Fused heterocyclic compounds quinoline

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 C 9 H 7 N . 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 .  T he 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.

4. Physical properties It is a colorless  hygroscopic  liquid S trong odor. Aged samples, especially if exposed to light, become yellow and later brown. S lightly 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

5. 1. Aro m at i c Chemical properties

6. 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.

7. 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

8. SYNTHESIS OF QUINOLINE

9. Combes quinoline synthesis Conrad- Limpach synthesis   Doebner reaction   Doebner -Miller reaction   Gould-Jacobs reaction Skraup synthesis   1. Combes quinoline synthesis  using  anilines  and β- di ketones . 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 .

10. Synthesis 1. Skraup Quinoline synthesis

11. Synthesis 1. Skraup Quinoline synthesis Mechanism

12. Synthesis 1. Skraup Quinoline synthesis

13. Synthesis 2. Doebner-Miller Synthesis

14. Synthesis 3. Friedlander Synthesis

15. Reactions 1. Electrophilic addition to N

16. Reactions 2. Electrophilic aromatic substitution

17. Reactions 3. Reduction reactions

18. Reactions 4. Oxidat i on

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

20. Medicinal uses Primaquine Hydroxychloroquine

21. Medicinal uses

22. Thank you..!!!