Question

Write the equations involved in the following reactions:
(a) Nitration of benzene (b) Friedel-Crafts alkylation.​

Answer 1

Answer:

Write equations of the following reactions:

(i) Friedel-Crafts reaction alkylation of anisole.

(ii) Nitration of anisole.

(iii) Bromination of anisole in ethanoic acid medium.

(iv) Friedel-Crafts acetylation of anisole.

Answer 2

Answer:

(a) Nitration of benzene

The nitro (NO₂) group can be added to benzene through the use of nitric acid (HNO₃) in the presence of sulfuric acid

C₆H₆ + HNO₃ → C₆H₅NO₂ + H₂O

This reaction proceeds through

1. activation of the electrophile by acid
2. attack of the activated electrophile by benzene
3. deprotonation to restore the aromatic ring (and regenerating the acid catalyst)

(b) Friedel-Crafts alkylation

• R-X must be an alkyl halide (typically alkyl chlorides, bromides, or iodides)
• Lewis acid often AlCl₃ but can vary widely (eg., FeCl₃, ZrCl₄)
• Carbocation rearrangements can occur.