Alkylbenzene is formed when benzene is treated with an alkyl halide in...
Friedel-Crafts alkylation reaction is the type of reaction that occurs when benzene is treated with an alkyl halide in the presence of anhydrous aluminum chloride to form alkylbenzene. This reaction involves the substitution of a hydrogen atom on the benzene ring with an alkyl group from the alkyl halide.
Mechanism of Friedel-Crafts alkylation reaction:
1. Formation of the electrophile: The anhydrous aluminum chloride reacts with the alkyl halide to form an alkyl cation, which is the electrophile in the reaction.
2. Attack of the electrophile: The electrophile attacks the benzene ring, which is a nucleophile due to the presence of pi electrons in the ring.
3. Formation of the intermediate: The alkyl cation becomes bonded to the benzene ring, forming an intermediate known as the arenium ion.
4. Rearrangement of the arenium ion: The arenium ion undergoes rearrangement to form a more stable carbocation intermediate, which is resonance-stabilized by the benzene ring.
5. Deprotonation: A chloride ion, which is present due to the reaction between the aluminum chloride and the alkyl halide, acts as a base and deprotonates the carbocation intermediate, forming the final product, alkylbenzene.
Advantages of Friedel-Crafts alkylation reaction:
1. It is a useful method for synthesizing alkylbenzenes, which are important intermediates in the production of various chemicals and materials.
2. The reaction is relatively simple and can be carried out under mild conditions.
3. The selectivity of the reaction can be controlled by adjusting the reaction conditions, such as the choice of alkyl halide and reaction temperature.
Disadvantages of Friedel-Crafts alkylation reaction:
1. The reaction can be limited by the availability of suitable alkyl halides, which may be expensive or difficult to obtain.
2. The reaction can also suffer from issues such as over-alkylation and side reactions, which can reduce the yield and purity of the final product.
Alkylbenzene is formed when benzene is treated with an alkyl halide in...
Aluminum chloride reacts with methyl chloride to form an electrophile. This electrophile attacks the π electron to form carbocation. As a result, alkylbenzene is formed along with HCl as product.
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