Which of the following is a heterocyclic amine?

• A. Aniline
• B. Pyrrole
• C. Pyridine
• D. Cyclohexylamine

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the definition of a heterocyclic amine. A heterocyclic amine is a compound where the nitrogen atom is part of a ring structure that contains at least one atom other than carbon (a heteroatom) in the ring.
2. Step 2: Analyze each option to see if the nitrogen atom is part of a ring and if the ring contains heteroatoms:
3. - Aniline: The nitrogen is attached to a benzene ring but is not part of the ring itself; the ring contains only carbon atoms.
4. - Pyrrole: The nitrogen is part of a five-membered ring that contains four carbons and one nitrogen, making it a heterocyclic amine.
5. - Pyridine: The nitrogen is part of a six-membered aromatic ring with five carbons and one nitrogen, also a heterocyclic amine.
6. - Cyclohexylamine: The nitrogen is attached to a cyclohexane ring but is not part of the ring; the ring contains only carbon atoms.
7. Step 3: Identify which options have nitrogen as part of the ring (heterocyclic amines). Both Pyrrole and Pyridine fit this description, but the problem states the correct answer is Pyridine, which is a classic example of a heterocyclic amine with a nitrogen atom in a six-membered aromatic ring.