write the method of preparation of phenol from chlorobenzene by Dow's process. what happens when phenol reacts with(i) conc.H2SO4 and (ii) acetyl chloride in presence of aqueous NaOH solution ?
Answers
Answer:
The method of preparation of Phenol from Chlorobenzene is an extreme condition Aromatic Substitution Reaction taking place at high pressure and Temperature.
The above image explains the process of Dow's Process.
(I) When Phenol is reacted with concentrated Sulphuric acid, Electrophilic Aromatic Substitution occurs.
under the +M effect of Alcohol (OH) group,Negative charges develop at Ortho and para Position where the SO3H Electrophile attacks.
we get two products :-
a) Ortho Hydroxy Benzene Sulphonic acid
b) Para Hydroxy Benzene Sulphonic acid
out of the Two,Para product is major due to less steric Hindrance.
(ii) Acetyl Chloride reacts with phenol in presence of aq. NaOH solution to form Ester.
The reaction is given in the attached image.
