Toady isn't really happy with the way this turned out. He decided to try acylation of OTC piperazine phosphate, sold as an anthelmintic. Turns out there is some sort of bright pink dye in it.

He proceeded with acylation, dissolving piperazine in MeOH..., adding benzoyl chloride then adding H2O made basic using Na2CO3 and ran into solubility issues.  Chances are he will just run the rxn again, using a better source of piperazine. But, he doesn't want to waste this initial effort. The dye is nontoxic (of course, its sold for human use in this form) but further than that, he doesn't know what it is, or what its soluble in)

Any ideas, people? the target end product is DM-235/sunifiram, a novel AMPAkine.

Gah..post disappeared into the aether.

Should have thought of sublimation and activated charcoal. He THINKS he has a few more grams of this colored piperazine. It also contains sennoside-b (a laxative) but at 15.3mg/4g of piperazine phosphate he is just ignoring this totally.  The dose range of sunifiram, this would result in absorption per given dose of picograms of sennoside, which will be absolutely inactive.


Ahhhh.....gotcha. Found it. Will try subliming it, then forming the mono-HCl salt. Although Toady might just bee a bit lazy, and purchase some n-BOC-protected piperazine. Or better yet, n-benzoylpiperazine, from there just a quick rxn with propionyl chloride. Workup should be a breeze starting from there. That was the plan to start with. Toady thinks he will shelve this pink n-benzoylpiperazine for now, and start again, removing the dye (and likely also the traces of sennoside-B) via sublimation.