Abstract A new series of 5-(4′-arylidine-3′-methyl-5′-oxo-4′,5′-dihydropyrazol-1-yl-sulfonyl)-8-quinolinols (la-c) were prepared via the reaction of 5-(3′-methyl-5′-oxo-4′,5′-dihydropyrazol-l-yl-sulfonyl)-8-quinolinols with selected aldehydes. These compounds were condensed with hydrazine, hydroxylamine, urea and thiourea to give 5-(3′-methyl-5′-acetyl-4′-substituted pyrazolo-[3′,4′-c]pyrazol-l-yl-sulfonyl)-8-quinolinols (2a-c), 5-[3′-methyl-4′-substituted pyrazol-1-yl-sulfonyl-[3′,4′-c]isoxazolo-]quinolinols (3a-c) and 5-[3′-methyl-4′-substituted pyrazol-1-yl-sulfonyl[3′,4′-c]pyrimidine-6′ one (thione)]-8-quinolinols (4a-c, 5a-c) respectively. Metal chelate of 2a.b.d and 3a,b,d with Fe2+, Cu2+, Hg2+ have been synthesized and characterized by elemental and IR spectral analysis. The synthesized compounds were biologically screened in vitro to study the structure activity relationship and the effect of complexation and the type of metal cation on the more biologically active compounds.