Consider the basic strength of unsubstituted aniline (). Which of the following specific structural — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

Ortho-substituted anilines (A and D), regardless of the substituent being electron-withdrawing ($-Cl$) or simply bulky ($-t-butyl$), suffer from Steric Inhibition of Protonation (SIP), making them less basic than aniline. A para-nitro group (C) exerts intense $-M$ and $-I$ effects, heavily withdrawing electron density and drastically decreasing basicity. A para-methoxy group (B), however, exerts a strong $+M$ effect, enriching the electron density on nitrogen and making it MORE basic than aniline.