Yellow Reactive Dyes Containing Benzimidazolone Group for Low-Salt Dyeing of Cotton

Yellow reactive dyes containing the benzimidazolone group were synthesized by a diazo-coupling process based on 5-aminobenzimidazolone and 2,4-diaminobenzenesulfonic acid. These reactive dyes were subsequently used for cotton dyeing. The structures of the dyes were confirmed by mass spectrometry, Fourier-transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The dyes demonstrated satisfactory light stability when exposed to simulating light. The results of cotton dyeing showed that the exhaustion and fixation of dyes were reasonably effective and acceptable as ‘low-salt-dyeing’ dyes.