p-Isopropyl phenylacetaldehyde (CAS 4395-92-0) — Floral Top to middle Note Fragrance Ingredient
p-Isopropyl phenylacetaldehyde
CAS 4395-92-0
What Is p-Isopropyl phenylacetaldehyde?
p-Isopropyl phenylacetaldehyde is a synthetic fragrance ingredient commonly found in perfumes and personal care products. It contributes fresh, floral-green notes with a subtle powdery character. This aldehyde is valued by perfumers for its ability to add diffusion and lift to fragrance compositions while blending seamlessly with other materials.
Safety Profile
GENERALLY SAFEWhat Does p-Isopropyl phenylacetaldehyde Smell Like?
p-Isopropyl phenylacetaldehyde opens with a crisp, green floralcy reminiscent of lily-of-the-valley stems snapped in morning dew. The heart reveals a delicate powdery character akin to orris root, softened by subtle honeyed undertones. As it dries down, it leaves a clean musky trail with remarkable tenacity for an aldehyde. The overall effect is like sunlight filtering through a greenhouse – simultaneously fresh and warm.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to enhance the green galbanum note while preventing excessive sharpness. Provides floralcy without sweetness.
Contributes to the legendary green freshness, acting as bridge between citrus top and floral heart notes.
Provides clean, uplifting character that complements the citrus-herbal accord.
Used sparingly to suggest sun-warmed fig leaves without overpowering the delicate fruit notes.
Enhances the crisp tea impression while adding subtle floral dimension.
2D Molecular Structure
SMILES: CC(C)C1=CC=C(CC=C)C=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
p-Isopropyl phenylacetaldehyde is an aromatic aldehyde with the isopropyl group para-positioned on the benzene ring. It’s synthesized through Friedel-Crafts alkylation of benzene followed by oxidation of the resulting isopropylbenzene. The aldehyde group’s electrophilic character makes it reactive with nucleophiles, requiring careful handling in formulations. Its molecular structure allows for excellent vapor pressure, contributing to its diffusion in fragrance compositions.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~250 °C (estimated) |
| Density | ~1.0 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Green floral modifier |
| Soap | 0.1-0.5% | Up to 1% | Provides freshness |
| Detergent | 0.05-0.2% | Up to 0.5% | Used for lift |
Classic Accords
Tip: Stabilize in ethanol before adding to aqueous systems to prevent aldehyde reactions.
Alternatives & Comparisons
More intense honey-floral character but less stable. Use when stronger projection is needed.
Similar green floralcy but with better stability in alkaline formulations.
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 confirms safe use at current industry levels.
Sustainability
As a synthetic material, p-Isopropyl phenylacetaldehyde has consistent quality without natural sourcing concerns. Production uses standard petrochemical feedstocks with typical industrial waste management. No known ecological toxicity at usage levels.
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References
- Arctander, S. (1969). Perfume and Flavor Chemicals. Montclair: Steffen Arctander.
- 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 4395-92-0Physical Properties
| Molecular Weight | 162.23 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.4🔬 PubChem |
| Boiling Point | 230 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.986💻 Calculated |
| SMILES | CC(C)C1=CC=C(C=C1)CC=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
Odor & Flavor
| Primary Descriptors | greenwoody• leffingwell |
| Functional Groups | aldehydearomatic💻 RDKit |
| “The perfumery literature is particularly inconsistent with respect to the nomenclature of the title chemical. Confusion goes so far, that odor descriptions can be totally misleading.”📖 Arctander | |
| p-Isopropylphenylacetaldehyde has a characteristic bark odor and a citrus, bittersweet, fruity flavor.📖 Fenaroli | |
Flavor Notes (Arctander)
| “The title aldehyde is also used in flavor compositions for fruit complexes, Lemon, Orange, Arak, etc. It was once used in combination with Coumarin to imitate the aroma of the Woodruff (Asperula odorata), also used in the flavoring of the German specialty "May Wine". In concentrations of less than 1”📖 Arctander |
Regulatory Status
| FEMA Number | FEMA 2954⚖️ FEMA GRAS |
| GRAS Status | Generally Recognized as Safe⚖️ FEMA GRAS |
| 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: DTXSID2052102
Physical Properties
| Molecular Weight | 160.26 g/mol🔬 EPA CompTox |
| Density | 0.97 g/cm^3🔬 EPA CTX |
| Boiling Point | 215.078 °C📊 OPERA |
| Melting Point | -57.568 °C📊 OPERA |
| Flash Point | 75.14 °C📊 OPERA |
| Refractive Index | 1.503 Dimensionless📊 OPERA |
| Molar Volume | 183.923 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.483 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.483 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.483 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.48 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0.008 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.319 mmHg📊 OPERA |
| Viscosity | 2.394 cP📊 OPERA |
| Surface Tension | 28.912 dyn/cm📊 OPERA |
| Thermal Conductivity | 125.8 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 0 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 0 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 54.345 cm^3/mol📊 OPERA |
| Polarizability | 21.544 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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