Synthesis novel pigments by the α-phenylhydrazation of 2-ketomethylquinoline derivatives

Azo dyes with the general formula X–NN–Y are well known to be important dyestuffs. Dyes with a hydroxy group are known to exhibit an azo–hydrazone tautomerism and NMR measurements are well suited to investigate this type of tautomerism. In particular multinuclear studies form the basis of a powerful investigation technique.The azo-coupling products have been prepared from derivatives of 2-ketomethylquinoline and aryldiazonium ions. Structure of the products obtained was studied by means of multinuclear NMR spectroscopy in CDCl3 solution, IR and Mass spectroscopy. Products are only present as hydrazone forms in both the solution and the solid state.