Synthesis and investigations of the absorption spectra of hetarylazo disperse dyes derived from 2,4-quinolinediol

Synthesis and tautomerism of aryl- and hetaryl-azo derivatives of bi- and tri-heterocycles

“…Similar reacions of the 4-amino-1,2,4-triazole-4(1H)-thione with the hydrazonoyl bromide having electron-withdrawing substituents in the N-aryl moiety directly afforded, however, the respective 7-arylhydrazono-3,6-diaryl [1,2,4]triazolo [3,4-b] [1,3,4]thiadiazines 168 as end products probably via in situ dehydrative cyclization of the respective thiohydrazonates 167 [75]. The isolated thiohydrazonates 167 were converted into the respective triazolothiadiazines 168 by treatment with acetic acid (Scheme 55) [75].…”

“…The formation of 72 was considered to result through a cyclodehydration path involving the aromatic ring of the hydrazone moiety. The mechanism suggested to account for the formation of 72 involves a rather unprecedented [3,5] rearrangement in which the sulfur atom is one of the termini, as depicted in Scheme 23 [39].…”

“…When the latter compound 162 was treated with aqueous 5% potassium hydroxide, it underwent intramolecular cyclization to furnish the respective 8-arylazo-2-phenyl-4-thioxo-3,4-dihydropyrazolo[1,5-a] [1,3,5]triazine 163 (Scheme 53) [73]. Recently, Shawali et al [75] reported that reaction of 4-amino-3-phenyl-1H-1,2,4-triazole-5-thiol 166 with 2-aryl-2-oxoetha nehydrazonoyl bromides 1E in ethanol in the presence of sodium ethoxide afforded the respective thiohydrazonates 167.…”

“…The interest in such colouring materials is due to the fact that many derivatives were found useful in the fields of material sciences and theoretical chemistry [2]. For example, many such azo dyes have been extensively used as dyes in various fields such as dyeing of textile fibers, coloured plastics, biological-medical studies and advanced applications in organic synthesis [3]. Recently, applications of such colouring materials to high technology have been attracting much attention.…”

Research on Synthesis of New Azo Calix[4]arene and its Dyeing Properties

“…By using the diazotization-coupling of the aromatic amine [4] , the oxidation-coupling of phenol aromatic ring [5] and other methods, the azo group can be introduced into the calixarene to constitute a host molecule with the color recognition function. Currently, the compound of azo group calixarene mainly contains nitrophenylazo calix [4]arene [6] , phenylazo calix [6]arene [7] , bis azo group bridged calix [8]arene [8] , thiazolyalzo calix[n]arene [9] , methylisoxazole azo group calix [4]arene [10] and thiadiazole azo group calix [4]arene [11] . Such compound has the nature of the calixarene and azo compounds, which is a type of dye, indicator and heavy metal complexing agent with special selectivity.…”