Monoazo dyes based on 5,10-dihydrophenophosphazine, Part 2: Azo acid dyes

2-Amino-5,10-dihydro-10-hydroxyphenophosphazine 10-oxide, a non-mutagenic aromatic amine, was diazotized and combined with various sulfonated naphthalene-based coupling components to give new monoazo dyes, the structures of which were confirmed using mass spectrometric and NMR analyses. Investigation of the properties of the target colorants as acid dyes indicated that they furnished deep shades on wool and silk; those dyes containing only one sulfonic acid group gave black shades on wool at 3% omf depth of shade whilst three of these dyes gave bluish-black shades and one gave a reddish-black shade on wool. The black color of the four shades was similar to that obtained using C.I. Acid Black 1 and the resultant fastness properties were generally good.