(+/-) Ethyl 3-mercaptobutyrate (CAS 156472-94-5) — Sweet Top to Middle Note Fragrance Ingredient
(+/-) Ethyl 3-mercaptobutyrate
CAS 156472-94-5
What Is (+/-) Ethyl 3-mercaptobutyrate?
Ethyl 3-mercaptobutyrate is a synthetic fragrance ingredient used to add fruity, tropical nuances to perfumes. It’s often found in modern fruity-floral fragrances. This ingredient matters because it can mimic the aroma of exotic fruits like passionfruit or guava, adding a juicy, vibrant character to scents without relying on natural extracts.
Safety Profile
USE WITH AWARENESSWhat Does (+/-) Ethyl 3-mercaptobutyrate Smell Like?
Ethyl 3-mercaptobutyrate bursts with a bright, tropical fruitiness reminiscent of ripe passionfruit and juicy guava. The initial impression is intensely sweet and slightly green, evolving into a more rounded, creamy fruitiness with time. The dry-down reveals a subtle sulfurous edge that adds complexity, like the skin of a perfectly ripe mango.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a top note to create an authentic passionfruit opening, blending with citrus and floral notes for a sun-kissed tropical effect.
Provides the juicy mango-papaya accord in this summer fragrance, paired with coconut and vanilla for a creamy dry-down.
2D Molecular Structure
SMILES: CCOC(=O)CC(C)S
Chemistry, Properties & Perfumer Guide
The Chemistry
Ethyl 3-mercaptobutyrate is a thioester compound synthesized from 3-mercaptobutyric acid and ethanol. The presence of the sulfur atom in the mercapto group contributes to its distinctive tropical fruit character. Industrial synthesis typically involves esterification under acidic conditions. The compound’s chirality affects its odor profile, with different enantiomers exhibiting varying intensity and character.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | Estimated 180-200 °C |
| Density | Approx. 1.0 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | For tropical fruit effects |
| Body Care | 0.1-0.5% | Up to 1% | Lower levels due to potency |
Classic Accords
Tip: Use in trace amounts with citrus top notes to enhance tropical fruit illusions.
Alternatives & Comparisons
For a less sulfurous, more apple-like fruitiness when a cleaner profile is desired.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA, but usage should follow general guidelines for sulfur-containing compounds.
EU Allergen Declaration
Not listed as an EU allergen.
GHS Classification
RIFM Assessment
RIFM has evaluated similar thioester compounds but no specific assessment for this material exists.
Sustainability
As a synthetic material, production can be controlled for minimal environmental impact. The esterification process is atom-efficient with water as the only byproduct.
Explore (+/-) Ethyl 3-mercaptobutyrate
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References
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID80935467
Physical Properties
| Molecular Weight | 148.22 g/mol🔬 EPA CompTox |
| Density | 1.036 g/cm^3📊 OPERA |
| Boiling Point | 192.378 °C📊 OPERA |
| Melting Point | -38.11 °C📊 OPERA |
| Flash Point | 52.176 °C📊 OPERA |
| Refractive Index | 1.455 Dimensionless📊 OPERA |
| Molar Volume | 145.483 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.512 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.507 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.362 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 3.96 Log10 unitless📊 OPERA |
| Water Solubility | 0.036 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.651 mmHg📊 OPERA |
| Viscosity | 1.176 cP📊 OPERA |
| Surface Tension | 29.328 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 | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 39.476 cm^3/mol📊 OPERA |
| Polarizability | 15.65 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.
