Answer: Primary amine with one less carbon.
- A Primary amine with one less carbon
- B Secondary amine formed by double substitution at nitrogen
- C Tertiary amine formed by exhaustive N-alkylation
- D Aromatic amine formed by direct ring amination
Correct answer: A. Primary amine with one less carbon
Explanation: Schmidt reaction: RCOOH + HN<sub>3</sub> → RNH<sub>2</sub> (primary amine with one fewer carbon, via isocyanate intermediate).
In aniline, the nitrogen's lone pair is pulled into the benzene ring through resonance, leaving less electron density available to accept a proton - which is why aniline is a much weaker base than methylamine, where the lone pair is fully available.
Concept context
Nitrogen-containing organic compounds. Covers classification (primary, secondary, tertiary), basicity comparison, preparation methods, and reactions including diazotization and coupling, key for understanding dyes and pharmaceuticals.