Nopyl acetate (CAS 128-51-8) — Woody Middle Note Fragrance Ingredient
Nopyl acetate
CAS 128-51-8
What Is Nopyl acetate?
Nopyl acetate is a synthetic fragrance ingredient used in perfumes and scented products. It contributes a fresh, woody aroma often found in masculine fragrances. This ester compound matters because it provides longevity and blending versatility, making it valuable for creating complex scent profiles that evolve beautifully on skin.
Safety Profile
GENERALLY SAFEWhat Does Nopyl acetate Smell Like?
Nopyl acetate opens with a crisp, pine-like freshness reminiscent of crushed evergreen needles. The heart reveals subtle floral undertones wrapped in clean linen warmth. Dry-down showcases its true strength – a polished woody base with faintly sweet, almost vanillic whispers that linger close to skin. Imagine walking through a sunlit conifer forest where the air carries traces of blooming heather.
2D Molecular Structure
SMILES: CC(=O)OCCC1=CC2CC(C1)C2(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Nopyl acetate is a synthetic ester derived from nopol (a terpene alcohol) and acetic acid. Its molecular structure features a bicyclic framework that contributes to excellent stability and diffusion properties. Industrial synthesis typically involves acid-catalyzed esterification under controlled conditions. The compound lacks chirality but demonstrates stereospecific odor reception.
Physical & Chemical Properties
| Boiling Point | Not available |
|---|---|
| Density | Not available |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 2-5% | Up to 10% | Adds woody freshness |
| Functional Fragrance | 0.5-2% | Up to 5% | Fabric softeners, detergents |
Classic Accords
Tip: Use with citrus top notes to prevent excessive sharpness in dry-down.
Alternatives & Comparisons
Similar woody character but with more pronounced pine notes. Preferred for cleaner, more transparent effects.
Deeper woody profile with excellent fixation. Used when more substantial base support is needed.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions. Compliant under all current standards.
RIFM Assessment
RIFM assessment complete – no safety concerns at current usage levels.
Sustainability
As a synthetic material, nopyl acetate production avoids natural resource depletion. Modern manufacturing processes achieve high atom efficiency with minimal waste streams. The compound’s stability reduces environmental persistence compared to some natural terpenes.
Explore Nopyl acetate
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References
- PubChem Compound Summary for Nopyl acetate CID Not available
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID6051645
Physical Properties
| Molecular Weight | 208.301 g/mol🔬 EPA CompTox |
| Density | 1.006 g/cm^3📊 OPERA |
| Boiling Point | 253.476 °C📊 OPERA |
| Melting Point | 56.786 °C📊 OPERA |
| Flash Point | 96.378 °C📊 OPERA |
| Refractive Index | 1.482 Dimensionless📊 OPERA |
| Molar Volume | 208.981 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.062 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.062 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.062 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.56 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.012 mmHg📊 OPERA |
| Viscosity | 5.98 cP📊 OPERA |
| Surface Tension | 30.683 dyn/cm📊 OPERA |
| Thermal Conductivity | 128.69 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 59.623 cm^3/mol📊 OPERA |
| Polarizability | 23.636 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.
