Name: Nomenclature of Haloalkanes and Haloarenes
Uploaded: 2019-07-19
Duration: 9 min 1 s
Description: Haloalkanes are formed by replacing a hydrogen atom in an alkane with a halogen atom. Haloarenes are derived by replacing the hydrogen atom attached to the b...

Question

Discuss the mechanism of formation of phenol from chlorobenzene by reaction with aqueous sodium hydroxide at high temperatures and pressure. How can you distinguish

o

-chlorotoluene from benzyl chloride?

Accepted Answer

The preparation of phenol from chlorobenzene is a nucleophilic substitution reaction. The reaction takes place in 2 steps. In the first step a carbanion is formed by the nucleophilic attack of ${OH}^{-}$ on the carbon carrying the chlorine. This is slow and rate determining step. In the second step which is fast, the halogen leaves the carbanion and phenol is formed.

Benzyl chloride and $o$ -chlorotoluene can be distinguished by silver nitrate test. Benzyl chloride on boiling with aqueous solution of potassium hydroxide undergoes hydrolysis to form benzyl alcohol and potassium chloride. The reaction mixture on acidification with dil. ${HNO}_{3}$ and addition of ${AgNO}_{3}$ gives white precipitate of silver chloride. $o$ -chlorotoluene do not show this reaction.

Discuss the mechanism of formation of phenol from chlorobenzene by reaction with aqueous sodium hydroxide at high temperatures and pressure. How can you distinguish $o$ -chlorotoluene from benzyl chloride?

Important Questions on Haloarenes (Aryl Halides)

Learn and Prepare for any exam you want !

Discuss the mechanism of formation of phenol from chlorobenzene by reaction with aqueous sodium hydroxide at high temperatures and pressure. How can you distinguish o-chlorotoluene from benzyl chloride?

Important Questions on Haloarenes (Aryl Halides)

Learn and Prepare for any exam you want !

Discuss the mechanism of formation of phenol from chlorobenzene by reaction with aqueous sodium hydroxide at high temperatures and pressure. How can you distinguish $o$ -chlorotoluene from benzyl chloride?