2-Methyl-4-phenylbutyraldehyde (CAS 40654-82-8) — Floral Top to Heart Note Fragrance Ingredient
2-Methyl-4-phenylbutyraldehyde
CAS 40654-82-8
What Is 2-Methyl-4-phenylbutyraldehyde?
2-Methyl-4-phenylbutyraldehyde is a synthetic fragrance ingredient used in perfumes and fine fragrances. It adds a fresh, floral, and slightly fruity character to compositions. This aldehyde is valued for its ability to enhance floral notes and provide a modern twist to classic accords.
Safety Profile
GENERALLY SAFEWhat Does 2-Methyl-4-phenylbutyraldehyde Smell Like?
2-Methyl-4-phenylbutyraldehyde opens with a bright, fresh aldehydic burst, reminiscent of citrus peels and green stems. The heart reveals a floral, slightly rosy character with a hint of fruity sweetness, like ripe pears. The dry-down is soft and musky, with a lingering warmth that blends seamlessly into woody bases.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to enhance the floral bouquet and add a modern aldehydic sparkle.
Adds a fresh, fruity-floral nuance to the radiant floral heart.
2D Molecular Structure
SMILES: CC(CCC1=CC=CC=C1)C=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Methyl-4-phenylbutyraldehyde is a synthetic aldehyde with a branched carbon chain. It is typically synthesized via hydroformylation of styrene derivatives. The molecule’s structure allows for versatile olfactory properties, blending floral, fruity, and aldehydic characteristics.
Physical & Chemical Properties
| Boiling Point | Not available |
|---|---|
| Density | Not available |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-5% | Up to 10% | Enhances floral and fruity notes |
| Functional Fragrance | 0.5-2% | Up to 5% | Adds freshness to detergents |
Classic Accords
Tip: Use in small doses to avoid overpowering the composition.
Alternatives & Comparisons
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific IFRA restrictions.
RIFM Assessment
RIFM has assessed this ingredient as safe for use in current practices.
Sustainability
Synthesized from petrochemical sources, with no known major environmental concerns. Efforts to improve synthetic routes for reduced environmental impact are ongoing.
Explore 2-Methyl-4-phenylbutyraldehyde
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References
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 40654-82-8Physical Properties
| Molecular Weight | 162.23 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.5🔬 PubChem |
| Boiling Point | 253 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.915💻 Calculated |
| SMILES | CC(CCC1=CC=CC=C1)C=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
Odor & Flavor
| Primary Descriptors | earthyfloralsweet• leffingwell |
| Functional Groups | aldehydearomatic💻 RDKit |
Regulatory Status
| IOFI Classification | Artificial📖 Fenaroli |
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: DTXSID80866005
Physical Properties
| Molecular Weight | 162.232 g/mol🔬 EPA CompTox |
| Density | 0.955 g/cm^3📊 OPERA |
| Boiling Point | 253 °C🔬 EPA CTX |
| Melting Point | 9.256 °C📊 OPERA |
| Flash Point | 108.774 °C📊 OPERA |
| Refractive Index | 1.5 Dimensionless📊 OPERA |
| Molar Volume | 169.466 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.549 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.549 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.549 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.85 Log10 unitless📊 OPERA |
| Water Solubility | 0.005 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.156 mmHg📊 OPERA |
| Viscosity | 2.607 cP📊 OPERA |
| Surface Tension | 32.301 dyn/cm📊 OPERA |
| Thermal Conductivity | 138.311 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 | 4 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 49.846 cm^3/mol📊 OPERA |
| Polarizability | 19.761 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.
