Polycyclic and heteroatomic aromatic compounds

How many pi electrons are present in a pyridine ring?

• 4

• 6

• 8

• 10

Which heterocycle is known for its use in the synthesis of pharmaceuticals?

• Pyridine

• Furan

• Thiophene

• Pyrrole

What is the IUPAC name for a five-membered ring containing one nitrogen atom?

• oxazole

• imidazole

• pyrrole

• furan

What is the structure of a pyrrole ring?

• Five-membered ring with three carbon atoms and two nitrogen atoms

• Four-membered ring with three carbon atoms and one nitrogen atom

• Five-membered ring with four carbon atoms and one nitrogen atom

• Six-membered ring with three carbon atoms and two nitrogen atoms

Which is most reactive in electrophilic aromatic substitution?

• furan

• oxazole

• pyrrole

• thiazole

Basicity order of following hereocyclic compound is

• thiophene > furan > pyrrole

• thiophene > pyrrole > furan

• pyrrole > furan > thiophene

• pyrrole > thiophene > furan

Furan when react with acetic anhydrides and lewis acid yield

• 2-acetyl furan

• 3-acetyl furan

• 4-acetyl furan

• all of these

Which of the following is the aromatic compound/s

• cyclopentadiene cation

• cyclopentadine anion

• cycloheptatrine anion

• cyclopropene anion

Thiophene on heating with acetic anhydride in presence of H3PO4 gives

• tetrahydrothiophene

• 2-acetyl thiophene

• 2-phenyl azo-thiophene

• Thiophene-2-Sulphonic acid

Pyridine on heating with Br2 AT 500K gives

• 2-bromo pyridine

• 3,5-dibromo pyridine

• both a and b

• 4-bromo pyridine