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 + HN3 → RNH2 (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.