4-Methyl-5-vinylthiazole (CAS 1759-28-0) — Sweet Heart Note Fragrance Ingredient
4-Methyl-5-vinylthiazole
CAS 1759-28-0
What Is 4-Methyl-5-vinylthiazole?
4-Methyl-5-vinylthiazole is a synthetic aroma chemical used to create nutty, roasted, and popcorn-like nuances in fragrances. You’ll encounter it in gourmand scents and some savory flavorings. This molecule matters because it adds realistic toasted notes at trace levels, enhancing complexity without overwhelming compositions.
Safety Profile
USE WITH AWARENESSWhat Does 4-Methyl-5-vinylthiazole Smell Like?
A powerhouse of toasted complexity – imagine popcorn kernels hitting hot oil with a sulfurous edge. Opens with sharp roasted hazelnuts and burnt caramel, evolving into a savory heart reminiscent of coffee beans and roasted barley. The dry-down reveals a lingering nutty-skin musk with faintly metallic undertones. Exceptionally diffusive at minute concentrations.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Provides roasted cocoa nuances that complement the vanilla-iris accord, adding gourmand depth without sweetness.
Used at trace levels to enhance the rum-almond accord with a photorealistic roasted coffee character.
2D Molecular Structure
SMILES: CC1=C(SC=N1)C=C
Chemistry, Properties & Perfumer Guide
The Chemistry
A thiazole derivative featuring both methyl and vinyl substituents. Synthesized via condensation reactions of α-haloketones with thioamides. The vinyl group contributes reactivity while the methyl group modulates volatility. Thiazoles are nitrogen-sulfur heterocycles known for their potent aroma characteristics at extremely low thresholds.
Physical & Chemical Properties
| Appearance | Clear to pale yellow liquid |
|---|---|
| Odor Threshold | <0.1 ppb |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.01-0.1% | Up to 0.3% | Extremely potent modifier |
| Functional Fragrance | 5-50 ppm | Up to 100 ppm | Savory enhancer |
Classic Accords
Tip: Always pre-dilute to 1% or lower before incorporating due to extreme potency.
Alternatives & Comparisons
Less aggressive roasted note with popcorn character, better for delicate compositions.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific restrictions under current IFRA standards.
GHS Classification
RIFM Assessment
Not currently evaluated by RIFM.
Sustainability
Synthetic production avoids agricultural land use. Typical synthesis routes involve petrochemical precursors, though green chemistry approaches are being explored.
Explore 4-Methyl-5-vinylthiazole
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References
- Burdock (2010). Fenaroli’s Handbook of Flavor Ingredients.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID5061952
Physical Properties
| Molecular Weight | 125.19 g/mol🔬 EPA CompTox |
| Density | 1.092 g/cm^3🔬 EPA CTX |
| Boiling Point | 187.026 °C📊 OPERA |
| Melting Point | -15 °C🔬 EPA CTX |
| Flash Point | 62.101 °C📊 OPERA |
| Refractive Index | 1.588 Dimensionless📊 OPERA |
| Molar Volume | 114.36 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.683 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.682 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.683 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.5 Log10 unitless📊 OPERA |
| Water Solubility | 0.122 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.547 mmHg📊 OPERA |
| Viscosity | 2.153 cP📊 OPERA |
| Surface Tension | 36.262 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 12.89 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 | 38.478 cm^3/mol📊 OPERA |
| Polarizability | 15.254 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.
