LD5050 - 11-5-2017 at 17:55
If a synth calls for formaldehyde is it possible to substitute with paraformaldehyde?
Magpie - 11-5-2017 at 18:09
How sensitive is the synthesis to water? If you look at the formula for paraformaldehyde you'll see that there is a water molecule for every 8-100
molecules of formaldehyde.
LD5050 - 11-5-2017 at 18:26
Well what I want to try to do is make some methylamine and I also would like to make dimethylamine with formaldehyde and ammonium chloride. For the
dimethylamine I was just planning on following a procedure for methylamine by formaldehyde and ammonium chloride but using an excess of CH2O and
running it at a slightly higher temp. But all I have is paraformaldehyde so I was wondering if I could use that instead.
CharlieA - 12-5-2017 at 08:38
According to Wikipedia, the font of all chemical knowledge (sarcasm intended), dry heating of paraformaldehyde gives formaldehyde gas, and heating
paraformaldehyde in water produces a solution of formaldehyde.
Crowfjord - 12-5-2017 at 08:58
The above is true, from experience. Although, it helps to have a small amount of acid or base present to catalyze the depolymerization in water. One
can also prepare a formaldehyde in methanol solution simply by refluxing paraformaldehyde in methanol for two or three hours. There are also methods
on the internet, for example on the rhodium archive, that detail the preparations of methylamine and maybe dimethylamine from paraformaldehyde and
ammonium chloride.
[Edited on 12-5-2017 by Crowfjord]
Amos - 12-5-2017 at 11:05
If you like, there are many preparations online for preparing concentrated formaldehyde/formalin solution from paraformaldehyde.
alive&kickin - 14-5-2017 at 18:23
CharlieA, there's really no need to be sarcastic about Wikipedia, I look on it quite frequently. The one really good thing about Wikipedia is on all
their articles there are always references. If something seems off, I always check out the references to make sure that someone didn't screw things
up.
Melgar - 15-5-2017 at 04:05
*sigh*
Another methylamine thread.
If you're following the synthesis that I'm 99% sure you are, then you'll be using hydrochloric acid in an aqueous solution, which will hydrolyze
paraformaldehyde to formaldehyde. It will also work with trioxane, hexamine, and possibly even broken keck clamps if you give it long enough. That
being said, if you want dimethylamine, it's easier to hydrolyze dimethylformamide, and if you want methylamine, it's easier to reduce nitromethane.