Question

What products are formed when the following compound is treated with Br₂ in the presence of FeBr₃?

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

To determine the products formed when the given compound is treated with Br₂ in the presence of FeBr₃, we need to understand the mechanism of electrophilic aromatic substitution, specifically bromination.

Step-by-Step Explanation:

1. The compound given is o-xylene, which is a benzene ring with two methyl groups in ortho positions.
2. The reaction involves bromine (Br₂) in the presence of a catalyst (FeBr₃), which helps generate the electrophile, Br⁺.
3. The FeBr₃ catalyst assists in polarizing the Br₂ molecule to form the strongly electrophilic bromine species, Br⁺.
4. o-xylene is highly activated towards electrophilic substitution because of the electron-donating methyl groups.
5. The presence of two ortho methyl groups directs the incoming bromine predominantly to the para position relative to one of the methyl groups, due to sterics and regioselectivity. Thus, the major product is 4-bromo-o-xylene.

Conclusion:

The product formed is 4-bromo-o-xylene. This matches the second option provided.

Therefore, the correct answer is the product shown in the image above.