Naphthol yellow S

Naphthol yellow S^[1]
Names
	Preferred IUPAC name Disodium 5,7-dinitro-8-oxidonaphthalene-2-sulfonate
	Other names Acid Yellow 1; Food Yellow 1; Sodium flavianate; Flavianic acid, sodium salt; C.I. 10316, Acid Yellow S, Amacid Yellow S, C.I. 10316, C.I. Acid Yellow 1, C.I. Food Yellow 1
Identifiers
CAS Number	846-70-8 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	3839220
ChEBI	CHEBI:87219 ;
ChemSpider	2006234;
ECHA InfoCard	100.011.537
EC Number	212-690-2;
PubChem CID	2724063;
UNII	08F8S9O3I5 ;
CompTox Dashboard (EPA)	DTXSID1041718 ;
	InChI InChI=1S/C10H6N2O8S.2Na/c13-10-7-3-5(21(18,19)20)1-2-6(7)8(11(14)15)4-9(10)12(16)17;;/h1-4,13H,(H,18,19,20);;/q;2*+1/p-2 Key: CTIQLGJVGNGFEW-UHFFFAOYSA-L;
	SMILES C1=CC2=C(C=C1S(=O)(=O)[O-])C(=C(C=C2[N+](=O)[O-])[N+](=O)[O-])[O-].[Na+].[Na+];
Properties
Chemical formula	C10H4N2Na2O8S
Molar mass	358.19 g·mol−1
Appearance	yellow solid
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H317, H373
Precautionary statements	P260, P272, P280, P302+P352, P314, P333+P313, P363, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Naphthol yellow S is an organic compound with the formula C₁₀H₄(SO₃Na)(ONa)(NO₂)₂. It is one of several isomers of sulfonated dinitro-1-naphthol. It is prepared by nitration of a trisulfonate of 1-naphthol, a process involving replacement of sulfonate groups with nitro.^[3] It is a derivative of 1-naphthol. At one time it was a popular food colorant but it was delisted in 1959 in the U.S.^[4]

References

↑ Naphthol Yellow S at Sigma-Aldrich
↑ "Naphthol Yellow S". pubchem.ncbi.nlm.nih.gov.
↑ Maarten R. van Bommel and Matthijs de Keijzer (2025). "The Nitro Dyes". In Maarten R. van Bommel and Matthijs de Keijzer (ed.). Bright Colours from the Past: The History, Chemistry, Characterisation and Application of Synthetic Dyes Between 1856 and 1914. Springer, Cultural Heritage Science series. doi:10.1007/978-3-031-88664-5.
↑ Sharma, Vinita; McKone, Harold T.; Markow, Peter G. (2011). "A Global Perspective on the History, Use, and Identification of Synthetic Food Dyes". Journal of Chemical Education. 88 (1): 24–28. Bibcode:2011JChEd..88...24S. doi:10.1021/ed100545v.

[1] Naphthol Yellow S at Sigma-Aldrich

[2] "Naphthol Yellow S". pubchem.ncbi.nlm.nih.gov.

[3] Maarten R. van Bommel and Matthijs de Keijzer (2025). "The Nitro Dyes". In Maarten R. van Bommel and Matthijs de Keijzer (ed.). Bright Colours from the Past: The History, Chemistry, Characterisation and Application of Synthetic Dyes Between 1856 and 1914. Springer, Cultural Heritage Science series. doi:10.1007/978-3-031-88664-5.

[4] Sharma, Vinita; McKone, Harold T.; Markow, Peter G. (2011). "A Global Perspective on the History, Use, and Identification of Synthetic Food Dyes". Journal of Chemical Education. 88 (1): 24–28. Bibcode:2011JChEd..88...24S. doi:10.1021/ed100545v.

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