Q.Outline the cumene process for the industrial manufacture of phenol, naming the useful by-product.

Benzene is Friedel-Crafts alkylated with propene (acid catalyst) to give cumene (isopropylbenzene), $\text{C}_6\text{H}_5\text{CH(CH}_3)_2$. Cumene is then oxidised by bubbling air through it to give cumene hydroperoxide, $\text{C}_6\text{H}_5\text{C(CH}_3)_2\text{OOH}$. Treating this hydroperoxide with dilute acid triggers a rearrangement and cleavage that gives phenol together with acetone, $\text{CH}_3\text{COCH}_3$, as a co-product. Acetone is itself a valuable industrial solvent and chemical feedstock, so this route is economically attractive because it produces two saleable prod …

Trace the three stages in order (alkylation, air oxidation, acid-catalysed cleavage), naming the interm …

Forgetting or misnaming the by-product (acetone), which is one of the reasons the cumene process is industrially preferre …