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JEE Main levelSingle correct optionDifficulty 2 of 3hx193

In the Reimer-Tiemann reaction of phenol with $CHCl X_{3}$ and aqueous $NaOH$ , the electrophile that attacks the phenoxide ring is

Aphosgene, $COCl X_{2}$
Bthe trichloromethyl anion, $CCl X_{3} X^{-}$
Cdichlorocarbene, $: CCl X_{2}$
Dthe chloronium ion, $Cl X^{+}$

Answer: C

Hydroxide removes a proton from

CHCl X_{3}

giving

CCl X_{3} X^{-}

, which loses

Cl X^{-}

to form the electron-deficient

: CCl X_{2}

. This electrophile attacks the electron-rich ortho position of phenoxide; hydrolysis then gives salicylaldehyde.

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