Question

The correct order of increasing basic nature of the following bases is:

• A. II < V < I < III < IV
• B. V < II < I < III < IV
• C. II < V < I < IV < III
• D. V < II < I < IV < III

Answer 1

Answer: (A)

II < V < I < III < IV

The correct order of increasing basic nature of the given bases is:

$II<V<I<III<IV$

$-OC{H}_3$ is strongest electron releasing group +M effect which opposes most the dispersion of lone pair of electron of nitrogen into the ring. Thus, $-OC{H}_3$ being at para position imparts highest basicity. $N{O}_2$ being at meta position stabilises the electron pair of nitrogen only by - I effect. While $N{O}_2$ being present at para position due to -M effect and -I effect stabilises the lone pair of electron of nitrogen, most and impart least basicity.