(4-Methylphenoxy)acetaldehyde (CAS 67845-46-9) — Green Top to middle Note Fragrance Ingredient
(4-Methylphenoxy)acetaldehyde
CAS 67845-46-9
What Is (4-Methylphenoxy)acetaldehyde?
(4-Methylphenoxy)acetaldehyde is a synthetic fragrance ingredient used to add green, floral, and slightly metallic nuances to perfumes. It’s found in fine fragrances and personal care products where a crisp, modern floral character is desired. This aldehyde contributes freshness and lift to floral compositions, helping create contemporary effects in designer perfumery.
Safety Profile
USE WITH AWARENESSWhat Does (4-Methylphenoxy)acetaldehyde Smell Like?
(4-Methylphenoxy)acetaldehyde opens with a sharp, green-aldehydic burst reminiscent of crushed stems and freshly cut foliage. This quickly softens into a delicate floralcy with hints of magnolia petals and a subtle metallic shimmer like cool stainless steel. The dry-down reveals a faint phenolic warmth, akin to the distant memory of clove-studded oranges. Though moderately tenacious, it primarily functions as a top-to-middle note that bridges crisp freshness with floral sophistication.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to create tension between the floral jasmine heart and sharp citrus top, adding a contemporary metallic edge that modernizes the white floral genre.
Provides the distinctive ‘grapefruit peel’ effect in the citrus accord, enhancing freshness with its green-phenolic character while avoiding actual citrus ingredients.
2D Molecular Structure
SMILES: CC1=CC=C(OCC=O)C=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
(4-Methylphenoxy)acetaldehyde belongs to the aromatic ether-aldehyde class, synthesized through the formylation of 4-methylphenol followed by O-alkylation. The para-methyl group stabilizes the aromatic ring while the acetaldehyde moiety provides reactivity. Its planar structure allows for efficient olfactory receptor binding, with the electron-rich ether oxygen enhancing volatility. Commercial synthesis typically employs Vilsmeier-Haack conditions to introduce the formyl group while avoiding unwanted side reactions.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~220 °C (estimated) |
| Density | ~1.05 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 3% | For fresh-floral effects |
| Functional Fragrance | 0.1-0.5% | Up to 1% | In detergents for green nuances |
Classic Accords
Tip: Stabilize in ethanol before adding to aqueous systems to prevent hydrolysis.
Alternatives & Comparisons
When greater diffusion and apple-like freshness is needed, though less metallic in character.
For similar effects without the methyl group’s slightly phenolic warmth.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted under IFRA standards. Listed on IFRA Transparency List.
GHS Classification
RIFM Assessment
Under review by RIFM as of 2023. Preliminary data suggests safe use at current industry levels.
Sustainability
Produced synthetically from petrochemical precursors with relatively low environmental impact due to efficient catalytic processes. No known ecological toxicity concerns at production volumes, though biodegradability data remains limited. Preferred over some natural aldehydes due to consistent quality and reduced agricultural inputs.
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References
- Brenna et al. (2012). Synthetic Routes to Aromatic Ether-Aldehydes. Journal of Agricultural and Food Chemistry.
- IFRA Standards Library (2023). 49th Amendment. IFRA
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 67845-46-9Physical Properties
| Molecular Weight | 150.17 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| Boiling Point | 246 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0174 mmHg @ 25°C📊 OPERA |
| Flash Point | 104.2 °C🔬 EPA CompTox |
| Involatility Index | 0.0015💻 Calculated |
| log Kp (skin permeability) | -2.338💻 Calculated |
| SMILES | CC1=CC=C(C=C1)OCC=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.6 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | floralgreen• leffingwell |
| Functional Groups | aldehydeetheraromatic💻 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: DTXSID0052380
Physical Properties
| Molecular Weight | 150.177 g/mol🔬 EPA CompTox |
| Density | 1.018 g/cm^3📊 OPERA |
| Boiling Point | 242.097 °C📊 OPERA |
| Melting Point | 26.848 °C📊 OPERA |
| Flash Point | 97.534 °C📊 OPERA |
| Refractive Index | 1.505 Dimensionless📊 OPERA |
| Molar Volume | 143.536 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.813 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.813 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.813 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.08 Log10 unitless📊 OPERA |
| Water Solubility | 0.014 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.033 mmHg📊 OPERA |
| Viscosity | 2.223 cP📊 OPERA |
| Surface Tension | 35.456 dyn/cm📊 OPERA |
| Thermal Conductivity | 149.12 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 | 1 count💻 Computed |
| Molar Refractivity | 42.576 cm^3/mol📊 OPERA |
| Polarizability | 16.878 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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