Question

1.explain with reason :- amines are basic substances while amides are neutral.

2.explain with reason :- although amino-group is o-&p-directing in aromatic electrophilic substitution reactions,aniline on nitration

gives a substential amount of m-nitroaniline.

Answer 1

(1) Amines are basic substances while amides are neutral. Because in amines lone pair of electrons on nitrogen is free to act as base. But in amides, lone pair on nitrogen is involved in conjugation with adjacent carbonyl group. ... This is the reason it is less basic than amines.

Answer 2

$\huge\textcolor{indigo}{\rm{Answer :-}}$

Reason :-

Under strongly acidic conditions of nitration (in the presence of a mixture of conc. $HNO_3 + H_2SO_4$), aniline gets protonated and is converted into anilinium ion having —$NH_3^+$ group.

This group is deactivating group and m-directing. So, the nitration on aniline gives o, p-nitroaniline (mainly p-product) while the nitration of aniline ion gives m-nitroaniline.

Thus, nitration of aniline gives a substantial amount of m-nitroaniline due to protonation of aniline.