Pararosaniline

Pararosaniline, pararosaniline free base, Basic Red 9, or C.I. 42500 is an organic compound with the formula (H₂NC₆H₄)₂C=(C₆H₄NH).^[1] It is the free base form of pararosaniline hydrochloride, [(H₂NC₆H₄)₃C]⁺Cl⁻, a magenta solid with a variety of uses as a dye.^[2][3] It is one of the four components of basic fuchsine.^[4] It is structurally related to other triarylmethane dyes called methyl violets (e.g. crystal violet) which feature methyl groups on nitrogen.

Pararosaniline

Names
IUPAC name [4-[Bis(4-aminophenyl)methylidene]-1-cyclohexa-2,5-dienylidene]dianiline
Other names Pararosaniline p-rosaniline C.I. 42500 Para magenta
Identifiers
CAS Number	479-73-2 Y 569-61-9 (HCl) Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:87663 N
ChemSpider	10819 N
ECHA InfoCard	100.106.992
KEGG	C19210 Y
PubChem CID	11293
UNII	20N4C0M8NM Y 444C2M8JKN (HCl) Y
CompTox Dashboard (EPA)	DTXSID5043845
InChI InChI=1S/C19H17N3/c20-16-7-1-13(2-8-16)19(14-3-9-17(21)10-4-14)15-5-11-18(22)12-6-15/h1-12,20H,21-22H2 N Key: AFAIELJLZYUNPW-UHFFFAOYSA-N N InChI=1/C19H17N3/c20-16-7-1-13(2-8-16)19(14-3-9-17(21)10-4-14)15-5-11-18(22)12-6-15/h1-12,20H,21-22H2 Key: AFAIELJLZYUNPW-UHFFFAOYAS
SMILES c1cc(ccc1C(=C2C=CC(=N)C=C2)c3ccc(cc3)N)N
Properties
Chemical formula	C19H17N3
Molar mass	287.36 g/mol 323.83 g/mol (HCl)
Appearance	Green crystalline solid
Melting point	268 to 270 °C (514 to 518 °F; 541 to 543 K) decomposes
Solubility in water	Slightly soluble
Hazards
Safety data sheet (SDS)	External MSDS
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

It is prepared by the condensation of aniline and p-aminobenzaldehyde [pt]. Alternatively, it arises from the oxidation of 4,4'-bis(aminophenyl)methane in the presence of aniline.

Uses

• It is used to dye polyacrylonitrile fibers.
• It is used to detect sulfur dioxide.^[5]
• Pararosaniline is used as a colorimetric test for aldehydes, in the Schiff test. It is the only basic fuchsine component suitable for making the aldehyde-fuchsine stain for pancreatic islet beta cells.^[6]
• It has use as an antischistosomal. ^[7]

Related compounds

• 4,4'-Thiodianiline
• 4,4'-Methylenedianiline
• 4,4'-Oxydianiline
• Dapsone