Question

The order of basicity of the compounds is

• A. $IV > I > III > II$
• B. $I > III > II > IV$
• C. $III > I > IV > II$
• D. $II > I > III > IV$

Answer 1

Answer: (B)

$I > III > II > IV$

Answer 2

The order of basicity is $I > III > II > IV$ The lone pair of electrons on N is more readily available for protonation in I and III then in II. Ill contains an oxygen atom which has -I effect due to which it is less basic than I. In compound IV lone pair of $e^-s$ on N-atom is contributed towards the aromatic sextet formation and hence is not at all available for protonation. Hence option (b) is correct.