Thanks for your input, so I presume what precipitates is actually a carbamic acid, not a carbamate?
downwardsfromzero said:
The carbamic acid has a proton (H+) which may then transfer to any nearby basic nitrogen - which in this case could be on either the DMT or the NMT:
R2NCO2H + R3N -> (R3NH)+ (R2NCO2)-
So the question is whether or not this reaction proceeds to any great degree.
Actually, looking at the reaction as stated in the original patent (attached to first post), it seems like the NMT would instead form a carbamate salt with itself more readily than with the DMT:
patent said:
2R2NH + CO2 -> (R2NCO2)-(R2NH)+
I'm no chemistry expert though, so correct me if I'm wrong.
I will note that there was a significant qualitative difference between the pre-dry-ice alkaloids and both the DMT and NMT that were collected separately afterwards. Both NMT and DMT fumarates were crystalline solids after separation but were a goo before separation. If there is any DMT that does precipitate with the NMT, it is surely a small quantity. I would love to do TLC to confirm this but I don't have the capabilities right now.
From further testing, it seems like it is better to use xylene as a solvent when adding dry ice, rather than naphtha, because too much DMT precipitates due to the drop in temperature, making it hard to make sure all of the NMT is reacted without several cycles of dry ice/warm bath. This doesn't happen with xylene.
My yields have been consistently around 0.7% DMT freebase (using the same source of bark). It's nothing near the 1.5% reported in the literature, but maybe my bark is not so great?