OXAZOLE

Oxazole provides a compact and highly adaptable heterocyclic framework for creating structurally diverse compounds in fine chemical and advanced synthesis applications.
Oxazole's derivatives are frequently incorporated into complex molecular architectures where controlled electronic behavior, ring stability, and substitution flexibility are important.
This versatility supports Oxazole's use across pharmaceutical research, crop-protection chemistry, fluorescent systems, specialty materials, and the preparation of high-value organic intermediates.

CAS Number: 288-42-6
EC Number: 206-020-8
Molecular Formula: C3H3NO
Molecular Weight: 69.06 g/mol

Synonyms: OXAZOLE, 1,3-Oxazole, 288-42-6, Oxazoles, FJZ20I1LPS, CHEBI:35597, DTXSID70182983, RefChem:389170, CHEBI:35790, DTXCID10105474, 206-020-8, MFCD00009751, 3-Azafuran, oxazol, Oxazole, 98%, PB17048, SCHEMBL14, CS-0020144, EN300-67789, Q413437, AA-511/25015522, F0001-0902, 3-Azafuran; (2,3-d) oxazole; 3-oxazolane; OXAZOLE;, 13-oxazole, EINECS 206-020-8, UNII-FJZ20I1LPS, AM20090378, FT-0606737, FT-0656517, SCHEMBL2856, SCHEMBL9206, SCHEMBL9379, SCHEMBL215314, SCHEMBL451698, SCHEMBL454236, 4-Methyl-5-EthoxyoxazoleOxazol, orb3029464, SCHEMBL1158985, SCHEMBL1876955, CHEMBL2171710, SCHEMBL15910507, PDK0161, SBB061419, STL557144, AKOS005206966, FO26619, HY-34631, DB-011626, NS00014384, O0287, ST51047437, F091888, J-017295, 1,3-Oxazol, 1,3-Oxazole, 1,3-Oxazole, 103851, 206-020-8, 288-42-6, Oxazole, 1，3-oxazole, 98%, AGN-PC-0BSZQ0, AGN-PC-0JK8YH, AGN-PC-0NKHKR, mono-oxazole, oxazol, oxazoline

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.

Oxazole is the parent molecule for a large class of heterocyclic aromatic compounds.
Oxazole is a weak base that can be used as an electron-deficient diene in the Diels-Alder cycloaddition reaction.
Oxazole undergoes nitration, sulfonation, halogenation, Friedel-Crafts alkylation, and acylation.

Oxazole is a five-membered heterocyclic compound featuring both nitrogen and oxygen in its ring structure, making it a valuable building block in organic synthesis.
Oxazole is recognized for its unique properties, including its ability to act as a versatile intermediate in the production of pharmaceuticals, agrochemicals, and various fine chemicals.

Oxazole derivatives are particularly significant in medicinal chemistry, where they serve as scaffolds for the development of novel drugs, including anti-inflammatory and antimicrobial agents.
Additionally, oxazole is utilized in the synthesis of dyes and pigments, enhancing its relevance in the textile and coatings industries.

Researchers and industry professionals appreciate oxazole for its stability and reactivity, which facilitate a range of chemical transformations.
Oxazole's derivatives can be tailored to exhibit specific biological activities, making them essential in drug discovery processes.
With its diverse applications and the potential for innovation in various sectors, oxazole remains a compound of interest for those looking to explore new chemical pathways and develop advanced materials.
    
Oxazole is a five-membered monocyclic heteroarene that is an analogue of cyclopentadiene with O in place of CH2 at position 1 and N in place of CH at position 3.
Oxazole is a mancude organic heteromonocyclic parent, a monocyclic heteroarene and a member of 1,3-oxazoles.

Oxazole ring is a biochemical present in various natural products.

