New azodisperse dyes with 4-hydroxymethyl-2-pyrazolin-5-one ring for dyeing polyester fabrics, Part 5

4-Hydroxymethyl-2-pyrazolin-5-one was used for the preparation of new 4-arylazo-4-hydroxymethyl-2-pyrazolin-5-one and the 4,4′-bisazo (o-, m- and p-phenylene) derivatives. Assessments of their dyeing performance on polyester fabrics are considered.