The synthesis, spectroscopic properties and theoretical calculation of some novel disperse disazo dyes derived from 3-amino-5-hydroxy-1-phenylpyrazole

Synthesis, Characterization, Absorption and Fastness Properties of Novel Monoazo Dyes Derived from 1-Phenyl-3-amino-4-(2-thiazolilazo)pyrazol-5-one

“…The synthesized new dyes may exist in five possible tautomeric forms, i.e., keto-azo (T 1 and T 5 ), keto-hydrazo (T 2 and T 4 ) and enol-azo (T 3 ). According to the calculation results in the literature, 17,[35][36][37][38][39][40] the most stable tautomeric form is keto-hydrazo form (T 2 ) for hetarylazopyrazolone dyes. This conclusion may occur from the intramolecular O−H bond.…”

Synthesis, antimicrobial activity and absorption studies of some novel heterocyclic dyes based on 4-hexylbenzene-1,3-diol

“…The condensation of β-enaminonitriles and β-ketoesters with hydrazines continues to be the most widely used method for constructing the aminopyrazoles and pyrazolones, respectively [6,7]. The amino derivatives of pyrazoles belong to important compounds used for preparation of other functional derivatives mainly for the synthesis of condensed heterocyclic systems [8][9][10][11][12]. Also, fused pyrazoles are important compounds that have many derivatives with a wide range of interesting properties, such as antihyperglycemic, analgestic, anti-inflammatory, antipyretic, anti-bacterial, hypoglycaemic and sedative-hypnotic activities.…”

The synthesis, characterisation and molecular structure of a new hetarylazoindole dye studied by X‐ray diffraction, spectral analysis and density functional theory calculation

“…Azo dyes have been intensively studied for both theoretical and practical purposes for many years [1–5]. In addition to the widespread application of azo dyes in textiles, medical areas, cosmetics, printing, drugs and food colouring, they have attracted the interest of many investigators because of their usage in high technology [6,7].…”