Question: Can anyone who's cleaned up oxime before, please recommend some amounts of some solvents to use to recover the most oxime (ie >75%) while removing the most impurity? (ie recrystallization or washing)
Background: Someone who would never make such a mistake, reacted 10g of mdp2p with the appropriate amounts of H2O, MeOH, Na2CO3 and (NH2OH)2.H2SO4. Well, he fitted the flask with a condenser, and although he turned his water on and it flowed into the condenser, it never ended up circulating... he didn't realize this. As a result, he evaporated most of his MeOH... he did detect this before things got dry in the flask. So some water was added, moved to the freezer, no oxime. Shit.
So the mixture was flooded with water, extracted 2x with DCM. Then the DCM distilled off. More H2O, MeOH, Na2CO3 and (NH2OH)2.H2SO4. This time everything goes alright. He adds some water, allows to sit for a day, and then filters the mixture. He washes what he gets with 150ml of water or so, then noticed that the crystals are BEIGE! At least the crunchy crystals seem to be the oxime (water insoluble, melt when heated). The recovery looks a bit low, less than the 10.9g of expected ketoxime (weighs 8g after sitting in the dessicator for an hour or so, maybe perhaps 5-7g when bone dry?) However it's still lots for his purposes and want to recover it as he's used up the last of his mdp2p.
What should be done to clean them up? Should they just be dried them and used as is? Or should he recrystallize them from IPA... wash with acetone something like that?
Thanx: Thanx!