Alizarine Yellow R

Alizarine Yellow R is a yellow colored azo dye made by the diazo coupling reaction. It is usually commercially available as a sodium salt. In its pure form, it is a rust-colored solid.^[2] It is mainly used as a pH indicator.

Alizarine Yellow R

Alizarin Yellow R (sodium salt)
Alizarin Yellow R (acid)
Names
IUPAC name Sodium 2-hydroxy-5-[(E)-(4-nitrophenyl)diazenyl]benzoate
Other names 5-[(p-Nitrophenyl)azo]salicylic acid sodium salt Chrome orange Mordant orange 1 C.I. 14030
Identifiers
CAS Number	1718-34-9 (Na salt) Y 2243-76-7 (acid)[1] Y
3D model (JSmol)	Interactive image
ChemSpider	17215762 Y
ECHA InfoCard	100.017.109
EC Number	209-536-1
PubChem CID	6504724 (Na salt)
UNII	R1T3O0G585 (Na salt) Y OBF2VZO457 (acid) Y
CompTox Dashboard (EPA)	DTXSID1033163
InChI InChI=1S/C13H9N3O5.Na/c17-12-6-3-9(7-11(12)13(18)19)15-14-8-1-4-10(5-2-8)16(20)21;/h1-7,17H,(H,18,19);/q;+1/p-1/b15-14+; Y Key: HXKKTXMJSVFQSL-WPDLWGESSA-M Y InChI=1/C13H9N3O5.Na/c17-12-6-3-9(7-11(12)13(18)19)15-14-8-1-4-10(5-2-8)16(20)21;/h1-7,17H,(H,18,19);/q;+1/p-1/b15-14+; Key: HXKKTXMJSVFQSL-QUIZLSBABP
SMILES [Na+].O=C([O-])c1cc(ccc1O)/N=N/c2ccc(cc2)[N+]([O-])=O
Properties
Chemical formula	C13H8N3NaO5 (Na salt) C13H9N3O5 (acid)
Molar mass	309.21 g mol−1 (Na salt) 287.23 g mol−1 (acid)
HazardsSigma-Aldrich Co., ALIZARINE YELLOW R. Retrieved on 09 April 2023.
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H319
Precautionary statements	P264, P270, P280, P301+P312, P305+P351+P338, P330, P337+P313, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Alizarine Yellow R (pH indicator)
below pH 10.1		above pH 12.0
10.1	⇌	12.0

Preparation

Alizarine Yellow R is produced by azo coupling of salicylic acid and diazonium derivative of 4-Nitroaniline