So recently I got a bit of the Fumarate salt of DMT. I set out to convert some to the base form and found out two things during the process:
1.) The molecular mass of DMT Fumarate is listed on pubchem as 304.346, but the actual molar mass is most likely 492.608, as in two equivalents of DMT per mole of DMT fumarate (fumaric acid has two acidic protons, pka1 = 3.03, pka2 = 4.44).
2.) I went to run it with sodium bicarbonate without really looking anything up (also I need to restock on some things, so it's all I have for a base at the moment) and found that it was not strong enough to precipitate out the base and LLE extract using naptha. Interestingly, the addition of the sodium bicarbonate did seem to precipitate out a colored impurity, with the solution going from very light brown to totally clear, and initial naptha pulls removing a brownish oil.
Converted the sodium bicarbonate to sodium carbonate by throwing it in the oven on some aluminum foil, and went on to successfully perform the extraction by adding it to the aqueous layer.
/u/SmokingtonWallace · N/A votes · 22nd January, 2022 - 23:00 · Link
Is an amine doubling on an acid salt actually a thing? Would the same thing apply to sulfate, tartrate, maleate etc. acid salts?
/u/socat2me · N/A votes · 26th January, 2022 - 10:05 · Link
It is a thing but as you've probably gathered it isn't always so straightforward as full ionization of the polyprotic acid with each acidic proton being replaced by the base at a 1:1 ratio. With some of the examples you listed, like sulfate, the parent acid is so strong that you'll always get full ionization (although monobasic sodium phosphate is actually a thing too--phosphorous and sulfur can do hypervalency/octet expansion) however with systems of weak acids and weak bases sometimes things can get a little messy, especially if you happen to have a system containing multiple acids and bases (which is a big part of why units of equivalence are used in medicine). With almost any system it has an overall neutral charge, but there is a mixture of different moieties that are at an equilibrium with each other, with the extent to which any given one is formed being governed by reaction conditions, but also by all the dissociation constants in the system (usually expressed with as a function of the negative logarithm operation denoted by p, i.e. pKa = -log[Ka] with the dissociation constant Ka being in units of molarity). As a simple example, amphetamine sulfate is dibasic, but amphetamine phosphate exists in the dibasic and monobasic (amphetamine biphosphate) form. For salt formation one of the factors is the pKa of the alkaloid's conjugate acid versus the pKa of the proton on the parent acid. For example, H2SO4 has two acidic protons, with pKa1 = of