Identify the major product [D] in the following reaction sequence:

Step-by-step solution

The starting material, benzanilide, has an activated benzene ring attached to the -NH- group and a deactivated ring attached to the -CO- group. Electrophilic aromatic substitution will preferentially occur on the activated ring. Friedel-Crafts alkylation with CH₃CH₂CH₂Cl and AlCl₃ involves the formation of a primary n -propyl carbocation, which rearranges to a more stable secondary isopropyl carbocation, (CH₃)₂CH^+ . This electrophile attacks the sterically less hindered para position of the activated ring to form