Question

The correct order of basicities of the following compounds is

(a) 2 > 1 > 3 > 4 

(b) 1 > 3 > 2 > 4 

(c) 3 > 1 > 2 > 4 

(d) 1 > 2  > 3 > 4

Answer 1

(b) 1 > 3 > 2 > 4 

Protonated compound of I is stabilised by two equivalent resonating structures, hence compound I should accept H⁺ most readily.

Further 2° amines are more basic than 1° amine, while amides are least basic because electron pair on nitrogen is involved in delocalisation.