Pyridine is a heterocyclic compound used as a weak base and solvent in synthetic chemistry. It can be synthesized via the Hantzsch pyridine synthesis through the condensation of an aldehyde, dicarbonyl compound, and ammonia. Alternatively, pyridine can be synthesized via the Chichibabin reaction through the reaction of hydrazine with a carbonyl compound. Pyridine undergoes various reactions at its nitrogen and carbon positions, including oxidation to form pyridine N-oxide, nucleophilic substitutions, and other reactions at the carbon atoms.

1. Heterocycles:Heterocycles:
PyridinePyridine
Dr. Taj Khan
Dept. of Pharmaceutical Chemistry, Oriental
college of pharmacy Sanpada, New Mumbai.

3. Electron density

4. Used in synthetic chemistry as Weak base and solvent

7. Synthesis of Pyridine:

8. Hantzsch pyridine synthesis:
Condensation of aldehyde, dicarbonyl compound X 2 and NH3

10. Reaction with Hydrazine:
Chichibabin reaction:

12. E +

13. Pyridine itself act as Nu

14. Reaction at P position of substituents

16. Reduction of pyridine:
Oxidation: Leads to formation of pyridine N-Oxide

17. Nucleophilic Reactions:

18. Other reaction at C atom: