Sciencemadness Discussion Board

Synthesis of 2,4-dinitrophenylhydrazine (Brady's reagent)

Hexavalent - 11-3-2012 at 02:22

Can anybody suggest a viable route to 2,4-dinitrophenylhydrazide starting from either nitric acid or a nitrate salt, perhaps phenol and hydrazine sulfate?

stygian - 11-3-2012 at 02:43

Would starting from trinitrobenzene, reducing a single NO2, diazotizing and reducing again be the way to do it? Or is a more circuitous method needed.

http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2... claims hydrazine sulphate + dinitrochlorobenzene does the trick.

[Edited on 11-3-2012 by stygian]

unionised - 11-3-2012 at 05:10

I have don e the analogous reaction of dinitrochlorobenzene with methylhydrazine to get dinitrophenyl methyl hydrazine.

I don't really recommend the reaction of a carcinogen with an unusually potent sensitiser to make a borderline explosive as an experiment for the amateur.
Have you run across a problem buying DNPH?

Hexavalent - 11-3-2012 at 06:14

I have never attempted to buy it . . .I would just like to prepare a sample for testing for carbonyl groups in numerous samples.