Table of Contents
Introduction of oxazole
Introduction of oxazole, it is the parent compound for various heterocyclic aromatic organic compounds. It is an azole having an oxygen & nitrogen atom separated by a carbon. With its unique properties and diverse applications, oxazole has become a key player in pharmaceuticals, agrochemicals, materials science, and organic synthesis. The aromaticity of oxazole is comparatively less than that of the thiazole. Oxazole is a weak base & its conjugate acid has a pKa value of 0.8.
In the realm of medicinal chemistry, oxazole derivatives have emerged as promising candidates for drug development. Their ability to interact with specific biological targets has led to the discovery of potent antimicrobial agents, anti-inflammatory drugs, and anticancer compounds. The structural flexibility of oxazole’s allows for modifications that can enhance their efficacy and selectivity against disease targets.
Oxazole’s also play a crucial role in materials science due to their exceptional thermal stability and electrical conductivity. These properties make them desirable for applications such as organic light-emitting diodes (OLEDs), organic semiconductors, and optoelectronic devices. Moreover, their incorporation into polymers enhances their mechanical strength and durability.
Physical properties of oxazole
1. It is a liquid with boiling point of 69°C.
2. It has a pyridine like colour.
3. It is miscible with water & some organic solvents.
4. It is weakly basic but more than isoxazole.
5. It is dipole moment is 1.5D.
Synthesis of oxazole
1. Robinson-Gabriel synthesis
In this reaction, oxazole’s are formed by the dehydration of 2-acylamino-ketones.
2. Fischer oxazole synthesis
In this reaction, discovered by Hermann Emil Fischer in 1896. Oxazole is formed by reacting cyanohydrins & aldehyde in the presence of anhydrous HCl.
Chemical reactions of oxazole
1. Reaction with acids(Protonation)
Oxazole accepts proton, act as base and forms oxazolium cation.
Oxazole’s are stable in presence of reducing agents. However, they can be reduced to oxazolidines with Na in ethanol.
Oxazole ring is not stable to oxidative conditions. Thus, it is opened by the action of oxidising agents such as cold KMnO4/chronic acid. However, the oxidation is stable with H2O2.
Medicinal uses of oxazole
1. Hexaprofen, flunoxaprofen are used as analgesic, anti-pyretic & anti-inflammatory drugs.
2. Its derivatives are used in pesticide, dyes, brightening agent and plastic.
3. It is used as building blocks for biochemical & pharmaceutical.
4. Diazole is a non-steroidal agent which shows analgesic & anti-pyretic activity.