Parrot

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Structural formula
Structural formula of Pararot
General
Surname Parrot
other names
  • 1 - [( E ) - (4-nitrophenyl) diazenyl] -2-naphthol ( IUPAC )
  • CI Pigment Red 1
  • CI 12070
  • Nitroaniline red
Molecular formula C 16 H 11 N 3 O 3
Brief description

red solid

External identifiers / databases
CAS number 6410-10-2
EC number 229-093-8
ECHA InfoCard 100,026,449
PubChem 22917
ChemSpider 13544963
Wikidata Q906600
properties
Molar mass 293.28 g mol −1
Physical state

firmly

Melting point

251 ° C

solubility

almost insoluble in water

safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 315-319-335
P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Parrot is a red azo pigment . It is one of the first azo dyes produced on an industrial scale (1885) and was used to dye wool and cotton. Today it is still used, for example, in colored pencils, but also in cheap printing inks and plastics.

Manufacturing

Parrot can be produced by an azo coupling reaction of diazotized 4-nitroaniline and β-naphthol .

Synthesis of para-red starting from p - nitroaniline ( 1 ). After the action of sulfuric acid and sodium nitrite, this reacts to form a diazonium salt ( 2 ), which is coupled with 2-naphthol to form parrot ( 3 ).

safety instructions

Azo compounds can be broken down reductively when absorbed in the body , releasing aromatic amines that were used in their production. If these starting materials have a carcinogenic effect, this also applies to the azo compounds themselves. However, since azo pigments are practically insoluble, they are not bioavailable and are therefore not toxicologically critical. A possible hazard could arise if the products are contaminated with the starting material through improper manufacture. In the present example this would be 4-nitroaniline, which according to the current state of knowledge does not have any carcinogenic properties.

Pararot produced in the laboratory and crushed with a spatula.

Individual evidence

  1. ↑ a b Pararot data sheet at Acros, accessed on February 20, 2010.
  2. ↑ Entry on Pararot. In: Römpp Online . Georg Thieme Verlag, accessed on December 28, 2014.
  3. ↑ a b Pararot data sheet from Sigma-Aldrich , accessed on April 18, 2011 ( PDF ).

Web links

Commons : Pararot  - collection of images, videos and audio files