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JEE Main levelSingle correct optionDifficulty 2 of 3nc206

Coupling of benzenediazonium chloride with phenol is carried out in mildly alkaline medium rather than in neutral or acidic medium because

  1. Aalkali converts phenol into benzene
  2. Balkali converts the diazonium ion to a stronger electrophile
  3. Calkali protonates the phenol oxygen
  4. Dphenoxide ion is much more strongly activated towards the weakly electrophilic diazonium ion than phenol itself

Answer: D

The diazonium ion is a weak electrophile and needs a strongly activated ring. In mild alkali a good fraction of phenol is present as phenoxide, which is far more reactive. Strong alkali is avoided because the diazonium ion would be converted to unreactive diazotate.
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