Question

What is the structural formula of Aspirin?
A)

B)

C)

D)

Answer 1

Hint: Salicylic acid serves as the starting material to prepare aspirin by acetylation. Acetylation is the process of addition of acetyl group ($$C{H}_{3}CO$$). Basic functional groups present in aspirin are ester and carboxylic acid.

Complete answer:
Salicylic acid is the common name of 2-hydroxybenzoic acid. It is acetylated using acetic anhydride $${(C{H}_{3}CO)}_{2}O$$ to give 2-acetoxybenzoic acid which is commonly known as aspirin.
Let us examine all the option given above one by one:
> Option (A): The compound given is 2- acetoxy phenol. It does have an ester group but instead of an acid functional group hydroxyl group is present. So, (A) is not correct.
> Option (B): Ester group is present in the compound but acid group is missing. It cannot be correct since it is a methyl ester of salicylic acid.
> Option (C): The given compound has both ester and acid functional groups. It is an acetyl derivative of salicylic acid or 2-hydroxybenzoic acid. It is, therefore, the correct structural formula of aspirin.
> Option (D): Though both the ester and acid functional groups are present in the compound, it is a mono-methyl ester of phthalic acid. So, it is not the correct answer.

Hence, the correct option is (C).


Additional Information Aspirin acts as a pain reliever. It reduces pain by inhibiting the synthesis of prostaglandins, chemicals that cause tissue inflammation and pain. It is a type of non-narcotic analgesics. It has anti-blood clotting properties and, therefore, is widely used to prevent heart attacks.

Synthesis of Aspirin:

Note: Do not mistake the structure given in option (D) as the answer. It might look similar to the structure of aspirin. Carefully check the connectivity of the carbon with the group present at position-2 with respect to the acid group on the benzene ring.