2-(5-Oxazolyl)benzoic Acid

This compound is typically isolated as a crystalline solid ranging from off-white to pale yellow. Its molecular formula is C10H7NO3, corresponding to a molecular weight of 189.17. The melting point generally exceeds 200 °C, often with decomposition observed upon prolonged heating. The calculated density is approximately 1.38 g/cm³ under ambient conditions. It exhibits moderate solubility in polar organic solvents such as dimethyl sulfoxide and dimethylformamide, limited solubility in methanol and ethanol, and negligible solubility in water and nonpolar solvents like dichloromethane and hexane. The molecule consists of a benzoic acid core with an oxazole ring directly attached at the 2position. The carboxylic acid is susceptible to deprotonation, esterification, and amide formation, while the oxazole nitrogen provides hydrogen bond accepting capability. Storage in tightly sealed containers protected from light and moisture at ambient temperature is generally adequate, though desiccated conditions are recommended for prolonged storage. Contact with strong oxidizing agents and strong bases should be avoided.

2(5Oxazolyl)benzoic acid is a bifunctional aromatic compound featuring an oxazole ring directly attached to the 2position of a benzoic acid moiety. The molecule combines an electronrich oxazole heterocycle with an electrondeficient benzoic acid, creating a pushpull system with unique electronic properties. The oxazole ring, a fivemembered aromatic heterocycle containing both oxygen and nitrogen atoms, provides hydrogen bond accepting capability through the nitrogen and can participate in πstacking interactions. The carboxylic acid group offers a versatile handle for further derivatization through amide bond formation, esterification, or salt generation. The ortho relationship between the oxazole and carboxylic acid enables potential intramolecular interactions and chelation with metal ions. This compact, multifunctional scaffold serves as a valuable building block in medicinal chemistry and materials science for constructing more complex molecules, where the oxazole ring can serve as a bioisostere for amide bonds or other heterocycles while the carboxylic acid provides a point of attachment for further elaboration.

Pharmaceutical Intermediate
In drug discovery, this oxazolebenzoic acid derivative is employed as a building block for synthesizing enzyme inhibitors and receptor modulators. The carboxylic acid enables convenient amide coupling with aminecontaining pharmacophores, while the oxazole ring can engage in hydrogen bonding and πstacking interactions with biological targets. Derivatives of this scaffold have been explored for their potential activity against cancer, inflammation, and infectious diseases, where the rigid, planar structure contributes to binding affinity and selectivity.

Building Block for Heterocyclic Synthesis
The compound serves as a precursor for constructing fused heterocyclic systems such as oxazolo[4,5c]quinolines and oxazolo[5,4b]pyridines through cyclocondensation reactions. These ring systems are investigated for their pharmacological properties, with the oxazole core providing conformational rigidity and hydrogenbonding capacity beneficial for target recognition. The carboxylic acid can be further elaborated after heterocycle formation to introduce additional diversity.

Ligand for Metal Complexes
The combination of oxazole nitrogen and carboxylate oxygen donors enables the compound to act as a bidentate ligand for transition metals. Metal complexes derived from this scaffold are studied for their catalytic activity in oxidation and crosscoupling reactions, as well as for their potential as luminescent materials. The rigid geometry imposed by the ortho substitution pattern ensures welldefined coordination geometries, facilitating the design of catalysts with predictable performance.

Organic Synthesis Building Block
As a versatile synthetic intermediate, 2(5oxazolyl)benzoic acid participates in diverse transformations including amide coupling, esterification, and transitionmetalcatalyzed crosscoupling reactions after appropriate activation. The oxazole ring can undergo electrophilic substitution at positions activated by the heteroatoms. Its utility extends to the synthesis of natural product analogs and functional materials where the combination of an oxazole heterocycle and a carboxylic acid imparts desirable properties such as metal coordination and hydrogenbonding capacity.