3-Ethylpyridine (CAS 536-78-7) — Woody Top to middle Note Fragrance Ingredient
3-Ethylpyridine
CAS 536-78-7
What Is 3-Ethylpyridine?
3-Ethylpyridine is a synthetic aroma chemical used in niche fragrances to add smoky, leathery nuances. It’s found in upscale perfumes aiming for unconventional smoky-woody profiles. This ingredient matters because it provides perfumers with a sharp, tobacco-like note that’s more diffusive than traditional pyridine derivatives, allowing for modern interpretations of classic leather accords.
Safety Profile
USE WITH AWARENESSWhat Does 3-Ethylpyridine Smell Like?
3-Ethylpyridine bursts with an intense, piercing smokiness reminiscent of charred oak barrels and extinguished candle wicks. The initial sharpness evolves into a dry tobacco leaf character, with subtle hints of roasted coffee beans in the heart. As it dries down, it reveals a surprisingly smooth leather undertone, like well-worn bookbinding leather. The overall effect is less animalic than traditional pyridine derivatives, making it useful for contemporary smoky compositions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the fragrance’s charcoal-like minerality, blending with incense to create a modern gothic effect. The 3-ethylpyridine adds diffusive smokiness without overwhelming the floral heart.
Contributes to the dark, resinous tobacco accord, providing lift to the heavy oud base. Its sharpness cuts through the density of other materials.
2D Molecular Structure
SMILES: CCC1=CC=CN=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
3-Ethylpyridine belongs to the alkylpyridine class, synthesized through catalytic alkylation of pyridine. The ethyl group at the 3-position creates distinct steric and electronic effects compared to 2- or 4-substituted pyridines. Industrial synthesis typically involves vapor-phase reactions over zeolite catalysts. Unlike simpler pyridines, the ethyl substitution reduces water solubility while increasing lipid affinity, which affects its performance in fragrance matrices.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | 165-167 °C |
| Density | 0.94 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Used sparingly for smoky effects |
| Functional Fragrance | 0.01-0.1% | Up to 0.3% | Masking agent in industrial products |
Classic Accords
Tip: Balance with ionones or coumarin to soften the sharp edges.
Alternatives & Comparisons
Less smoky but more popcorn-like, useful when a softer pyridine character is desired.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards.
GHS Classification
RIFM Assessment
Under evaluation by RIFM for comprehensive safety assessment.
Sustainability
As a synthetic material, 3-ethylpyridine has minimal environmental impact in production. Its high potency means very small quantities are needed, reducing overall material consumption. The synthesis route avoids heavy metals or hazardous reagents common in older pyridine production methods.
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 536-78-7Physical Properties
| Molecular Weight | 107.15 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.7🔬 PubChem |
| Boiling Point | 166 °C🔬 EPA CompTox |
| Vapor Pressure | 2.542 mmHg @ 25°C📊 OPERA |
| Flash Point | 48.9 °C🔬 EPA CompTox |
| Involatility Index | 0.2647💻 Calculated |
| log Kp (skin permeability) | -2.147💻 Calculated |
| SMILES | CCC1=CN=CC=C1🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Moderate💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | nuttyroastedsmokytobacco• leffingwell |
| Functional Groups | aromatic💻 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: DTXSID6060212
Physical Properties
| Molecular Weight | 107.156 g/mol🔬 EPA CompTox |
| Density | 0.954 g/cm^3🔬 EPA CTX |
| Boiling Point | 165.5 °C🔬 EPA CTX |
| Melting Point | -76.94 °C🔬 EPA CTX |
| Flash Point | 48.975 °C🔬 EPA CTX |
| Refractive Index | 1.499 Dimensionless📊 OPERA |
| Molar Volume | 115.475 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.66 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 1.273 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.629 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 3.74 Log10 unitless📊 OPERA |
| Water Solubility | 2.309 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 2.519 mmHg🔬 EPA CTX |
| Viscosity | 1.225 cP📊 OPERA |
| Surface Tension | 32.882 dyn/cm📊 OPERA |
| Thermal Conductivity | 140.675 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 12.89 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 33.893 cm^3/mol📊 OPERA |
| Polarizability | 13.436 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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