Question

Which of the following product is formed when salicylic acid is treated with (CH₃CO)₂O in the presence of acid ?

• A. o-C₆H₄(COOCH₃)(OH) — methyl 2-hydroxybenzoate
• B. o-C₆H₄(OCOCH₃)(OH)
• C. o-C₆H₄(COCH₃)(COOH)
• D. o-C₆H₄(OCOCH₃)(COOH) — aspirin (acetylsalicylic acid)

Hint:

Acetic anhydride acetylates the phenolic -OH of salicylic acid → aspirin; -COOH stays.

Answer 1

The Correct Option is D

Identify the functional groups and the reagent's job. Salicylic acid carries a $phenolic$ hydroxyl next to a carboxylic acid. Acetic anhydride is an acetylating agent: under acid it converts a phenol –OH into an acetate ester –OCOCH₃, leaving the –COOH group unchanged.
The result is acetylsalicylic acid (aspirin), with substituents –OCOCH₃ and –COOH on the ring. Options keeping a free –OH (no acetylation) or esterifying the acid instead are incorrect. Correct option: (D).