Douchermann - 19-7-2008 at 01:12
I've spent a few hours determining the best method I have available to produce pyridine hydrochloride. So far a 50:50 methanol:pyridine mixture has
worked the best, but the best is not the greatest yet. Also, it is ridiculously deliquescent, visibly dissolving in it's own water as I try to put it
in a container. Is it possibly to dry it out in an oven at sub melting point temps (below 140C). Vacuum dessicators are out of the question, and is
there anything I can add to the methanol to precipitate it out. If ether is added, it just forms two distinct layers even through thorough agitation.
If the HCl(g) is just bubbled into pyridine, it clogs the tube with crystals - same goes for ether solutions of pyridine. I'm basically just looking
for tips or tricks or personal experiences. Thanks in advance.
Sauron - 19-7-2008 at 01:38
Yes it is very hygroscopic and the only way to keep it dry is to prepare it in an inert atmosphere in anhydrous conditions and store it that way. That
means N2 or Ar cylinder, glove box or dry bag, etc. It is a whole lot easier to buy!
Because of its unfortunte properties it has long been the bane of procedure in which pyridine is used as an acid scavenger, so much so that
non-hygroscopic teriary amine substites such as diethylaniline are often used because they are easier to filter off. The pyridine salt just goes
liquid in the filter and gets sucked back into the product. Ugh.
Douchermann - 19-7-2008 at 09:47
Would an oven at least turn it from soup into a more solid mass? I figured, I could do the filtering inside, where the air conditioning sucks up most
of the moisture, but do the gassing outside. I deffinitely would buy it, but I'm out of money at the moment, and it's expensive for the amount I
need. Thanks for your help by the way.