2-Methylpropyl pentanoate (CAS 10588-10-0) — Sweet Top-middle Note Fragrance Ingredient
2-Methylpropyl pentanoate
CAS 10588-10-0
What Is 2-Methylpropyl pentanoate?
2-Methylpropyl pentanoate is a synthetic ester used in fruity and sweet fragrance compositions. You’ll encounter it in body sprays, air fresheners, and some tropical-inspired perfumes. It matters because it adds a juicy, pear-like freshness to blends without being overpowering, making it a versatile tool for perfumers creating approachable, wearable scents.
Safety Profile
GENERALLY SAFEWhat Does 2-Methylpropyl pentanoate Smell Like?
2-Methylpropyl pentanoate bursts with a crisp, effervescent fruitiness reminiscent of just-ripe Bartlett pears drizzled with lime juice. The top note has a sparkling quality like champagne bubbles, transitioning to a heart of candied apple skins and a whisper of banana. As it dries down, it leaves a clean, slightly waxy impression like the inside of a fresh honeydew melon rind, with a subtle green undertone that prevents the sweetness from becoming cloying.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the citrus top notes with a dewy fruit effect, creating the illusion of Mediterranean lemon groves after rain.
Provides a radiant berry-like lift to the lychee accord, enhancing the fragrance’s luminous quality.
Contributes a coconut-water freshness that reads as aquatic without marine notes.
Adds a neon-bright fruitiness that contrasts with the coffee base.
Forms the core of the pear accord, tempered with citrus to prevent excessive sweetness.
2D Molecular Structure
SMILES: CCCCC(=O)OCC(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Methylpropyl pentanoate belongs to the ester class, formed via Fischer esterification between isobutyl alcohol and pentanoic acid. Unlike many fruit esters derived from short-chain acids, its 5-carbon backbone provides greater tenacity while maintaining volatility. Industrial synthesis typically uses acid catalysis under reflux, with yields improved by removing water via azeotropic distillation. The branched isobutyl group introduces steric hindrance that affects evaporation rate and olfactory properties.
Physical & Chemical Properties
| Boiling Point | 176-178 °C |
|---|---|
| Density | 0.865 g/cm³ |
| Refractive Index | 1.408-1.412 |
| Flash Point | 62 °C |
| Solubility | Insoluble in water, soluble in alcohol |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Fruit top note enhancer |
| Body Care | 0.1-0.5% | Up to 1% | Adds freshness to shower gels |
| Candles | 1-3% | Up to 8% | Good throw in paraffin |
| Air Fresheners | 2-5% | Up to 10% | Bright diffusive quality |
Classic Accords
Tip: Use with ionones to create dimension in fruit accords – they’ll round out the sharp edges.
Alternatives & Comparisons
More banana-like, shorter lasting. Use when needing brighter top notes in citrus blends.
Deeper berry character. Better for jammy red fruit effects in gourmands.
Pineapple-like with more tenacity. Ideal for tropical bases.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted under current IFRA standards (Amendment 49).
RIFM Assessment
RIFM evaluation confirms safe use at current industry levels with margin of exposure >100.
Sustainability
As a fully synthetic material, 2-Methylpropyl pentanoate avoids agricultural land use. Its production from petrochemical feedstocks raises carbon footprint concerns, but modern catalytic processes achieve ~85% atom efficiency. Biotech routes using engineered yeast to produce precursors are under development but not yet commercially viable.
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781420090772
- IFRA Standards Library. Amendment 49 (2019). IFRA
- PubChem Compound Summary for Esters PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID1065134
Physical Properties
| Molecular Weight | 158.241 g/mol🔬 EPA CompTox |
| Density | 0.876 g/cm^3📊 OPERA |
| Boiling Point | 179 °C🔬 EPA CTX |
| Melting Point | -67.838 °C📊 OPERA |
| Flash Point | 58.672 °C📊 OPERA |
| Refractive Index | 1.417 Dimensionless📊 OPERA |
| Molar Volume | 180.955 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.072 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.072 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.072 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.43 Log10 unitless📊 OPERA |
| Water Solubility | 0.004 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.25 mmHg📊 OPERA |
| Viscosity | 1.079 cP📊 OPERA |
| Surface Tension | 25.509 dyn/cm📊 OPERA |
| Thermal Conductivity | 132.724 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.
