JEE Main 26 Feb 2021 Shift 2 Solved Paper

Here, 4-methoxybenzaldehyde in series of reaction finally forms 4-(iodomethyl) phenol (A). Let us compute the reaction step by step with mechanism as follows
(i) In first step, oxidising agent ( p-methoxybenzaldehyde) reacts with formaldehyde in presence of strong base NaOH to give p-methoxybenzyl alcohol along with sodium salt of methanoic acid. It is known as Cannizzaro's reaction. (ii) In second step, deprotonation of p-methoxybenzyl alcohol in presence of sodium hydride (NaH) to form alkoxide which further react with bromoethane in presence of DMF to give 1-ethoxymethyl-4-methoxybenzene.(iii) In last step, 1-ethoxymethyl-4-methoxybenzene undergoes solvolysis reaction followed by SN2 attack of two iodide ion (I ‌−) to give 4-iodomethyl phenol, iodoform and iodoethane.