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.

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.

2-Acetyl-6-cyano-7-ethyl-3-methylthiazolo[3.2-a]-pyrimidine-S-one (3) prepared by reaction of compound (1) with 3-chloropentan-2.4-dione followed by ring closure, was used as starting material to synthesise other heterocyclic compounds. The acetyl compound (3) was easily condensed with different amines to produce the imines (4-8). or the corresponding chalcone (9) when allowed to react with an aromatic aldehyde in presence of zinc chloride. Coupling of compound (3) with benzene diazonium chloride gave the phenylazo derivative (10). When compound (4) was treated with a-haloketones or a-haloesters, the thiazoline or thiazolidine compounds (11-15) were produced. Compound (15) was condensed with aromatic aldehydes to give the corresponding arylidene-derivatives (16a-c). Finally the chalcone (9) was reacted with hydrazine hydrate, phenyl hydrazine and hydroxyl amine to give pyrazolo and isoxazole compounds (17-19) respectively.

2-Acetyl-6-cyano-7-ethyl-3-methylthiazolo[3.2-a]-pyrimidine-S-one (3) prepared by reaction of compound (1) with 3-chloropentan-2.4-dione followed by ring closure, was used as starting material to synthesise other heterocyclic compounds. The acetyl compound (3) was easily condensed with different amines to produce the imines (4-8). or the corresponding chalcone (9) when allowed to react with an aromatic aldehyde in presence of zinc chloride. Coupling of compound (3) with benzene diazonium chloride gave the phenylazo derivative (10). When compound (4) was treated with a-haloketones or a-haloesters, the thiazoline or thiazolidine compounds (11-15) were produced. Compound (15) was condensed with aromatic aldehydes to give the corresponding arylidene-derivatives (16a-c). Finally the chalcone (9) was reacted with hydrazine hydrate, phenyl hydrazine and hydroxyl amine to give pyrazolo and isoxazole compounds (17-19) respectively.

8-Quinolinol reacts with cinnamonitrile derivatives in presence of a basic catalyst to afford pyrano[3,2-h]quinolines (3a–f). The reaction of 3a with reagents such as acetic anhydride/pyridine, formamide, formic acid/formamide, and carbon disulfide gave the fused heterotetracyclic systems pyrimido[4′,5′: 6,5]pyrano[3,2-h]quinolines

8-Quinolinol reacts with cinnamonitrile derivatives in presence of a basic catalyst to afford pyrano[3,2-h]quinolines (3a–f). The reaction of 3a with reagents such as acetic anhydride/pyridine, formamide, formic acid/formamide, and carbon disulfide gave the fused heterotetracyclic systems pyrimido[4′,5′: 6,5]pyrano[3,2-h]quinolines

Some new sulphonyl-N-heterocyclo-8-hydroxy quinolines have been synthesised by the reaction of 8-hydroxyquinoline-5-sulphonyl hydrazide with different active methylene compounds. The pyrazole, pyrazoline, pyrazolidine and pyridazine derivatives were reacted with some metal cations to give the corresponding chelates. All synthesized compounds have been screened in vitro for their biological activities

Some new sulphonyl-N-heterocyclo-8-hydroxy quinolines have been synthesised by the reaction of 8-hydroxyquinoline-5-sulphonyl hydrazide with different active methylene compounds. The pyrazole, pyrazoline, pyrazolidine and pyridazine derivatives were reacted with some metal cations to give the corresponding chelates. All synthesized compounds have been screened in vitro for their biological activities