Hexanoic acid, 2-ethyl-, methyl ester (CAS 816-19-3) — Sweet Top to Middle Note Fragrance Ingredient
Hexanoic acid, 2-ethyl-, methyl ester
CAS 816-19-3
What Is Hexanoic acid, 2-ethyl-, methyl ester?
Hexanoic acid, 2-ethyl-, methyl ester is a synthetic fragrance ingredient used in perfumes and flavorings. It contributes fruity, wine-like notes to compositions. Consumers encounter it in fine fragrances, personal care products, and some food flavorings. This ester matters because it adds complexity to fruity and floral accords while being more stable than natural alternatives, offering consistent performance across different product formulations.
Safety Profile
GENERALLY SAFEWhat Does Hexanoic acid, 2-ethyl-, methyl ester Smell Like?
This ester opens with a bright, fruity burst reminiscent of green apples and pineapple skins, with a subtle fermented wine-like undertone. The heart reveals a smoother, almost floral character akin to ripe strawberries macerated in sugar. Dry-down brings a whisper of fatty, cheesy nuance that grounds the sweetness, like the rind of a fine brie. The evolution is surprisingly long-lasting for an ester, with the fruity facets persisting for hours before fading into a clean, slightly waxy trail.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a fruity top note enhancer, contributing to the fragrance’s vibrant opening while blending seamlessly with citrus and floral components.
Provides a juicy, tropical fruit effect that lasts into the mid-phase, supporting the pineapple and passionfruit accord.
2D Molecular Structure
SMILES: CCCCC(CC)C(=O)OC
Chemistry, Properties & Perfumer Guide
The Chemistry
Methyl 2-ethylhexanoate belongs to the ester class, synthesized via esterification of 2-ethylhexanoic acid with methanol. Esters like this are prized in perfumery for their fruity olfactory characteristics. The branched ethyl group influences both the volatility and odor profile, making it more wine-like than straight-chain hexanoate esters. While not found in nature, similar esters occur in fermented products, explaining its complex olfactory profile that bridges fruity and fermented impressions.
Physical & Chemical Properties
| Boiling Point | 198 °C |
|---|---|
| Density | 0.865 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-5% | Up to 10% | Fruity modifier |
| Functional Fragrance | 0.5-2% | Up to 5% | Flavor enhancer |
Classic Accords
Tip: Use in fruity bases to add depth and persistence to top notes.
Alternatives & Comparisons
More intensely fruity with apple character; use when a stronger top note impact is desired.
Simpler fruity note; use when less complexity is needed in the formula.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted by IFRA. Generally recognized as safe at typical usage levels.
RIFM Assessment
RIFM has evaluated similar esters and found them safe as used in fragrance formulations.
Sustainability
As a synthetic material, this ester has consistent quality without natural variation. Production is energy-intensive but avoids agricultural land use. The carbon footprint is moderate compared to some natural alternatives that require extensive cultivation and processing.
Explore Hexanoic acid, 2-ethyl-, methyl ester
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- PubChem Compound Summary for Methyl 2-ethylhexanoate PubChem CID
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 816-19-3Physical Properties
| Molecular Weight | 158.24 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3🔬 PubChem |
| Boiling Point | 179 °C🔬 EPA CompTox |
| Vapor Pressure | 4.4 mmHg @ 25°C📊 OPERA |
| Flash Point | 57 °C🔬 EPA CompTox |
| Involatility Index | 0.377💻 Calculated |
| log Kp (skin permeability) | -1.535💻 Calculated |
| SMILES | CCCCC(CC)C(=O)OC🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Moderate💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | fattyfruityherbalorriswoody• leffingwell |
| Functional Groups | esterether💻 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: DTXSID9052559
Physical Properties
| Molecular Weight | 158.241 g/mol🔬 EPA CompTox |
| Density | 0.873 g/cm^3🔬 EPA CTX |
| Boiling Point | 176.12 °C📊 OPERA |
| Melting Point | -56.103 °C📊 OPERA |
| Flash Point | 57 °C🔬 EPA CTX |
| Refractive Index | 1.417 Dimensionless📊 OPERA |
| Molar Volume | 180.955 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1173.685 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.392 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.392 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.43 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 3.325 mmHg🔬 EPA CTX |
| Viscosity | 1.109 cP📊 OPERA |
| Surface Tension | 25.879 dyn/cm📊 OPERA |
| Thermal Conductivity | 132.647 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 | 45.478 cm^3/mol📊 OPERA |
| Polarizability | 18.029 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.
![Spiro[bicyclo[2.2.1]heptane-s,4′-[1,2]dioxane], 1,7,7-trimethyl-2′-(methylethyl)-, (1R,2S,2’S,4R) (CAS 188199-50-0) — Woody Middle to base Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/spiro-bicyclo-2-2-1-heptane-s-4-039-1-2-dioxane-1-7-7-trimet-1-768x439.webp)
![Phenol, 2-methoxy-, reaction products with 2,2-dimethyl-3-methylenebicyclo[2.2.1]heptane, hydrogenated (CAS 70955-71-4) — Woody Base Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/phenol-2-methoxy-reaction-products-with-2-2-dimethyl-3-methy-1-768x439.webp)