Question

Benzene reacts with n-propyl chloride in the presence of anhydrous `AlCl_(3)` to give predominantly
A. `n-`Propylbenzene
B. Isopropylbenzene
C. `3-`Propyl`-1-`chlorobenzene
D. No reaction

Answer 1

Correct Answer - B
Propyl carbonium ion, `CH_(3)CH_(2)overset(+)CH_(2)` is primary carbonium ion, it rearranges to the more stable secondary carbonium ion `CH_(3)overset(+)CHCH_(2)` which then reacts to form isopropylbenzene.
`underset("Propyl carbonium ion"(1^(@))(CH_(3)-underset(H)underset(|)(C )H-overset(o+)(C )H_(2))rarr underset("Iso Propyl carbonium ion"(2^(@))(CH_(3)-overset(o+)(C )H-CH_(3))`