Synthesis and application of yellow azo-anthraquinone disperse dyes for polylactide fibres

1-Phenyl-3-methyl-5-pyrazolonyl azo-anthraquinone dyes having high light fastness on polylactide fibres were synthesised from 1-aminoanthraquinone via a diazotisation-coupling reaction with 1-phenyl-3-methyl-5-pyrazolones. The structures of these new dyes were confirmed using mass spectrometry, infrared and proton nuclear magnetic resonance spectroscopy and combustion analyses. Their dyeing behaviour on polylactide fibres was also determined, whereupon it was found that the title dyes could be applied at a relatively low dyeing temperature and that the corresponding dyed fabrics had good fastness properties.