Question

Mechanism of dows process

Answer 1

• Dow's process is one of the methods of preparation of phenol. In this method chlorobenzene is heated with aq. NaOH at about 623k and 300 atm. pressure to form sodium phenoxide, which is acidified by dilute acid like HCl to form phenol.

• Mechanism:—

• In first step, base removes hydrogen from the benzene ring,in the form of H+ ion to form carbanion which loses Cl- ion to form benzyne as an intermediate.

• In second step benzyne get attacked by nucleophile OH- to form Carbanion which subsequently get protonated to form phenol.

Answer 2

Dow's process is one of the methods of preparation of phenol. In this method chlorobenzene is heated with aq. NaOH at about 623k and 300 atm. pressure to form sodium phenoxide, which is acidified by dilute acid like HCl to form phenol.

Mechanism:—

In first step, base removes hydrogen from the benzene ring,in the form of H+ ion to form carbanion which loses Cl- ion to form benzyne as an intermediate.

In second step benzyne get attacked by nucleophile OH- to form Carbanion which subsequently get protonated to form phenol.