2-Phenyl-2-butenal (CAS 4411-89-6) — Floral Middle Note Fragrance Ingredient
2-Phenyl-2-butenal
CAS 4411-89-6
What Is 2-Phenyl-2-butenal?
2-Phenyl-2-butenal is a synthetic fragrance ingredient often used to add depth to floral and fruity perfumes. It’s found in various personal care products like soaps and lotions. This molecule matters because it contributes a unique spicy, floral character that perfumers use to create complex scent profiles.
Safety Profile
USE WITH AWARENESSWhat Does 2-Phenyl-2-butenal Smell Like?
2-Phenyl-2-butenal opens with a sharp, green floralcy reminiscent of crushed geranium leaves, quickly transitioning to a honeyed, slightly spicy heart. The dry-down reveals a warm, ambery depth with a subtle leathery nuance. Its character evolves like a sun-warmed garden, starting bright and herbal before settling into a golden, resinous glow.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used sparingly to enhance the floral bouquet, adding a modern green-floral facet to the classic aldehydic structure.
Provides a crisp, contemporary edge to the floral heart, balancing the sweetness of ylang-ylang.
2D Molecular Structure
SMILES: CC=C(C=O)C1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Phenyl-2-butenal belongs to the α,β-unsaturated aldehyde class, known for their reactivity and distinctive odor profiles. While not found in nature, it’s synthesized through aldol condensation reactions. Its structure features both aromatic and aliphatic components, creating a bridge between floral and spicy odor characteristics.
Physical & Chemical Properties
| Boiling Point | Not available |
|---|---|
| Density | Not available |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Used as floral modifier |
| Soaps | 0.1-0.5% | Up to 1% | Adds complexity to floral bases |
Classic Accords
Tip: Stabilize with antioxidants to prevent polymerization during storage.
Alternatives & Comparisons
Provides similar spicy warmth but with stronger cinnamon character and greater substantivity.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards.
RIFM Assessment
Under review by RIFM for comprehensive safety assessment.
Sustainability
As a synthetic material, production can be controlled for minimal environmental impact. No natural resources are depleted in its manufacture, though petrochemical feedstocks are typically used.
Explore 2-Phenyl-2-butenal
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Brenna et al. (2002). Structure-Odor Relationships. Chemical Reviews. DOI: 10.1021/cr000049t
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID20863391
Physical Properties
| Molecular Weight | 146.189 g/mol🔬 EPA CompTox |
| Density | 1.023 g/cm^3📊 OPERA |
| Boiling Point | 253.574 °C📊 OPERA |
| Melting Point | 20.236 °C📊 OPERA |
| Flash Point | 92.496 °C📊 OPERA |
| Refractive Index | 1.53 Dimensionless📊 OPERA |
| Molar Volume | 147.592 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.132 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.132 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.132 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.21 Log10 unitless📊 OPERA |
| Water Solubility | 0.012 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.106 mmHg📊 OPERA |
| Viscosity | 1.63 cP📊 OPERA |
| Surface Tension | 35.097 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 17.07 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 2 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 45.604 cm^3/mol📊 OPERA |
| Polarizability | 18.079 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.
