Question

Write only reactions for the preparation of benzophenone from benzonitrile.

Answer 1

The preparation of benzophenone from benzonitrile is a three-step process.
The structure of the benzophenone is as follows.

The structure of the benzonitrile is as follows.

Complete step by step solution:
Step-1:
In the step-1 hydrolysis of benzonitrile takes place. The chemical reaction of hydrolysis of benzonitrile is as follows.

-In the above reaction benzonitrile undergoes hydrolysis and forms benzoic acid as the product.
-Generally, nitriles undergo hydrolysis and form carboxylic acids as the products.
Step-2:
In step-2 benzoic acid undergoes reaction with soda lime under heat and forms benzene as the product. The reaction of benzoic acid with soda lime is as follows.

-The above reaction is called a decarboxylation reaction.
-A mixture of sodium hydroxide and calcium hydroxide is called soda lime.
Step-3:
-In step-3 benzene reacts with benzoyl chloride in presence of anhydrous aluminium chloride and forms benzophenone as the product.

-The above reaction is an example of an electrophilic substitution reaction.
-The above reaction is called Friedel craft’s acylation reaction.

Additional information:
-Benzophenone is used as an additive for plastics.
-Perfumes, sunscreen lotions, nail polish, and shampoo contain benzophenone in their composition.
-The molecular formula of benzophenone is ${{C}_{13}}{{H}_{10}}O$.
-Benzophenone is a liquid and sweet-smelling organic compound in nature.

Note: Benzophenone in excess amounts is toxic. Generally, Cyanide compounds are called nitriles as per IUPAC nomenclature. We cannot prepare benzophenone from benzonitrile in a single-step reaction. Here we discussed the easiest way of preparation of benzophenone from benzonitrile.