@vecktor thanks so much for replying! I got a few questions:
Yeah I was thinking of doing it 3 times, each time recrystallising half and chucking the rest. Fingers crossed that's enough to get rid of the impurity if it can be done via this method
go from boiling to ice cold let it stand and
collect all the crystals, Rule 1, don't throw anything away. the impurities end up in the mother liquor. Also don't even throw the mother liquor away until you have what you want. Best practice is to allow the mother liquor to evaporate and allow the stuff you don't want to crystallize too.
The other good practice, but often tricky to do simply, is to filter the hot solution whilst it is still hot to remove any insoluble material
If you want to recrystallize again then recrystallize all the crystals from the previous crystallization. guessing half or whatever is a waste of time your total product will get smaller and smaller without trying too hard.
I would guess that MDDMA is only present at 10% or less and a single crystallization would remove it. If it is dimers then a single re-crystallization will remove it.
look up melting point determination, it is very simple with a tube and thermometer in a test tube of oil and that gives you a check of purity, be aware the literature says that the hydrochloride exists as multiple hydrated forms so what you are looking for is the increase in mp to stop.
from Pihkal: Only the anhydrous form has a sharp mp; the published reports describe all possible one degree melting point values over the range from 148-153 ° C. The variously hydrated polymorphs have distinct infrared spectra, but have broad mps that depend on the rate of heating.
So 99% IPA and don't worry about drying. Cool, that's nice and straight forward
Yeah that comment came from the bluelight post. Looked authoritative but I wasn't in a position to judge haha
Right, so just poor the near boiling ipa into the 'MDMA' conical flask? I guess I've just got to do that carefully
or put cold IPA in and heat it in the conical flask with the powder.
Right. To room temperature, or after that to fridge then freezer?
And is there value in adding the freezer cooled anhydrous acetone to the mix to help the MDMA crystallise out?
no acetone, you are not trying to crash out everything from solution you are trying to only crystalise the saturated component.
Anhydrous acetone is a bit of a myth most drying agents make diacetone alcohol from two acetone molecules and then this forms mesityl oxide. acetone so acetone plus drying agent is dry but impure.
One big worry I have, because I want to discard half each time, is how to judge when that amount has crystallised. If I just leave it the impurities will crystallise out as well. At the moment all I've got is eyeballing it. But visually I don't know how good my guess is going to be. Any ideas?
Thanks, I'm going to give it my best shot. I guess some of my questions might be a bit dumb but I appreciate that if this is worth doing then only if done right.
I was thinking of getting a hot plate/stirrer. I know there's concerns about heating up IPA but I'm assuming the quantities here are not too risking. Would the magnetic stirrer in the IPA be useful while heating or unnecessary?
you can heat it with a hot air gun, hold the flask with a glove and swirl it when you heat it.