Heterocyclic compound oxazole

This slide discusses about Heterocyclic compound Oxazole. i.e oxygen and nitrogen atom in five membered ring.

1. Heterocyclic compound - Oxazole Lecture by S.Mathivanan ., M.Pharm Asst Professor Pharmacy

2. Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles . Oxazole is a weak base; its conjugate acid has a pKa of 0.8, compared to 7 for imidazole .

3. The first oxazole was prepared in 1840 by Zinin , who obtained the compound he called azobenzil from the reaction of benzil with alcoholic ammonia. Japp's formulation was the first recognition of the oxazole nucleus as an identity but six years later, in 1882, an independent series of observations led Hantzsch to a similar formulation of the oxazole nucleus.

4. Natural products and their derivatives have always been valuable sources for lead discovery in medicinal and agricultural chemistry because their novel scaffolds can provide modes of action different from those of existing agents. Pimprinine is an indole alkaloid first isolated from the filtrates of Streptomyces pimprina cultures in 1963. Members of this family display a range of biological activities, such as antiepileptic effects, platelet-aggregation-inhibitory effects, antitumor activity, and fungicidal activity.

5. Structural analog Isoxazole is an azole with an oxygen atom next to the nitrogen. Isoxazole rings are found in some natural products, such as ibotenic acid . Amanita muscaria

6. Physical properties It is a liquid Boiling point 69.5°C Pyridine like odour Miscible with water and some other organic solvents. Weakly basic (But slightly more than iso-oxazole ) Dipole moment : 1.5 D

7. CHEMICAL PROPERTIES

8. 1 H-NMR spectra of Oxazole

9. NMR spectra Oxazole exhibits characteristic resonances in 1 H NMR and 13 C NMR spectra. 1 H NMR – δ value between 7.00 to 8.00 ppm . 13 C NMR – Shows typical aromatic resonances. The shielding or de-shielding effect of C(2 ) substitution on the C(4) and C(5) resonances is < 2 ppm .

10. SYNTHESIS OF OXAZOLE

11. Fischer oxazole synthesis: Discovered by Hermann Emil Fischer in 1896. Oxazole is formed by reacting cyanohydrins and aldehyde in the presence of anhyd . HCl

12. REACTIONS OF OXAZOLE

13. Linezolid Napthooxazole

14. oxazole compounds could readily bind with a variety of enzymes and receptors in biological systems and show broad biological activities like antibacterial, antifungal, antiviral, antitubercular , anticancer, anti-inflammatory and so on. Up to now, a large number of oxazole -based medicinal drugs have been extensively used in clinic, such as Linezolid , Oxacillin , Sulfisoxazole , Raltegravir , Furazolidone as well as Toloxatone

15. Ditazole : NSAIDs Darglitazone : Thiazolidinedione class of drug. Act as an agonist of peroxisome prolifrator activated receptor- γ (PPAR- γ )

16. Thank you my dear students..!!!!