Question

Aspirin is obtained by acetylation of

• A. Phenol
• B. Salicylaldehyde
• C. 2-Hydroxybenzoic acid
• D. Benzoic acid

Hint:

Aspirin is acetylsalicylic acid. It is made by acetylation, which means replacing the hydrogen of an –OH group with an acetyl group (using acetic anhydride or acetyl chloride).

Answer 1

The Correct Option is C

Step 1: Recall what aspirin is.
Aspirin is the common name of acetylsalicylic acid. The word acetyl tells us an acetyl group \((CH_3CO-)\) has been put on.

Step 2: Understand acetylation.
Acetylation means replacing the hydrogen of a phenolic \(-OH\) group with an acetyl group, usually using acetic anhydride or acetyl chloride.

Step 3: Find the starting material.
To make acetylsalicylic acid we must start from salicylic acid. Salicylic acid is 2-hydroxybenzoic acid, which has both a phenolic \(-OH\) and a \(-COOH\) group.

Step 4: Acetylate the right group.
The phenolic \(-OH\) of 2-hydroxybenzoic acid is acetylated, turning \(-OH\) into \(-OCOCH_3\), giving aspirin.

Step 5: Conclude.
So aspirin is obtained by the acetylation of 2-hydroxybenzoic acid (salicylic acid).

\[ \boxed{\text{2-Hydroxybenzoic acid}} \]