Arrange the following in decreasing order of their basicity
Arrange the following in decreasing order of their basicity
B $\gt$ C $\gt$ A
B $\gt$ A $\gt$ C
A $\gt$ B $\gt$ C
A $\gt$ C $\gt$ B
Solution
Basicity $\propto+I$ effect
$\cdot \propto+M$ effect
For option (B) nitrogen lone pair is not part of conjugation it is more easily available for donation so it is more basic.
For option (A) $\mathrm{OCH}_3$ group is +M group which increase the basicity of nitrogen.
For option (C) $\mathrm{NO}_2$ is a electron withdrawing group. It shows -M effect and pull electron from nitrogen of aniline so lone pair on nitrogen are less available for donation.
