This PPT includes the information about Quinoline nucleus ( fused heterocyclic compound ) Benzene fused with pyridine ring.

1. Fused Heterocyclic compounds
Quinoline (1-benzopyridine)
Lecture by
S.Mathivanan.,M.Pharm
Asst professor
Pharmacy

2. • Quinoline is a heterocyclic aromatic organic
compound with the chemical formula C9H7N.
• Heterocyclic analogue of naphthalene which
can be obtained by fusing a benezene ring to
pyridine nucleus. Other names
1-Azanaphthalene
1-Benzazine
Benzazine
Benzazabenzene
Benzopyridine
1-Benzine
Quinolin
Chinoline
Chinoleine
Chinolin
Leucol
Leukol
Leucoline

3. • Quinoline was first extracted from coal tar in 1834 by German
chemist Friedlieb Ferdinand Runge; he called quinoline leukol ("white
oil" in Greek).
• Coal tar remains the principal source of commercial quinoline.
• In 1842, French chemist Charles Gerhardt obtained a compound by
dry distilling quinine, strychnine, or cinchonine with potassium
hydroxide; he called the compound Chinoilin or Chinolein.
• The German chemist August Hoffmann eventually recognized that
the differences in behaviors was due to the presence of contaminants
and that the two compounds were actually identical.

5. Physical properties
• It is a colorless hygroscopic liquid
• Strong odor.
• Aged samples, especially if exposed to light,
become yellow and later brown.
• Slightly soluble in cold water but dissolves readily
in hot water and most organic solvents
• Density : 1.093 g/mL
• Melting point : −15 °C
• Boiling point : 237 °C

6. 1. Aromatic
Chemical properties

7. Resonating structure of Quinoline :
• The resonance energy of quinoline has been calculated from the
heat of combustion data and is found to be 47.3 kcal/mole. This value
is lower than the resonance energy of naphthalene (61.0 kcal/mole)
• The resonance hybrid of quinoline is represented by the 5 canonical
structures (a-e), Among which (a-c) corresponds to Naphthalene.

8. • Weak Base: As both quinoline and
isoquinoline are similar like pyridine, where
nitrogen electron pair are not involved in the
conjugation with ring. Both undergoes
nucleophilic substitution reaction readily on
heterocyclic ring and electrophilic substitution
more readily than pyridine.
• Hydrogen bonding

9. SYNTHESIS OF QUINOLINE

10. Combes quinoline synthesis
Conrad-Limpach synthesis
Doebner reaction
Doebner-Miller reaction
Gould-Jacobs reaction
Skraup synthesis
1. Combes quinoline synthesis using anilines and β-diketones.
2. Conrad-Limpach synthesis using anilines and β-ketoesters.
3. Doebner reaction using anilines with an aldehyde and pyruvic acid to form quinoline-4-carboxylic acids
4. Doebner-Miller reaction using anilines and α,β-unsaturated carbonyl compounds.
5.Gould-Jacobs reaction starting from an aniline and ethyl ethoxymethylenemalonate
6. Skraup synthesis using ferrous sulfate, glycerol, aniline, nitrobenzene, and sulfuric acid.

11. Synthesis
1. Skraup Quinoline synthesis

12. Synthesis
1. Skraup Quinoline synthesis
Mechanism

13. Synthesis
1. Skraup Quinoline synthesis

14. Synthesis
2. Doebner-Miller Synthesis

15. Synthesis
3. Friedlander Synthesis

17. Reactions
1. Electrophilic addition to N

18. Reactions
2. Electrophilic aromatic substitution

19. Reactions
3. Reduction reactions

20. Reactions
4. Oxidation

21. Reactions
5. Nucleophilic substitution
If the C-2 position is occupied then the nucleophilic attack will be preferred at C-4 position.

22. Medicinal uses
Primaquine
Hydroxychloroquine

23. Medicinal uses

24. Thank you..!!!