Oxazole is a unsaturated five-membered nitrogen, oxygen containing heteroaromatic with a pyridine like nitrogen and an oxygen atom present at 1,3-positions of the ring.
Oxazoles are weakly basic, similar to imidazoles and can exist in partially reduced (2,5-dihydrooxazole or 4,5-dihydrooxazole) and completely reduced (oxazolidine) forms.

Oxazole and its derivatives are actively involved as building blocks for bio chemicals and pharmaceuticals like flopristin and darglitazone.
Oxazole is also involved in industrial applications such as in dyes, fluorescent brightening agents, textile auxiliaries and plastics.

Oxazole is a five-membered heterocyclic compound characterized by a ring structure that contains one nitrogen and one oxygen atom.
Oxazole is classified as an aromatic compound due to its cyclic structure and the presence of alternating double bonds, which contribute to its stability.

Oxazole is typically a colorless liquid or solid, depending on its specific form and purity.
Oxazole has a distinctive odor and is soluble in organic solvents such as alcohols and ethers, but is less soluble in water.

Oxazole exhibits basic properties due to the nitrogen atom, which can participate in protonation reactions.
Oxazole derivatives are of significant interest in medicinal chemistry, as they are found in various biologically active compounds, including pharmaceuticals and agrochemicals.

Oxazole can undergo various chemical reactions, such as electrophilic substitution and nucleophilic attack, making it versatile in synthetic organic chemistry.
Oxazole is used for identification in chemical databases and regulatory contexts.

Oxazole is a five-membered aromatic heterocyclic compound containing one oxygen atom and one nitrogen atom in the ring.
Oxazole has the molecular formula C3H3NO and is an important structural unit in organic chemistry, medicinal chemistry, and specialty chemical synthesis.
The oxazole ring is found in numerous natural products, pharmaceutical intermediates, biologically active compounds, and functional materials.

Oxazole derivatives are widely used as building blocks in the synthesis of pharmaceuticals, agrochemicals, dyes, fluorescent compounds, and advanced organic materials.
Their aromatic heterocyclic structure provides good chemical versatility and allows a broad range of substitutions at different positions of the ring, making oxazole chemistry useful for designing molecules with specific biological, electronic, and physicochemical properties.

Uses of Oxazole:
Oxazole and its derivatives are actively involved as building blocks for bio chemicals and pharmaceuticals like flopristin and darglitazone.
Oxazole is also involved in industrial applications such as in dyes, fluorescent brightening agents, textile auxiliaries and plastics.

Oxazole and its derivatives are widely used as versatile heterocyclic building blocks in pharmaceutical, agrochemical, and specialty chemical synthesis.
The oxazole ring is frequently incorporated into biologically active molecules because its compact aromatic structure can contribute to favorable molecular rigidity, polarity, and binding interactions.
Oxazole derivatives are used in the development and preparation of pharmaceutical intermediates and research compounds associated with antimicrobial, antifungal, anti-inflammatory, anticancer, antiviral, and enzyme-modulating applications.

In agrochemical chemistry, substituted oxazoles are employed as intermediates in the synthesis of herbicides, fungicides, insecticides, and other crop-protection compounds.
Oxazole structures are also valuable in natural-product synthesis, since the ring occurs in several complex biologically active molecules and can be introduced as part of synthetic routes toward such compounds.

In materials science, certain oxazole derivatives are used in fluorescent compounds, dyes, optical materials, organic electronic systems, and functional polymers.
Their conjugated aromatic structure can be modified to tune electronic, photophysical, and charge-transport properties.
Oxazole-based compounds are additionally utilized in analytical chemistry, ligand design, molecular probes, and specialty research reagents.

In organic synthesis, oxazole serves as a useful intermediate for preparing more complex nitrogen- and oxygen-containing heterocycles.
Functional groups attached at different positions of the oxazole ring can undergo further substitution, coupling, oxidation, reduction, or ring-transformation reactions, allowing the preparation of structurally diverse molecules.
This broad synthetic flexibility makes oxazole derivatives valuable across medicinal chemistry, fine chemical production, advanced materials research, and laboratory-scale synthesis.

