Sciencemadness Discussion Board

crystallization from acetic acid

chemrox - 16-9-2016 at 16:15

I made a heterocyclic amine phosphate and the stuff will not dissolve in hot alcohol(s) acetone, ether, acetonitrile, anything polar/organic. It will dissolve in hot acetic acid. However it goes back into solution when brought back to room temp. The only thing I've been able to do with it so far is collect the frozen cryx and wash them in alcohol. This was a cmpd I had lying around for years. I got it from spectrum and it's since been added to proscribed lists so I can't be more specific other than it's a benzyl something.
I'm seeking experience from someone who has had to use acetic acid or anhydride to recryx and might have some general insights to share. Why do I have to recryx the product? The material aged in the bottle. The argon leaked out and it has some brown impurities that come long with the acid adduct. I might have to run the base on a column or distill it but would rather not.

CRUSTY - 16-9-2016 at 17:17

Hmm... A heterocyclic amine phosphate containing a Benzyl group... If you're working with what I think you are, have you tried plain methanol? As to "why" one would recrystallize it, it depends. Often it's just because it looks pretty, but I imagine it also hinders surface oxidation, since a crystal has magnitudes less surface area than a powder.

Also, what do you mean about it going back into solution? Was it ever not in solution at some temperature?