Question

Which of the N atoms is least basic in the given compound?

• A. a
• B. b
• C. c
• D. d

Answer 1

The correct option is A a

In (a), electron pair of $N{H}_2$ attached to benzene undergoes resonance i.e. lone pair on nitrogen is delocalised and hence less basic than other amine groups as lone pair involved in resonance is the major effect while considering the basicity than inductive effect. In (b), there is no inductive and resonance effect, hence least basic among (b), (c) and (d). In between (c) and (d), (c) has two methyl groups and (d) has one methyl group. Hence, (c) is more basic than (d).