Azoic dyes

Summary

The utility, as azoic coupling components, of diketones prepared by the action of sodamide and similar reagents ono-benzoyloxyaryl methyl ketones has been investigated. 2-benzoylacetyl-1-naphthol gives weak dyeings when used as a “naphthol” for impregnation of cotton, and development with diazonium salts. The shades lacked fastness to soaping and light. On coupling the diketone in substance with diazonium salts, mono-and disazo dyes were obtained; the constitution of the former, which could have two possible structures, has been proved to be 4-benzeneazo-2-benzoylacetyl-1-naphthol by an unambiguous synthesis from 4-benzeneazo-2-acetyl-1-naphthol through the corresponding benzoate. The monoazo dye from 1-benzoylacetyl-2-naphthol has been prepared. 4-benzamido-2-benzoylacetyl-1-naphthol and 4-acetoacetamido-2-acetyl-1-naphthol have also been studied as “naphthols”.

We are grateful to Imperial Chemical Industries (Dyestuffs Group) and to the Sir Dorab Tata Trust for the award of research fellowships to two of us. We are also thankful to Mr. T. S. Gore for carrying out the microanalyses.