Benzene is treated with 1-chloro-2,2-dimethylpropane ((CH3)3C-CH2Cl) and anhydrous AlCl3. The major product is

(2-methylbutan-2-yl)benzene (tert-pentylbenzene)

(2,2-dimethylpropyl)benzene (neopentylbenzene)

(2-methylbutan-2-yl)benzene (tert-pentylbenzene)

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JEE Advanced levelSingle correct optionDifficulty 3 of 3o2148

Benzene is treated with 1-chloro-2,2-dimethylpropane ( $(CH X_{3}) X_{3} C - CH X_{2} Cl$ ) and anhydrous $AlCl X_{3}$ . The major product is

A(2,2-dimethylpropyl)benzene (neopentylbenzene)
B(3-methylbutan-2-yl)benzene
C(2-methylbutyl)benzene
D(2-methylbutan-2-yl)benzene (tert-pentylbenzene)

Answer: D

Ionisation would give a primary neopentyl cation, which is very unstable. A 1,2-methyl shift (concerted with ionisation) converts it to the tertiary cation

(CH X_{3}) X_{2} C X^{+} - CH X_{2} CH X_{3}

. This cation alkylates benzene, giving tert-pentylbenzene.

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Benzene is treated with 1-chloro-2,2-dimethylpropane ((CHX3​)X3​C−CHX2​Cl) and anhydrous AlClX3​. The major product is

Answer: D

More questions on Electrophilic aromatic substitution: mechanism and directing effects

Benzene is treated with 1-chloro-2,2-dimethylpropane ( $(CH X_{3}) X_{3} C - CH X_{2} Cl$ ) and anhydrous $AlCl X_{3}$ . The major product is