Identify the major product B in the following reaction sequence:

Step-by-step solution

The given reactant contains two amino groups: a secondary aromatic amine (part of the tetrahydroquinoline ring) and a primary aliphatic amine ( - NH ₂ ). The lone pair of electrons on the nitrogen atom of the secondary aromatic amine is delocalized into the benzene ring due to resonance, making it less nucleophilic. On the other hand, the primary aliphatic amine has a localized lone pair, making it significantly more nucleophilic. When treated with 1 equivalent of acetaldehyde ( CH ₃ CHO ), the more nucleophilic pr