Applications of Oxazole:
Oxazole and its derivatives are actively involved as building blocks for bio chemicals and pharmaceuticals like flopristin and darglitazone.
Oxazole is also involved in industrial applications such as in dyes, fluorescent brightening agents, textile auxiliaries and plastics.

Oxazole can be used:
Oxazole is used in the intramolecular Diels–Alder (IMDA) cycloaddition reaction to synthesis natural products.
Oxazole is used as a precursor in the ring opening, nucleophilic addition and recyclization as well as [2 + 2], [3 + 2], and [4 + 2] cycloaddition reactions.

Chemical Reactivity of Oxazole:
Oxazole is a five-membered, nitrogen-oxygen heteroaromatic separated by methine (-CH) with a delocalized 6π electron ring system.
However, complete delocalization of π electrons is restricted due to the presence of an electronegative oxygen atom (see the following diagram).
The oxazole is considered to be a hybrid heteroaromatic system since its nitrogen atom behaves as a pyridine type and its oxygen atom behaves as a furan type.

Preparation of Oxazole:
The classic synthetic route the Robinson–Gabriel synthesis by dehydration of 2-acylaminoketones.
The Fischer oxazole synthesis from cyanohydrins and aldehydes is also widely used.
Other methods are known including the reaction of α-haloketones and formamide and the Van Leusen reaction with aldehydes and TosMIC.

Synthesis of Oxazole:
Due to the numerous applications of oxazole-based compounds in diverse fields, many exciting advances in the synthesis of these molecules have been reported.
In the past, considerable attention has been made to develop high yielding protocols for the construction of oxazoles involving simple substrates.

Generally, this scaffold has been constructed by using intramolecular condensation reactions in the presence of dehydrating agents.
Apart from these, many eco-friendly and one-pot methodologies are also available to prepare these pharmaceutically important molecules.

From Primary Amides (a) The parent oxazole ring system was constructed on the heating of formamide with ethyl-α-hydroxyketosuccinate followed by alkaline hydrolysis and decarboxylation.

Biosynthesis of Oxazole:
In biomolecules, oxazoles result from the cyclization and oxidation of serine or threonine nonribosomal peptides.
Oxazoles are not as abundant in biomolecules as the related thiazoles with oxygen replaced by a sulfur atom.

Reactions of Oxazole:
With a pKa of 0.8 for the conjugate acid (oxazolium salts), oxazoles are far less basic than imidazoles (pKa = 7).
Deprotonation of oxazoles occurs at C2, and the lithio salt exists in equilibrium with the ring-opened enolate-isonitrile, which can be trapped by silylation.
Formylation with dimethylformamide gives 2-formyloxazole.

Electrophilic aromatic substitution takes place at C5, but requiring electron donating groups.
Nucleophilic aromatic substitution takes place with leaving groups at C2.

Diels–Alder reactions involving oxazole (as dienes) and electrophilic alkenes has been well developed as a route to pyridines.
In this way, alkoxy-substituted oxazoles serve a precursors to the pyridoxyl system, as found in vitamin B6.
The initial cycloaddition affords a bicyclic intermediate, with an acid-sensitive oxo bridgehead.

In the Cornforth rearrangement of 4-acyloxazoles is a thermal rearrangement reaction with the organic acyl residue and the C5 substituent changing positions.

Various oxidation reactions.
One study reports on the oxidation of 4,5-diphenyloxazole with 3 equivalents of CAN to the corresponding imide and benzoic acid.
In the balanced half-reaction three equivalents of water are consumed for each equivalent of oxazoline, generating 4 protons and 4 electrons (the latter derived from CeIV).

Stability and Reactivity of Oxazole:

Chemical stability:
Oxazole is generally stable under normal temperatures and recommended storage conditions.

