Question

Amines are classified as primary, secondary and tertiary amine.
(a) Represent the structure of secondary and tertiary amine.
(b) How will you convert nitrobenzene to aniline?
(c) Aniline does not undergo Friedel-Crafts reaction. Why?

Answer 1

(b) Conversion of $\text{nitrobenzene}$ to $\text{aniline}$:
$\text{Nitrobenzene}$, on reduction with $\text{Sn/HCl}$ gives $\text{aniline}$.

(c) Aniline does not undergo Friedel-Crafts reaction (alkylation and acetylation) due to salt formation with aluminum chloride, the Lewis acid, which is used as a catalyst. Due to this, the nitrogen of aniline acquires positive charge and hence acts as a strong deactivating group for further reaction.