Question

When Friedel-Crafts alkylation of benzene is carried out with $n$ -propyl bromide, the major product is

• A. $n$ -propyl benzene
• B. isopropyl benzene
• C. $2$ -ethyl benzene
• D. None of the above

Answer 1

Answer: (B)

During Friedel-craft alkylation of benzene with $n$- propyl bromide, the product will be isopropyl benzene (cumene) not $n$-propyl benzene because isopropyllum ion is more stable (as it is $2°$ carbocation) than $n$-propylium ion ($1°$ carbocation).

Thus