Write chemical reaction for the preparation of phenol from chlorobenzene.


There are many ways to this conversion. Two of them are given below:-


(a)


In the above conversion, the chlorobenzene is treated with a base such as NaOH, KOH etc. (strong base). The base abstracts the hydrogen from the C-2 position (it can also abstract the hydrogen from the C-6 position, as both are equally acidic) leaving the negative charge at that position.


In the next step Cl- leaves, leaving behind the positive charge at that carbon. Both the negative charge and positive charge forms a bond resulting Benzyne as the intermediate.


After the formation of the Benzyne intermediate OH- of the base attacks at the C-1 position and further, the H+ attacks to stabilize the negative charge thus resulting in the phenol.


(b) The second method is as follows:



The reaction can start from benzene also. Chlorination of benzene gives Chlorobenzene. When it is further treated with NaOH and H2O at 350°C it results in the formation of sodium phenoxide which on further treatment H+ gives Phenol as the final product.


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