Reactivity:
Oxazole is a volatile, flammable liquid and its vapors may form ignitable mixtures with air when exposed to suitable ignition sources.

Conditions to avoid:
Avoid heat, flames, sparks, hot surfaces, static discharge, and other sources of ignition.

Incompatible materials:
Avoid strong oxidizing agents and other highly reactive materials.

Hazardous decomposition products:
Thermal decomposition or combustion may generate carbon monoxide, carbon dioxide, nitrogen oxides, and irritating fumes.

Handling and Storage of Oxazole:

Safe handling:
Handle in a well-ventilated area and prevent contact with the skin and eyes.
Keep away from heat, sparks, flames, and other ignition sources, and use non-sparking equipment where appropriate.

Storage conditions:
Keep the container tightly closed in a cool, dry, and well-ventilated place.
Store away from ignition sources and incompatible substances; TCI specifically recommends keeping the material cool and well ventilated.

First Aid Measures of Oxazole:

Inhalation:
Move the affected person to fresh air and keep them at rest.
Obtain medical attention if breathing difficulties or persistent symptoms occur.

Skin contact:
Remove contaminated clothing immediately and rinse the affected skin thoroughly with water.
Wash before reusing contaminated clothing.

Eye contact:
Rinse cautiously with plenty of water for several minutes.
Remove contact lenses if present and easy to do, continue rinsing, and obtain immediate medical attention.

Ingestion:
Rinse the mouth with water and seek medical advice promptly.
Do not induce vomiting unless instructed by medical personnel.

Firefighting Measures of Oxazole:

Suitable extinguishing media:
Use dry chemical, carbon dioxide, water spray, or alcohol-resistant foam as appropriate.
Dry sand may also be suitable for small fires.

Specific fire hazards:
Oxazole is flammable and may be ignited by heat, sparks, or flames.
Oxazole's reported flash point is approximately 19°C.

Protective equipment:
Firefighters should wear appropriate protective clothing and self-contained breathing apparatus when necessary.

Accidental Release Measures of Oxazole:

Personal precautions:
Eliminate all ignition sources, provide adequate ventilation, and restrict access to the affected area.
Avoid contact with spilled material and use appropriate personal protective equipment.

Cleanup methods:
Absorb the spill with dry earth, sand, or another suitable non-combustible absorbent material.
Collect the absorbed material using clean, non-sparking tools and transfer it to a suitable closed container.

Environmental precautions:
Prevent the material from entering drains, waterways, or confined areas where vapors may accumulate.

Exposure Controls/Personal Protective of Oxazole:

Engineering controls:
Use adequate general ventilation or local exhaust ventilation to minimize vapor accumulation.

Eye protection:
Wear chemical safety goggles or suitable eye and face protection.

Hand protection:
Wear suitable chemical-resistant protective gloves.

Skin protection:
Wear appropriate protective clothing to minimize direct skin contact.

Respiratory protection:
Use suitable respiratory protection when ventilation is inadequate or significant vapor exposure may occur.

Hygiene measures:
Wash hands and exposed skin thoroughly after handling.
Keep contaminated work clothing separate and avoid eating, drinking, or smoking in handling areas.

Identifiers of Oxazole:
Article #: O0287
Purity / Analysis method: >98.0%(GC)
Molecular formula / Molecular mass: C3H3NO = 69.06
Physical state (20 °C): Liquid
Storage temperature: Room Temperature (Recommended in a cool and dark place, <15°C)
Store under inert gas: Stored under inert gas
Conditions to avoid: Air Sensitive
CAS RN: 288-42-6
Reaxys registration number: 103851
PubChem substance ID: 87574273
MDL number: MFCD00009751

CAS No.: 288-42-6
Chemical Name: Oxazole
CBNumber: CB8420295
Molecular Formula: C3H3NO
Molecular Weight: 69.06

