Sciencemadness Discussion Board

Uses of Urea - Carbamide - CO(NH2)2

AlphaDecay - 26-3-2014 at 18:34

Does anyone know any use of urea in the field of synthesizing common lab chemicals/substances/reagents?

Urea is an easy obtainable chemical compound, but I can't find anything about its chemical reactions on the internet.

Metacelsus - 26-3-2014 at 19:03

You can try reacting it with propylene (or ethylene) glycol to form the cyclic carbonate. The reaction is tricky, however.

http://www.sciencemadness.org/talk/viewthread.php?tid=27478#...

ParadoxChem126 - 26-3-2014 at 19:41

It can be used to convert benzoic acid into benzamide. Aniline can then be made from benzamide via the Hofmann rearrangement. Aniline is a very useful starting point in organic syntheses.

http://www.sciencemadness.org/talk/viewthread.php?tid=4201&a...

AlphaDecay - 9-4-2014 at 14:45

I've been searching the net and I found that Nitroguanidine can be made this way: urea + ammonium nitrate fused together with silica gel as a catalyst, which gives Guanidine Nitrate, that through dehydration with H2SO4 gives Nitroguanidine . Can I use ordinary sand or quartz powder instead of silica gel, since all of them are Silicon Dioxide?

Post which shows this reaction:
http://www.sciencemadness.org/talk/viewthread.php?tid=14342#...

Sorry for any english misspell.

gdflp - 9-4-2014 at 15:14

Sand or quartz have impurities which make them less than ideal so I would try to get silica gel or sodium silicate(Which you can make in to silica quite easily). Another reaction you can try is heating urea with potassium or sodium nitrate to yield the corresponding cyanate.

Bert - 9-4-2014 at 15:17

There is another nitroguanidine synthesis starting from urea and sulfamic acid, carried out at lower temperatures.



Via Axt: Nitroguanidine from sulfamic acid and urea

AlphaDecay - 9-4-2014 at 15:21

What is the ratio urea-ammonium nitrate-catalyst(silica gel)?

AlphaDecay - 10-4-2014 at 09:29

http://www.google.com/patents/US4390726
I found this:
"EXAMPLE 2
Below another discontinuous process for the production of guanidine nitrate from urea and ammonium nitrate.

A melt consisting of

60.0 kgs of urea

120.0 kgs of ammonium nitrate temperature 120° C.

40.0 kgs of silicagel

is passed into the stirred reactors.

The mixture is heated."

Could the ratio be 3-6-2 by weight?