Write the reaction involved in the following:
Friedel-Crafts acylation of anisole
Friedel-Crafts acylation of anisole
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Solution and Explanation
In Friedel-Crafts acylation an acyl group (\(-COR\)) is introduced into an aromatic ring using an acid chloride and anhydrous \(AlCl_3\). The methoxy (\(-OCH_3\)) group of anisole is ortho/para directing, and substitution occurs mainly at the para position.
Step 1:
Anisole is treated with acetyl chloride (\(CH_3COCl\)) in the presence of anhydrous \(AlCl_3\) as catalyst.
Step 2:
The acylium ion (\(CH_3CO^+\)) attacks the ring mainly at the para position to give p-methoxyacetophenone (4-methoxyacetophenone) as the major product.
Answer: \(C_6H_5OCH_3 + CH_3COCl \xrightarrow{anhyd.\ AlCl_3}\) 4-methoxyacetophenone (p-\(CH_3O\text{-}C_6H_4\text{-}COCH_3\)) \(+ HCl\).
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(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
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(v) Aniline does not undergo Friedel-Crafts reaction.
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