Azo Dyes from Substituted 2‐Aminothiophens

Abstract

This paper concerns the effects of the position and the nature of substituents on the colour of azo dyes derived from 2‐arainothiophens. Of primary interest is the colour shift from the red of phenylazo dyes to the greenish blue of the analogous 5‐substituted 3‐nitro‐2‐thienylazo dyes. The greenish blue of 2‐amino‐3‐nitro‐5‐aeyl(or aroyl)thiophen dyes is in striking contrast with the violet—red of 2‐amino‐5‐acylthiophen dyes and the violet of dyes from 2‐amino‐3:5‐bismethylsulphonylthiophen. Even simple aniline coupling components afford blues to blue‐greens with the 5‐substituted 2‐amino‐3‐nitrothiophens. However, progressively increased bathoehromic shifts to bluish green are obtained with the following coupler types— tetrahydroquinoline, benzomorpholine, and 2‐alkoxy‐5‐acetamidoaniline. Dyes from 2‐amino‐3‐nitro‐5‐acylthiophens, particularly, have excellent affinity for secondary cellulose acetate and give good exhaustion and level dyeing. They colour cellulose acetate deep, bright blues to greens. Dyed fabrics have superior gas‐fume fastness, moderate light fastness, and good dischargeability.

The Contribution of Disperse Dyes to Progress and Development in Textile Coloration: An Historical Review containing Personal Experience

“…There were at the time one or two monoazo blue dyes [ 121 using a dihydroxytetrahydrobenzquinoline end component, but they had poor light fastness on secondary acetate. Introduction of a nitroaminothiazole fist component by Eastman Kodak [13] with benzenoid end components produced useful high-yielding blues of better light fastness. There have since been useful deep-dyeing blues based on azobenzene in which both rings are heavily substituted.…”

Synthesis and Absorption Properties of Trisubstituted Hetarylazo Indole Dyes

“…Heterocyclic diazo derivatives have been used generally in the synthesis of disperse dyes because they are brighter and have higher strength than azo dyes obtained from substituted aromatic amines. The absorption properties of these dyes are often influenced by solvents and exhibited bathochromism after increasing the polarity of the solvent [4][5][6].…”

Synthesis and antibacterial assessment ofN-[4-(4-substituted phenyl)-1,3-thiazol-2-yl]-1,3,5-triazin-2-amine

“…Phenyl, 4-chlorophenyl and 4-nitrophenyl thiazole-2-amine derivatives were synthesized according to literature procedures[ 9 10 ], with the help of corresponding acetophenone, thiourea, thionyl chloride and bromine. The designed compounds were prepared in two step reactions, first step consists of nucleophilic substitution of two chlorines in cyanuric chloride in presence of aq.…”