3651-02-3

Basic information

• Product Name: 4-(phenylazo)-1-naphthol
• Synonyms: 4-(phenylazo)-1-naphthol;1-Naphthalenol, 4-(phenylazo)-;4-(Phenylazo)-1-naphthalenol;C.I.12000;C.I.Solvent Brown 4;1-(Phenylazo)-4-naphthol;1-Naphthalenol, 4-(phenylazo)- (9ci);1-Naphthol, 4-(phenylazo)- (8ci)
• CAS NO: 3651-02-3
• Molecular Formula: C₁₆H₁₂N₂O
• Molecular Weight: 248.27928
• EINECS: 222-891-7
• Mol File: 3651-02-3.mol

Chemical Properties

• Boiling Point: 391.35°C (rough estimate)
• Flash Point: 199.7°C
• Appearance: /
• Density: 1.1077 (rough estimate)
• Vapor Pressure: 8.03E-07mmHg at 25°C
• Refractive Index: 1.5800 (estimate)
• CAS DataBase Reference: 4-(phenylazo)-1-naphthol(CAS DataBase Reference)
• NIST Chemistry Reference: 4-(phenylazo)-1-naphthol(3651-02-3)
• EPA Substance Registry System: 4-(phenylazo)-1-naphthol(3651-02-3)

Safety Data

• Hazardous Substances Data: 3651-02-3(Hazardous Substances Data)

Usage

Uses

Used in Oil and Paraffin Color Industry:
4-(phenylazo)-1-naphthol is used as a colorant for oil and paraffin applications due to its dark red to light brown color and solubility in various solvents.
Used in Dye Industry:
4-(phenylazo)-1-naphthol is used as a dye in the dye industry, where its color and solubility properties make it suitable for coloring various materials.
Used in Analytical Chemistry:
4-(phenylazo)-1-naphthol is used as a reagent in analytical chemistry for the detection and determination of certain metal ions, such as copper and silver, due to its ability to form colored complexes with these ions.
Used in Heat-resistant Applications:
4-(phenylazo)-1-naphthol is used in applications requiring heat resistance, as it has a melting point of 182°C and remains stable at high temperatures.
Used in Light Fastness Applications:
4-(phenylazo)-1-naphthol is used in applications requiring light fastness, as it maintains its color and properties when exposed to light.
Used in Chemical Stability Applications:
4-(phenylazo)-1-naphthol is used in applications requiring chemical stability, as it remains insoluble in water and shows well resistance to sodium carbonate (5%) and hydrochloric acid (5%) solutions.

Preparation

aniline diazotization, and Naphthalen-1-ol coupling.

Standard

Light Fastness

Melting point

Stable

ISO

General

InChI:InChI=1/C16H12N2O/c19-16-11-10-15(13-8-4-5-9-14(13)16)18-17-12-6-2-1-3-7-12/h1-11,17H

Upstream product

• 2684-02-8 benzenediazonium 
• 64-17-5 ethanol 
• 90-15-3 α-naphthol 
• 100-34-5 benzene diazonium chloride 
• 64-19-7 acetic acid 
• 62-53-3 aniline 
• 586-96-9 Nitrosobenzene 
• 59-88-1 phenylhydrazine hydrochloride 
• 130-15-4 [1,4]naphthoquinone 
• 104354-87-2 Phenyl-phenylazo-methyl-hydroperoxide; compound with benzene 
• 66881-37-6 1,4-Naphtochinon-N-methylphenylhydrazon 
• 109057-65-0 C₁₆H₁₂N₂O 
• 121-69-7 N,N-dimethyl-aniline 
• 135-19-3 β-naphthol 

