
$$\text{C}_6\text{H}_6 + \text{Conc. HNO}_3 + \text{Conc. H}_2\text{SO}_4 \xrightarrow{323\text{--}333\text{ K}} \text{C}_6\text{H}_5\text{NO}_2 + \text{H}_2\text{O}$$
Electrophile: Nitronium ion ($$\text{NO}_2^+$$) generated via$$\text{HNO}_3 + 2\text{H}_2\text{SO}_4 \rightleftharpoons \text{NO}_2^+ + \text{H}_3\text{O}^+ + 2\text{HSO}_4^-$$