Sciencemadness Discussion Board

What will be the reaction of phenol added to mixture of aqueous NaNO2 and Conc HCl

rajdeep - 1-12-2011 at 21:07

Well i guess the product will be picric acid but just want to know if this is correct. However i want to know whether a chemical " Saxitoxin, Pls check the structure in wekepidia" will react with this to give some kind azo dye complex.

So its like Saxitoxin+ Aq NaNO2 + Coc HCl + Phenol= Complex Azo ( ?????)

Can any one help me on it !

LHcheM - 2-12-2011 at 20:33

I think it's unlikely that an azo dye will form..,

From the structure of Saxitoxin, you can see that there's a dense arrangement of Nitrogen atoms, both primary and secondary, primary amines react with nitrous acid to give N-nitrosoamines and alkyl diazonium salts which is very unstable, the decomposition products also consists of a mixture of ketones and aldehydes due to rearrangements and hydrolysis.

For secondary amines, the primary product would be N-nitrosoamines, but this would not react with Phenol to give azo dyes

AndersHoveland - 3-12-2011 at 02:02

The reaction of benzene with nitrogen dioxide, at 25degC, produces nitrobenzene as essentially the only product.
http://pubs.acs.org/doi/abs/10.1021/jo00200a035

Whereas the reaction of NO2 with other benzene derivitives tends to produce 1,2-quinones.
Quote:
The quantitative formation of nitrophenols from phenol by reaction with nitrogen dioxide in solution involves stages, the first being the abstraction of a hydrogen atom from the hydroxyl group by NO2 and the second the reaction of the phenoxy radical formed with NO2. In the case of 4-methylphenol... into 4-methyl-2-nitrophenol.