Pararosaniline Explained

Pararosaniline, Basic Red 9, or C.I. 42500 is an organic compound with the formula [(H₂NC₆H₄)₃C]Cl. It is a magenta solid with a variety of uses as a dye.^[1] It is one of the four components of basic fuchsine. (The others are rosaniline, new fuchsine and magenta II.)^[2] It is structurally related to other triarylmethane dyes called methyl violets including crystal violet, which feature methyl groups on nitrogen.

It is prepared by the condensation of aniline and para-aminobenzaldehyde. 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.^[3]
• 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.^[4]
• It has use as an Antischistosomal. ^[5]

Related compounds

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

Further reading

• .
• .

Notes and References

1. Thomas Gessner and Udo Mayer "Triarylmethane and Diarylmethane Dyes" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim.
2. Horobin RW, Kiernan JA (2002) Conn's Biological Stains, 10th ed. Oxford: BIOS.
3. Analytical Chemistry. 34. 12. 0003-2700. 1962. 1660–1662. 10.1021/ac60192a001. Effect of Pararosaniline in the Trace Determination of Sulfur Dioxide.. 2023-03-03. J. B. Pate, J. P. Lodge, A. F. Wartburg.
4. Mowry . RW . Emmel . VM . 1978 . Aldehyde fuchsin staining, direct or after oxidation: problems and remedies, with special reference to pancreatic B cells, pituitaries and elastic fibers . Stain Technology . 53 . 3 . 141–154 . 10.3109/10520297809111457. 83035 .
5. GB. 908634. Pharmaceutical compositions containing pararosaniline or derivatives thereof. 1962-10-24. Parke, Davis & Co..