A direct iodination of benzene is not possible because
- iodine is an oxidizing agent
- resulting $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{I}$ is reduced to $\mathrm{C}_{6} \mathrm{H}_{6}$ by HI
- HI is unstable
- the ring gets deactivated
Solution
Asked in: JEE-TOPICTESTS-CHEMISTRY