3. Introduction of Phenol
• Phenol :
• Phenol is an aromatic compound. The chemical formula of this organic compound
is C6H6O. Phenol is also known as Carbolic acid.
• It consists of a hydroxyl group and phenyl group attached to each other. It
considerably dissolves in water. Earlier it was used as carbolic soap.
4. • It is mildly acidic and is corrosive to the respiratory tract, eyes, and skin.
• Structure of Phenol (Carbolic acid)- C6H6O
5. Physical properties
• 1 Phenol is a colourless,deliquescent solid.
• 2 It is crystalline in nature.
• 3 Its melting point is 41⁰C.
• 4 Its boiling point is181.7⁰C.
• 5 It has a distinct odour that is sickeningly sweet and tarry.
• 6 It is sparingly soluble in water forming pink solution at
room temperature (Due to the formation of HBond)
6. • 7 Phenols are less soluble in alcohols than water.
• 8 Phenol is acidic in nature with a ph of 5-6.
• 9 Phenol is a COMBUSTIBLE SOLId.
• 10 Its is highly poisonous.
7. Preparation of Phenol
• DOW PROCESS:
• In the Dow process, chlorobenzene is reacted with dilute sodium
hydroxide at 300°C and 3000 psi pressure.
8. From Diazonium Salts
• When an aromatic primary amine is treated with nitrous (NaNO2 +
HCl) acid at 273 – 278 K, diazonium salts are obtained.Upon
warming with water, these diazonium salts finally hydrolyze to
phenols
9. FROM BENZENE SULPHONIC ACID
• Benzenesulphonic acid can be obtained from benzene by reacting
it with oleum. This benzene sulphonic acid which is treated with
sodium hydroxide at high temperatures for the formation of
sodium phenoxide. Finally, sodium phenoxide on acidification gives
phenol.
10. FROM GRIGNARD REAGENT
• In the presence of dry ether, chlorobenzene or bromobenzene is
first transformed into phenyl magnesium halide. The Grignard
reagent produces phenol when it reacts with oxygen and is then
hydrolysed by a mineral acid.
