Question

The major product formed in the following reaction sequence is
 

 

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

The sequence \[ \text{Benzene} \rightarrow \text{Cumene} \rightarrow \text{Cumene Hydroperoxide} \rightarrow \text{Phenol} \] is known as the Cumene Process, the most important industrial method for the manufacture of phenol.

Answer 1

The Correct Option is A

Step 1: Identify the first reaction.
Benzene reacts with isopropyl chloride in the presence of anhydrous \(AlCl_3\). This is a Friedel-Crafts alkylation reaction. \[ C_6H_6 + (CH_3)_2CHCl \xrightarrow{AlCl_3} C_6H_5CH(CH_3)_2 \] Thus, isopropylbenzene (cumene) is formed.

Step 2: Reaction of cumene with oxygen.
Cumene undergoes air oxidation with oxygen to form cumene hydroperoxide. \[ C_6H_5CH(CH_3)_2 \xrightarrow{O_2} C_6H_5C(CH_3)_2OOH \] This is the industrial Cumene Process.

Step 3: Acidic hydrolysis of cumene hydroperoxide.
On treatment with \[ H_3O^+ \] cumene hydroperoxide undergoes cleavage to give phenol and acetone. \[ C_6H_5C(CH_3)_2OOH \xrightarrow{H_3O^+} C_6H_5OH + (CH_3)_2CO \]

Step 4: Identify the major aromatic product.
The aromatic product obtained is \[ C_6H_5OH \] which is phenol.
Acetone is formed as the accompanying carbonyl compound.

Step 5: Final conclusion.
Therefore, the major product formed in the given reaction sequence is \[ \boxed{\text{Phenol}} \] Hence, option (1) is correct.