Methyl isobutyrate (CAS 547-63-7) — Sweet Top Note Fragrance Ingredient
Methyl isobutyrate
CAS 547-63-7
What Is Methyl isobutyrate?
Methyl isobutyrate is a fruity-smelling ester commonly used in food flavorings and perfumes. You’ll find it in strawberry candies, apple-flavored drinks, and some fresh citrus perfumes. This ingredient matters because it adds a bright, juicy top note that makes fragrances smell immediately appealing and approachable.
Safety Profile
GENERALLY SAFEWhat Does Methyl isobutyrate Smell Like?
Methyl isobutyrate bursts with an intensely fruity, almost effervescent quality reminiscent of freshly cut green apples and ripe strawberries. The opening is sharply sweet, like biting into a just-picked raspberry with its tart juice still clinging to your lips. As it evolves, it softens into a candied citrus character – think lemon drops dissolving on your tongue. The dry-down reveals a subtle woody undertone that prevents the sweetness from becoming cloying, leaving a clean, refreshing trail.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the citrusy freshness, methyl isobutyrate creates that initial ‘bite’ of crisp green apple that makes Light Blue so instantly recognizable and refreshing.
The fruity facets of methyl isobutyrate blend seamlessly with bergamot in this classic cologne, adding a modern juicy twist to the traditional citrus structure.
2D Molecular Structure
SMILES: COC(=O)C(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Methyl isobutyrate is a simple ester formed from methanol and isobutyric acid. Industrially produced via acid-catalyzed esterification, this small molecule (C6H12O2) exemplifies how minor structural changes dramatically alter scent – the branched isobutyl group creates a fruitier character than its straight-chain counterpart. While occasionally found in trace amounts in fruits, commercial production is entirely synthetic. The molecule’s compact size contributes to its high volatility and intense top-note character.
Physical & Chemical Properties
| Boiling Point | 92-93 °C |
|---|---|
| Density | 0.889 g/cm³ |
| Refractive Index | 1.3840 |
| Flash Point | 7 °C |
| Vapor Pressure | 49.6 mmHg at 25°C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Used sparingly for fruity top notes |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Adds freshness to cleaning products |
Classic Accords
Tip: Use at 0.1-0.5% in citrus accords to add dimensionality without overwhelming the composition.
Alternatives & Comparisons
Similar fruity character but slightly sweeter and less sharp, with better longevity in the heart phase.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions apply.
GHS Classification
RIFM Assessment
RIFM has evaluated methyl isobutyrate and found no significant safety concerns at current usage levels.
Sustainability
As a synthetic material produced from petrochemical feedstocks, methyl isobutyrate’s environmental impact comes primarily from manufacturing energy use. However, its high potency means very small quantities are needed, reducing overall footprint. Some manufacturers are exploring bio-based production routes using fermented isobutanol.
Explore Methyl isobutyrate
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. PMID 30000942
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 547-63-7Physical Properties
| Molecular Weight | 102.13 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.2🔬 PubChem |
| Boiling Point | 91 °C🔬 EPA CompTox |
| Vapor Pressure | 49.56 mmHg @ 25°C📊 OPERA |
| Flash Point | 4.4 °C🔬 EPA CompTox |
| Involatility Index | 5.2855💻 Calculated |
| log Kp (skin permeability) | -2.471💻 Calculated |
| SMILES | CC(C)C(=O)OC🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Very fast💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | appleapricotfruitypineapplerum• leffingwell |
| Functional Groups | esterether💻 RDKit |
| Methyl isobutyrate has a fruity (apple–pineapple) odor and a sweet flavor reminiscent of apricot.📖 Fenaroli | |
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: DTXSID5060275
Physical Properties
| Molecular Weight | 102.133 g/mol🔬 EPA CompTox |
| Density | 0.888 g/cm^3🔬 EPA CTX |
| Boiling Point | 91.5 °C🔬 EPA CTX |
| Melting Point | -84.8 °C🔬 EPA CTX |
| Flash Point | 5.67 °C🔬 EPA CTX |
| Refractive Index | 1.385 Dimensionless📊 OPERA |
| Molar Volume | 114.928 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.387 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.387 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.387 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 2.89 Log10 unitless📊 OPERA |
| Water Solubility | 0.206 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 49.41 mmHg🔬 EPA CTX |
| Viscosity | 0.523 cP📊 OPERA |
| Surface Tension | 23.49 dyn/cm📊 OPERA |
| Thermal Conductivity | 131.334 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 | 1 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 26.947 cm^3/mol📊 OPERA |
| Polarizability | 10.683 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.
