Question

Which of the following is a heterocyclic aromatic compound?

• A.
• B.
• C.
• D. None of the above

Answer 1

The correct option is B

Heterocyclic aromatic compounds are a major class of organic compounds characterized by the fact that some or all of the atoms in their molecules are joined in rings containing at least one atom other than carbon and follow Huckel's rule which states that if a cyclic, planar conjugated molecule has (4n + 2) $\pi$-electrons, it is considered as an aromatic compound.

The most common heterocycles are those having five or six-membered rings and containing hetero atoms like N, O, S.

This compound is an heterocyclic aromatic compound because it is a cyclic, planar conjugated molecule containing 6 $\pi$-electrons (S has a lone pair of electrons) and an hetero atom (S).