3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)- (CAS 4314-14-1) — Green Base Note Fragrance Ingredient
3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-
CAS 4314-14-1
What Is 3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-?
3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)- is a synthetic aromatic compound used in specialty fragrances and industrial applications. Consumers might encounter it in niche perfumes or functional products where intense, long-lasting scent is desired. Its molecular structure allows for unique olfactory properties that can’t be achieved with natural ingredients alone.
Safety Profile
USE WITH AWARENESSWhat Does 3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)- Smell Like?
This synthetic molecule delivers a bold, assertive aroma with sharp metallic undertones and a faintly medicinal edge. The initial impression is intensely chemical – like hot circuitry or ozone after a thunderstorm. As it dries down, it reveals hidden warmth reminiscent of sun-baked industrial materials. The dry-out phase lingers with an almost electrical zing that modern perfumers use to create avant-garde metallic accords.
2D Molecular Structure
SMILES: CC1=NN(C(=O)C1N=NC1=CC=CC=C1)C1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
This phenylazopyrazole derivative belongs to the azole class of heterocyclic compounds. The azo group (-N=N-) contributes to its intense coloration potential and photochemical reactivity. Industrial synthesis typically involves diazotization reactions followed by coupling with active methylene compounds. The phenyl groups at positions 2 and 4 create steric hindrance that affects both its physical properties and odor characteristics.
Physical & Chemical Properties
| Molecular Weight | 279.31 g/mol |
|---|---|
| XLogP | 4.1 (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Industrial Fragrances | 0.1-0.5% | Up to 1% | For functional products requiring extreme longevity |
| Conceptual Perfumery | Trace amounts | <0.01% | Used as an olfactory ‘spice’ |
Classic Accords
Tip: Use microencapsulation to tame this material’s aggressive diffusion.
Alternatives & Comparisons
For similar metallic effects with better safety profile and more predictable behavior in blends.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently listed in IFRA standards – considered a specialty material.
GHS Classification
RIFM Assessment
No RIFM assessment available – treat as professional-use only material.
Sustainability
As a synthetic material produced in controlled industrial settings, this compound avoids natural resource depletion but requires careful handling due to its persistence in the environment. The azo group in its structure necessitates responsible waste management to prevent potential breakdown into aromatic amines.
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References
- PubChem Compound Summary CID 4314-14-1 PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 4314-14-1Physical Properties
| Molecular Weight | 278.31 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.3🔬 PubChem |
| Boiling Point | 344 °C🔬 EPA CompTox |
| Vapor Pressure | 0 mmHg @ 25°C📊 OPERA |
| Flash Point | 195.7 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -2.055💻 Calculated |
| SMILES | CC1=NN(C(=O)C1N=NC2=CC=CC=C2)C3=CC=CC=C3🔬 PubChem |
Volatility & Performance
| Fragrance Note | Base💻 Calculated |
Odor & Flavor
| Functional Groups | aromatic💻 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: DTXSID5052098
Physical Properties
| Molecular Weight | 278.315 g/mol🔬 EPA CompTox |
| Density | 1.203 g/cm^3📊 OPERA |
| Boiling Point | 371.954 °C📊 OPERA |
| Melting Point | 156.796 °C📊 OPERA |
| Flash Point | 214.384 °C📊 OPERA |
| Refractive Index | 1.65 Dimensionless📊 OPERA |
| Molar Volume | 225.991 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.486 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.467 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.04 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 8 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0 mmHg📊 OPERA |
| Surface Tension | 49.448 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 57.39 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 4 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 2 count💻 Computed |
| Molar Refractivity | 82.422 cm^3/mol📊 OPERA |
| Polarizability | 32.674 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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