Downstream Products

• 24390-69-0 1-phenylazo-4-methoxynaphthalene 
• 6628-97-3 2-(phenylamino)naphthoquinone 
• 103021-63-2 4,4'-Bis(phenylazo)-2,2'-binaphthyl-1,1'-diol 
• 94330-96-8 1-Acetoxy-4-phenylazonaphthalene 
• 21720-68-3 2-(phenylamino)-4-(phenylimino)-1(4H)-naphthalenone 
• 94208-85-2 (4-ethoxy-[1]naphthyl)-phenyl-diazene 
• 101350-40-7 N-(4-Oxy-naphthyl-⁽¹⁾)-p-phenylendiamin 
• 131-22-6 4-phenylazo-1-naphthylamine 
• 117940-41-7 C₂₆H₁₄N₂O₃ 
• 5290-66-4 2,4-Bis-phenylazo-[1]naphthol 
• 54478-82-9 benzenediazonium; hydroxide 
• 130-15-4 [1,4]naphthoquinone 
• 71-43-2 benzene 
• 108-95-2 phenol 

Relevant articles and documents

Tautomerism in 1-phenylazo-4-naphthols: Experimental results vs quantum-chemical predictions

The reliability in the description of the tautomerism of 1-phenylazo-4-naphthol by using of HF and MP2 ab initio levels of theory and DFT methods with variety of pure GGA (OLYP), hybrid (B3LYP and B3PW91), long range corrected (LC-BLYP) and double-hybrid (B2PLYP and mPW2PLYP) functionals with large number of basis sets was estimated. In this evaluation three criteria were used: reproduction of the bond lengths in the structures of the individual tautomers, description of the non-planarity of the enol tautomer and prediction of the position of the tautomeric equilibrium (G value) at 298 K. The results show that in substantial number of cases HF reasonably covers all requirements. The tested pure (OLYP) and hybrid functionals (B3LYP and B3PW91) fail in the prediction of the position of the equilibrium independent on the basis set. The situation is slightly better at the long range corrected functional (LC-BLYP), which give predominance of the enol tautomer at 6-31+G (*) (*) and D95++ (*) (*). The double hybrid functionals give very good description with D95++ (*) (*) basis set, but at substantial computational costs.

Polar and Hydrogen-Bonding Interactions in Supercritical Fluids. Effects on the Tautomeric Equilibrium of 4-(Phenylazo)-1-naphthol

The azo-hydrogen tautomeric equilibrium of 4-(phenylazo)-1-naphthol is compared in various liquid and supercritical fluid solvents.The less polar azo tautomer is dominant in the dilute gas phase, compressed ethane, and liquid alkanes.In liquid and supercritical CO2, the equilibrium shifts toward the more polar hydrazone, to yield similar amounts of the two tautomers.This shift is attributed to the Lewis acidity and large quadrupole moment of CO2.The dominance of the hydrazone tautomer in fluoroform (>90percent) can be attributed to that solvent's large dipole moment and ability to act as a strong electron acceptor (hydrogen bond donor).Since acid-base interactions are prevalent at the lowest pressure studied (1000 psia), changes in the equilibrium constant as a function of pressure have been assigned primarily to increases in the nonspecific polar interactions.The large differences in the polarities, acidities, and basicities of these fluids, despite their similar polarizabilities per volume, are of interest for manipulating chemical processes and for practical application of supercritical fluid science and technology.

An environmentally friendly approach to the green synthesis of azo dyes with aryltriazenes via ionic liquid promoted C-N bonds formation

An efficient and green approach for the synthesis of azo dyes has been developed via the Br?nsted acidic ionic liquid (IL) promoted diazo coupling reaction of naphthols with aryltriazenes. The reaction was carried out with the aryltriazenes as diazotizing

Nano-Fe3O4 encapsulated-silica supported boron trifluoride as a novel heterogeneous solid acid for solvent-free synthesis of arylazo-1-naphthol derivatives

