A facile synthesis of some new pyrazolo[1,5-a]pyrimidine heterocyclic disazo dyes and an evaluation of their solvatochromic behaviour

作者：Tsai Pi Chen; Wang Ing Jing^*

来源：Dyes and Pigments, 2007, 74(3): 578-584.

DOI：10.1016/j.dyepig.2006.03.022

• hetarylazopyrazole
• dihetarylazo-pyrazolo[1,5-a]pyrimidine
• disazo dyes
• solvents' effect

Hetarylmalononitriles (thiazolylmalononitrile and benzothiazolylmalononitrile) were prepared by the coupling reaction of malononitrile with heterocyclic amines in nitrosyl sulfuric acid. 4-Hetarylazo-3,5-diaminopyrazole compounds were obtained by the reaction of hetarylmalononitriles with hydrazine hydrate (64%). Both compounds can react with arylazo- and hetarylazornalononitriles to give 3,6-di-(aryl or hetaryl)azo-2,5,7-triaminopyrazolo[1,5-a]pyrimidine heterocyclic disazo dyes. These dyes were characterized by elemental and spectral analyses (IR, H-1 NMR and mass). The solvatochromic behaviour in various solvents was evaluated.

• 出版日期2007