SWIM had made some PAA from some crude benzyl cyanide a while back, part of which was never purified all the way. The other part was of course purified and used to make you know what. The part that was not purified all the way was stored for months until now. When SWIM had first made the shit, after everything was said and done he had a solution of the sodium salt of PAA in H2O. Acidified with HCl, then boiled. The plan was to boil off some of the H2O then filter while hot, cooling to precipitate the PAA. Well, first SWIM began boiling in a metal pot, not even thinking about the left over HCl in the mix (fucking duh!), and came back to find the shit fizzing and boiling wildly out of control. After cooling SWIM dumped the contents out, which now acquired a kinda greyish color. So SWIM said fuck it and placed in glass pot and continued boiling. After a while it was taken off of the heat and immediately filtered, which got rid of some of the greyish stuff, and after sufficient cooling some pearlescent honey smelling goodness precipitated, which still held some greyish hue. This is the PAA that was filtered out, recrystallized from fresh boiling water, and used with success. The remaining solution still looked very cloudy (like small amounts of milk mixed with water, yellowish greyish brown water that is, maybe with a hint of green), and still smelled very strongly of that stank pee/honey smell of PAA. Plus SWIM only got some of the expected yeild (although it was known that the nitrile precursor wasn't so pure itself).
So SWIM boiled off as much water as he could with the time allotted, and poured the remaining greyish whitish goup into a container, sealed it and stored it.
Well last night SWIM came across it was was wondering if it would still be viable. The goup had settled and a yellowish greenish layer of water remained on top, this was pour off. The goup was poured/slid into a 500mL beaker. Around 130-150mL's of the goup was had. SWIM heated some fresh H2O to a boil and poured it into to mess, stirring wildly and filtered. Again much of the greyish shit came out, although there is still some present in the mix. Other than the greyish shit, nothing was really in the filter so any PAA must still be in the solution as thought. No problem, cooling should precipitate it. Well, the filtrate became thicker on cooling, more soupy like, and more of that whitish cloudiness appears with maybe a hint of pearlescence (could be the lighting), but filtration really won't get it out it just seems to go through. It's as if the PAA won't fully crystallize or something. The honey smell now is fainter than when SWIM originally packed it up, but it's still there. Also that darkish grey color still prevails.
So basically the question is:
Should SWIM maybe boil some H2O off then cool again, this time maybe in the freezer for a little while (maybe it wasn't cold enough)?
Or maybe should SWIM add carbonate to re-make the sodium salt making it water soluable, filter and maybe boil down some (or even try to isolate the salt), then re-acidify and try to get the remaining PAA to precipitate?
Or should SWIM just chuck the whole thing?
It really doesn't matter, as SWIM just came across it and wondered if it would be worth fucking with or not. Hate to waste valuable precursor. Thanks for your time.
