alpha-Propylphenethyl alcohol (CAS 705-73-7) — Floral Heart Note Fragrance Ingredient
alpha-Propylphenethyl alcohol
CAS 705-73-7
What Is alpha-Propylphenethyl alcohol?
Alpha-Propylphenethyl alcohol is a synthetic fragrance ingredient used in perfumes and scented products. It adds a floral, slightly rosy character to compositions. You’ll encounter it in fine fragrances, soaps, and air fresheners. This molecule matters because it provides perfumers with a stable, long-lasting floral note that blends well with other ingredients. Its synthetic nature ensures consistent quality and availability compared to natural alternatives.
Safety Profile
GENERALLY SAFEWhat Does alpha-Propylphenethyl alcohol Smell Like?
Alpha-Propylphenethyl alcohol opens with a crisp, green floral character reminiscent of crushed rose stems. As it evolves, the heart reveals a honeyed, slightly powdery floralcy akin to peony petals dusted with icing sugar. The dry-down is surprisingly tenacious, leaving a soft musk-tinged floral trail that lingers close to the skin. When diluted, it takes on a more transparent quality, like floral water droplets on warm skin.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the modern rose accord, providing a crisp green lift to balance the jammy damascone notes.
Contributes to the peony-mirabilis accord, adding a honeyed floral depth that bridges the top and heart notes.
2D Molecular Structure
SMILES: CCCC(O)CC1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
Alpha-Propylphenethyl alcohol belongs to the aromatic alcohol class, structurally similar to phenethyl alcohol but with an additional propyl group. This modification increases its lipophilicity and substantivity. Synthesized typically via Grignard reaction or catalytic hydrogenation of corresponding ketones, it offers perfumers a stable building block for floral accords. The propyl side chain influences both volatility and odor profile compared to its shorter-chain analogs.
Physical & Chemical Properties
| Appearance | Colorless liquid |
|---|---|
| Solubility | Soluble in alcohol, slightly soluble in water |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | Floral modifier |
| Soap | 0.5-1% | Up to 2% | Provides stable floral note |
Classic Accords
Tip: Use with citrus top notes to prevent the floral character from becoming too heavy.
Alternatives & Comparisons
For a lighter, more diffusive floral note when substantivity isn’t required.
When seeking a more woody-floral character with better solubility in aqueous systems.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted under current IFRA standards.
RIFM Assessment
Considered safe for use in current applications based on RIFM data.
Sustainability
As a synthetic material, alpha-Propylphenethyl alcohol avoids agricultural land use. Production typically uses petrochemical feedstocks, though bio-based routes are being explored. Its efficiency in formulations (requiring lower doses than some naturals) contributes to reduced environmental load.
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References
- Bauer et al. (2001). Common Fragrance and Flavor Materials.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID6052451
Physical Properties
| Molecular Weight | 164.248 g/mol🔬 EPA CompTox |
| Density | 0.961 g/cm^3🔬 EPA CTX |
| Boiling Point | 247 °C🔬 EPA CTX |
| Melting Point | 17.063 °C📊 OPERA |
| Flash Point | 108.762 °C📊 OPERA |
| Refractive Index | 1.515 Dimensionless📊 OPERA |
| Molar Volume | 169.654 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.755 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.345 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.74 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.74 Log10 unitless📊 OPERA |
| Water Solubility | 0.006 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.013 mmHg📊 OPERA |
| Viscosity | 9.787 cP📊 OPERA |
| Surface Tension | 35.257 dyn/cm📊 OPERA |
| Thermal Conductivity | 142.337 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 20.23 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 4 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 51.194 cm^3/mol📊 OPERA |
| Polarizability | 20.295 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.
