Nitration - Definition and Overview

Nitration occurs with aromatic organic compounds via an electrophilic substitution mechanism involving the attack of the electron-rich benzene ring by the nitryl (nitronium) cation.

Benzene is nitrated by refluxing with concentrated sulfuric acid and concentrated nitric acid at 50°C.

(1) 2H₂SO₄ + HNO₃ ---> 2HSO₄^2- + NO₂⁺ + H₃O⁺

(2) C₆H₆ + NO₂⁺ ---> C₆H₅NO₂ + H⁺

(3) H⁺ + H₃O⁺ + 2HSO₄^2- ---> H₂O + 2H₂SO₄

The sulfuric acid is regenerated and hence acts as a catalyst.