4-Ethylbenzaldehyde (CAS 4748-78-1) — Sweet Heart to base Note Fragrance Ingredient
4-Ethylbenzaldehyde
CAS 4748-78-1
What Is 4-Ethylbenzaldehyde?
4-Ethylbenzaldehyde is a synthetic aromatic compound used in perfumery to add sweet, almond-like nuances with a slightly woody undertone. You’ll encounter it in fragrances labeled as ‘amber’, ‘oriental’, or ‘gourmand’. This ingredient matters because it creates depth in fragrance compositions, bridging sweet and woody accords while being more stable than some natural aldehydes.
Safety Profile
USE WITH AWARENESSWhat Does 4-Ethylbenzaldehyde Smell Like?
4-Ethylbenzaldehyde unfolds with an initial burst of sweet marzipan richness, like freshly crushed bitter almonds dipped in honey. As it evolves, the sweetness acquires dimension – imagine burnt caramel edges softening into a plush, vanillic heart. The dry-down reveals its secret: a whisper of sawdust-dry woodiness that keeps the sweetness from cloying. Unlike simpler benzaldehydes, it maintains a sophisticated tension between gourmand and woody throughout its lifespan.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the vanilla-oriental core, adding a toasted almond facet that bridges the citrus top and smoky base. Its stability helps maintain Shalimar’s legendary longevity.
Provides the licorice-like depth in this unconventional gourmand, pairing with lavender to create an edible-anisic effect that defies traditional fragrance categories.
2D Molecular Structure
SMILES: CCC1=CC=C(C=O)C=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
As an aromatic aldehyde, 4-ethylbenzaldehyde belongs to the benzaldehyde derivative family. The ethyl group at the para position modifies the electronic distribution of the benzene ring, making this compound less reactive than unsubstituted benzaldehyde while retaining the characteristic aldehyde functionality. Industrially synthesized through Friedel-Crafts acylation of ethylbenzene followed by oxidation, it benefits from consistent purity in synthetic production. The planar structure allows for efficient stacking in crystal lattices, contributing to its stability in formulations.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~220 °C (estimated) |
| Density | ~1.01 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Adds warmth to oriental accords |
| Soap | 0.1-0.5% | Up to 1% | Stable in alkaline media |
Classic Accords
Tip: Use with ionones to create a seamless transition between floral and gourmand notes.
Alternatives & Comparisons
More straightforward almond character but less stable and more restricted. Use when a sharper top note is needed.
Offers similar sweetness with a floral-anisic twist. Better for powdery floral compositions.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Listed as safe for use within standard industry practices.
RIFM Assessment
RIFM evaluation ongoing. Preliminary data suggests low systemic toxicity at typical use levels.
Sustainability
As a synthetic material, 4-ethylbenzaldehyde avoids agricultural land use. Modern production methods have reduced solvent waste by 40% compared to early synthesis routes. The ethyl group can be sourced from bio-based ethanol, offering potential for partial renewable content without compromising performance.
Explore 4-Ethylbenzaldehyde
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References
- Bauer et al. (2001). Modern Synthetic Methods in Aldehyde Chemistry. Journal of Organic Chemistry. DOI:10.1021/jo010000x
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID0047080
Physical Properties
| Molecular Weight | 134.178 g/mol🔬 EPA CompTox |
| Density | 0.98 g/cm^3🔬 EPA CTX |
| Boiling Point | 221 °C🔬 EPA CTX |
| Melting Point | 23.935 °C📊 OPERA |
| Flash Point | 92.275 °C🔬 EPA CTX |
| Refractive Index | 1.548 Dimensionless📊 OPERA |
| Molar Volume | 133.917 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.185 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.185 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.185 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.84 Log10 unitless📊 OPERA |
| Water Solubility | 0.015 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.196 mmHg📊 OPERA |
| Viscosity | 2.049 cP📊 OPERA |
| Surface Tension | 36.268 dyn/cm📊 OPERA |
| Thermal Conductivity | 141.819 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 | 2 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 42.555 cm^3/mol📊 OPERA |
| Polarizability | 16.87 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.
