Number of compounds from the following which cannot undergo Friedel-Crafts reactions is: toluene, nitrobenzene, xylene, cumene, aniline, chlorobenzene, m-nitroaniline, m-dinitrobenzene
Answer
4
Solution
Friedel-Crafts reactions fail when the ring carries a strongly deactivating group (–NO2) or a basic –NH2 group, which forms a complex with the Lewis acid AlCl3 (N becomes positive and deactivates the ring).
Toluene, xylene and cumene (alkyl groups, activating) and chlorobenzene (only weakly deactivating) do react.
The compounds that cannot react are:
[figure]
∴ Number = 4
Answer: 4