Question

What are the major products(if they form) , when the given compounds reacts with Aq.KOH and Alc.KOHseperately ?
a)1,4-dichlorobenzene
b)1-Bromo-4-chlorobenzene

Answer 1

Dear Student,

Aqueous KOH is used for hydrolysis of haloarenes and alcoholic KOH is used for dehydrohalogenation.
However, haloarenes do not undergo hydrolysis under ordinary conditions. It can occur if electron withdrawing group is attached at the otho or papa position, but since both Cl and Br has +M effect, therefore, no reaction will occur.
Reaction doesnot even occur with alc. KOH as the aromaticity of the ring will get disturbed if elimination occurs.