Nano-Fe3O4 encapsulated-silica supported boron trifluoride (Fe3O4@SiO2-BF3) as a new type of green heterogeneous solid acid was prepared by the immobilization of BF3·Et2O on the surface of Fe3O4@SiO2 core-shell nanoparticles and characterized by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission-scanning electron microscope (FE-SEM), energy dispersive X-ray (EDS), and transmission electron microscope (TEM). Then, this super solid acid was used as an acidic reagent for the synthesis of aryl diazonium salts as a starting reactant, followed by its diazo coupling with 1-naphthol in a basic solvent-free medium at room temperature. The main advantages of this clean method were high yields, short reaction times, the possibility of performing it at room temperature, and no need of corrosive and toxic liquid acids and solvents. In addition, the long-term stability of aryl diazonium salts supported on Fe3O4@SiO2-BF3 magnetic nanoparticles (MNPs) at room temperature was one of the most important results of this procedure. This journal is

Facile synthesis of 1-naphthol azo dyes with nano Sio2/Hio4 under solvent-free conditions

Nano-silica supported periodic acid (nano-SPIA) has been utilized as a heterogeneous reagent for a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under solvent-free conditions at room temperature. This method has some advantages, the reaction workup is very easy and the catalyst can be easily separated from the reaction mixture and one-pot procedure. The related products have been obtained in good to excellent yields, high purity and short reaction times. The structures of the products have been characterized by several techniques using UV-Vis, FT-IR, 1H NMR, 13C NMR and mass spectra.

Nanosilica/NaNO2: Novel heterogeneous system for synthesis of Azo compounds

Various azo compounds are synthesized by electrophonic substitution reaction in the presence of Nanosilica/NaNO2as a catalyst. Copyright Taylor & Francis Group, LLC.

Synthesis and photochemical properties of cationic cyclopentadienyliron containing arylazo chromophores

Two kinds of cationic cyclopentadienyliron complexes containing arylazo chromophores (Azo-Fc) were synthesized through the nucleophilic aromatic substitution reactions of cyclopentadienyliron chlorobenzene complexes. The synthesized Azo-Fc was characterized by LC-MS, IR, and 1H NMR. The influence of substituents and the aryl ring on spectral data of the synthesized compounds is described. Unlike other cationic cyclopentadienyliron complexes, Azo-Fc hardly underwent photolysis and showed no photo-initiating abilities in the cationic polymerization under photo-irradiation; in addition, trans/cis isomerization by irradiation is possible at different wavelengths.

A green alternative to synthetize azo compounds

Different nitrates were used as sources of nitrosonium ion to obtain diazonium salts. Diverse azo compounds were synthetized in acetonitrile giving very good yields and free of by-products in comparison with traditional synthesis. Among the tested species, the best combination for para red synthesis was nitric acid and gaseous hydrogen chloride.

Tautocrowns: a concept for a sensing molecule with an active side-arm

A new sensing molecule containing aza-15-crown-5 as a receptor and 4-(phenyldiazenyl)naphthalen-1-ol as a signal converter has been synthesized. In the free ligand, the hydrogen bonding between the tautomeric OH group and the nitrogen atom from the macrocycle fully shifts the tautomeric equilibrium towards the enol form. The complexation reverses the equilibrium as a result of the strong interaction between the metal ion captured in the macrocyclic moiety and the tautomeric carbonyl group. The complex formation is accompanied by strong bathochromic (between 60 and 100 nm) and hyperchromic effects on the absorption spectra. Obviously, the tautomeric OH/C{double bond, long}O groups play the role of an active side-arm in the complexation, supporting it via formation of a 3D cavity and giving possibility for ejection of the guest compound under stimuli to shift the tautomeric process back.

Exploiting tautomerism for switching and signaling

Good form: Attaching a flexible piperidine unit to 4-(phenyldiazenyl) naphthalen-1-ol allows construction of a tautomeric switch, where directed shift of the tautomeric equilibrium can be achieved through protonation and deprotonation (see picture). The developed molecular switch shows acceptable complexation with small alkali- and alkaline-earth-metal ions and forms a promising base for further development of effective molecular sensors.