Dyes from benzamide

Aqueous sodium chloride solution, containing benzamide was electrolysed (pH = 2), using platinised titanium anode and graphite cathode. The filtrate of the reaction mixture (pH = 4.5) was diazotised and coupled with α‐naphthol in NaOH and also with β‐naphthol in NaOH. Dyes were produced. These dyes were matched with the standard dyes prepared from aniline. Uv‐visible absorption spectral study reveals that the dyes produced are slightly different from the standard dyes. During the course of the reaction benzamide is converted into aniline with a long chain polymeric unit having a free amino end; and/or a polymeric unit which generates a free amino end during the process of diazotisation.