3-Mercaptohexyl acetate (CAS 136954-20-6) — Sweet Top to middle Note Fragrance Ingredient
3-Mercaptohexyl acetate
CAS 136954-20-6
What Is 3-Mercaptohexyl acetate?
3-Mercaptohexyl acetate is a powerful synthetic fragrance ingredient used to create tropical, fruity aromas reminiscent of passionfruit and guava. You’ll encounter it in modern perfumes and body care products where a juicy, exotic top note is desired. This thiol compound matters because it revolutionized fruit accords with its intense aroma at extremely low concentrations, allowing perfumers to create realistic tropical effects without overwhelming compositions.
Safety Profile
USE WITH AWARENESSWhat Does 3-Mercaptohexyl acetate Smell Like?
At first sniff, 3-Mercaptohexyl acetate bursts forth with an explosive tropical fruit character – imagine overripe passionfruit dripping with juice, crossed with the tangy sweetness of pink guava. The sharp sulfurous edge quickly mellows into a more rounded, jammy fruitiness that suggests mango skins and pineapple cores. Over time, it develops a subtle green rhubarb nuance before fading to a soft musky-sweet trail. Though potent, it never loses its juicy dimensionality, making it invaluable for modern fruity-floral compositions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to amplify the coffee accord with a forbidden fruit effect, creating addictive contrast against the vanilla base.
Provides the hyper-realistic lychee top note that makes this fruity floral instantly recognizable and modern.
Contributes to the elusive ‘burnt sugar’ effect in the heart, adding dimension to the amberwood base.
2D Molecular Structure
SMILES: CCCC(S)CCOC(C)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
3-Mercaptohexyl acetate is a sulfur-containing ester (C8H16O2S) belonging to the class of mercapto alcohols. The thiol (-SH) group is responsible for both its potent aroma and reactivity. Industrially synthesized through esterification of 3-mercaptohexan-1-ol with acetic anhydride, this chiral molecule exists as (R) and (S) enantiomers with different olfactory properties. The acetate group increases volatility compared to the free alcohol form, making it ideal for top notes. Its molecular structure allows for both hydrogen bonding and hydrophobic interactions, contributing to excellent diffusion.
Physical & Chemical Properties
| Molecular Weight | 176.27 g/mol |
|---|---|
| Boiling Point | ~220 °C (estimated) |
| Density | ~1.02 g/cm³ (estimated) |
| Vapor Pressure | 0.01 mmHg at 25°C (estimated) |
| XLogP | 2.1 (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.01-0.1% | Up to 0.5% | Extremely powerful – use sparingly |
| Body Care | 0.001-0.01% | Up to 0.05% | Adds exotic fruit nuance |
| Functional Products | 0.0001-0.001% | Up to 0.005% | Masking agent for sulfur notes |
Classic Accords
Tip: Always pre-dilute to 1% or less before incorporating into blends due to extreme potency.
Alternatives & Comparisons
The alcohol precursor with slightly less fruity but more natural tropical character, better for delicate floral applications.
More grapefruit-like with cleaner sulfur character, useful when a less jammy tropical effect is desired.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted under IFRA standards, but usage should follow good practice guidelines for sulfur compounds.
EU Allergen Declaration
Not listed as an EU allergen, but thiol-containing compounds may require special labeling under certain conditions.
GHS Classification
RIFM Assessment
RIFM has conducted safety assessment confirming safe use at current industry levels.
Sustainability
As a synthetic material, 3-Mercaptohexyl acetate doesn’t impact natural resources. However, sulfur chemistry requires careful waste management. The extreme potency means very small quantities are needed, reducing overall environmental load compared to less powerful alternatives.
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References
- Brenna et al. (2002). Structure-activity relationships on sulfur-containing odorants. Journal of Agricultural and Food Chemistry. DOI:10.1021/jf020229w
- IFRA Standards Library IFRA
- PubChem Compound Summary for 3-Mercaptohexyl acetate PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 136954-20-6Physical Properties
| Molecular Weight | 176.28 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.1🔬 PubChem |
| Boiling Point | 186 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -2.284💻 Calculated |
| SMILES | CCCC(CCOC(=O)C)S🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
Odor & Flavor
| Primary Descriptors | fruitygrapefruitsulfuroustropical• leffingwell |
| Functional Groups | esteretherthiol💻 RDKit |
Sensory Thresholds
| Odor Detection Threshold | 0.0001 ppm (n=2)📖 van Gemert |
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: DTXSID50869866
Physical Properties
| Molecular Weight | 176.27 g/mol🔬 EPA CompTox |
| Density | 0.994 g/cm^3🔬 EPA CTX |
| Boiling Point | 225.507 °C📊 OPERA |
| Melting Point | -30.711 °C📊 OPERA |
| Flash Point | 96.142 °C📊 OPERA |
| Refractive Index | 1.458 Dimensionless📊 OPERA |
| Molar Volume | 178.496 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.456 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.456 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.361 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.45 Log10 unitless📊 OPERA |
| Water Solubility | 0.016 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.062 mmHg📊 OPERA |
| Viscosity | 1.595 cP📊 OPERA |
| Surface Tension | 29.849 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 3 count💻 Computed |
| Rotatable Bonds | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 48.742 cm^3/mol📊 OPERA |
| Polarizability | 19.323 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.
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