Why does 2,6-dimethyl-N,N-dimethylaniline exhibit a significantly higher basic strength compared to — Amines Chemistry Question

💡 Solution & Explanation

In N,N-dimethylaniline, the lone pair on nitrogen is delocalized into the aromatic ring, rendering it weakly basic. However, in 2,6-dimethyl-N,N-dimethylaniline, the bulky ortho methyl groups sterically clash with the methyls residing on the nitrogen. This forces the entire $-N(CH_3)_2$ group to twist out of the planar alignment of the ring (Steric Inhibition of Resonance). The lone pair is thereby trapped and localized on the nitrogen atom, drastically enhancing its availability for protonation.