Consider the following reaction sequence: Aniline NaNO ₂ , HCl, 273 K P H ₂ O, warm Q (i) NaOH, CO ₂ (ii) H ^+ R Ac ₂ O, H ^+ S The IUPAC name of the major product S is:

Step-by-step solution

Aniline reacts with NaNO ₂ and HCl at 273 K to form benzene diazonium chloride (P). Warming the diazonium salt with water hydrolyzes it to phenol (Q). Phenol undergoes Kolbe's reaction with NaOH and CO ₂ followed by acidification to yield salicylic acid (2-hydroxybenzoic acid) as product R. Finally, reaction of salicylic acid with acetic anhydride ( Ac ₂ O ) in the presence of an acid catalyst ( H ^+ ) results in the acetylation of the phenolic - OH group, producing 2-acetoxybenzoic acid (commonly known as aspirin)