Question

Arrange the following:

In increasing order of basic strength: C₆H₅NH₂, C₆H₅NHCH₃, C₆H₅CH₂NH₂.

 

Answer 1

C₆H₅NHCH₃ is more basic than C₆H₅NH₂ due to the presence of electron-donating −CH₃ group in C₆H₅NHCH₃.

Again, in C₆H₅NHCH₃, −C₆H₅ group is directly attached to the N-atom. However, it is not so in C₆H₅CH₂NH₂. Thus, in C₆H₅NHCH₃, the −R effect of −C₆H₅ group decreases the electron density over the N-atom. Therefore, C₆H₅CH₂NH₂ is more basic than C₆H₅NHCH₃.

Hence, the increasing order of the basic strengths of the given compounds is as follows:

C₆H₅NH₂ < C₆H₅NHCH₃ < C₆H₅CH₂NH₂.