Anisole undergoes Friedel-Crafts reaction with alkyl halide and acyl halide in the presence of anhydrous aluminum chloride as a Lewis acid catalyst. The reaction introduces the alkyl and acyl groups at ortho and para positions.
Describe the Friedel-Crafts reaction of anisole and the positions at which alkyl and acyl groups are introduced in the presence of anhydrous aluminum chloride.
Share
In the Friedel-Crafts reaction of anisole with anhydrous aluminum chloride (AlCl₃), the methoxy group (OCH₃) activates the benzene ring, making it susceptible to electrophilic aromatic substitution. The electrophile, often generated in situ, reacts with the activated benzene ring. For alkylations, the alkyl group substitutes at the ortho and para positions, yielding a mixture of ortho and para isomers. In acylations, the acyl group introduces exclusively at the ortho position due to steric hindrance preventing para substitution. The reaction is a valuable method for synthesizing substituted aromatic compounds, but it may suffer from polyalkylation in alkylations.