Oxazole

• CAS: 288-42-6
• Catalog Number: ACM288426
• Category: Main Products
• Molecular Weight: 69.0628
• Molecular Formula: C3H3NO
• Synonyms: 3-Azafuran; (2,3-d) oxazole; 3-oxazolane; OXAZOLE
• IUPAC Name: 1,3-oxazole
• SMILES: C1=COC=N1
• InChI Key: ZCQWOFVYLHDMMC-UHFFFAOYSA-N
• Boiling Point: 69-70ºC
• Melting Point: -3ºC
• Flash Point: 19ºC
• Density: 1.05
• Appearance: clear to pale yellow liquid
• EC Number: 206-020-8
• Exact Mass: 69.02150
• Hazard Statements: F:Flammable;Xi:Irritant
• MDL Number: MFCD00009751
• Packing Group: II
• Safety Description: S16-S26-S36
• Size: 1g,5g,25g,100g
• WGK Germany: 3

Case Study

Oxazole as Versatile Building Block for Regioselective C-H Functionalization

Joshi, Sweta. The Pharma Innovation Journal (2017). 6(1): 109-117.

Oxazole is a five-membered heterocyclic compound containing oxygen and nitrogen at the 1,3-positions of the ring, recognized as a privileged scaffold in medicinal chemistry. 1,3-Oxazole derivatives exhibit a broad spectrum of pharmacological activities including analgesic, anti-inflammatory, antimicrobial, anticancer, antidepressant, antidiabetic, antiobesity, anticonvulsant, and diuretic properties. The structural versatility of the oxazole scaffold allows for extensive substitution patterns that significantly modulate biological activity, and its photophysical properties further enable applications in semiconductor devices and nonlinear optical materials.
Experimental Protocol: The authors conducted a comprehensive literature survey of oxazole chemistry spanning from the first synthesis of 2-methyloxazole in 1876 to contemporary research. They systematically cataloged natural oxazole-containing compounds, described key synthetic methodologies including cyclodehydration, cycloisomerization, and metal-catalyzed cross-coupling reactions, and compiled pharmacological screening data from published studies. The review also examined spectroscopic characterization methods (NMR, IR, UV) and structure-activity relationships across different oxazole derivatives.
Performance Evaluation: The review demonstrates that oxazole derivatives consistently exhibit potent biological activities across multiple therapeutic areas. Spirocyclopropyl oxazolones were identified as a novel class of herpes protease inhibitors. Phenacyl oxazolone derivatives showed promise in anticancer drug synthesis through intermolecular Diels-Alder reactions. The breadth of documented activities confirms oxazole as a versatile pharmacophore suitable for further drug development, with particular promise in anticancer and anti-inflammatory applications.

Oxazole in Natural Product Synthesis: A Scaffold for Bioactive Heterocycles

Shiroudi, Abolfazl, et al. New Journal of Chemistry 45.4 (2021): 2237-2248.

The oxidation reaction of oxazole initiated by hydroxyl (OH) radicals was investigated through computational methods to determine the dominant reaction pathways and kinetics under atmospheric conditions. Shiroudi, A., et al. employed density functional theory (DFT) calculations at the M06-2X and omegaB97XD levels of theory, coupled with transition state theory (TST) and Rice-Ramsperger-Kassel-Marcus (RRKM) kinetic calculations. The study examined both OH-addition and H-abstraction pathways, revealing that OH radical attack onto carbon atoms of the oxazole ring proceeds significantly faster than H-abstraction from the C-H bonds by several orders of magnitude. Pressure and temperature effects on rate coefficients were systematically evaluated across a wide range of atmospheric conditions.
Experimental Protocol: Electronic structure calculations were performed using DFT methods at the M06-2X/aug-cc-pVTZ and omegaB97XD/aug-cc-pVTZ levels. Reaction pathways were characterized for OH-addition at the C2, C4, and C5 positions and H-abstraction from the corresponding C-H bonds. Transition state structures were optimized and verified by intrinsic reaction coordinate calculations. RRKM theory was applied to compute pressure-dependent rate constants over the range of 0.001 to 1000 bar and temperatures from 200 to 400 K. Branching ratios were calculated to quantify regioselectivity.
Performance Evaluation: The effective kinetic rate coefficients demonstrated that the two-step reaction mechanism predominates under atmospheric conditions. OH-addition to the carbon adjacent to the oxygen atom (C2 position) was identified as the most favorable pathway, exhibiting the lowest barrier height from a kinetic perspective. Branching ratio analysis revealed that regioselectivity decreases with decreasing pressure and increasing temperature. The high-pressure limit required pressures above 100 bar to be reached, indicating that falloff behavior is significant under tropospheric conditions. These findings provide critical kinetic data for atmospheric chemistry models of heterocyclic compound degradation.

Custom Q&A

What is the molecular formula of oxazole?

The molecular formula of oxazole is C3H3NO.

What are some synonyms for oxazole?

Some synonyms for oxazole include 1,3-Oxazole, 3-Azafuran, and OXAZOLE.

What is the CAS number of oxazole?

The CAS number of oxazole is 288-42-6.

What is the InChI of oxazole?

The InChI of oxazole is InChI=1S/C3H3NO/c1-2-5-3-4-1/h1-3H.

What is the molecular weight of oxazole?

The molecular weight of oxazole is 69.06g/mol.

How many hydrogen bond donor counts are there in oxazole?

There are 0 hydrogen bond donor counts in oxazole.

How many hydrogen bond acceptor counts are there in oxazole?

There are 2 hydrogen bond acceptor counts in oxazole.

What is the topological polar surface area of oxazole?

The topological polar surface area of oxazole is 26Ų.

How many heavy atoms are there in oxazole?

There are 5 heavy atoms in oxazole.

Is oxazole a canonicalized compound?

Yes, oxazole is a canonicalized compound.