2-Methylbenzoxazole (CAS 95-21-6) — Green Top to Middle Note Fragrance Ingredient
2-Methylbenzoxazole
CAS 95-21-6
What Is 2-Methylbenzoxazole?
2-Methylbenzoxazole is a synthetic aromatic compound used in perfumery to add green, nutty, and slightly woody nuances. It’s found in trace amounts in some roasted foods but is primarily manufactured for fragrance use. This ingredient matters because it can mimic natural green notes without relying on plant extracts, offering consistency and sustainability benefits.
Safety Profile
GENERALLY SAFEWhat Does 2-Methylbenzoxazole Smell Like?
2-Methylbenzoxazole opens with a sharp, green character reminiscent of crushed leaves and fresh-cut grass. The heart reveals a nutty, almost popcorn-like warmth with subtle woody undertones. Dry-down is surprisingly persistent for a synthetic, leaving a clean, slightly sweet trail that blends well with citrus and woody accords.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to enhance the radical green character of this groundbreaking fragrance, providing a synthetic alternative to natural galbanum.
2D Molecular Structure
SMILES: CC1=NC2=CC=CC=C2O1
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Methylbenzoxazole belongs to the benzoxazole class of heterocyclic compounds. It’s synthesized through condensation reactions between o-aminophenols and aldehydes. The methyl group at position 2 creates steric hindrance that affects both volatility and odor characteristics. This planar aromatic molecule exhibits good stability in most fragrance formulations.
Physical & Chemical Properties
| Boiling Point | 198-200 °C |
|---|---|
| Density | 1.08 g/cm³ |
| Refractive Index | 1.545 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Green accent note |
| Functional Fragrances | 0.01-0.1% | Up to 0.2% | Clean, green effects |
Classic Accords
Tip: Use sparingly to avoid overpowering green notes; excellent for creating ‘cut grass’ effects.
Alternatives & Comparisons
When a more floral-green character is desired without the nutty undertones of methylbenzoxazole.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA.
RIFM Assessment
No specific RIFM assessment found; general benzoxazole class considered low risk.
Sustainability
As a synthetic material, 2-methylbenzoxazole avoids agricultural impacts but requires petrochemical feedstocks. Modern production methods aim to minimize waste and energy use. Not biodegradable but used in minimal quantities.
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References
- Bauer et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 95-21-6Physical Properties
| Molecular Weight | 133.15 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.2🔬 PubChem |
| Boiling Point | 200.5 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0028 mmHg @ 25°C📊 OPERA |
| Flash Point | 75 °C🔬 EPA CompTox |
| Involatility Index | 0.0003💻 Calculated |
| log Kp (skin permeability) | -1.95💻 Calculated |
| SMILES | CC1=NC2=CC=CC=C2O1🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 3.8 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | burntfloralpungentsweettobaccovanilla• leffingwell |
| Functional Groups | aromatic💻 RDKit |
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.
Physicochemical Properties
DTXSID: DTXSID50870432
Physical Properties
| Molecular Weight | 133.15 g/mol🔬 EPA CompTox |
| Density | 1.142 g/cm^3📊 OPERA |
| Boiling Point | 200.5 °C🔬 EPA CTX |
| Melting Point | 7.333 °C🔬 EPA CTX |
| Flash Point | 78.318 °C📊 OPERA |
| Refractive Index | 1.594 Dimensionless📊 OPERA |
| Molar Volume | 115.843 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.785 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.785 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.785 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5 Log10 unitless📊 OPERA |
| Water Solubility | 0.032 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.17 mmHg📊 OPERA |
| Viscosity | 3.766 cP📊 OPERA |
| Surface Tension | 43.136 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.03 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 2 count💻 Computed |
| Molar Refractivity | 39.311 cm^3/mol📊 OPERA |
| Polarizability | 15.584 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