CAS: 288-42-6
IUPAC Name: 1,3-oxazole
Molecular Formula: C3H3NO
InChI Key: ZCQWOFVYLHDMMC-UHFFFAOYSA-N
SMILES: O1C=CN=C1
Molecular Weight (g/mol): 69.06
Synonym: oxazole

CAS Number: 288-42-6
3D model (JSmol): Interactive image
Beilstein Reference: 103851
ChEBI: CHEBI:35597
ChEMBL: ChEMBL2171710
ChemSpider: 8898
ECHA InfoCard: 100.005.474
EC Number: 206-020-8
Gmelin Reference: 485850
MeSH: D010080
PubChem CID: 9255
UNII: FJZ20I1LPS
CompTox Dashboard (EPA): DTXSID70182983
InChI: InChI=1S/C3H3NO/c1-2-5-3-4-1/h1-3H
Key: ZCQWOFVYLHDMMC-UHFFFAOYSA-N
InChI: InChI=1/C3H3NO/c1-2-5-3-4-1/h1-3H
Key: ZCQWOFVYLHDMMC-UHFFFAOYAD
SMILES: C1=COC=N1

Empirical Formula (Hill Notation): C3H3NO
CAS Number: 288-42-6
Molecular Weight: 69.06
UNSPSC Code: 12352100
NACRES: NA.22
PubChem Substance ID: 24853776
EC Number: 206-020-8
Beilstein/REAXYS Number: 103851
MDL number: MFCD00009751
Assay: 98%

Properties of Oxazole:
Melting Point: −87-−84 °C(lit.)
Boiling Point: 69-70 °C(lit.)
Density: 1.05 g/mL at 25 °C(lit.)
Refractive Index: n20/D 1.425(lit.)
Flash Point: 66 °F
Storage Temperature: Sealed in dry,2-8°C
Solubility: Chloroform, Methanol (Slightly)
pKa: 0.8(at 33℃)
Form: clear liquid
Color: Colorless to Almost colorless
Water Solubility: Miscible with alcohol and ether. Slightly miscible with water.
BRN: 103851
InChI: 1S/C3H3NO/c1-2-5-3-4-1/h1-3H
InChIKey: ZCQWOFVYLHDMMC-UHFFFAOYSA-N
SMILES: c1cocn1
LogP: 0.120
CAS DataBase Reference: 288-42-6(CAS DataBase Reference)
NIST Chemistry Reference: Oxazole(288-42-6)

Chemical Formula: C3H3NO
Molar Mass: 69.06 g/mol
Density: 1.050 g/cm3
Boiling Point: 69.5 °C (157.1 °F; 342.6 K)
Acidity (pKa): 0.8 (of conjugate acid)

Molecular Weight: 69.06 g/mol
XLogP3: 0.1
Hydrogen Bond Donor Count: 0
Hydrogen Bond Acceptor Count: 2
Rotatable Bond Count: 0
Exact Mass: 69.021463719 Da
Monoisotopic Mass: 69.021463719 Da
Topological Polar Surface Area: 26 Ų
Heavy Atom Count: 5
Complexity: 30.1
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes

Quality Segment: 100
Assay: 98%
Refractive Index: n20/D 1.425 (lit.)
Boiling Point: 69-70 °C (lit.)
Melting Point: −87-−84 °C (lit.)
Density: 1.05 g/mL at 25 °C (lit.)
SMILES String: c1cocn1
InChI: 1S/C3H3NO/c1-2-5-3-4-1/h1-3H
InChI Key: ZCQWOFVYLHDMMC-UHFFFAOYSA-N

Specifications of Oxazole:
Appearance (Color): Clear colorless to pale yellow
Assay (GC): ≥98.0%
Form: Liquid
Refractive Index: 1.4240-1.4280 @ 20°C
Appearance: Colorless to almost colorless clear liquid
Purity (GC): min. 98.0 %

Names of Oxazole:

Preferred IUPAC name:
1,3-Oxazole