Description

Azo compounds have for a great many years occupied a dominant position in the field of coloring matters due to their versatility. A large volume of publications and patents have appeared describing their synthesis and dyeing properties. Among these, azo dyes using heterocyclic amines have become important as they give brighter and stronger results than those based on aniline-based diazo compounds. The pyrazole derivatives based azo dyes are known as disperse dyes with excellent brightness of shade. This class of dyes was established as an alternative to the more expensive anthraquinone dyes. Also pyrazole derivatives are very important class of heterocycles due to their biological and pharmacological activities. Also, they are used as key starting material for the synthesis of commercial aryl/hetarylazopyrazole dyes. All these properties aroused my interest in synthesizing new heterocyclic compounds including the pyrazole and pyridazine moieties and studying their dyeing properties on polyester fabrics.