COMEDK20269 May 2026Evening ShiftChemistryCarboxylic Acid DerivativesActual
Identify the reagents, [A] and [B] used up when Salicylic acid undergoes the following reactions:
Options
- AA: ( CH ₃ CO )₂ O H ^+ B: CH ₃ CHO H ^+
- BA = CH ₃ COCl (warm) B = CH ₃ Br (warm)
- CA: CH ₃ OH H ^+ B: ( CH ₃ CO )₂ O H ^+(warm)
- DA: CH ₃ COO ^- OH ^- B: CH ₃ Cl (warm)
Correct answer
C. A: CH ₃ OH H ^+ B: ( CH ₃ CO )₂ O H ^+(warm)
Step-by-step solution
Salicylic acid (2-hydroxybenzoic acid) contains both a carboxylic acid group ( - COOH ) and a phenolic hydroxyl group ( - OH ). In reaction [A], the - COOH group is converted into an ester group ( - COOCH ₃ ), while the phenolic - OH group remains unaffected. This product is methyl salicylate (oil of wintergreen). This transformation is a Fischer esterification, which requires methanol ( CH ₃ OH ) in the presence of an acid catalyst ( H ^+ ). Thus, reagent [A] is CH ₃ OH H ^+ . In reaction [B], the phenolic - OH gr