Abstract

Novel Quinoline based α-β unsaturated ketones or chalcones on condensation followed by cyclization with hydrazine hydrate using solvents such as ethanol and acetic acid afforded a series of biologically active pyrazoline derivatives (4a-d and 5a-d) respectively. Chalcones (3a-d) were prepared by treating 8-methyl-2-(4-methylphenoxy) quinoline-3-carbaldehyde (1) with different substituted acetophenones (2a-d) by Claisen-Schmidt condensation. Chemical transformations, elemental analysis and IR, 1H NMR, Mass spectra were used to established the structures of the newly synthesized 3b, 4a and 5a. The title compound 5b was evaluated in-vitro for its antimicrobial activity against two Gram positive and Gram negative bacteria at different concentrations. Similarly, antioxidant properties of all pyrazoline derivatives were evaluated and they showed moderate to good activity.