Arrange the following compounds in the decreasing order of their relative rate of electrophilic aromatic substitution (Friedel-Crafts alkylation) with isopropyl chloride in the presence of anhydrous AlCl ₃ : (i) (ii) (iii)

Step-by-step solution

The rate of electrophilic aromatic substitution (such as Friedel-Crafts alkylation) depends on the electron density of the benzene ring. Electron-donating groups activate the ring by increasing electron density, while electron-withdrawing groups deactivate the ring by decreasing electron density. 1. In phenol (ii), the - OH group is a strongly activating group because its +M (resonance) effect is much stronger than its -I (inductive) effect. This makes the ring highly electron-rich and most reactive towards electro