Nitration Of Benzene.pdf 5p3h3n

The Nitration of Benzene

The Nitration of Benzene This page gives you the facts and a simple, uncluttered mechanism for the electrophilic substitution reaction between benzene and a mixture of concentrated nitric acid and concentrated sulfuric acid.

UC Davis ChemWiki is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

1

The electrophilic substitution reaction between benzene and nitric acid Benzene is treated with a mixture of concentrated nitric acid and concentrated sulfuric acid at a temperature not exceeding 50°C. As temperature increases there is a greater chance of getting more than one nitro group, -NO2, substituted onto the ring. Nitrobenzene is formed: \[ C_6H_6 + HNO_3 \rightarrow C_6H_5NO_2 + H_2O\] or:

The concentrated sulfuric acid is acting as a catalyst.

The formation of the electrophile The electrophile is the "nitronium ion" or the "nitryl cation", \(NO_2^+\). This is formed by reaction between the nitric acid and the sulphuric acid.

\[ HNO_3 + 2H_2SO_4 \rightarrow NO_2^+ 2HSO_4^- + H_3O^+\]

The electrophilic substitution mechanism Stage one

Stage two

UC Davis ChemWiki is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

2

Contributors Jim Clark (Chemguide.co.uk)

UC Davis ChemWiki is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

3