Abstract

A novel series of 4-amino-1-phenyl-3methyl-5-pyrazolone based metal complex azo acid dyes (1a- 5d) has been prepared from p- Sulphophenyl methyl pyrazolone (1). The synthetic route included the nitrosation of the p-sulphophenyl methyl pyrazolone followed by the reduction to 4-amino-1-(psulphophenyl)- 3-methyl-4-amino-5-pyrazolone (II). Diazotization of intermediate (II) and then coupling was done with Naphthol derivatives (1a-5d), in alkaline medium to produce different acid dyes. These dyes were further processed for metallization with 3d transition metals like iron; chromium and copper. The structures of the novel dyes were confirmed by spectroscopic techniques. The synthesized dyes were applied on leather to evaluate their light fastness, wash fastness and perspiration fastness and most of the dyes were shown to possess high values (rating 4-5).