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Consider the following functional groups when attached to a benzene ring: - NO ₂ , - Cl , - CH ₃ , - OH , - CN , - Br , - OCH ₃ , - CF ₃ , - F , - NHCOCH ₃ , - CHO The number of groups that are deactivating towards electrophilic aromatic substitution but direct the incoming electrophile to ortho and para positions is

Correct answer

3

Step-by-step solution

In electrophilic aromatic substitution, activating groups are generally ortho/para directing, while deactivating groups are generally meta directing. However, halogens are a notable exception. They are deactivating overall because their strong inductive electron withdrawal ( -I effect) makes the ring less reactive than benzene. At the same time, they are ortho/para directing because their resonance effect ( +R effect) via lone pair donation stabilizes the carbocation intermediate when the electrophile attacks at th

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