Question

The herbicide propanil, shown below, is synthesized commercially from chlorobenzene. Which sequence of reactions would be the most effective for carrying out this synthesis?

• A. Chlorination, nitration, reduction, acylation
• B. Nitration, chlorination, reduction, acylation
• C. Chlorination, reduction, nitration, acylation
• D. Nitration, reduction, chlorination, acylation

Answer 1

The correct option is B Nitration, chlorination, reduction, acylation


$-N{H}_2$ group is required at para position, so start with nitration first which can be reduced to amine in further step. Since chlorobenzene is ortho, para directing group hence chlorination in first step leads to blocking of para position.