{{chembox | Watchedfields = changed | verifiedrevid = 457130888 | ImageFile = Aminoazobenzene.svg | ImageSize = 220 | ImageName = Skeletal formula | ImageFile1 = Aniline-yellow-3D-balls.png | ImageSize1 = 220 | ImageName1 = Ball-and-stick model | PIN = 4-(Phenyldiazenyl)aniline | OtherNames = ''para''-Aminoazobenzene<br />4-Phenylazoaniline<br />AAB<br />Brasilazina oil Yellow G<br />Ceres Yellow<br /> Fast spirit Yellow<br />Induline R<br />Oil Yellow AAB<br />Oil Yellow AN<br />Oil Yellow B<br />Oil Yellow 2G<br />Oil Yellow R<br />Organol Yellow<br />Organol Yellow 2A<br />Solvent Yellow<br />Somalia Yellow 2G<br />Stearix Brown 4R<br />Sudan Yellow R<br />Sudan Yellow RA<br />C.I. 11000 |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 5828 | InChI = 1/C12H11N3/c13-10-6-8-12(9-7-10)15-14-11-4-2-1-3-5-11/h1-9H,13H2/b15-14+ | InChIKey = QPQKUYVSJWQSDY-CCEZHUSRBB | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C12H11N3/c13-10-6-8-12(9-7-10)15-14-11-4-2-1-3-5-11/h1-9H,13H2/b15-14+ | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = QPQKUYVSJWQSDY-CCEZHUSRSA-N | CASNo = 60-09-3 | CASNo_Ref = {{cascite|correct|CAS}} | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 57X2AH42T1 | EINECS = 200-453-6 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 83761 | PubChem = 6051 | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = C19187 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 233869 | SMILES = N(=N/c1ccc(N)cc1)\c2ccccc2 }} |Section2={{Chembox Properties | Formula = C<sub>6</sub>H<sub>5</sub>N=NC<sub>6</sub>H<sub>4</sub>NH<sub>2</sub> (C<sub>12</sub>H<sub>11</sub>N<sub>3</sub>) | MolarMass = 197.24 g/mol | Appearance = | MeltingPtC = 123 to 126 | MeltingPt_notes = | BoilingPt= > | BoilingPtC = 360 | Solubility = | Density = 1.19 g/mL | pKa = 2.82 (25&nbsp;ºC) | MagSus = −118.3·10<sup>−6</sup> cm<sup>3</sup>/mol }} |Section3={{Chembox Hazards | MainHazards = Highly toxic <br /> Suspected carcinogen | NFPA-H = 0 | NFPA-F = 2 | NFPA-R = 1 | GHSPictograms = {{GHS08}}{{GHS09}} | FlashPt = | AutoignitionPt = | LD50 = 200 mg/kg (mouse) | GHSSignalWord = Danger }} }}{{More citations needed|date=June 2025}} '''Aniline Yellow''' is a yellow azo dye and an aromatic amine. It is a derivative of azobenzene. It has the appearance of an orange powder. Aniline Yellow was the first azo dye. It was first produced in 1861 by C. Mene. The second azo dye was Bismarck Brown in 1863. Aniline Yellow was commercialized in 1864 as the first commercial azo dye, a year after aniline black. It is manufactured from aniline.

==Uses== Aniline Yellow is used in microscopy for vital staining,<ref>{{Cite web|url=http://www.microscopy-uk.org.uk/mag/artfeb00/rhvital.html|title=Vital staining for protozoa}}</ref> in pyrotechnics for yellow colored smokes, in yellow pigments and inks including inks for inkjet printers. It is also used in insecticides, lacquers, varnishes, waxes, oil stains, and styrene resins. It is also an intermediate in synthesis of other dyes, e.g. chrysoidine, indulines, Solid Yellow, and Acid Yellow.

==Safety== Aminoazobenzene compounds are often carcinogenic.<ref>{{cite journal |doi=10.1016/s0143-7208(02)00070-0 |title=Mutagenicity of aminoazobenzene dyes and related structures: A QSAR/QPAR investigation |date=2002 |last1=Garg |first1=Ashish |last2=Bhat |first2=Krishna L. |last3=Bock |first3=Charles W. |journal=Dyes and Pigments |volume=55 |pages=35–52 }}</ref> <!-- so what, irrelevant to this topic==Toxic oil syndrome== Aniline Yellow was initially implicated in the 1981 Spanish Toxic Oil Syndrome (TOS), although further study suggested the cause was likely contaminated tomatoes.<ref>{{Cite web|url=https://www.theguardian.com/education/2001/aug/25/research.highereducation|title = The Spanish cooking oil scandal|website = TheGuardian.com|date = 24 August 2001}}</ref>

The initial theory of the incident proposed that a Madrid-based company imported denaturated rapeseed oil, dyed by aniline yellow to mark it as unsuitable for human consumption, to be used as a fuel in steel mills. At the time, rapeseed oil was not legal for import for cooking use in Spain. However, the company (or smaller merchants) was accused of distilling the oil to remove the dye and selling it to households, possibly as much more valuable olive oil for cooking. Patients presented with a rash of pneumonia-type illnesses, with a second stage with lesions, weight loss, paralysis, and muscle wasting. The net result was over 20,000 sick and 400 dead. The chemistry of the poisonous reaction is still subject of debate; later forensic evidence suggests that organophosphate poisoning from locally-grown vegetables may be a more likely cause of the symptoms.<ref>{{cite web|url=http://www.researchinformation.co.uk/fse/fse0301/0301issue.php |title=FSE Editorial |access-date=2006-02-02 |url-status=dead |archive-url=https://web.archive.org/web/20070312035802/http://www.researchinformation.co.uk/fse/fse0301/0301issue.php |archive-date=2007-03-12 }}</ref><ref>{{cite web |last1=Woffinden |first1=Bob |title=Cover-up |url=https://www.theguardian.com/education/2001/aug/25/research.highereducation |website=The Guardian |access-date=28 March 2023 |date=24 August 2001}}</ref>-->

==See also== *Direct Yellow 4 *Titan yellow

==References== {{Reflist}}

Category:Azo dyes Category:Vital stains Category:Solvent dyes Category:4-Aminophenyl compounds Category:Phenyl compounds