Unlike other aromatic amines, why is the following amine stongly basic ?

Answer

Due to the presence of bulkey `-NO_(2)` groups on its ortho positions, the `-Nme_(2)` group goes outside the plane of resonance to avoid steric repulsion. The `C-N` bond rotates and hence the lone pair of N goes perpendicular to the plane of benzene ring. As a result the resonance is stopped and hence the ione pair is readily available as a base.