This post describes the extraction of freebase piperazine from commercial animal dewormer, note that this only applies for the powder stuff, and for the syrupy one you might have to use solvent extraction instead.
The “Why?”s
Now you may ask, why would you want to extract dog dewormer? And to that my answer is, “because it looked cool”. In reality, my reason being that it’s a relatively simple amine that’s available OTC that can be a building block for various coordination complexes and organic compounds.
The Process Itself
This is the exact process I’ve used on my first run, so the molar proportions are a bit small, but you could always scale up providing you have a way to filter large amounts of precipitates.
100 grams (one entire bag) of the piperazine dewormer is dissolved in 350 ml of hot distilled water, and stirred until the solution clears up. 53.4 grams of Oxalic Acid Dihydrate are measured out and added in small portions with stirring in-between additions, giving us a cloudy solution and after a short bit, a mass of precipitate of Piperazine Dioxalate (MW=262.166 g/mol). The solution is left to boil and stir for a while after. After ~20 minutes of stirring the piperazine dioxalate is filtered off and thoroughly washed with hot water and methanol to get rid of any contaminants like lactose. The solid is dried thoroughly on the pump.
A hot solution of 15.75 grams of Barium Hydroxide Octahydrate in 800 ml of water (perhaps too much) was prepared, to which 13.31 grams of the piperazinium dioxalate were added in portions under vigorous stirring. The hot solution was left to stir for a while to ensure complete liberation of piperazine freebase.
The barium oxalate precipitate was filtered on a buchner funnel and washed thoroughly with hot distilled water to get every last bit of piperazine in it out. The resulting solution was evaporated on a hotplate over an entire day and white crystals of piperazine freebase were obtained after the 100 ml of remaining solution were placed in the freezer.
The resulting product is 6.7 grams of a white crystalline powder, which burns cleanly with little to no residue.