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Phenyl-2-nitropropene crystallization

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armageddon:
Oh, and since this is the "probs w/Xtalisation"-thread about nitropropenes:

If your post-reaction mixture doesn't behave like it should in terms of producing crystals, try to pour it over crushed ice, let that melt and filter to recover P2NP crystals...

I think it's the combined effects of sudden cooling, giving impurities a possibility to be "washed out" (perhaps they even "creep" into the ice? dunno..) and exposing the P2NP oil to a surface of solid crystal working as seeding crystals that makes Xtalisation happen here...

For SWIM this always works as a last effort before thinking he's fucked up and throwing away the whole shit; 'cuz workup is a bit hard due to the crystal size being very small, clogging filters, but it's always worth a try before discarding what you prepared in hours of lab work, breathing toxic fumes... :(  ::)  :)  ;D

futurealchemist:
nitro compound and aldehyde into IPA with ethylenediamine diacetate as a catalyst. allow to react at room temp for a few days and set into fridge to crystallize. voila.

Tsathoggua:
One could try TETA (triethylenetetramine) as amine catalyst, using GAA, and once the reaction is complete.

This was done with 2,5-dimethoxy-4-methylnitrostyrene, and when complete, the entirety of the reaction fluid was poured onto ice. The result, crystallized near instantly, after which, filtration at the Buchner, and then washing with H2O cleaned it up nicely. Did a final recrystallization from ice-cold MeOH, and that removed the very last traces of pumpkin-orange, which in any case formed only a slight halo around the exterior of the mass of crystals, which were filtered off from the ice/traces of ice water from its melting, in this case, whilst Tsath' has never done it with a nitropropene, formation of crystalline product was immediate.

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