Sudan II

Sudan II (Solvent Orange 7, C.I. 12140, C18H16N2O)[1] is a lysochrome (fat-soluble dye) azo dye used for staining of triglycerides in frozen sections, and some protein bound lipids and lipoproteins on paraffin sections. It has the appearance of red powder with melting point 156–158 °C and maximum absorption at 493(420) nm.[1]

Sudan II
Names
IUPAC name
1-(2,4-Dimethylphenylazo)-2-naphthol
Other names
see text
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard100.019.537 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C18H16N2O/c1-12-7-9-16(13(2)11-12)19-20-18-15-6-4-3-5-14(15)8-10-17(18)21/h3-11,21H,1-2H3/b20-19+ checkY
    Key: JBTHDAVBDKKSRW-FMQUCBEESA-N checkY
  • InChI=1/C18H16N2O/c1-12-7-9-16(13(2)11-12)19-20-18-15-6-4-3-5-14(15)8-10-17(18)21/h3-11,21H,1-2H3/b20-19+
    Key: JBTHDAVBDKKSRW-FMQUCBEEBZ
  • Cc3ccc(/N=N/c1c2ccccc2ccc1O)c(C)c3
Properties
C18H16N2O
Molar mass276.339 g·mol−1
Melting point156 to 158 °C (313 to 316 °F; 429 to 431 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Uses

In industry, it is used to color nonpolar substances like oils, fats, waxes, greases, various hydrocarbon products, and acrylic emulsions.[2]

It was used as food dye under the designation FD&C Red 32 in the US until the FDA banned its use in food in 1956 due to toxicity.[3]

References