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Solvent dyes and colorants for plastics

4-Hydroxyazobenzene

Also known as 4-Phenylazophenol, 4-(Phenylazo)phenol, p-Phenylazophenol

CAS 1689-82-3Formula C12H10N2OMolar mass 198.23 g/molEC 216-880-6
GHS signal word: Warning. Pictograms: Harmful or irritant 8 suppliers listed
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4-Hydroxyazobenzene chemical structure, C12H10N2O, CAS 1689-82-3
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Yellow leaves from benzene, orange prisms from alc
Melting point
155 to 157
Boiling point
220 to 230
Solubility
INSOL IN WATER, VERY SOL IN ALC & ETHER, SOL IN BENZENE, CONCN SULFURIC ACID & DIL ALKAL…
HS code
320419
Category
Solvent dyes and colorants for plastics
Illustrative photo, yellow pigment powder in an open kraft paper sack in a chemical plant
Typical packagingIllustrative packaging image, not the actual product

What is 4-Hydroxyazobenzene?

Plain description, key identifiers and synonyms

4-Hydroxyazobenzene is a member of azobenzenes.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
4-phenyldiazenylphenol
CAS number
1689-82-3 CAS number cross-checkedOther or deprecated CAS: 16391-33-6, 20714-70-9, 37790-28-6
EC number
216-880-6
Molecular formula
C12H10N2O
UNII
VX4306NSH1
MDL number
MFCD00002330
InChIKey
BEYOBVMPDRKTNR-UHFFFAOYSA-N
InChI
InChI=1S/C12H10N2O/c15-12-8-6-11(7-9-12)14-13-10-4-2-1-3-5-10/h1-9,15H
SMILES (canonical and isomeric)
C1=CC=C(C=C1)N=NC2=CC=C(C=C2)O

Synonyms

  • 4-Phenylazophenol
  • 4-(Phenylazo)phenol
  • p-Phenylazophenol
  • p-Hydroxyazobenzene
  • C.I. Solvent Yellow 7
  • Pirocard Green 491
  • Organol Yellow AP
  • Phenol, p-(phenylazo)-
  • p-Benzeneazophenol
  • Azobenzene, 4-hydroxy-
  • Zlut rozpoustedlova 7
  • CI Solvent Yellow 7
  • CI 11800
  • C.I. 11800
  • 4-(phenyldiazenyl)phenol
  • Solvent Yellow 7
  • Phenol, 4-(phenylazo)-
  • Phenol, 4-(2-phenyldiazenyl)-
  • 4-phenyldiazenylphenol
  • p-(Phenylazo)phenol
  • (E)-4-(phenyldiazenyl)phenol
  • 4-[(E)-Phenyldiazenyl]phenol
  • (E)-4-Phenylazophenol
  • 4-(2-phenyldiazen-1-yl)phenol
  • 4-(Phenyldiazenyl), phenol
Show all 35 synonyms
  • p-(Benzeneazo)phenol
  • Phenol, 4-[(1E)-2-phenyldiazenyl]-
  • 4-(2-Phenylhydrazono)cyclohexa-2,5-dienone
  • p-(phenylazo)-phenol
  • 4-Benzeneazophenol
  • 4-Phenylazophenol, 98%
  • 4-[Phenyldiazenyl]phenol #
  • 2-16-00-00038 (Beilstein Handbook Reference)
  • Phenol,4-(phenylazo)-(E)-
  • (Z)-4-(Phenyldiazenyl)phenol

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
Yellow leaves from benzene, orange prisms from alcexp.
Melting point
155 to 157exp.
Boiling point
220 to 230exp.
Solubility
INSOL IN WATER, VERY SOL IN ALC & ETHER, SOL IN BENZENE, CONCN SULFURIC ACID & DIL ALKALI (YELLOW)exp.
Vapour pressure
2.31 × 10⁻⁷ mm Hg @ 25 °Cexp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
198.23 g/molcalc.
Exact mass
198.0793 Dacalc.
LogP (octanol/water)
3.81calc.
Topological polar surface area
44.95 Ųcalc.
Hydrogen bond donors
1calc.
Hydrogen bond acceptors
3calc.
Rotatable bonds
2calc.
Heavy atoms
15calc.
Rings
2calc.
Aromatic rings
2calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccc(N=Nc2ccccc2)cc1

c1ccc(N=Nc2ccccc2)cc1

2 rings, 14 atoms, the Azobenzene ring system.

3,419 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
Precautionary statements (16)
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

4-Hydroxyazobenzene suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 8 suppliers
8 of 8 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

8 suppliers in 3 countries

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4-Hydroxyazobenzene price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

To color varnishes, fats, waxes, resins, and soaps.

Chemical intermediate for c.i. Sulfur green 18 (no current u.s. Prodn).

How it is made

It can be made by coupling diazotized aniline with phenol (Oddo and Puxeddu, 1905)...

Regulatory status

Inventories, regulations and trade controls that list this substance

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code 4-Hydroxyazobenzene is traded under.

HS 3204.19Indicative HS code

Synthetic organic colouring matter and preparations based thereon as specified in note 3…

World exports in 2024
$1.08B
+0.2% vs 2023, imports $1.14B
2019 to 2024
Top exporters
  1. United States23.7%
  2. India * partner reported12.4%
  3. China9.0%
Top importers
  1. Germany7.5%
  2. France * partner reported6.4%
  3. Mexico5.4%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for 4-Hydroxyazobenzene is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about 4-Hydroxyazobenzene, based on the data on this page

What is 4-Hydroxyazobenzene?

4-Hydroxyazobenzene is a member of azobenzenes.

What is the CAS number of 4-Hydroxyazobenzene?

The CAS registry number of 4-Hydroxyazobenzene is 1689-82-3. Other or deprecated CAS numbers: 16391-33-6, 20714-70-9, 37790-28-6.

What is the molecular formula and weight of 4-Hydroxyazobenzene?

The molecular formula of 4-Hydroxyazobenzene is C12H10N2O and its molar mass is 198.23 g/mol.

What is 4-Hydroxyazobenzene used for?

To color varnishes, fats, waxes, resins, and soaps. Chemical intermediate for c.i. Sulfur green 18 (no current u.s. Prodn).

Is 4-Hydroxyazobenzene hazardous?

4-Hydroxyazobenzene carries the GHS signal word "Warning". Main hazards: causes skin irritation, causes serious eye irritation, may cause respiratory irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of 4-Hydroxyazobenzene?

4-Hydroxyazobenzene is usually classified under HS code 320419 (Synthetic organic colouring matter and preparations based thereon as specified in note 3…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy 4-Hydroxyazobenzene?

CompoundList lists 8 suppliers of 4-Hydroxyazobenzene in China, India and Singapore. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy 4-Hydroxyazobenzene in India?

2 suppliers in India list 4-Hydroxyazobenzene on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of 4-Hydroxyazobenzene?

Suppliers quote 4-Hydroxyazobenzene on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle 4-Hydroxyazobenzene

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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