Which of the following statements accurately describe the chemical behavior and properties of Pyridi — Aromatic Hydrocarbons Chemistry Question
Question
Which of the following statements accurately describe the chemical behavior and properties of Pyridine during electrophilic aromatic substitution?
💡 Solution & Explanation
Pyridine is highly deactivated due to the electronegative nitrogen withdrawing electron density. In Friedel-Crafts reactions, the basic nitrogen lone pair rapidly reacts with the Lewis acid catalyst (like $AlCl_3$) to form an $N$ -complex salt, placing a full positive charge on nitrogen and powerfully deactivating the ring, causing the reaction to fail. When EAS does occur under drastic conditions, it favors C-3 to avoid positive charge on nitrogen. Nitrogen contributes only one electron to the $\pi$ -system; its lone pair resides in an orthogonal $sp^2$ orbital.