3,4-Dihydro-5-methylnaphthalen-1(2H)-one (CAS 6939-35-1) — Woody Middle to base Note Fragrance Ingredient
3,4-Dihydro-5-methylnaphthalen-1(2H)-one
CAS 6939-35-1
What Is 3,4-Dihydro-5-methylnaphthalen-1(2H)-one?
3,4-Dihydro-5-methylnaphthalen-1(2H)-one is a synthetic fragrance ingredient used in perfumery to create woody, amber-like scents. You’ll encounter it in niche fragrances and some modern woody compositions. This molecule matters because it provides a cost-effective alternative to natural woody materials while offering excellent stability and blending properties in fragrance formulations.
Safety Profile
USE WITH AWARENESSWhat Does 3,4-Dihydro-5-methylnaphthalen-1(2H)-one Smell Like?
This molecule presents a rich, woody character with subtle amber undertones. The initial impression is dry and slightly phenolic, evolving into a warm, musky-woody heart. The dry-down reveals a persistent woody-balsamic character with faint animalic nuances. Imagine the scent of sun-warmed cedar planks blended with a whisper of leather and a touch of vanilla-like sweetness.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a woody backbone in this contemporary scent, providing depth and longevity while maintaining clarity in the woody accord.
Serves as an amber enhancer, adding dry woody facets that balance the sweetness of vanilla and tonka bean.
2D Molecular Structure
SMILES: CC1=C2CCCC(=O)C2=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
3,4-Dihydro-5-methylnaphthalen-1(2H)-one belongs to the tetralone class of compounds. As a synthetic material, it’s produced through catalytic hydrogenation of methylnaphthalenes followed by oxidation. The molecule features a partially saturated naphthalene core with a ketone functionality at position 1, contributing to its woody odor characteristics.
Physical & Chemical Properties
| Boiling Point | Not available |
|---|---|
| Density | Not available |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | Woody modifier |
| Functional Fragrance | 0.5-1% | Up to 2% | Base note stabilizer |
Classic Accords
Tip: Use in small quantities to enhance woody accords without overwhelming other notes.
Alternatives & Comparisons
When a more transparent woody effect is desired, though less amber-like in character.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards.
RIFM Assessment
Under evaluation by RIFM, preliminary data suggests moderate safety profile.
Sustainability
As a synthetic material, this compound offers consistent quality without natural sourcing concerns. Production typically involves petrochemical feedstocks, though newer green chemistry routes may reduce environmental impact.
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References
- Bauer, K. 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 6939-35-1Physical Properties
| Molecular Weight | 160.21 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.4🔬 PubChem |
| Boiling Point | 242 °C🔬 EPA CompTox |
| Vapor Pressure | 0.1148 mmHg @ 25°C📊 OPERA |
| Flash Point | 122.7 °C🔬 EPA CompTox |
| Involatility Index | 0.0098💻 Calculated |
| log Kp (skin permeability) | -1.973💻 Calculated |
| SMILES | CC1=C2CCCC(=O)C2=CC=C1🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 1.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | balsamicwoody• leffingwell |
| Functional Groups | ketonearomatic💻 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: DTXSID3052438
Physical Properties
| Molecular Weight | 160.216 g/mol🔬 EPA CompTox |
| Density | 1.092 g/cm^3📊 OPERA |
| Boiling Point | 270.185 °C📊 OPERA |
| Melting Point | 40.413 °C📊 OPERA |
| Flash Point | 114.993 °C📊 OPERA |
| Refractive Index | 1.557 Dimensionless📊 OPERA |
| Molar Volume | 149.035 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.846 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.846 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.846 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.72 Log10 unitless📊 OPERA |
| Water Solubility | 0.003 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.041 mmHg📊 OPERA |
| Viscosity | 5.391 cP📊 OPERA |
| Surface Tension | 40.275 dyn/cm📊 OPERA |
| Thermal Conductivity | 133.869 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 17.07 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 47.994 cm^3/mol📊 OPERA |
| Polarizability | 19.026 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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