Pyrazine, methyl (methylthio)- (CAS 67952-65-2) — Sweet Heart to base Note Fragrance Ingredient
Pyrazine, methyl (methylthio)-
CAS 67952-65-2
What Is Pyrazine, methyl (methylthio)-?
Methyl (methylthio)pyrazine is a synthetic aroma chemical that contributes roasted, nutty, and coffee-like nuances to fragrances and flavorings. You’ll encounter it in gourmand perfumes, chocolate scents, and some savory food flavorings. This molecule matters because it’s exceptionally potent—a tiny amount can dramatically alter a fragrance’s character, adding depth and realism to food-inspired compositions.
Safety Profile
USE WITH AWARENESSWhat Does Pyrazine, methyl (methylthio)- Smell Like?
Methyl (methylthio)pyrazine erupts with an intense roasted coffee bean aroma, dark and slightly bitter like freshly ground espresso. The initial burst evolves into nutty nuances—think hazelnuts toasted in a cast iron pan—with an underlying savory edge reminiscent of roasted bell peppers. As it dries down, it reveals a surprisingly sweet, almost caramelized character that lingers close to the skin. This transformative molecule behaves like a culinary alchemist, turning simple compositions into complex gourmand experiences with its evolving roasted-sweet-savory profile.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a coffee accord amplifier, adding photorealistic roasted depth to the vanilla-caffeine theme without overwhelming the floral heart.
Forms the molecular backbone of the coffee illusion, blending with patchouli to create a dark, addictive gourmand signature.
Provides the crucial roasted facet that makes the coffee-pancake accord smell freshly brewed rather than synthetic.
Works synergistically with vanillin to create the impression of coffee beans caramelizing in a roaster.
Used at minimal dosage to add photorealistic coffee shop aromatics that persist through the woody dry down.
2D Molecular Structure
SMILES: C*.CSC1=NC=CN=C1 |c:5,7,t:3,lp:3:2,5:1,8:1,m:1:9.7.6|
Chemistry, Properties & Perfumer Guide
The Chemistry
Methyl (methylthio)pyrazine belongs to the alkylpyrazine class, sulfur-containing heterocyclic compounds responsible for many roasted food aromas. While pyrazines occur naturally in coffee and roasted meats, this specific derivative is exclusively synthetic. Industrial synthesis typically involves nucleophilic substitution reactions on chloropyrazine precursors with methanethiol. The sulfur bridge increases volatility compared to non-thiolated pyrazines while maintaining exceptional olfactory potency. Chirality isn’t a factor as the molecule lacks stereocenters, but the sulfur oxidation state significantly impacts odor characteristics.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~210 °C (estimated) |
| Flash Point | >100 °C |
| 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% | Gourmand modifier |
| Functional Fragrance | 0.001-0.01% | Up to 0.05% | Coffee/roasted accents |
| Flavorings | 1-10 ppm | Up to 50 ppm | Savory enhancer |
Classic Accords
Tip: Always pre-dilute to 1% or lower before incorporating – its potency can overwhelm entire compositions if added neat.
Alternatives & Comparisons
Less roasted, more green bell pepper character; better for fresh vegetable accords.
Similar roasted profile but without sulfurous depth; useful when cleaner top notes are needed.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted under IFRA standards. Listed in IFRA Transparency List with no usage limits specified.
EU Allergen Declaration
Not listed in EU allergen regulation (EC) No 1223/2009 Annex III.
GHS Classification
RIFM Assessment
RIFM has reviewed related alkylpyrazines but no specific assessment found for this derivative. Considered safe at current usage levels.
Sustainability
As a synthetic molecule, production doesn’t rely on agricultural resources but requires controlled chemical synthesis. The sulfur component typically comes from petrochemical sources. Energy-intensive manufacturing is offset by extreme potency—micro-quantities deliver significant olfactory impact, reducing overall material requirements per formulation.
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781439832279
- Pyrazine derivatives in food flavorings (2018). Flavour and Fragrance Journal, 33(4), 225-239. DOI:10.1002/ffj.3444
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 67952-65-2Physical Properties
| Molecular Weight | 140.21 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| log Kp (skin permeability) | -2.277💻 Calculated |
| SMILES | CC1=NC=CN=C1SC🔬 PubChem |
Odor & Flavor
| Primary Descriptors | burnthazelnutnuttyroasted• 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: DTXSID4047707
Physical Properties
| Molecular Weight | 140.21 g/mol🔬 PubChem |
Partition & Solubility
| LogP (Octanol-Water) | 1.782 dimensionless💻 Computed |
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 | 38.55 cm^3/mol💻 Computed |
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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