Question

Arrange the given compounds in the decreasing order of their basic strengths:

• A. B > A > C > D
• B. A > C > B > D
• C. C > A > B > D
• D. A > B > C > D

Answer 1

The correct option is B A > C > B > D

A: Amidine
It's conjugate acid formed will be stabilized with equivalent resonating structures , and $s{p}^2$ hybridised nitrogen will be more basic here because the lone pair of other nitrogen is involved in resonance.


C: It has two alkyl groups, showing +I effect and hence increasing the electron density making it more basic than B (ethylamine) where there is only one alkyl group.
In D: The lone pair is delocalised so it is less available on the nitrogen atom, hence it is least basic.


Correct order is:
A > C > B > D