Question

What is the major product when toluene reacts with concentrated sulfuric acid (H\(_2\)SO\(_4\)) under heating conditions?

• A. Benzene sulfonic acid
• B. p-Toluenesulfonic acid
• C. o-Toluenesulfonic acid
• D. A mixture of o- and p-toluenesulfonic acids

Hint:

In electrophilic aromatic substitution reactions with methylated benzene rings (like toluene), the methyl group directs the incoming group to the ortho and para positions.

Answer 1

The Correct Option is D

When toluene reacts with concentrated sulfuric acid under heating conditions, electrophilic aromatic substitution occurs. The sulfonation reaction typically produces a mixture of ortho- and para- products due to the electron-donating methyl group on the toluene ring. The methyl group directs the sulfonic acid group to the ortho and para positions, making a mixture of o- and p-toluenesulfonic acids as the major products. - Option (A) is incorrect as toluene has a methyl group that directs substitution to the ortho and para positions, not to the benzene ring.
- Option (B) is incorrect as only the para product is favored, but both ortho and para products are formed.
- Option (C) is incorrect as the ortho product is not the only one produced. Therefore, the correct answer is option (D).