Synthesis of 4,4'-dihydroxyazobenzeneand 4'-Dihydroxyphenylazo-2-naphthol from Diazotised aniline and Anthocyanins from Delonix regia flower

The synthesis of 4-phenylazo phenol by coupling anthocyanins extracted from Delonix regia flowers with diazotised aniline is presented in this paper. Also reported here is the reduction of 4-phenylazo phenol to yield 4-aminophenol and coupling of 4-aminophenol to phenol and 2-naphthol which yielded 4,4'-dihydroxyazobenzene and 4'-hydroxyphenylazo-2-naphthol, respectively. The structures of the compounds were confirmed by 1H- and 13C-NMR spectroscopy after purification by column chromatography on silica gel.