question_answer

Which one of the nitrogen atoms in\[{{H}_{2}}\underset{I}{\mathop{N}}\,-\underset{II}{\mathop{N}}\,H-\overset{\begin{smallmatrix}  O \\  || \end{smallmatrix}}{\mathop{C}}\,-\underset{III}{\mathop{N}}\,{{H}_{2}}\] is the most nudeophilic?

A)  III

B)  I

C)  II

D)  All three nitrogen atoms are equally strong nudeophilic centres

Correct Answer: B

Solution :

        Electron present on nitrogen atom II and III takes part in conjugation with carbonyl group. Hence, due to this reason availability of electron present on these nitrogen atom decreases simultaneously nucleophilicity   decreases. While electron present on nitrogen atom (I) do not take part in conjugation and are most nucleophilic in nature.