Synthesis of new disperse azo dyes based on oxopyridine core

Introduction

Oxo pyridine azo compounds have been extensively studied and proved to be excellent colorants for application in the fields of dyeing and printing. ([6] Shams, 1992). 3-Cyano-4-substituted -6-phenyl-2-pyridone derivatives had been prepared by cyclisation of ethyl-2-cyano-3-substituted acrylates with-3-acetylpyrene in the presence of ammonium acetate. Reaction of the synthesised pyridone derivatives with POCl₃ /PCl₅ gave the 2-chloro-3-cyano-4-substituted -6-pyrenyl-2-pyridone, which had been prepared by interaction of the corresponding 3-cyano pyridone derivative and methyl iodide. The fluorescence behaviour of the synthesised compounds had also been studied ([1] Chen and Wang, 1995).

The condensation of appropriate amines with glutaconic anhydride to produce benzimidazole substituted couplers containing pyridone as a basic moiety had been reported ([2] Dikshit et al. , 1985). The authors discussed the synthesis of a series of azo disperse dyes through coupling the resulting glutaconimides with diazotized arylamines.

The synthesis of hetarylazopyridone dyes by coupling 1-butyl-3-cyano-6-hydroxy-4-methyl-2-(1H)pyridone with diazotized aminothiazoles and aminobenzothiazoles had been reported. Visible absorption spectra of the dyes had been examined in various solvents and the compounds in solution exhibited hydrazone common anion equilibrium. The hetarylazopyridones readily underwent acid dissociation into the common anion in methanol, DMF and DMSO ([3] Ertan and Eyduran, 1994).

The 5-arylazo-pyrid-2-one dye systems had been synthesised and characterised. The effects of the structural configuration of the pyridinone dye systems on the shifts of the ultraviolet-visible absorption maxima had been investigated. The structural effects of the poly functionally substituted pyridinone dye systems on the intensity of colour and fastness properties of the dyed fabrics had also been discussed ([5] Helal, 2004).

Thus, in continuation of our program dealing with the design and synthesis of novel functionalised pendant and fused heterocyclic azo dye systems and evaluation of the scope and limitation of their utility for dyeing and printing on various substrates (b11 b7 b8 b9 b10 Shams et al. , 1988, 1991, 2001a, b, c; [5] Helal, 2004), we herein report the synthesis of four novel systems of azo dyes based on polyfunctionalised oxo pyridine core. The aim of the present work is to evaluate the dyeing performance of the synthesised dyes on nylon 6 and polyester fabrics.

Experimental

Materials

Nylon 6 (210 denier/35 filament) and polyester knitted fabric (40 denier/34 filament) used in this work were supplied by...