Sciencemadness Discussion Board

Oxamide and HNO3 ->?

Per - 6-8-2007 at 02:09

Last time I made attemptions with Oxamide and I asked me what could happen if it is treated with nitric acid?

H2N-OC-CO-NH2 + HNO3 ->?

May it forms a salt or decomposes the amide to CO2, N2 and water.


Also I asked me if it´s possible to make other amides with Oxamide as precursor and how?

Nicodem - 6-8-2007 at 09:00

The protonated aliphatic amides generally have the pKa of about -0.5 in water. I don't know the pKa of oxamide itself but it should be thereabout as well. It is therefore extremely unlikely that you can crystallize a nitrate of oxamide.
The oxidation of oxamide with HNO3 should happen readily upon heating to a temperature where the rate of HNO3 decomposition to NO2 is high enough (since nitric oxides readily oxidize the –CONH2 group, while HNO3 does not). But at room temperature the oxidation is probably too slow to be of concern.

Per - 7-8-2007 at 03:16

Now I tried this:

I put a small amount of Oxamide in yellow 98% HNO3, firstly nothing happened but after a few seconds the Oxamide dissolved completely in the acid and the temperature didn´t increase.
After putting more Oxamide in this solution until it was saturated the acid was still yellow.
Then I poured the solution into water and small white crystals precipitated.

So it seems that you´re right, I didn´t guess that it´s so stable.
With this experience I assume converting this amine into others wouldn´t be easy too.

Rosco Bodine - 7-8-2007 at 18:56

More here

http://www.sciencemadness.org/talk/viewthread.php?tid=40&...

and here

http://www.sciencemadness.org/talk/viewthread.php?tid=18&...

[Edited on 7-8-2007 by Rosco Bodine]