Question

Explain the industrial production of phenol of high purity and less production cost and also explain the bromination of phenol.

Answer 1

The cumene process (cumene-phenol process, Hock process) is an industrial process for synthesizing phenol and acetone from benzene and propylene.

This process converts two relatively cheap starting materials, benzene and propylene, into two more valuable ones, phenol and acetone. Other reactants required are oxygen from air and small amounts of a radical initiator.

Reaction of phenol with bromine is known as bromination of phenol. Solvent has great influence on the reaction.In different solvents ,different products are obtained.Action of bromine on phenol can be explained as.

1. Reaction with bromine in water: Phenol reacts with bromine water to give 2,4,6-tribromophenol. In water ionisation is fascilitated. Phenol get ionised to form phenoxide ion,which is even better ortho-para directing.Bromine also get ionised to larger extent to form large number of bromonium ions.

2. Reaction with bromine in $C{S}_2$: Phenol reacts with bromine in presence of Carbon disulphide to form mixture of o-bromophenol and p-bromophenol. Among which p-bromophenol predominates. In $C{S}_2$ ionisation is not fascilitated that much.