2-Ethyl-5-methylpyrazine (CAS 13360-64-0) — Sweet Heart to base Note Fragrance Ingredient
2-Ethyl-5-methylpyrazine
CAS 13360-64-0
What Is 2-Ethyl-5-methylpyrazine?
2-Ethyl-5-methylpyrazine is a synthetic aroma chemical used to create nutty, roasted, and coffee-like notes in perfumes and food flavors. You’ll encounter it in gourmand fragrances, coffee-flavored products, and some savory snacks. This pyrazine compound matters because it provides the authentic roasted character that’s difficult to achieve with natural materials alone, allowing perfumers to create realistic edible accords at trace concentrations.
Safety Profile
USE WITH AWARENESSWhat Does 2-Ethyl-5-methylpyrazine Smell Like?
2-Ethyl-5-methylpyrazine bursts with an intense roasted coffee bean character, evolving into a rich hazelnut creaminess with subtle earthy undertones. The top note is all dark roast bitterness, like freshly ground espresso beans, which mellows into a heart of toasted almonds and warm bread crust. In dry-down, it leaves a lingering cocoa powder trace with just a whisper of smokiness. Its potency means a drop can transform a composition – too much overwhelms, but just enough creates mouthwatering depth.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Provides the addictive coffee shop realism that forms the fragrance’s signature gourmand heart, blending with vanilla and white flowers.
Used here to enhance the coffee absolute with hyper-realistic roasted notes, creating an alarm-clock freshness.
Contributes to the gourmand illusion of steaming coffee and pancakes, pairing with maple and lavender.
Amplifies the coffee-rose concept with its nutty facets, making the accord more three-dimensional.
Forms the photorealistic coffee core that persists through the fragrance’s development.
2D Molecular Structure
SMILES: CCC1=CN=C(C)C=N1
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Ethyl-5-methylpyrazine belongs to the alkylpyrazine class, six-membered heterocyclic nitrogen compounds responsible for many roasted and toasted aromas. While pyrazines occur naturally in coffee, chocolate, and roasted meats, this specific isomer is predominantly synthesized. Industrial production typically involves condensation reactions of diketones with diamines under controlled heating. The ethyl and methyl substituents at positions 2 and 5 create its distinctive odor profile – minor positional isomer changes dramatically affect scent character. Its low odor threshold (parts per billion range) makes it exceptionally potent in formulations.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~200 °C (estimated) |
| Density | ~0.98 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.01-0.1% | Up to 0.5% | Used sparingly for gourmand effects |
| Functional Fragrance | 0.001-0.01% | Up to 0.05% | Masking agent in cleaning products |
| Flavor | 1-10 ppm | Up to 50 ppm | Coffee/chocolate enhancer |
Classic Accords
Tip: Always pre-dilute to 1% or lower before blending due to extreme potency.
Alternatives & Comparisons
More earthy/peanut-like character when a less coffee-forward pyrazine is needed.
For greener bell pepper notes while maintaining pyrazine structure.
Natural alternative when regulations permit, though less stable and more complex.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted under IFRA standards. Classified as a pyrazine derivative with no specific usage limits.
GHS Classification
RIFM Assessment
RIFM has evaluated related pyrazines but no specific assessment found for this isomer.
Sustainability
As a synthetic material, 2-ethyl-5-methylpyrazine has minimal agricultural impact but requires energy-intensive manufacturing. Its extreme potency means very small quantities are needed, reducing overall environmental load compared to natural coffee extracts which require large-scale cultivation and solvent extraction.
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9780849330346
- Pyrazines in Flavors (2005). Perfumer & Flavorist, 30(2). Industry Journal
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 13360-64-0Physical Properties
| Molecular Weight | 122.17 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1🔬 PubChem |
| Boiling Point | 176 °C🔬 EPA CompTox |
| Vapor Pressure | 0.6457 mmHg @ 25°C📊 OPERA |
| Flash Point | 63 °C🔬 EPA CompTox |
| Involatility Index | 0.063💻 Calculated |
| log Kp (skin permeability) | -2.735💻 Calculated |
| SMILES | CCC1=NC=C(N=C1)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | greennuttyroasted• leffingwell |
| Functional Groups | aromatic💻 RDKit |
| 2-Ethyl-5-methylpyrazine has an odor threshold of 100 ppb in water.📖 Fenaroli | |
Sensory Thresholds
| Odor Detection Threshold | 0.0386 ppm (n=3)📖 van Gemert |
Regulatory Status
| IOFI Classification | Nature Identical📖 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: DTXSID6065422
Physical Properties
| Molecular Weight | 122.171 g/mol🔬 EPA CompTox |
| Density | 0.991 g/cm^3📊 OPERA |
| Boiling Point | 174.921 °C📊 OPERA |
| Melting Point | 16.451 °C📊 OPERA |
| Flash Point | 64.965 °C📊 OPERA |
| Refractive Index | 1.501 Dimensionless📊 OPERA |
| Molar Volume | 124.973 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.025 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.025 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.025 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.47 Log10 unitless📊 OPERA |
| Water Solubility | 1.587 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.277 mmHg📊 OPERA |
| Viscosity | 2.314 cP📊 OPERA |
| Surface Tension | 35.446 dyn/cm📊 OPERA |
| Thermal Conductivity | 130.413 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 | 36.81 cm^3/mol📊 OPERA |
| Polarizability | 14.592 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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