• The question of the fixation of the aromatic double bonds in hydroxy-chromones and coumarins. Formation of azo-dyes

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    • Keywords


      Coumarin; Chrysin; Diazonium Salt; Caustic Soda; Umbelliferone

    • Abstract


      The formation of azo-dyes using one and more than two molecular proportions of diazotisedp-nitraniline and the following compounds has been investigated: (i) 2-methyl-3-methoxy-7-hydroxychromone, (2) 7-hydroxyflavone, (3) 7-hydroxycoumarin and (4) 4-methyl-7-hydroxycoumarin. (I) yielded a bis-azo dye with two molecules of the reagent and with one molecule of it a large proportion of the same bis-azo dye contaminated with the mono-azo compound. The other three behaved alike yielding mono-azo dyes with one molecule of the reagent and the same mono-azo compound predominantly mixed with considerable amounts of the bis-compounds when more than two molecular proportions of the reagent were employed. The factors controlling the composition of the azo-dyes that are formed seem to be very complex.

    • Author Affiliations


      S Rangaswami1 T R Seshadri1

      1. Department of Chemistry, Andhra University, Waltair
    • Dates


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