Question

Describe the following electrophilic substitution reaction using phenol.

1. Nitrosation 

2. Nitration 

3. Sulphonation

Answer 1

1. Nitrosation:

Phenol can be readily nitrosoated at low temperature with nitrous acid.

2. Nitration: 

Phenol can be nitrated using 20% nitric acid at room temperature, a mixture of ortho and para nitro phenols are formed.

3. Phenol when treated with Conc.HNO₃ and Conc.H₂SO₄ , picric acid is formed.

4. Sulphonation:

Phenol when reacts with Conc.H₂SO₄ at 280K, o – phenol suiphonic acid is formed as major product. But when the reaction is carried out at 313K, the major product is p – phenol suiphonic acid.