Pigment Red 2

Product NamePIGMENT RED 2
SynonymsC.I.Pigment Red 2; C.I.PR2; PR2; P.R.2
CAS NO.6041-94-7
Molecular Weight436.29
Molecular FormulaC23H15Cl2N3O2
ColorRed powder

Molecular structure formula:  

Fastness Properties of Pigment Red 2:

Light Fastness4-5
Heat Resistance(℃)140
Water Resistance5
Oil Resistance2-3
Acid Resistance5
Alkali Resistance5
Alcohol Resistance4-5

Main application: Water based ink, Offset ink, Solvent based ink, Plastic, Paint, Textile printing

We have various pigment grades and properties to meet different customers’ needs, please specify your application and requirements so that we can recommend accordingly.  E-mail: sy@sypigment.com

Product Description of Pigment Red 2:

Pigment Red 2 is neutral red, slightly yellowish than CI Pigment Red 112, but the light fastness is 0.5-1 grade lower than that, with larger particle size and lower transparency; mainly used in offset printing and packaging inks, textile printing and dyeing and viscose fibers The original paste coloring is less used for paint coloring; the resistance to varnish, high temperature sterilization and solvent resistance is lower than that of Pigment Red 112.

Pigment Red 2 is an azo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.

TDS (Pigment Red 2) MSDS (Pigment Red 2)

Safety Information

Stability/Shelf Life:

Stable. Incompatible with strong oxidizing agents.

Fire Hazards:

Flash point data for this chemical are not available, however it is probably combustible. (NTP, 1992)

Fire Fighting:

Fires involving this compound can be controlled using a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)

Nonfire Spill Response:

SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then dampen the solid spill material with toluene, then transfer the dampened material to a suitable container. Use absorbent paper dampened with toluene to pick up any remaining material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent-wash all contaminated surfaces with toluene followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned. STORAGE PRECAUTIONS: You should store this material in a refrigerator. (NTP, 1992)

Personal Protective Equipment:

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)


  • Pigment Red 2
  • 6041-94-7
  • C.I.12310
  • C23H15Cl2N3O2
  • 4-[(2,5-Dichlorophenyl)azo]-3-hydroxy-N-phenylnaphthalene-2-carboxamide
  • 2-Naphthalenecarboxamide, 4-((2,5-dichlorophenyl)azo)-3-hydroxy-N-phenyl-
  • 2-Naphthalenecarboxamide, 4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-phenyl-
  • 4-[(2,5-dichlorophenyl)diazenyl]-3-hydroxy-N-phenylnaphthalene-2-carboxamide
  • 4E)-4-[(25-dichlorophenyl)hydrazinylidene]-3-oxo-N-phenylnaphthalene-2-carboxamide
  • 4-(2,5-Dichlorophenyl)azo-3-hydroxy-N-phenylnaphthalene-2-carboxamide
  • 4-((2,5-Dichlorophenyl)azo)-3-hydroxy-N-phenylnaphthalene-2-carboxamide
  • CCRIS 6092
  • EINECS 227-930-1
  • Pigment red
  • starbld0009541
  • C.I. 12310
  • EC 227-930-1
  • SCHEMBL375519
  • DTXSID3025914
  • SCHEMBL12955213
  • SCHEMBL16323767
  • SCHEMBL21784292
  • MFCD00071979
  • ZINC33839075
  • (4E)-4-[(2,5-dichlorophenyl)hydrazinylidene]-3-oxo-N-phenylnaphthalene-2-carboxamide
  • S296
  • 041P947
  • W-110082
  • 4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-phenyl-2-naphthalene-carboxamide
  • 4-[(E)-(2,5-Dichlorophenyl)diazenyl]-3-hydroxy-N-phenyl-2-naphthamide
  • 4-[(E)-(2,5-Dichlorophenyl)diazenyl]-3-hydroxy-N-phenyl-2-naphthamide #
  • 2-Naphthalenecarboxamide, 4-(2-(2,5-dichlorophenyl)diazenyl)-3-hydroxy-N-phenyl-
  • N-Phenyl-1,2-dihydro-2-oxo-1-[2-(2,5-dichlorophenyl)hydrazono]naphthalene-3-carboxamide

IUPAC Name:  4-[(2,5-dichlorophenyl)diazenyl]-3-hydroxy-N-phenylnaphthalene-2-carboxamide

InChI: InChI=1S/C23H15Cl2N3O2/c24-15-10-11-19(25)20(13-15)27-28-21-17-9-5-4-6-14(17)12-18(22(21)29)23(30)26-16-7-2-1-3-8-16/h1-13,29H,(H,26,30)


Canonical SMILES: C1=CC=C(C=C1)NC(=O)C2=CC3=CC=CC=C3C(=C2O)N=NC4=C(C=CC(=C4)Cl)Cl

Property NameProperty Value
Molecular Weight436.3
Hydrogen Bond Donor Count2
Hydrogen Bond Acceptor Count4
Rotatable Bond Count4
Exact Mass435.0541321
Monoisotopic Mass435.0541321
Topological Polar Surface Area74 Ų
Heavy Atom Count30
Formal Charge0
Isotope Atom Count0
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count0
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently-Bonded Unit Count1
Compound Is CanonicalizedYes