Question

Nitrobenzene is used as a solvent for Friedel-crafts alkylation of bromo benzene because

• A. Nitrobezene cannot be used in alkylation
• B. Nitrobenzene is less reactive than bromobenzene
• C. Nitrobenzene is more reactive than bromobenzene
• D. None of the above

Answer 1

Answer: (B)

Nitrobenzene is less reactive than bromobenzene

Nitrobenzene is used as a solvent in Friedel-Craft's reaction

because it does not interfere in the reaction due to less

reactivity than bromobenzene.

Nitro ($-N{O}_2$) group strongly deactivates aromatic rings to

electrophilic aromatic substitution reactions because they

draw electron density away from the ring by resonance,

thus destabilizing the carbocation intermediate.

Friedel-Crafts reactions are particularly sensitive to

deactivating substituents and cannot occur on molecules

with moderate to strong deactivating groups on them.

Hence, Option B is correct.