3-Ethyl-2,5-dimethylpyrazine (CAS 13360-65-1) — Sweet Middle Note Fragrance Ingredient
3-Ethyl-2,5-dimethylpyrazine
CAS 13360-65-1
What Is 3-Ethyl-2,5-dimethylpyrazine?
3-Ethyl-2,5-dimethylpyrazine is a synthetic aroma compound that creates rich, nutty, roasted aromas. You’ll encounter it in coffee, chocolate, and savory flavorings. This pyrazine matters because it adds depth to gourmand fragrances and food flavors at extremely low concentrations.
Safety Profile
USE WITH AWARENESSWhat Does 3-Ethyl-2,5-dimethylpyrazine Smell Like?
A powerhouse of roasted depth, 3-ethyl-2,5-dimethylpyrazine bursts with freshly ground coffee beans and cocoa nibs. The initial impression is intensely nutty – think hazelnuts roasted in cast iron. As it evolves, earthy potato skin and tobacco leaf nuances emerge. The dry-down reveals a lingering toasted bread character that blends beautifully with vanilla and woods. Exceptionally potent – one drop can dominate a formula.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here at trace levels to amplify the dark chocolate accord, adding roasted coffee nuances that make the gourmand composition feel more adult and sophisticated.
The pyrazine creates photorealistic coffee bean facets that persist through the heart notes, complementing the rose-vanilla core with its bitter roasted character.
2D Molecular Structure
SMILES: CCC1=C(C)N=CC(C)=N1
Chemistry, Properties & Perfumer Guide
The Chemistry
As an alkylpyrazine, this compound belongs to the heterocyclic nitrogen-containing aroma chemicals. Pyrazines form through Maillard reactions during roasting processes. Synthetically, it’s produced via condensation reactions of α-diketones with diamines. The ethyl and methyl substitutions at positions 2,3,5 create its distinctive roasted odor profile at concentrations as low as 0.1 ppb.
Physical & Chemical Properties
| Boiling Point | 198-200 °C |
|---|---|
| Density | 0.99 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.01-0.1% | Up to 0.5% | Extremely potent – use sparingly |
| Functional Fragrance | 0.001-0.01% | Up to 0.05% | For fabric conditioners, candles |
Classic Accords
Tip: Always pre-dilute to 1% in ethanol before incorporating – direct use can overwhelm a formula.
Alternatives & Comparisons
Less intense roasted character, works better when subtle nutty notes are needed without dominating the composition.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted by IFRA. Self-regulated due to potency.
RIFM Assessment
RIFM evaluation complete – safe at current use levels.
Sustainability
Synthetic production avoids agricultural land use. Manufacturing requires controlled conditions but has low environmental impact due to small quantities needed.
Explore 3-Ethyl-2,5-dimethylpyrazine
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References
- Belitz et al. (2009). Food Chemistry. Springer. ISBN 978-3-540-69934-7
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 13360-65-1Physical Properties
| Molecular Weight | 136.19 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.5🔬 PubChem |
| Boiling Point | 180.5 °C🔬 EPA CompTox |
| Vapor Pressure | 0.2291 mmHg @ 25°C📊 OPERA |
| Flash Point | 69.4 °C🔬 EPA CompTox |
| Involatility Index | 0.0212💻 Calculated |
| log Kp (skin permeability) | -2.466💻 Calculated |
| SMILES | CCC1=NC(=CN=C1C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 0.9 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | almondburntchocolatenutty• leffingwell |
| Functional Groups | aromatic💻 RDKit |
Sensory Thresholds
| Odor Detection Threshold | 0.0271 ppm (n=9)📖 van Gemert |
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: DTXSID1065423
Physical Properties
| Molecular Weight | 136.198 g/mol🔬 EPA CompTox |
| Density | 0.973 g/cm^3📊 OPERA |
| Boiling Point | 180.5 °C🔬 EPA CTX |
| Melting Point | 39.514 °C📊 OPERA |
| Flash Point | 69.475 °C🔬 EPA CTX |
| Refractive Index | 1.501 Dimensionless📊 OPERA |
| Molar Volume | 141.249 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.483 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.483 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.483 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.81 Log10 unitless📊 OPERA |
| Water Solubility | 0.602 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.682 mmHg📊 OPERA |
| Viscosity | 2.867 cP📊 OPERA |
| Surface Tension | 34.637 dyn/cm📊 OPERA |
| Thermal Conductivity | 126.056 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 25.78 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 41.634 cm^3/mol📊 OPERA |
| Polarizability | 16.505 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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