JEE MainChemistryAlcohols Phenols and Ethers
Consider the following reaction sequence: Anisole Br ₂ in CS ₂ 'A' (major product) 'A' HNO ₃, H ₂ SO ₄ (1 equivalent) 'B' (major product) The major products 'A' and 'B' respectively are:
Options
- AA = 4-bromoanisole ; B = 4-bromo-2-nitroanisole
- BA = 2-bromoanisole ; B = 2-bromo-4-nitroanisole
- CA = 4-bromoanisole ; B = 4-bromo-3-nitroanisole
- DA = 4-bromoanisole ; B = 4-nitroanisole
Correct answer
A. A = 4-bromoanisole ; B = 4-bromo-2-nitroanisole
Step-by-step solution
In the first step, bromination of anisole with Br ₂ in CS ₂ yields 4-bromoanisole as the major product 'A' due to less steric hindrance at the para position compared to the ortho position. In the second step, 4-bromoanisole undergoes nitration. The molecule has two substituents: - OCH ₃ (a strongly activating, ortho/para directing group) and - Br (a weakly deactivating, ortho/para directing group). When directing effects oppose each other, the more powerful activating group determines the regiochemistry. Therefore,