Synthesis and Spectroscopic Characterization of Water Soluble Triazene Dyes Based on Glyco-conjugated Pyrazolone Derivatives Catalyzed by an Acidic Ionic Liquid Supported on Silica-Coated Magnetite Nanoparticles

Abstract

Novel water soluble triazene dyes based on glyco-conjugated pyrazolone amines were synthetized by using N-propyl-2-pyrrolidonium hydrogen sulfate supported on silica-coated magnetite nanoparticle as acid catalyst. This organic-inorganic hybrid composite showed an excellent catalytic activity toward diazotization reaction of pyrazolone amines performing triazene dyes under solvent-free conditions in high yields. The spectroscopic properties confirmed the tendency of these dyes to exist in their hydrazo-keto tautomer forms. The study of the solubility of these dyes in water showed that their water solubility requires a minimum percentage weight of 50% of the carbohydrate part.