2-Methylbutyl 2-methylbutyrate (CAS 2445-78-5) — Sweet Top to middle Note Fragrance Ingredient
2-Methylbutyl 2-methylbutyrate
CAS 2445-78-5
What Is 2-Methylbutyl 2-methylbutyrate?
2-Methylbutyl 2-methylbutyrate is a synthetic fragrance ingredient used to add fruity, apple-like notes to perfumes and flavored products. You’ll encounter it in body sprays, candles, and some food flavorings. This ester compound matters because it provides a cost-effective way to create natural-smelling fruity accords without relying on volatile natural extracts that might degrade quickly.
Safety Profile
GENERALLY SAFEWhat Does 2-Methylbutyl 2-methylbutyrate Smell Like?
2-Methylbutyl 2-methylbutyrate bursts with a juicy, crisp green apple aroma that’s slightly fermented at the edges, like apple cider. The top note has a bright, almost pear-like sweetness that quickly settles into a more rounded, jammy fruit character. As it dries down, it reveals subtle woody undertones that prevent the fruitiness from becoming cloying. The overall effect is like biting into a perfectly ripe apple with a faint hint of banana in the background.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as the primary apple note to create an authentic, mouthwatering green apple cocktail effect without alcohol’s harshness.
Provides subtle fruity depth beneath the dominant citrus notes, enhancing the perception of juicy freshness.
Contributes to the crisp apple top note that defines this iconic fragrance, blending with rose and magnolia.
2D Molecular Structure
SMILES: CCC(C)COC(=O)C(C)CC
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Methylbutyl 2-methylbutyrate is an ester formed from 2-methylbutanol and 2-methylbutyric acid. It’s part of the branched-chain ester family that mimics many natural fruit aromas. Industrially produced via acid-catalyzed esterification, this compound’s branched structure gives it greater stability than straight-chain fruit esters. The molecule’s chirality affects its odor profile, with different enantiomers contributing subtly different fruity nuances.
Physical & Chemical Properties
| Boiling Point | 198-200 °C |
|---|---|
| Density | 0.86 g/cm³ |
| Refractive Index | 1.412 |
| Vapor Pressure | 0.1 mmHg at 20°C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Fruity top note modifier |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Air fresheners, detergents |
| Flavor | 5-15 ppm | Up to 50 ppm | Apple, banana flavors |
Classic Accords
Tip: Use with bergamot or lime oils to brighten fruity compositions and prevent them from becoming too heavy.
Alternatives & Comparisons
For a greener, less sweet apple note with better persistence in the heart phase.
When a more pronounced banana-like fruity character is desired with higher volatility.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions. Listed in IFRA Transparency List with no usage limits.
RIFM Assessment
RIFM evaluation concluded safe use at current levels in fragrances.
Sustainability
As a synthetic material, 2-methylbutyl 2-methylbutyrate reduces pressure on agricultural resources compared to natural fruit extracts. Modern production methods minimize solvent waste and energy use. Being biodegradable, it doesn’t accumulate in the environment. Some manufacturers now offer bio-based versions derived from renewable feedstocks.
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781439847503
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 2445-78-5Physical Properties
| Molecular Weight | 172.26 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.2🔬 PubChem |
| Boiling Point | 70 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.479💻 Calculated |
| SMILES | CCC(C)COC(=O)C(C)CC🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
Odor & Flavor
| Primary Descriptors | appleberryfruitygreenpineappletropicalwaxy• leffingwell |
| Functional Groups | esterether💻 RDKit |
| 2-Methylbutyl-2-methyl butyrate has a fruity, berry, apple like aroma.📖 Fenaroli | |
Sensory Thresholds
| Odor Detection Threshold | 0.0424 ppm (n=2)📖 van Gemert |
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: DTXSID40862947
Physical Properties
| Molecular Weight | 172.268 g/mol🔬 EPA CompTox |
| Density | 0.865 g/cm^3📊 OPERA |
| Boiling Point | 185.677 °C📊 OPERA |
| Melting Point | -66.999 °C📊 OPERA |
| Flash Point | 63.704 °C📊 OPERA |
| Refractive Index | 1.42 Dimensionless📊 OPERA |
| Molar Volume | 197.838 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.705 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.705 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.705 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.59 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.817 mmHg📊 OPERA |
| Viscosity | 1.27 cP📊 OPERA |
| Surface Tension | 25.349 dyn/cm📊 OPERA |
| Thermal Conductivity | 126.715 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 | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 50.07 cm^3/mol📊 OPERA |
| Polarizability | 19.849 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.
