A simple, rapid, efficient, and environmentally benign procedure for synthesis of 2-pyrazoline derivatives has been achieved by reacting 2 ? -hydroxychalcones with hydrazine hydrate under solvent-free grinding technique.The short reaction time, cleaner reaction, easy workup, higher yields, and mild reaction conditions make this protocol practical and economically attractive in comparison with the classical reaction.

The four Schiff bases (I - IV) were synthesized by the condensation reaction of 1(1-hydroxynaphthalen-2-yl)ethanone, 1-(4-chloro-1hydroxynaphthalen-2-yl)ethanone and 1-(4-bromo-1-hydroxynaphthalen-2-yl)ethanone with propane-1,3-diamine and pentane-1,3-diamine. The structural analysis is done by UVvis., FT-IR, 1H NMR, 13C NMR, LCMS and elemental analyses. These compounds were assayed for antibacterial (Escherichia coli and Salmonella Typhi) activity and antioxidant (2,2-Diphenyl-1-Picryl Hydrazyl(DPPH) and Hydroxyl radical scavenging method) activity. The antibacterial and antioxidant activities of synthesized Schiff bases exhibited better degrees of inhibitory effects. Among these, Schiff base 2,2'-((propane-1,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(4-chloronaphthalen-1-ol) (II) exhibited excellent antibacterial activity with MICs of 0.12, 0.25, 0.5 and 1 mg/ml against E. coli and Salmonella Typhi. Furthermore, two Schiff bases such as, 2,2'-((propane-1,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(naphthalen-1-ol) (I) and 2,2'-((pentane-1,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(4-bromonaphthalen-1-ol) (IV) exhibited promising antioxidant activity.

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Objectives: The chemistry of chalcones has generated intensive scientific studies throughout the world. Especially interest has been focused on the synthesis and biodynamic activities of isoxazoline derivatives. In recent year numerous isoxazoline derivatives have been synthesized for their anticancer, anti-inflammatory, cytotoxic, antiviral activities. The reaction of substituted chalcones with hydroxylamine hydrochloride in presence of acetic acid gave isoxazoline derivatives. : The five membered oxygen and Nitrogen containing compounds exhibited Material and methods antioxidant, analgesic, antibacterial, antifungal activities. Therefore the attempt have been made to synthesize chlorosubstituted isoxazolines by the reaction of different substituted chalcones with hydroxylamine hydrochloride in presence of few drops of acetic acid. All the synthesized compounds confirmed by TLC and spectral analysis and also screened for their antibacterial activity. : The novel chloro-substituted isoxazolines showed good to moderate Results antibacterial activity against Gram+ve and Gram-ve bacterial strains tested. : These compounds Conclusion containing chloro, bromo, iodo groups were found showed potent antibacterial, antifungal activities. These findings promoted us to to synthesize novel chloro-substituted isoxazolines derivatives which are found to be potential antibacterial agents.

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