1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol (CAS 85-83-6) — Citrus N/A Note Fragrance Ingredient
1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol
CAS 85-83-6
What Is 1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol?
This synthetic compound is primarily used as a dye in industrial applications rather than fragrances. Consumers might encounter it in colored plastics, inks, or certain cosmetics where pigmentation is required. While not a traditional fragrance ingredient, its chemical properties make it relevant for specialty applications in product formulation.
Safety Profile
PROFESSIONAL USEWhat Does 1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol Smell Like?
This compound is not characterized by any notable olfactory properties. As an azo dye, its primary function is visual pigmentation rather than fragrance contribution. In pure form, it may exhibit minimal odor, typically described as faintly chemical or neutral, with no discernible top, heart, or base notes.
2D Molecular Structure
SMILES: CC1=CC=CC=C1N=NC1=CC(C)=C(C=C1)N=NC1=C(O)C=CC2=C1C=CC=C2
Chemistry, Properties & Perfumer Guide
The Chemistry
1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol is a synthetic azo dye belonging to the diarylazo chemical class. These compounds are characterized by their -N=N- azo bridges between aromatic rings, which confer strong chromophoric properties. Industrial synthesis typically involves diazotization reactions of aromatic amines followed by coupling with naphthol derivatives. The methyl substitutions on the phenyl rings increase the compound’s hydrophobicity and lightfastness compared to simpler azo dyes.
Physical & Chemical Properties
| Primary Use | Industrial dye |
|---|---|
| Color | Orange-red pigment |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Industrial Dyes | 0.1-5% | Up to 10% | Pigment concentration varies by application |
| Cosmetics | 0.01-1% | Regulated | Restricted to non-skin contact uses |
Classic Accords
Tip: This material requires specialized handling equipment and should only be used by trained professionals in controlled environments.
Alternatives & Comparisons
Similar azo dye with better characterized safety profile for limited cosmetic applications.
Alternative yellow-orange azo dye with higher solubility in organic matrices.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not evaluated by IFRA – industrial use only
GHS Classification
RIFM Assessment
No RIFM assessment – not a fragrance material
Sustainability
As an industrial synthetic chemical, this compound raises typical environmental concerns associated with azo dyes, including potential aquatic toxicity and persistence. Modern manufacturing processes aim to minimize heavy metal contaminants that were historically present in azo dye production. Proper wastewater treatment is essential when using this material industrially.
Explore 1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Color Index International (2021). Azo Dyes Classification. Society of Dyers and Colourists. Color Index
- EU Commission Regulation (EC) No 552/2009 on cosmetic colorants EU Regulation
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID8041743
Physical Properties
| Molecular Weight | 380.451 g/mol🔬 EPA CompTox |
| Density | 1.174 g/cm^3📊 OPERA |
| Boiling Point | 489.923 °C📊 OPERA |
| Melting Point | 199 °C🔬 EPA CTX |
| Flash Point | 384.679 °C📊 OPERA |
| Refractive Index | 1.645 Dimensionless📊 OPERA |
| Molar Volume | 319.052 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 5.932 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 5.932 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 5.927 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 10.44 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 | 46.131 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 69.67 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 5 count💻 Computed |
| Rotatable Bonds | 4 count💻 Computed |
| Aromatic Rings | 4 count💻 Computed |
| Molar Refractivity | 115.658 cm^3/mol📊 OPERA |
| Polarizability | 45.85 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.
