conversion of chlorobenzene to phenol by dows process follow which mechanism?
Dow's Process
When chlorobenzene is heated with NaOH solution at 623K under 300 atm pressure, it forms sodium phenoxide which upon acidification gives phenol.
Mechanism
The reaction is believed to occur via benzyne mechanism. Chlorobenzene forms benzyne by removal of H+ by the attack of base then removal Cl-. The benzyne is attacked by OH- where a negative charge appears at the ortho position w.r.t. OH on the benzene ring. This reacts with H-OH or HCl, where H+ is taken by negatively charged ortho carbon and formation of phenol takes place.
When chlorobenzene is heated with NaOH solution at 623K under 300 atm pressure, it forms sodium phenoxide which upon acidification gives phenol.
Mechanism
The reaction is believed to occur via benzyne mechanism. Chlorobenzene forms benzyne by removal of H+ by the attack of base then removal Cl-. The benzyne is attacked by OH- where a negative charge appears at the ortho position w.r.t. OH on the benzene ring. This reacts with H-OH or HCl, where H+ is taken by negatively charged ortho carbon and formation of phenol takes place.