CA Index Name: 2-Naphthalenol, 1-[2-[2-methyl-4-[2-(2-methylphenyl)diazenyl]phenyl]diazenyl]-
Other Names: 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl)azo]phenyl]azo]-; 2-Naphthol, 1-(4-o-toly-lazo-o-tolylazo)-; C.I. Solvent Red 24; 1-(2'-Methyl-4'-(2"-methylphenylazo)phenylazo)-2-naphthol; 1-[4-(o-Tolylazo)-o-tolylazo]-2-naphthol; 20,3-Dimethyl-4-(2-hydroxynaphthylazo)azobenzene; Aizen SOT Red 1; At-lasol Red 4B; Biebrich Scarlet BPC; Biebrich Scarlet Red; Brasilazina Oil Red B; C.I. 26105; Candle Scarlet 2B; Candle Scarlet B; Candle Scarlet G; Ceres Red BB; Dispersol Red PP; Enial Red IV; Fast Oil Red B; Fast Red BB; Fat Ponceau R; Fat Red 2B; Fat Red B; Fat Red BB; Fat Red BS; Fat Red TS; Fat Soluble Dark Red; Grasal Brilliant Red B; Grasan Brilliant Red B; Hidaco Oil Red; Japan Red 501; Lacquer Red V; Lacquer Red VS; NSC 10472; Oil Red; Oil Red 282; Oil Red 2B; Oil Red 3; Oil Red 3B; Oil Red 47; Oil Red 7; Oil Red A; Oil Red APT; Oil Red B; Oil Red BB; Oil Red BS; Oil Red D; Oil Red ED; Oil Red F; Oil Red GO; Oil Red RC; Oil Red RR; Oil Red S; Oil Red SST Extra; Oil Red TAX; Oil Red ZD; Oil Scarlet; Oil Scarlet 48; Oleal Red BB; Oleosol Red BB; Organol Red B; Orient Oil Red RR; Plastoresin Red F; Red 3R Soluble in Grease; Resinol Red 2B; SOT Red 1; Scarlet R; Scarlet R (solvent dye); Scarlet oil; Scarlet red; Silotras Red T 3B; Solvent Red 24; Somalia Red IV; Stearix Red 4B; Stearix Red 4S; Sudan (IV) dye; Sudan 4; Sudan IV; Sudan P; Sudan Red 380; Sudan Red 4BA; Sudan Red BB; Sudan Red BBA; Sudan Red IV; TU 6-14-8780; Tertro-gras Red N; Toyo Oil Red BB; Waxoline Red O; Waxoline Red OM; Waxoline Red OS
Merck Index Number: 8393
Chemical / Dye Class: Azo
Molecular Formula: C24H20N4O
Molecular Weight: 380.44
Physical Form: Dark red-brown powder
Solubility: Insoluble in water; soluble in benzene, methanol, acetone, isopropanol; slightly soluble in ethanol
Melting Point: 184-186 °C (decompose)
Boiling Point: 618.8 ± 55.0 °C, pressure: 760 Torr
pKa: 13.52 ± 0.50, most acidic, temperature: 25 °C
Absorption (λmax): 520 nm, 357 nm
Synthesis: Synthetic methods
Staining Applications: Fat globules; fats; lipids; fish oil; lipoproteins; CYP1A1 proteins; proteins; starch; nucleic acids; tissues; waxes
Biological Applications: Detecting atherosclerosis; diapers; skin care products; shampoos; hair colors; stents; dental impression materials
Industrial Applications: Plasma display panels; liquid crystal display device; color filters; semiconductor devices; photoresists; recording materials; inks; toners; lenses; pesticides; laundry detergents; textiles; clay; gasoline; diesel fuels; petroleum products
Safety / Toxicity: Mutagenicity
Certification / Approval: Certified by Biological Stain Commission (BSC)