Pyrazine, 2-methyl-3-(methylthio)- (CAS 2882-20-4) — Spicy Heart to base Note Fragrance Ingredient
Pyrazine, 2-methyl-3-(methylthio)-
CAS 2882-20-4
What Is Pyrazine, 2-methyl-3-(methylthio)-?
2-Methyl-3-(methylthio)pyrazine is a synthetic aroma chemical that adds savory, roasted notes to fragrances and flavored foods. You might encounter it in gourmand perfumes or meat flavorings. This molecule is prized for its ability to create complex, umami-like depth at extremely low concentrations, making it a powerful tool for perfumers and flavorists alike.
Safety Profile
USE WITH AWARENESSWhat Does Pyrazine, 2-methyl-3-(methylthio)- Smell Like?
A potent, diffusive burst of roasted nuts and coffee grounds dominates the opening, with a distinct meaty undertone reminiscent of seared beef. As it evolves, the pyrazinic character reveals green bell pepper nuances with a sulfurous edge. The dry-down lingers as a warm, savory skin scent with traces of toasted sesame and black pepper. Exceptionally powerful at concentrations below 0.1%, requiring careful dosage to avoid overwhelming compositions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used sparingly to enhance the leather accord with roasted, animalic facets that bridge the floral heart and woody base.
Contributes smoky, narcotic depth to the cannabis accord, amplifying the fragrance’s controversial edginess.
Provides the charred wood illusion in this campfire-inspired composition, blending with cade oil and styrax.
Creates an ink-like mineral effect when combined with violet leaf, suggesting printer’s ink on paper.
Adds a subtle gamey complexity to the frankincense-rich oriental composition, enhancing its ceremonial quality.
2D Molecular Structure
SMILES: CSC1=NC=CN=C1C
Chemistry, Properties & Perfumer Guide
The Chemistry
This alkylthio-substituted pyrazine belongs to the heterocyclic nitrogen compounds class, structurally featuring a methyl group at position 2 and a methylthio group at position 3 on the pyrazine ring. Synthesized through nucleophilic substitution reactions on chloropyrazines or via condensation of α-diketones with sulfur-containing amines. The methylthio group (-SCH3) significantly lowers the odor threshold compared to unsubstituted pyrazines, contributing to its exceptional potency. Unlike many pyrazines, it lacks significant chirality due to its symmetrical substitution pattern.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~210 °C (estimated) |
| Density | ~1.1 g/cm³ (estimated) |
| Vapor Pressure | Low (estimated) |
| Solubility | Soluble in alcohol, oils; insoluble in water |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.01-0.1% | Up to 0.3% | Extremely potent – use in trace amounts |
| Functional Fragrance | 0.001-0.01% | Up to 0.05% | For masculine deodorants |
| Flavor | 0.5-5 ppm | Up to 10 ppm | Meat and savory applications |
| Home Care | 0.0001-0.001% | Up to 0.005% | For ‘leather’ cleaner scents |
Classic Accords
Tip: Counterbalance sulfurous aspects with ionones or damascones to create more wearable compositions.
Alternatives & Comparisons
Less sulfurous, more green bell pepper character. Preferred for fresh applications where meaty notes are undesirable.
Milder roasted nut profile without sulfur notes. Better for mass-market formulations requiring broader appeal.
Popcorn-like aroma that shares some roasted qualities but lacks the animalic depth.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted under IFRA standards, but recommended usage below 0.3% in fine fragrances due to potency.
GHS Classification
RIFM Assessment
RIFM evaluation ongoing. Preliminary data suggests low systemic toxicity but potential for skin sensitization at high concentrations.
Sustainability
Synthesized from petrochemical precursors with relatively high atom economy. No known ecological hazards at usage levels, but energy-intensive production. Not known to bioaccumulate. Some manufacturers are exploring bio-based synthesis routes using fermentation-derived intermediates.
Explore Pyrazine, 2-methyl-3-(methylthio)-
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781420090869
- Leffingwell, J.C. (2002). Pyrazines in Flavors. Leffingwell Reports. Leffingwell Report
- McGorrin, R.J. (2011). The Significance of Volatile Sulfur Compounds in Food Flavors. ACS Symposium Series. DOI:10.1021/bk-2011-1068.ch001
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 2882-20-4Physical Properties
| Molecular Weight | 140.21 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| Boiling Point | 213 °C🔬 EPA CompTox |
| Vapor Pressure | 0.01 mmHg @ 25°C📊 OPERA |
| Flash Point | 87.5 °C🔬 EPA CompTox |
| Involatility Index | 0.0009💻 Calculated |
| log Kp (skin permeability) | -2.277💻 Calculated |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.9 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | greenspicy• leffingwell |
| 2-Methyl-3(or 5 or 6)-methylthiopyrazine has a roasted almond, hazelnut aroma.📖 Fenaroli | |
Sensory Thresholds
| Odor Detection Threshold | 0.002 ppm (n=2)📖 van Gemert |
Regulatory Status
| IOFI Classification | Artificial📖 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: DTXSID70863048
Physical Properties
| Molecular Weight | 140.2 g/mol🔬 EPA CompTox |
| Density | 1.15 g/cm^3🔬 EPA CTX |
| Boiling Point | 216.912 °C📊 OPERA |
| Melting Point | 55.886 °C📊 OPERA |
| Flash Point | 84.206 °C📊 OPERA |
| Refractive Index | 1.562 Dimensionless📊 OPERA |
| Molar Volume | 122.099 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.81 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 1.532 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.532 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.01 Log10 unitless📊 OPERA |
| Water Solubility | 0.06 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.124 mmHg📊 OPERA |
| Surface Tension | 44.193 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 25.78 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 3 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 39.612 cm^3/mol📊 OPERA |
| Polarizability | 15.703 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.
