question_answer

Nitrobenzene on reaction with conc. \[HN{{O}_{3}}/{{H}_{2}}S{{O}_{4}}\]at \[80-100{{\,}^{o}}C\]forms which one of the following products?

A)  1, 2-dinitrobenzene

B)  1, 3-dinitrobenzene

C)  1.4-dinitrobenzene

D)  1, 2, 4-trinitrobenzene

Correct Answer: B

Solution :

\[N{{O}_{2}}\]group being electron withdrawing reduces electron density at output positions. Hence, now the mefa-position becomes electron rich on which the electrophile (nitronium ion) attacks during nitration. \[HN{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\xrightarrow{{}}{{H}_{2}}NO_{3}^{+}+HSO_{4}^{-}\] \[{{H}_{2}}O+\underset{\text{electrophile}}{\mathop{NO_{2}^{+}}}\,\]