Synthesis of some bis-azo dyes based on 4,4'-diamino-dipheny1amine2-sulphonic acid has been described. The properties of these dyes have been compared with similar dyes derived from benzidine. Since benzidine is one of the established carcinogens, the possibility to replace it with 4,4 1 d i amino-diphenylamine-2-su1phonic acid for the production of some direct dyes has been studied.
