Question

$C_6{H}_6\underset{AlC{l}_3}{\overset{C{H}_{3}COCl}{\to }}A\underset{HCl}{\overset{Zn-Hg}{\to }}B$
The end product in the above sequence is:

• A. toluene
• B. ethyl benzene
• C. both the above
• D. none of the above

Answer 1

The correct option is B ethyl benzene

When benzene is alkylated, along with mono alkyl benzene, polyalkylation products are also obtained.
Hence, instead of direct alkylation, acylation is preferred. This is followed by the reduction of carbonyl group to methylene group.
$\underset{benzene}{C_6{H}_6}\underset{AlC{l}_3}{\overset{C{H}_{3}COCl}{\to }}\underset{A,actophenone}{C_6{H}_{5}COC{H}_3}\underset{HCl}{\overset{Zn-Hg}{\to }}\underset{B,ethylbenzene}{C_6{H}_{5}C{H}_{2}C{H}_3}$.