Disazo (Bishydrazone) pigments based on pyrazolones

Robert Christie*, Adrian Abel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The most important classical orange organic pigments are disazopyrazolones, also referred to as diarylide oranges. The first pigment in this series, CI Pigment Orange 13, was discovered in 1910 although it was a further 20 years before it was introduced as a commercial product. Currently, two orange disazopyrazolones are extremely important industrial organic pigments, while two red products are of lesser importance. The products are structurally analogous to the disazoacetoacetanilides (diarylide yellows), which are discussed in a separate chapter. For example, they are symmetrical compounds that exist in the bis-ketohydrazone tautomeric form. The pigments also exhibit similar technical and color properties compared with disazoacetoacetanilide pigments, for example providing high color strength and transparency, features that determine their importance as printing ink pigments. They are manufactured in a process that parallels those used for the disazoacetoacetanilide (diarylide) yellows, but with coupling components containing the pyrazolone heterocyclic system, in place of acetoacetanilides.

Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalPhysical Sciences Reviews
Issue number1
Early online date29 Jun 2021
Publication statusPublished - Jan 2022


  • disazopyrazolone pigments, disazopyrazolones, pyrazolones, pyrazolone oranges, bishydrazone, diarylide oranges, diarylide yellows, tartrazine, azo coupling, bis-diazotization

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Physics and Astronomy(all)


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