrystalized from boiling hexane with a few mls of Ethyl Acetate added (these were the 2 hardest
things to get!) This afforded 48.8g of DMT, a 35% yield. Not high but it was still a fun adventure. The DMT was
immediately mailed 3500 miles away."
Found this (yes again) at a desk in the library, looked like there was a stack of journals next to it as well.
Amazing the detailed notes ppl leave in the library here.
psychokitty
Member
posted 11-16-1999 10:20 PM
Like I said, you ARE the MAN. It goes without saying that I'm impressed. You're definitely paving the way to
success for many of us.
--PK
Slappy
Moderator
posted 11-17-1999 01:23 AM
I think he not-meant Trptamine, not Tryptophan in the second step.
KrZ
Member
posted 11-17-1999 08:22 AM
Heh, yes tryptamine indeed. My mistake.
Rhodium
Administrator
posted 11-17-1999 11:15 AM
I thought tryptamine cyclized to a beta-carboline on attempted methylation with formaldehyde? But you should
know if it was the real stuff you got.
Bright Star
Member
posted 11-17-1999 11:32 AM
Bra-fuckin-vo.
Anyone know how to paste PGP into Hushmail?
KrZ
Member
posted 11-17-1999 12:22 PM
J. Med. Chem., 1995, Vol. 38, No. 18 pg 3577. half-way down the page "The general method for dimethylation of
indoleethylamines is illustrated below for
(S)-N,N-dimethyl-2-[5-[(2-oxo-1,3-oxoazolidin-4-yl)methyl)-1H-indol-3-yl]ethylamine."
KrZ
Member
posted 11-17-1999 12:35 PM
You should just be able to export your key to a text file, select and paste, and then do the same with any
message you might want to send? Is something not working? Works fine on other free-web-mail servers. Why
would tryptamine cyclicize? How exactly does that mechanism work?
Rhodium
Administrator
posted 11-17-1999 03:16 PM
I don't know the mechanism, but it is called "Pictet-Spengler cyclization". After a formaldehyde molecule has
added to the side-chain nitrogen, the other end of it bites the 2-position of indole, water is liberated and you
have a betacarboline instead of a tryptamine... It is acid catalyzed and it only takes place in solutions with a pH
< 7.
KrZ
Member
posted 11-17-1999 05:30 PM
I see now, in the notes above they said they used 14g GAA and the freebase of tryptamine. That 14g isn't going
to make the reaction mix very acidic. This does occur at pH < 7, but the optimal rate is acheived at lower pH? If
so then perhaps cyclization is kept relatively low. No pH testing was done in the notes for this reaction, if only
they had kept tabs we could have the answer :-( Even in the sample reaction below they only reported 52%
yield, a good sign.
http://orgchem.chem.uconn.edu/namereact/pictetspengler.html