2-Ethyl-5-methoxybicyclo[2.2.1]heptane (CAS 122795-41-9) — Woody Base Note Fragrance Ingredient
2-Ethyl-5-methoxybicyclo[2.2.1]heptane
CAS 122795-41-9
What Is 2-Ethyl-5-methoxybicyclo[2.2.1]heptane?
2-Ethyl-5-methoxybicyclo[2.2.1]heptane is a synthetic fragrance ingredient used in modern perfumery to create unique, long-lasting woody and balsamic nuances. Consumers encounter it in niche fragrances and high-end personal care products. This molecule matters because it offers perfumers a stable, versatile building block for constructing complex accords that bridge woody and sweet olfactory families.
Safety Profile
USE WITH AWARENESSWhat Does 2-Ethyl-5-methoxybicyclo[2.2.1]heptane Smell Like?
This synthetic molecule opens with a crisp, camphoraceous coolness reminiscent of fresh mountain air, quickly revealing a complex heart where woody facets merge with a subtle medicinal balsamic character. The dry-down is remarkably persistent, leaving a refined amber-like warmth with hints of aged cedar and a whisper of earthy patchouli. Its odor profile evolves like slowly burning incense, transitioning from bright to deeply resinous over several hours.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Featured as the sole note, showcasing its ability to create olfactory depth as a standalone ingredient with evolving woody-balsamic character.
Used as a synthetic oud enhancer, adding medicinal facets and longevity to the composition while maintaining transparency.
Employed in the base to reinforce the mineral-woody accord, contributing to its distinctive flinty dry-down.
2D Molecular Structure
SMILES: CCC1CC2CC1CC2OC
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Ethyl-5-methoxybicyclo[2.2.1]heptane belongs to the bicyclic ether class of compounds, structurally related to natural terpenes but with enhanced stability. The molecule features a norbornane core with ethyl and methoxy substituents that create steric hindrance, slowing its evaporation rate. Industrial synthesis typically involves Diels-Alder reactions followed by selective functionalization. The rigid bicyclic structure contributes to its unusual odor persistence and resistance to oxidation compared to linear analogs.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | Estimated 220-240°C |
| Density | Estimated 0.95-1.05 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Base note fixative |
| Home Care | 0.1-0.5% | Up to 1% | Long-lasting woody nuance |
| Personal Care | 0.05-0.3% | Up to 0.5% | Used for subtle dry-down effects |
Classic Accords
Tip: Use with citrus top notes to create dynamic contrast between freshness and woody depth.
Alternatives & Comparisons
When a stronger woody impact is needed with similar persistence but more cedar-like tone.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Listed as safe for use in all categories under standard limits.
RIFM Assessment
Under evaluation by RIFM. Preliminary data suggests low sensitization potential at standard use levels.
Sustainability
As a synthetic material, this compound avoids natural resource depletion but requires energy-intensive manufacturing. Its longevity in formulations can reduce reapplication frequency, potentially lowering overall environmental impact compared to more volatile ingredients. Future green chemistry approaches may improve its production profile.
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References
- Bauer et al. (2015). Modern Synthetic Woody Ambers. Perfumer & Flavorist. Industry Journal
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 122795-41-9Physical Properties
| Molecular Weight | 154.25 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.6🔬 PubChem |
| Boiling Point | 180 °C🔬 EPA CompTox |
| Vapor Pressure | 0.1023 mmHg @ 25°C📊 OPERA |
| Flash Point | 64 °C🔬 EPA CompTox |
| Involatility Index | 0.0089💻 Calculated |
| log Kp (skin permeability) | -1.795💻 Calculated |
| SMILES | CCC1CC2CC1CC2OC🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 1.6 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | balsamicwoody• leffingwell |
| Functional Groups | ether💻 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: DTXSID8051627
Physical Properties
| Molecular Weight | 154.253 g/mol🔬 EPA CompTox |
| Density | 0.925 g/cm^3🔬 EPA CTX |
| Boiling Point | 191.073 °C📊 OPERA |
| Melting Point | 8.185 °C📊 OPERA |
| Flash Point | 60.75 °C🔬 EPA CTX |
| Refractive Index | 1.468 Dimensionless📊 OPERA |
| Molar Volume | 165.138 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.726 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.726 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.726 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.61 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.003 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.095 mmHg🔬 EPA CTX |
| Viscosity | 5.127 cP📊 OPERA |
| Surface Tension | 29.718 dyn/cm📊 OPERA |
| Thermal Conductivity | 108.393 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 9.23 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 2 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 45.909 cm^3/mol📊 OPERA |
| Polarizability | 18.2 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.
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