Methyl p-tert-butylphenylacetate (CAS 3549-23-3) — Floral Middle to base Note Fragrance Ingredient
Methyl p-tert-butylphenylacetate
CAS 3549-23-3
What Is Methyl p-tert-butylphenylacetate?
Methyl p-tert-butylphenylacetate is a synthetic fragrance ingredient used in perfumes and personal care products. It’s often found in floral and musky compositions. This molecule contributes a clean, powdery character that helps balance brighter top notes in fragrances.
Safety Profile
GENERALLY SAFEWhat Does Methyl p-tert-butylphenylacetate Smell Like?
Methyl p-tert-butylphenylacetate presents a soft, powdery-musky character with subtle floral undertones. The scent evolves from a clean, slightly soapy opening to a warm, skin-like drydown. Imagine the comforting scent of freshly laundered linen blended with the faintest whisper of violet petals. Its tenacity allows it to serve as a subtle fixative, gently anchoring brighter notes without overwhelming them.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a supporting musk in the legendary floral-aldehyde composition, adding subtle powdery depth that complements the rose-jasmine heart.
Provides a clean counterpoint to the vanilla-amber base, preventing the oriental accord from becoming overly sweet.
2D Molecular Structure
SMILES: COC(=O)CC1=CC=C(C=C1)C(C)(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Methyl p-tert-butylphenylacetate belongs to the phenylacetic ester class of fragrance compounds. The tert-butyl group increases molecular bulk, slowing evaporation and modifying odor characteristics compared to simpler phenylacetates. While not found in nature, its structure mimics certain musky-smelling macrocyclic compounds. Industrial synthesis typically involves esterification of p-tert-butylphenylacetic acid with methanol under acidic conditions.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Strength | Medium |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Used as supporting musk |
| Soap | 0.1-0.5% | Up to 1% | Adds clean, powdery character |
Classic Accords
Tip: Use with ionones to create sophisticated powder accords without excessive sweetness.
Alternatives & Comparisons
Offers similar powderiness with more pronounced floral character.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards.
RIFM Assessment
No specific RIFM evaluation published.
Sustainability
As a synthetic material, production avoids natural resource depletion. Manufacturing typically uses petrochemical feedstocks, though greener synthesis routes may be possible. Biodegradability data is limited.
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References
- Bauer et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID0063070
Physical Properties
| Molecular Weight | 206.285 g/mol🔬 EPA CompTox |
| Density | 0.991 g/cm^3📊 OPERA |
| Boiling Point | 266.051 °C📊 OPERA |
| Melting Point | 31.274 °C📊 OPERA |
| Flash Point | 104.077 °C📊 OPERA |
| Refractive Index | 1.492 Dimensionless📊 OPERA |
| Molar Volume | 208.927 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.627 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.627 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.627 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.35 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.014 mmHg📊 OPERA |
| Viscosity | 4.226 cP📊 OPERA |
| Surface Tension | 31.662 dyn/cm📊 OPERA |
| Thermal Conductivity | 126.393 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 2 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 60.597 cm^3/mol📊 OPERA |
| Polarizability | 24.023 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.
